Rotation supporting device and supporting mechanism position adjusting mechanism of shaft supporting device

Abstract

A support mechanism (30) for rotatably supporting both axial ends of a screw shaft (21) is provided with: a bearing unit (41) provided with a moving-side bearing housing (51) and a pair of angular ball bearings (33B); a support table (43); and a housing position adjustment mechanism (44) disposed between the bearing unit (41) and the support base (43). The housing position adjustment mechanism (44) has: a support table-side member (61) provided on the support table (43) side; a bearing housing-side member (62) provided on the bearing housing (51) side and capable of moving relative to the support base-side member (61) in the axial direction; a working fluid housed in a pressure chamber (66) formed between the support table-side member (61) and the bearing housing-side member (62), a reservoir chamber (71) formed in either the support table-side member or the bearing housing-side member, and a damping hole (72) connecting the pressure chamber (66) and the reservoir chamber (71); a belleville spring (80) disposed in a compressed state within the pressure chamber (66) between opposing axial end surfaces of the support table-side member (61) and the bearing housing-side member (62); and a hollow member (90) housed in the storage chamber (71). Thus, even if the axial lengths of the screw shaft and the rotating shaft change due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

Description

Technical Field

[0001] The present invention relates to a rotary support device for supporting a rotary shaft such as a ball screw feed device or a spindle device, and a support mechanism position adjustment mechanism for a shaft support device that supports a shaft. Background Art

[0002] In a ball screw feed device, high axial rigidity is required to maintain the feed accuracy of the screw shaft. Conventionally, as a method of imparting rigidity to the screw shaft of the ball screw device, generally, the following method is used: that is, a plurality of angular contact bearings are combined and preloaded, and they are arranged at one end or both ends of the screw shaft, and the screw shaft is fixedly supported axially. Further, in consideration of the thermal expansion of the screw shaft, a method of pre-applying a tension in the axial direction to the screw shaft to elongate it by a specified amount is adopted. In Patent Document 1, a pre-tightening mechanism is described, which pre-applies a tension to the feed screw (screw shaft) by adjusting the axial dimension of a spacer, and when the feed screw elongates due to a temperature rise beyond the pre-tension amount, the bearing is axially moved by the pressure of a disc spring or a fluid, and a tension is imparted to the feed screw.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Utility Model Registration No. 2573982 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] However, if a load such as a pre-tension or a pre-tightening force imparted to the feed screw is too large, a large load is applied to the bearing, and there is a risk of bearing damage. Therefore, generally, a disc spring or an externally supplied fluid such as that of the pre-tightening mechanism described in Patent Document 1 is arranged within a range where an excessive load is not applied to the bearing axially. However, in the case of using a disc spring, the load becomes weaker as the shaft elongates, and thus it can only cope with elongation of 3 to 4 degrees Celsius in temperature rise. In a machining center or the like, the temperature rise of the ball screw exceeds 4 degrees Celsius in many cases, and in this case, the sufficient load of the disc spring does not function, and there is a problem of reduction in axial support rigidity.

[0008] Further, in the method of supplying fluid from the outside and applying a load by oil pressure, in addition to an external device represented by an oil pressure pump, there are also problems that the ball screw feed device becomes large-sized, and the cost increases and additional energy consumption is caused.

[0009] Furthermore, such problems exist not only in ball screw feed devices, but also in rotary support devices such as spindle devices that rotatably support both axial ends of a rotating shaft through a pair of support mechanisms.

[0010] The present invention has been completed in view of the above problems, and its object is to provide a rotary support device and a support mechanism position adjustment mechanism for a shaft support device that can continuously and stably maintain the axial support rigidity even when the axial length of the rotating shaft changes due to the influence of heat.

[0011] Technical means for solving technical problems

[0012] The above object of the present invention is achieved by the following configuration.

[0013] [1] A rotary support device including a rotating shaft and a pair of support mechanisms that rotatably support both axial ends of the rotating shaft, and

[0014] One of the pair of support mechanisms includes:

[0015] A bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft in the bearing housing and can support an axial load;

[0016] A support table that is penetrated by the rotating shaft or disposed around the rotating shaft; and

[0017] A housing position adjustment mechanism disposed between the bearing unit and the support table,

[0018] The housing position adjustment mechanism includes:

[0019] A support table side member disposed on the support table side, penetrated by the rotating shaft or disposed around the rotating shaft;

[0020] A bearing housing side member disposed on the bearing housing side, penetrated by the rotating shaft or disposed around the rotating shaft, and capable of axially moving relative to the support table side member;

[0021] A working fluid housed in a pressure chamber formed between the support table side member and the bearing housing side member, a storage chamber formed in the support table side member or the bearing housing side member, and a damping hole communicating the pressure chamber and the storage chamber;

[0022] An elastic member disposed in a compressed state between opposing axial end faces of the support table side member and the bearing housing side member in the pressure chamber; and

[0023] A hollow member housed in the storage chamber.

[0024] [2] A support mechanism position adjustment mechanism for a shaft support device, which is provided in one of a pair of support mechanisms in a shaft support device having a shaft and a pair of support mechanisms provided at both axial ends of the shaft for supporting the shaft, and

[0025] One of the pair of support mechanisms has a support body penetrated by the shaft or arranged around the shaft,

[0026] The support mechanism position adjustment mechanism of the shaft support device includes:

[0027] A first component, which is provided on one of the shaft side and the support body side, and can be penetrated by the shaft or arranged around the shaft;

[0028] A second component, which is provided on the other of the shaft side and the support body side, can be penetrated by the shaft or arranged around the shaft, and can move relatively axially with respect to the first component;

[0029] A working fluid, which is accommodated in a pressure chamber formed between the first component and the second component, a storage chamber formed in the first component or the second component, and a damping hole communicating the pressure chamber with the storage chamber;

[0030] An elastic component, which is arranged in a compressed state between the opposing axial end faces of the first component and the second component in the pressure chamber; and

[0031] A hollow component, which is accommodated in the storage chamber.

[0032] Advantages of the Invention

[0033] According to the rotary support device of the present invention, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0034] In addition, according to the support mechanism position adjustment mechanism of the shaft support device of the present invention, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated. Brief Description of the Drawings

[0035] Figure 1 It is a cross-sectional view of a table feed system of a machine tool of a ball screw feed device according to the first embodiment of the present invention.

[0036] Figure 2 It is provided with Figure 1 An enlarged cross-sectional view of a support mechanism with the shown housing position adjustment mechanism.

[0037] Figure 3 is Figure 2 the front view in the direction A of

[0038] Figure 4 is a cross-sectional view showing a modified example of the disc spring.

[0039] Figure 5 Figures (a)-(c) of

[0040] Figure 6 are cross-sectional views showing the first to third modified examples of the hollow member disposed in the pressure chamber.

[0041] Figure 7 is a cross-sectional view showing the sixth modified example of the hollow member.

[0042] Figure 8 Figures (a)-(c) of

[0043] Figure 9 are cross-sectional views of the hollow member of the seventh to ninth modified examples of the first embodiment.

[0044] Figure 10 Figures (a) and (b) of

[0045] Figure 11 are cross-sectional views of the hollow member of the fifteenth to seventeenth modified examples of the first embodiment.

[0046] Figure 12 is the drawing corresponding to the ball screw feed device of the second embodiment of the present invention Figure 2 of

[0047] Figure 13 is Figure 12 the enlarged view of part XIII of

[0048] Figure 14 Figures (a)-(c) of

[0049] Figure 15 are the main part enlarged cross-sectional views showing examples of applying wear-resistant members to the sealing grooves of the ball screw feed device of the modified example of the second embodiment. Figure 2 of

[0050] Figure 16 is the drawing corresponding to the ball screw feed device of the third embodiment of the present invention Figure 2 of

[0051] Figure 17 This is a view corresponding to the back-to-back combination of a pair of angular contact ball bearings of the bearing unit in the second modification of the present invention Figure 2 of the figure.

[0052] Figure 18 This is a view corresponding to the side-by-side combination of a pair of angular contact ball bearings of the bearing unit in the third modification of the present invention Figure 2 of the figure.

[0053] Figure 19 (a) of is a schematic side view showing a first example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers, and (b) is a schematic side view showing a second example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers.

[0054] Figure 20 (a) of is a schematic side view showing a third example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers, and (b) is a schematic side view showing a fourth example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers.

[0055] Figure 21 This is a schematic side view showing a fifth example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers.

[0056] Figure 22 This is a sectional view taken along the line XXII-XXII of Figure 20 (a).

[0057] Figure 23 This is a view corresponding to the ball screw feed device of the fifth embodiment of the present invention Figure 2 of the figure.

[0058] Figure 24 This is a view corresponding to the ball screw feed device of the first modification of the fifth embodiment of the present invention Figure 2 of the figure.

[0059] Figure 25 This is a view corresponding to the ball screw feed device of the second modification of the fifth embodiment Figure 2 of the figure.

[0060] Figure 26 This is Figure 25 an enlarged view of part XXVI.

[0061] Figure 27 This is a view corresponding to the ball screw feed device of the third modification of the fifth embodiment of the present invention Figure 2 of the figure.

[0062] Figure 28 This is a view corresponding to the ball screw feed device of the fourth modification of the fifth embodiment of the present invention Figure 2 of the figure.

[0063] Figure 29 (a) is for filling the working fluid into the pressure chamber, and is provided at the phase of the oil supply passage formed in the bearing housing side member corresponding to Figure 2 The enlarged sectional view of, (b) is a sectional view showing a modified example of the set bolt of (a).

[0064] Figure 30 (a) of is to replace Figure 29 The sectional view of the set plug used in place of the set bolt of (a) of, (b) is a sectional view showing an example of combining the set plug of (a) with the disc-shaped member, (c) is a sectional view showing a modified example of the disc-shaped member of (b), and (d) is a sectional view showing another modified example of the disc-shaped member of (b).

[0065] Figure 31 is a sectional view of the table feed system of a machine tool of a ball screw feed device to which a modified example of the present invention is applied.

[0066] Figure 32 is a sectional view showing a first example of the housing position adjustment mechanism in which the support table is arranged on the axial end side with respect to the bearing unit.

[0067] Figure 33 is a sectional view showing a second example of the housing position adjustment mechanism in which the support table is arranged on the axial end side with respect to the bearing unit.

[0068] Figure 34 is a sectional view showing a third example of the housing position adjustment mechanism in which the support table is arranged on the axial end side with respect to the bearing unit.

[0069] Figure 35 is a sectional view showing a fourth example of the housing position adjustment mechanism in which the support table is arranged on the axial end side with respect to the bearing unit.

[0070] Figure 36 is a sectional view showing the rotary support device of the present invention.

[0071] Figure 37 is a sectional view showing another rotary support device of the present invention.

[0072] Figure 38 is a sectional view showing a shaft support device applying the support mechanism position adjustment mechanism of the present invention.

[0073] Figure 39 is Figure 38 The enlarged view of part XXXIX of. Detailed Description of the Invention

[0074] Hereinafter, an example of the rotary support device or the shaft support device of the present invention, that is, each embodiment of the ball screw feed device will be described in detail based on the drawings.

[0075] (First Embodiment)

[0076] Figure 1 The worktable feed system of a machine tool showing a ball screw feed device applying the first embodiment is shown. In addition, regarding Figures 1 - 3 , the axial direction ( Figure 1 the left - right direction) of the screw shaft 21 of the ball screw feed device 20 is set as the X - direction, the direction parallel to the mounting surface 1a of the base 1 and orthogonal to the axial direction of the screw shaft 21 ( Figure 1 the direction perpendicular to the paper surface) is set as the Y - direction, and the direction perpendicular to the mounting surface 1a of the base 1 ( Figure 1 the up - down direction) is set as the Z - direction. In addition, Figure 2 and in each figure corresponding to Figure 2 , the dashed line indicates the bolt fastening part.

[0077] The worktable feed system 10 includes a moving worktable 11 fixed to the nut 23 of the ball screw feed device 20, and is configured to move the moving worktable 11 freely in the X - direction by driving the screw shaft 21 of the ball screw feed device 20 with a drive motor 12. On the moving worktable 11, a pair of linear guides 13 ( Figure 1 only one is shown in the figure) are provided on both sides in the Y - direction with respect to the ball screw feed device 20. Each linear guide 13 includes: a guide rail 15 disposed on the base 1 in parallel with the screw shaft 21 via a track mounting table 14; and two sliders 16 fixed to the lower surface of the moving worktable 11 and straddling the guide rail 15. Thus, by rotating the screw shaft 21 with the drive motor 12, the moving worktable 11 is guided by the pair of linear guides 13 and reciprocates linearly together with the nut 23.

[0078] The ball screw feed device 20 includes: a screw shaft 21 having a helical thread groove 21b formed on its outer peripheral surface; a nut 23 disposed around the screw shaft 21, having a helical thread groove (not shown) formed on its inner peripheral surface, and being fitted with a nut housing 22 fixed to the lower surface of the moving worktable 11; and a plurality of balls (not shown) rollably disposed between the thread groove of the nut 23 and the thread groove 21b of the screw shaft 21.

[0079] The screw shaft 21 includes: a large - diameter portion 24 formed at the axial center and having a thread groove 21b formed thereon; and small - diameter portions 25 formed at both axial ends of the large - diameter portion 24. An external thread 25a is formed on the outer peripheral surface of the tip side of the small - diameter portion 25. In addition, at the tip of one side (the right side in the figure) of the screw shaft 21, a small - diameter shaft portion 27 is provided. A rotary shaft 12a of the drive motor 12 is connected to the small - diameter shaft portion 27 via a coupling 28.

[0080] In addition, in the lead screw shaft 21, one side of the lead screw shaft 21 on the side connected to the drive motor 12 is rotatably supported by the first support mechanism 30, and the other side (left side in the figure) of the lead screw shaft 21 is rotatably supported by the second support mechanism 40.

[0081] The first support mechanism 30 includes: a fixed-side bearing housing 31 fixed to the base 1; and a pair of angular contact ball bearings 33, 33 that rotatably support the lead screw shaft 21 relative to the fixed-side bearing housing 31 and are arranged in a face-to-face combination. Each of the pair of angular contact ball bearings 33, 33 includes: an outer ring 34 embedded in the fixed-side bearing housing 31; an inner ring 35 externally fitted to the small-diameter portion 25 of the lead screw shaft 21; and a plurality of balls 36 that are arranged between the outer ring 34 and the inner ring 35 so as to roll freely with a contact angle.

[0082] For the pair of angular contact ball bearings 33, 33, the outer ring 34 of the angular contact ball bearing 33 on the axially inner side abuts against the inward flange 31a of the fixed-side bearing housing 31, and the outer ring 34 of the angular contact ball bearing 33 on the axially outer side is fixed by an outer ring pressing member 37 fastened to the fixed-side bearing housing 31. In addition, the inner ring 35 of the angular contact ball bearing 33 on the axially inner side abuts against the step portion 21a between the large-diameter portion 24 and the small-diameter portion 25 of the lead screw shaft 21, and the inner ring 35 of the angular contact ball bearing 33 on the axially outer side is fastened by a fastening nut 38a screwed onto the external thread 25a.

[0083] Therefore, the first support mechanism 30 supports the lead screw shaft 21 in a state where the axial position of the lead screw shaft 21 is fixed.

[0084] Also refer to Figure 2 and Figure 3 , the second support mechanism 40 includes: a bearing unit 41 disposed at the other end of the lead screw shaft 21; a support table 43 fixed to the base 1 on the axially central side relative to the bearing unit 41; and a housing position adjustment mechanism 60 disposed between the bearing unit 41 and the support table 43. A through hole 43a through which the lead screw shaft 21 passes is provided in the support table 43.

[0085] The bearing unit 41 includes: a movable-side bearing housing 51; and a pair of angular contact ball bearings 53, 53 that rotatably support the lead screw shaft 21 relative to the movable-side bearing housing 51.

[0086] Each of the pair of angular contact ball bearings 53, 53 includes: an outer ring 54 embedded in the movable-side bearing housing 51; an inner ring 55 externally fitted to the small-diameter portion 25 of the lead screw shaft 21; and a plurality of balls 56 that are arranged between the outer ring 54 and the inner ring 55 so as to roll freely with a contact angle.

[0087] In a pair of angular contact ball bearings 53, 53, the outer ring 54 of the angular contact ball bearing 53 on the inner axial side abuts against the inward flange 51a of the moving side bearing housing 51, and the outer ring 54 of the angular contact ball bearing 53 on the outer axial side is fastened by an outer ring pressing member 47 fixedly attached to the moving side bearing housing 51. The outer rings 54, 54 are axially positioned relative to the moving side bearing housing 51. Further, the inner ring 55 of the angular contact ball bearing 53 arranged on the outer axial side is fastened by a fastening nut 38b screwed onto the external thread 25a via a spacer 48.

[0088] That is, a pair of angular contact ball bearings 53, 53, the moving side bearing housing 51, and the outer ring pressing member 47 can be unitized into a bearing unit 41 in a state where a predetermined preload is applied to the pair of angular contact ball bearings 53, 53 arranged in a face-to-face combination, and the bearing unit 41 can be easily mounted relative to the lead screw shaft 21 and the housing position adjusting mechanism 60, respectively. In this configuration, the moving side bearing housing 51 can also be integrated with the bearing housing side member 62 as needed.

[0089] The housing position adjusting mechanism 60 includes: a support table side member 61 provided on the support table 43 side and penetrated by the lead screw shaft 21; and a bearing housing side member 62 provided on the moving side bearing housing 51 side and capable of axially moving relative to the support table side member 61. The support table side member 61 and the bearing housing side member 62 are axially opposed to each other.

[0090] In the support table side member 61, an annular portion 61a protruding toward the support table 43 side is fitted into the through hole 43a of the support table 43 and fixed to the support table 43 by a plurality of bolts (not shown). In the bearing housing side member 62, an annular portion 62a protruding toward the moving side bearing housing 51 side is fitted into the inward flange 51a and fixed to the moving side bearing housing 51 by a plurality of bolts 63 (refer to Figure 3 )

[0091] Further, on the side surface of the bearing housing side member 62 on the support table side member 61 side, a bottomed annular recess 64 opening toward the support table side member 61 side (axially one side) is provided. On the other hand, on the side surface of the support table side member 61 on the bearing housing side member 62 side, an annular protrusion 65 protruding into the annular recess 64 toward the bearing housing side member 62 side (axially the other side) is provided. The annular recess 64 and the annular protrusion 65 are slidably fitted axially, and an annular pressure chamber 66 is formed between the bottom surface, the inner surface 64a, and the outer surface 64b of the annular recess 64 and the top surface of the annular protrusion 65.

[0092] Further, an annular storage chamber 71 is formed in the annular protrusion 65, and at least one place in the circumferential direction ( Figure 2Axial damping holes 72 are formed at two positions in the middle.

[0093] The storage chamber 71 is located on the top surface side of the annular convex portion 65 relative to the groove portion where the O-ring 67 is disposed later. It opens to the outer surface 65a of the annular convex portion 65 and is formed in a disk-shaped groove.

[0094] Moreover, in the pressure chamber 66, the storage chamber 71, and the damping holes 72, the working fluid, such as working oil 70, is accommodated in a compressed state. Including the gap g between the outer surface 65a of the annular convex portion 65 and the inner surface 64a of the annular concave portion 64, the working oil 70 circulates in the pressure chamber 66, the storage chamber 71, and the damping holes 72.

[0095] In addition, in the pressure chamber 66, a plurality of disc springs 80, which are elastic members, are disposed in a compressed state between the opposing axial end faces of the support table side member 61 and the bearing housing side member 62, that is, between the bottom surface of the annular concave portion 64 and the top surface of the annular convex portion 65. Therefore, in the pressure chamber 66, the space other than the plurality of disc springs 80 is filled with the working oil 70.

[0096] Furthermore, in the storage chamber 71, a hollow member 90 configured on the premise of a sealing structure is disposed, and the space other than the hollow member 90 in the storage chamber 71 is filled with the working oil 70.

[0097] The working oil 70 has an elastic effect when an external force is applied, and is a working fluid that has been confirmed to be rigid industrially and is given rigidity when compressed.

[0098] Specifically, it is known that the bulk modulus of the working oil is affected by gas mixing, etc. (refer to the non-patent literature (Junichi Oshimaru, Hirohisa Tanaka, "Measurement of the Bulk Modulus of Working Oil", Hydraulics and Pneumatics, Vol. 19, No. 7, 1988, p. 580-583)). In this embodiment, the types of the working oil or gas are appropriately selected so that even when the temperature rise is more than 4 degrees and the pressure chamber 66 expands axially according to the axial elongation of the lead screw shaft 21, the desired axial rigidity can be imparted to the lead screw shaft by the pressure acting on the bearing housing side member 62.

[0099] In addition, as the working fluid, it is not limited to oil. As long as it has an elastic effect when compressed and can exhibit rigidity, it can be any liquid such as water, or it can also be a gas.

[0100] Furthermore, the magnitude of the axial load applied to the lead screw shaft 21 by the working fluid can be set not only based on the setting of the tightening amount of the fastening nut 38b, but also considering the volume expansion caused by the temperature rise of the working fluid due to the temperature rise of the angular contact ball bearings 53, 53 and the lead screw shaft 21 during the operation of the ball screw feed device 20. In addition, the magnitude of the axial load applied to the lead screw shaft 21 by the working fluid can also be set considering the volume expansion caused by the temperature rise of the working fluid due to the environmental change around the ball screw feed device during the operation of the ball screw feed device 20.

[0101] When multiple disc springs 80 function as a series spring, as Figure 2 shown, they are axially overlapped and arranged in such a way that the convex-side surfaces and the concave-side surfaces of adjacent disc springs 80 face each other. Additionally, when multiple disc springs 80 function as a parallel spring, although not shown, in the axial direction, the disc springs 80 are arranged to overlap with the same orientation.

[0102] The hollow member 90 has an elliptical cross-sectional shape with an inner diameter larger than the outer diameter of the outer-facing surface 64b of the annular recess 64 and an outer diameter smaller than the inner diameter of the inner-facing surface 64a of the annular recess 64, and is formed as an annular doughnut-shaped structure body, which is composed of an elastically deformable rubber, resin, metal, etc. or a combination thereof. Additionally, inside the hollow member 90, any liquid or gas that has an elastic effect when an external force is applied and whose rigidity has been industrially confirmed is built in.

[0103] However, from the perspective of assemblability, the hollow member 90 is preferably structured to be divided into multiple parts in the circumferential direction.

[0104] Furthermore, O-rings 67 are installed between the outer-facing surface 65a of the annular protrusion 65 and the inner-facing surface 64a of the annular recess 64, and between the inner-facing surface 65b of the annular protrusion 65 and the outer-facing surface 64b of the annular recess 64. Specifically, the O-rings 67 are arranged to be in sliding contact with the inner-facing surface 64a and the outer-facing surface 64b of the opposing annular recess 64 in the annular sealing grooves 68 formed on the outer-facing surface 65a and the inner-facing surface 65b of the annular protrusion 65, and seal the radial gaps between the outer-facing surface 65a of the annular protrusion 65 and the inner-facing surface 64a of the annular recess 64, and between the inner-facing surface 65b of the annular protrusion 65 and the outer-facing surface 64b of the annular recess 64. Additionally, the sealing grooves 68 can also be formed on the inner-facing surface 64a and the outer-facing surface 64b of the annular recess 64. Also, one O-ring 67 and one sealing groove 68 are respectively arranged between each pair of opposing surfaces, but multiple ones can also be arranged. Thus, the O-rings 67 prevent the working oil 70 filled in the pressure chamber 66 and the storage chamber 71 from leaking. From the perspective of preventing wear, the O-rings 67 can also be surface-treated to have wear resistance, etc.

[0105] In addition, a rotation prevention mechanism 75 for preventing relative rotation between the support table side member 61 and the bearing housing side member 62 is provided. Specifically, for example, in the bearing housing side member 62, through holes 77 penetrating in the radial direction are formed at at least one place in the circumferential direction so that the tip of the positioning pin 76 protrudes from the inner surface 64a of the annular recess 64. Further, the tip of the positioning pin 76 is inserted into a long hole 78 formed in the outer surface 65a of the annular protrusion 65 formed in the support table side member 61 in the axial direction so that the bearing housing side member 62 can move in the axial direction. Alternatively, instead of the positioning pin 76, a rotation direction positioning key (not shown) having the same rotation prevention function can be inserted into the long hole 78 so that the bearing housing side member 62 can move in the axial direction.

[0106] After the working oil 70 and the plurality of disc springs 80 are housed in the pressure chamber 66 and the working oil 70 and the hollow member 90 are respectively housed in the storage chamber 71, such a housing position adjustment mechanism 60 fastens the fastening nut 38b. As a result, the bearing housing side member 62 is pressed toward the support table side member 61 side via the pair of angular contact ball bearings 53, 53 and the moving side bearing housing 51. Thereby, the working oil 70 is compressed, a pressure in the lead screw axial direction is applied to the working oil 70, the plurality of disc springs 80 are compressed, a pressure in the lead screw axial direction is applied to the plurality of disc springs 80, and further, the hollow member 90 is compressed, and a pressure in the lead screw axial direction is also applied to the hollow member 90.

[0107] On the other hand, since the support table side member 61 is fixed to the base 1 via the support table 43, the bearing housing side member 62 and the moving side bearing housing 51 are pressed to the left direction in the figure due to the pressure of the working oil 70 and the plurality of disc springs 80 housed in the pressure chamber 66 in a compressed state, the working oil 70 and the hollow member 90 housed in the storage chamber 71 in a compressed state. Thereby, a state is formed in which a tension is applied to the lead screw shaft 21 in advance to the Figure 1 , 2 middle left direction.

[0108] In addition, the pressures of the working oil 70 and the plurality of disc springs 80 housed in the pressure chamber 66 and the pressures of the working oil 70 and the hollow member 90 housed in the storage chamber 71 can be controlled to any magnitude respectively by the fastening amount of the fastening nut 38b. That is, the magnitude of the axial load applied to the lead screw shaft 21 can be set to any magnitude by the fastening nut 38b.

[0109] Furthermore, as described above, the magnitude of the axial load applied to the lead screw shaft 21 by the working oil 70 can be set in consideration of the volume expansion caused by the temperature rise of the working oil 70 during the operation of the ball screw feed device 20 in addition to the setting of the fastening amount of the fastening nut 38b.

[0110] Next, the operation of the ball screw feed device 20 of the present embodiment will be described.

[0111] In the ball screw feed device 20, if the lead screw shaft 21 is rotationally driven by the drive motor 12 to cause the moving worktable 11 fixed to the nut 23 to reciprocate linearly, then as the movement progresses, the drive motor 12, angular contact ball bearings 33, 53, nut 23, etc. generate heat, and the temperature of the ball screw feed device 20 gradually rises. The lead screw shaft 21 axially elongates due to thermal expansion.

[0112] If the lead screw shaft 21 axially expands and elongates due to heat, then Figure 1 In the ball screw feed device 20 of the present embodiment shown, since the right end portion of the lead screw shaft 21 is fixed to the fixed-side bearing housing 31 via the angular contact ball bearings 33, 33, the lead screw shaft 21 elongates in the left direction. If the lead screw shaft 21 axially (left direction) elongates due to the influence of heat, the bearing unit 41 and the bearing housing side member 62 move in the same direction following the axial elongation of the heat-expanded lead screw shaft 21 through the interaction of the pressure of the working oil 70 and the plurality of disc springs 80 housed in the pressure chamber 66 and the pressure of the working oil 70 and the hollow member 90 housed in the storage chamber 71.

[0113] In the present embodiment, it is designed such that when the lead screw shaft 21 axially elongates, the working oil 70, the plurality of disc springs 80, and the hollow member 90 also continuously press the bearing unit 41 and the bearing housing side member 62 to the left. In the working oil 70, the pressure chamber 66, and the storage chamber 71, there is a large degree of design freedom. By appropriately selecting the physical properties of the working oil 70 filled in the pressure chamber, the size or shape of the pressure chamber and the storage chamber, the pressure of the working oil 70 is also exerted in addition to the pressure of the plurality of disc springs 80 and the hollow member 90, so that a larger axial elongation can be accommodated and a sufficient and appropriate load can be applied. Therefore, even when the temperature rise amount of the ball screw feed device 20 is higher than 4 degrees, the pair of angular contact ball bearings 53, 53 can be axially moved to maintain the axial support rigidity, and the axial rigidity of the ball screw feed device 20 is stabilized.

[0114] In particular, since the working oil 70 can flow between the pressure chamber 66 and the storage chamber 71 via the damping holes, the plurality of disc springs 80, the hollow member 90, and the working oil 70 can be designed to share the load of pressing the bearing unit 41 and the bearing housing side member 62, and can also vary corresponding to the amount of axial elongation of the lead screw shaft 21 when the temperature rise amount is higher than 4 degrees. Thus, during the axial elongation of the lead screw shaft 21, the state of using the pair of angular contact ball bearings 33, 33 as fixed support portions is maintained, and the axial rigidity of the ball screw feed device 20 is stabilized.

[0115] In the case of such an embodiment, since excessive loads are not applied to the pair of angular contact ball bearings 33, 33 and 53, 53, there is no risk of excessive wear or seizure due to poor lubrication, and the service life of the pair of angular contact ball bearings 33, 33 and 53, 53 is extended.

[0116] That is, in this embodiment, since it is not necessary to apply the pre-tension of the magnitude given by the spacer in the ball screw described in Patent Document 1 to the lead screw shaft 21, excessive loads are not applied to the pair of angular contact ball bearings 33, 33 and 53, 53 either.

[0117] Furthermore, in the ball screw feed device 20 of this embodiment, it is not necessary to provide an external device such as an accumulator or a pump for supplying the working oil 70 to the pressure chamber 66 or the storage chamber 71, and the housing position adjustment mechanism 60 can be simplified. As a result, the energy supplied from the outside can be saved, and the pressure in the pressure chamber 66 and the storage chamber 71 can be maintained with minimal change.

[0118] In addition, the O-ring 67 of this embodiment also functions as a damping mechanism. That is, when machining a workpiece placed on the moving table 11, due to the vibration generated in the moving table 11, the lead screw shaft 21 with relatively low rigidity also tends to vibrate. The vibration of the lead screw shaft 21 is also transmitted to the bearing housing side member 62 via the pair of angular contact ball bearings 33, 33 and the moving side bearing housing 51, but the vibration of the bearing housing side member 62 is attenuated by the O-ring 67 between the bearing housing side member 62 and the support table side member 61. Therefore, the vibration of the lead screw shaft 21 can also be attenuated, and the unevenness of the machining surface quality of the workpiece placed on the moving table 11 can be suppressed.

[0119] At this time, the O-ring 67 disposed between the bearing housing side member 62 and the support table side member 61 attenuates not only the axial vibration of the lead screw shaft 21 but also the radial vibration of the lead screw shaft 21.

[0120] In addition, the working oil 70 of the housing position adjustment mechanism 60 is stored not only in the pressure chamber 66, the storage chamber 71, and the damping hole 72, but also in the gaps between the outer surface 65a of the annular convex portion 65 and the inner surface 64a of the annular concave portion 64, and between the inner surface 65b of the annular convex portion 65 and the outer surface 64b of the annular concave portion 64, and in the gaps closer to the pressure chamber 66 than the O-ring 67. Therefore, by compressing the working oil 70, the pressure in the working oil 70 acts not only axially but also radially. Thereby, the bearing housing side member 62 is supported on the support table side member 61 with sufficient and appropriate radial load.

[0121] As a result, the housing position adjustment mechanism 60 can impart radial support rigidity to the lead screw shaft 21 via a pair of angular contact ball bearings 53, 53 and the bearing housing 51. Further, it can also have a centering function for the lead screw shaft 21.

[0122] In addition, when the axial elongation of the lead screw shaft 21 occurs as described above, even when vibration is generated due to the elastic deformation during the recovery of the disc springs 80 and the hollow member 90 from the compressed state, the O-ring 67 can attenuate the vibration.

[0123] Furthermore, when the disc springs 80 and the hollow member 90 recover from the compressed state, the working oil 70 passes through the damping holes 72 and the gap g between the outer surface 65a of the annular protrusion 65 and the inner surface 64a of the annular recess 64, thereby enabling the attenuation of the vibration. Therefore, similar to the above-mentioned O-ring 67, when machining a workpiece placed on the moving table 11, the vibration transmitted to the lead screw shaft 21 can be attenuated, and furthermore, the unevenness of the machining surface quality of the workpiece can be improved.

[0124] In addition, the working oil 70 in the pressure chamber 66 exhibits a damping hole effect due to the minute gaps generated by passing through between the disc springs 80 or the contact portions between the disc springs 80 and the inner surface of the pressure chamber 66. Therefore, the vibration of the above-mentioned lead screw shaft 21 or the vibration of the plurality of disc springs 80 can be attenuated.

[0125] Therefore, in the ball screw feed device 20 of the present embodiment, by accommodating the working oil 70 and the plurality of disc springs 80 in the pressure chamber 66, and accommodating the working oil 70 and the hollow member 90 in the storage chamber 71, and allowing the pressure chamber 66 and the storage chamber 71 to communicate through the damping holes 72, even if the axial length of the lead screw shaft 21 changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibration in the axial and radial directions can be attenuated.

[0126] In addition, as Figure 4 shown, a plurality of through holes 80a penetrating the conical plate portion in the axial direction can be formed in the disc-shaped disc spring 80. In addition, a plurality of slits (not shown) can also be formed. Thus, the disc spring 80 also functions as a damping hole, and by allowing the working oil 70 to flow through the plurality of through holes 80a or the slits, the attenuation effect can be further exerted.

[0127] In addition, in the above embodiment, the hollow member 90 has an elliptical cross-sectional shape, but it is not limited thereto. It can be a rectangular cross-sectional shape as shown in (a) of Figure 5 , or it can be a triangular cross-sectional shape as shown in (b) of Figure 5 . In addition, in the above embodiment, the hollow member 90 is formed in a ring shape, but it is not limited thereto. It can also be formed by one or more spherical shapes, semi-circular arc shapes (not shown), etc. as shown in (c) of Figure 5 .

[0128] In addition, Figure 6 (a) of Figure 6 and (b) of are cross-sectional views of a ring-shaped hollow member 90 which is a modification of the present embodiment. As in this modification, the hollow member 90 may also be configured to have at least one rib portion 90a protruding from its inner peripheral surface. The shape of the rib portion 90a may be formed in a ring shape over the entire circumference of the hollow member 90, or may be formed locally in the circumferential direction of the hollow member 90. In addition, the rib portion 90a only needs to be formed in a part of the circumferential direction of the ring-shaped cross section.

[0129] Since the hollow member 90 has such a rib portion 90a, when the hollow member 90 is compressed and deformed due to the pressure generated in the storage chamber 71, by abutting the rib portion 90a and the inner peripheral surface opposing the rib portion 90a, excessive deformation such as plastic deformation of the hollow member 90 can be prevented from occurring. Thereby, leakage of the liquid or gas contained in the hollow member 90 into the storage chamber 71 can also be prevented.

[0130] In addition, the rib portion 90a can also be applied to a shape other than a ring shape of the hollow member. For example, it can also be formed inside the above-mentioned spherical or semi-circular arc-shaped hollow member.

[0131] Furthermore, as in the modification shown in Figure 7 , at least one outer layer 100 covering the entire surface (mold) may be provided on the hollow member 90. Thereby, the rigidity of the hollow member 90 can be changed, and in addition, the surface of the hollow member 90 can be protected from the influence of working fluids such as the working oil 70.

[0132] In addition, the outer layer 100 may be made of the same material as the hollow member, but may also be made of other materials.

[0133] In addition, in the above-mentioned embodiment, the hollow member 90 is integrally formed without seams, is not likely to generate local stress concentration, and can be easily manufactured. However, the hollow member 90 is not limited to integral formation. For example, it may also be configured as an assembly having a hollow cross-section formed by integrating two or more components via the edge portions of the two or more components. Alternatively, the hollow member 90 may also be formed by bending a component and joining the edge portions of the component to form a hollow cross-section.

[0134] Specifically, in a modification assuming the ring-shaped component shown in Figures 8 - 10 , the hollow member 90 is configured as an assembly: formed by integrating and joining the ring-shaped components 101 and 102 via rib portions 101a and 102a formed on the two peripheral edges of the two or more ring-shaped components 101 and 102, and having a hollow cross-section. As a method of joining the ring-shaped components 101 and 102, an appropriate method may be selected from adhesion, fusion bonding, connection by a mechanical locking mechanism, etc.

[0135] For example, as shown in (a) to (c) of Figure 8 , the hollow member 90 is composed of an outer diameter side annular member 101 and an inner diameter side annular member 102 that are bisected in the radial direction, and a hollow cross-section is formed by the arcuate portions 101b and 102b of the annular members 101 and 102. In addition, Figure 8 in (a) and (b) of Figure 8 , either one of the rib portions 101a and 102a is longer than the other, and they are joined or fusion-bonded to each other. In particular, as shown in (b) of Figure 8 , the tip of the longer rib portion 102a can also be bent to cover the side surface of the shorter rib portion 101a. Further, as shown in (c) of

[0136] , the tip of the shorter rib portion 101a can also be covered by the tip of the longer rib portion 102a, and they are joined in a continuous or discontinuous U-shaped fastening structure to seal the interior. Figure 9 Alternatively, as shown in (a) to (c) of Figure 9 , the hollow member 90 is composed of a left annular member 101 and a right annular member 102 that are bisected in the axial direction, and a hollow cross-section is formed by the arcuate portions 101b and 102b of the annular members 101 and 102. In addition, Figure 9 in (a) and (b) of Figure 9 , either one of the rib portions 101a and 102a is longer than the other, and they are joined or fusion-bonded to each other. In particular, as shown in (b) of

[0137] , the tip of the longer rib portion 102a can also be bent to cover the side surface of the shorter rib portion 101a. Further, as shown in (c) of Figure 10 , the tip of the shorter rib portion 101a can also be covered by the tip of the longer rib portion 102a, and they are joined in a continuous or discontinuous U-shaped fastening structure to seal the interior. Figure 10 in (a) of Figure 10 , and in (b) of

[0138] , at least one of the opposing surfaces of the rib portions 101a and 102a of the annular members 101 and 102 that are bisected ( Figure 11In a modified example premised on the annular member shown in (a) to (c), the hollow member 90 is formed by bending the annular member 104 having a strip-shaped cross section so as to have a hollow cross section over the entire circumference, and the rib portions 104a and 104b formed at the peripheral edge of the annular member 104 are joined to each other. In this case, as a method of joining the annular member 104, an appropriate method may be selected from adhesion, fusion bonding, connection by a mechanical locking mechanism, etc.

[0139] That is, Figure 11 in (a) and (b), either one of the rib portions 104a and 104b is longer than the other, and they are joined to each other by adhesion or fusion bonding. In particular, as shown in Figure 11 (b), the tip of the longer rib portion 104b may be bent so that the side surface of the shorter rib portion 104a is covered by the rib portion 104b. Further, as shown in Figure 11 (c), the tip of the shorter rib portion 104a may be covered by the tip of the longer rib portion 104b, and they may be joined in a manner of sealing the inside by a continuous or discontinuous U-shaped fastening structure.

[0140] Thus, by adopting the structure shown in Figures 8 - 11 , even by a method other than integral molding, it is possible to easily manufacture the deformable hollow member 90.

[0141] In addition, the peripheral edge portions of the annular members 101, 102, and 104 may also be configured without the rib portions 101a, 102a, 104a, and 104b as shown in Figures 8 - 11 . That is, the peripheral edge portions of the arc-shaped portions 101b and 102b of the annular members 101 and 102 may be joined by an appropriate joining method to form the hollow member 90, or the peripheral edge portion of the bent portion of the annular member 104 may be joined by an appropriate joining method to form the hollow member 90.

[0142] In addition, Figures 8 - 11 the configuration shown in is not limited to being premised on an annular member, and may also be applied to a planar member or a bent member for forming a spherical shape or a semi-circular arc shape as shown in Figure 4 (c).

[0143] In addition, in the above-described embodiment, the storage chamber 71 is formed on the outer diameter side so as to open to the outer surface 65a of the annular convex portion 65, but it may also be formed on the inner diameter side so as to open to the inner surface 65b of the annular convex portion 65.

[0144] Furthermore, as long as the damping function can be exerted, the cross-sectional shape or length of the damping hole 72 may be arbitrarily formed.

[0145] In addition, although not shown, the support table side member 61 may also be integrally formed with the support table 43, and the bearing housing side member 62 may also be integrally formed with the moving side bearing housing 51.

[0146] (Second Embodiment)

[0147] Next, with reference to Figure 12 and Figure 13 , the ball screw feed device according to the second embodiment of the present invention will be described. In addition, in the present embodiment, the configuration of the housing position adjustment mechanism 60 of the second support mechanism 40 is different from that of the first embodiment.

[0148] In the housing position adjustment mechanism 60 of the second embodiment, the seal grooves 68 formed in the outer surface 65a and the inner surface 65b of the annular convex portion 65 are composed of a tapered surface 69a whose groove depth becomes shallower as it is farther from the pressure chamber 66 side, and annular axial side surfaces 69b, 69c that extend radially from the axial end edges of the tapered surface 69a.

[0149] In addition, the axial distance between the axial side surfaces 69b, 69c may be wider than the axial width of the O-ring 67 in a state where it is elastically deformed and installed in the seal groove 68. As a result, the working oil 70 that has passed through the gap g from the pressure chamber 66 winds around to the vicinity of the boundary between the axial side surface 69b with a deeper groove depth and the tapered surface 69a.

[0150] Therefore, as the pressure of the working oil 70 in the pressure chamber 66 increases, the working oil 70 presses the O-ring 67 toward the atmospheric pressure side, and the O-ring 67 further improves the sealing performance through the wedge structure between the tapered surface 69a of the seal groove 68 and the inner surface 64a or the outer surface 64b of the opposing annular concave portion 64. As a result, even when relative movement occurs between the support table side member 61 and the bearing housing side member 62, it is possible to prevent the working oil 70 from leaking to the atmospheric pressure side and continuously maintain the axial rigidity of the ball screw feed device 20.

[0151] In addition, as a modification of the present embodiment, as shown in (a) to (c) of Figure 14 , an abrasion-resistant member 59 may be interposed between at least one of the inner surface 64a of the O-ring 67 and the annular concave portion 64 and the outer surface 65a of the annular convex portion 65 (in the present embodiment, the tapered surface 69a of the seal groove 68 formed in the outer surface 65a).

[0152] Specifically, as shown in (a) of Figure 14 , the abrasion-resistant member 59 may be formed as an annular member having a U-shaped cross-section so as to be located between the outer peripheral surface of the O-ring 67 and the inner surface 64a of the annular concave portion 64, and between the inner peripheral surface of the O-ring 67 and the tapered surface 69a of the seal groove 68 formed in the outer surface 65a of the annular convex portion 65.

[0153] In addition, as shown in (b) of Figure 14 , the wear-resistant member 59 can be formed as an annular member with a linear cross-section in such a manner that it is located between the inner circumferential surface of the O-ring 67 and the tapered surface 69a of the seal groove 68 formed on the outward-facing surface 65a of the annular convex portion 65. Further, as shown in (c) of Figure 14 , the wear-resistant member 59 can be formed as an annular member with a linear cross-section in such a manner that it is located between the outer circumferential surface of the O-ring 67 and the inward-facing surface 64a of the annular concave portion 64.

[0154] As the wear-resistant member 59, a resin material such as a fluororesin or a metal material after appropriate surface treatment is used.

[0155] Figure 14 In any of the configurations (a) to (c) of

[0156] , by using the wear-resistant member 59, the stress concentration applied to the O-ring 67 can be dispersed, and damage such as wear of the O-ring 67 or the contact surface in contact with the O-ring 67 can be suppressed. Figure 13 In addition, the wear-resistant member 59 can also be interposed between the O-ring 67 shown in Figure 13 and at least one of the outward-facing surface 64b of the annular concave portion 64 and the inward-facing surface 65b of the annular convex portion 65 (in

[0157] , the tapered surface 69a of the seal groove 68 formed on the inward-facing surface 65b). Figure 14 In addition, in (a) to (c) of Figure 2 , the wear-resistant member 59 is interposed between the O-ring 67 and the opposing surface opposed to the O-ring 67 in the seal groove 68 having the tapered surface 69a. On the other hand, the wear-resistant member 59 can also exhibit the above-described effect even when it is interposed between the O-ring 67 and the opposing surface opposed to the O-ring 67 in the seal groove 68 with a uniform groove depth as shown in

[0158] Regarding other configurations and operations, they are the same as those of the first embodiment.

[0159] (Third Embodiment)

[0160] Next, with reference to Figure 15 , the ball screw feed device according to the third embodiment of the present invention will be described. In addition, in the present embodiment, the configuration of the housing position adjustment mechanism 60 of the second support mechanism 40 is different from that of the first embodiment.

[0161] In the housing position adjustment mechanism 60 of the third embodiment, heating elements 180, 181 serving as the working medium volume change portion, such as heating wires and rubber heaters, are arranged annularly or discretely on the outer circumferential surfaces of the support table side member 61 and the bearing housing side member 62.

[0162] Thus, heat from the heating elements 180 and 181 is transferred from the support base side member 61 and the bearing housing side member 62 to the hollow member 90 and the working oil 70 within the pressure chamber 66, heating the hollow member 90 and the working oil 70. As a result, the volumes of the hollow member 90 and the working oil 70 can expand. Consequently, when the lead screw shaft 21 elongates axially, a load is generated within the pressure chamber 66 due to the volume expansion of the hollow member 90 and the working oil 70, and thus the axial support rigidity can be maintained.

[0163] In addition, in the present embodiment, heating elements 180 and 181 are installed as the working medium volume change portions on the outer peripheral surfaces of the support base side member 61 and the bearing housing side member 62. However, alternatively, cooling jackets, cooling assemblies, etc., i.e., cooling media 182 and 183, can be installed instead.

[0164] By using the cooling media 182 and 183, even when the load generated within the pressure chamber 66 due to the volume expansion of the hollow member 90 and the working oil 70 is excessive, the hollow member 90 and the working oil 70 can be cooled, causing the volumes of the hollow member 90 and the working oil 70 to contract. Thereby, it is possible to prevent the axial support rigidity of the ball screw feed device 20 from becoming excessively large and to continuously maintain the axial support rigidity in a stable state.

[0165] In addition, in the present embodiment, since the temperatures of the hollow member 90 and the working oil 70 are affected by the components of the ball screw feed device 20, the installation environment, the operating cycle, etc., a feedback loop for the temperatures of the components, the hollow member 90, the working oil 70, etc. can also be formed by using the heating elements 180 and 181 and the cooling media 182 and 183, thereby controlling the hollow member 90 or the working oil 70 to a target temperature. Further, in the present embodiment, the operations of the heating elements 180 and 181 and the cooling media 182 and 183 can also be feedback-controlled by considering the volume change of the working oil 70, the pressure state within the pressure chamber 66, the axial relative displacement between the support base side member 61 and the bearing housing side member 62, etc.

[0166] In addition, in the present embodiment, the working medium volume change portion is installed on both the support base side member 61 and the bearing housing side member 62, but it can also be installed on either the support base side member 61 or the bearing housing side member 62.

[0167] Furthermore, in the present embodiment, the working medium volume change portion is provided on the outer peripheral surfaces of the support base side member 61 and the bearing housing side member 62. However, as long as it is a portion capable of expanding and contracting the volumes of the hollow member 90 and the working oil 70 within the pressure chamber 66, it can also be installed at any position such as the axial side surface, the inner peripheral surface, the interior, etc.

[0168] In addition, a heating element may be installed on either the support table side member 61 or the bearing housing side member 62, and a cooling medium may be installed on the other one. Additionally, the heating element and the cooling medium may also be configured to coexist in either the support table side member 61 or the bearing housing side member 62.

[0169] Regarding other configurations and operations, they are the same as those of the first embodiment.

[0170] (Fourth Embodiment)

[0171] Next, with reference to Figure 16 , the ball screw feed device of the sixth embodiment of the present invention will be described. In addition, in this embodiment, the difference from the first embodiment is that the second support mechanism 40 further has another housing position adjustment mechanism 160.

[0172] That is, in the second support mechanism 40 of the fourth embodiment, between the bearing unit 41 and the support table 43, there is also provided another housing position adjustment mechanism 160 disposed adjacent to the housing position adjustment mechanism 60.

[0173] Another housing position adjustment mechanism 160 includes: another support table side member 161, which is provided on the support table 43 side and is penetrated by the lead screw shaft 21; another bearing housing side member 162, which is provided on the bearing housing 51 side and is penetrated by the lead screw shaft 21 and can relatively move axially with respect to the other support table side member 161; another working fluid 170, which is housed in another pressure chamber 166 formed between the other support table side member 161 and the other bearing housing side member 162, another storage chamber 171 formed in either the other support table side member 161 or the other bearing housing side member 162, and a damping hole 172 that communicates the other pressure chamber 166 with the other storage chamber 171; an elastic member 80, which is disposed in the other pressure chamber 166 in a compressed state between the opposing axial end faces of the other support table side member 161 and the other bearing housing side member 162; and a hollow member 90, which is housed in the other storage chamber 171. That is, the second support mechanism 40 has two housing position adjustment mechanisms 60 and 160 configured in series and arranged in series axially.

[0174] As Figure 16 shown, in the case of another housing position adjustment mechanism 160 as well, the other bearing housing side member 162 has an annular recess 164, and the other support table side member 161 has an annular protrusion 165 that is slidably fitted axially within the annular recess 164. Additionally, a plurality of disc springs 80 and the other working fluid 170 are disposed in another pressure chamber 166 formed between the annular recess 164 and the annular protrusion 165. The other working fluid 170 is applied to a material exemplified as the working oil 70.

[0175] In addition, in the present embodiment, in the other support base side member 161, an annular portion 161a protruding toward the support base 43 side is fitted into the through hole 43a of the support base 43 and fixed to the support base 43 with a plurality of bolts (not shown). Further, the support base side member 61 of the housing position adjustment mechanism 60 and the other bearing housing side member 162 of the other housing position adjustment mechanism 160 are integrally formed by a single member or by connecting the two members.

[0176] In this way, by axially arranging two housing position adjustment mechanisms 60 and 160 in series, even when the elongation of the lead screw shaft is larger, the axial rigidity of the ball screw feed device 20 can be stably maintained. In addition, the centering property and coaxiality in the axial direction can also be improved.

[0177] In addition, the other housing position adjustment mechanism 160 is not limited to the same configuration as the housing position adjustment mechanism 60 as Figure 16 shown, and may have other configurations as long as it has a pressure generating unit housed in a state of being compressed in a pressure chamber 166 formed between the other support base side member 161 and the other bearing housing side member 162. For example, as the pressure generating unit, a hollow member 90 may be arranged in the other pressure chamber 166 instead of an elastic member such as a spring.

[0178] In addition, the second support mechanism 40 may have three or more housing position adjustment mechanisms in addition to the two housing position adjustment mechanisms 60 and 160, as long as the plurality of housing position adjustment mechanisms are axially arranged in series.

[0179] Regarding other configurations and operations, they are the same as those in the first embodiment.

[0180] In addition, in the first to fourth embodiments, a pair of angular contact ball bearings of the bearing unit applied to the second support mechanism are arranged in a face-to-face combination, but the combination arrangement is not limited to this. That is, the pair of angular contact ball bearings 53, 53 may also be arranged in a back-to-back combination as Figure 17 shown, or in various support forms such as a side-by-side combination as Figure 18 shown. In addition, as Figure 17 shown, when the pair of angular contact ball bearings 53, 53 are arranged in a back-to-back combination, an inner ring spacer 49 is sometimes arranged between the step between the large diameter portion 24 and the small diameter portion 25 of the lead screw shaft 21 and the inner ring 55 of the axially inner angular contact ball bearing 53.

[0181] In addition, the pair of angular contact ball bearings 33, 33 of the first support mechanism are also arranged in a face-to-face combination, but may also be arranged in various support forms such as a back-to-back combination or a side-by-side combination.

[0182] Further, although not shown, the angular contact ball bearings 33 and 53 do not necessarily consist of two angular contact ball bearings, and may also consist of three or more angular contact ball bearings.

[0183] Further, in the above-described embodiment, the other housing position adjustment mechanism 160 and the housing position adjustment mechanism 60 are arranged adjacent to each other in the axial direction, but are not limited thereto, and may also be configured to be arranged adjacent to and juxtaposed with the housing position adjustment mechanism 60 in the radial direction.

[0184] Thus, it is possible to suppress the axial dimension of the ball screw feed device 20, and it is easier to maintain the axial rigidity of the ball screw feed device 20 in a state where an axial load larger than that when a separate housing position adjustment mechanism is arranged is generated.

[0185] In addition, in the above-described embodiment, the annular concave portion is provided on the bearing housing side member, and the annular convex portion is provided on the support table side member. However, the present invention is not limited thereto, and the annular concave portion may be provided on the support table side member, and the annular convex portion may be provided on the bearing housing side member.

[0186] Further, in the above-described embodiment, the pressure chamber 66 and the storage chamber 71 are formed in an annular shape by the annular concave portion 64 and the annular convex portion 65. However, a plurality of concave portions and convex portions may be formed in the circumferential direction to form a plurality of pressure chambers and a plurality of storage chambers. In this case, it may also be configured as follows: working oil and an elastic member are arranged in the plurality of pressure chambers, working oil and a hollow member are arranged in the storage chamber, and an O-ring is arranged between the inner circumferential surface of the concave portion and the outer circumferential surface of the convex portion, having a function of leaking and attenuating the working oil.

[0187] In this case, the damping holes that communicate the storage chamber and the pressure chamber are also provided in each convex portion.

[0188] For example, as shown in (a) of Figure 19 , four pressure chambers 66 and storage chambers 71 may be arranged in the circumferential direction around the lead screw shaft 21. As shown in (b) of Figure 19 , two pressure chambers 66 and storage chambers 71 that are adjacent to and juxtaposed with each other in the radial direction may be arranged in the circumferential direction around the lead screw shaft 21, that is, a total of eight pressure chambers 66 and storage chambers 71. Or, as shown in (a) of Figure 20 , two pressure chambers 66 and storage chambers 71 may be arranged in the circumferential direction around the lead screw shaft 21, that is, the pressure chambers 66 and storage chambers 71 on both sides in the width direction (Y direction) of the lead screw shaft 21. As shown in (b) of Figure 20 , three pressure chambers 66 and storage chambers 71 that are adjacent to and juxtaposed with each other in the radial direction (in this example, the width direction) may be arranged in the circumferential direction around the lead screw shaft 21, that is, a total of six pressure chambers 66 and storage chambers 71. In this case, the height dimension of the support table side member 61 or the bearing housing side member 62 can be suppressed.

[0189] Furthermore, as shown in Figure 21 , two pressure chambers 66 and storage chambers 71 may also be circumferentially arranged around the lead screw shaft 21, that is, the pressure chambers 66 and storage chambers 71 on both sides in the vertical direction of the lead screw shaft 21. In this case, the width dimensions of the support table side member 61 or the bearing housing side member 62 can be suppressed.

[0190] Here, Figure 22 is a schematic cross-sectional view taken along line XXII-XXII of (a) in Figure 20 . In this case, the two pressure chambers 66 and the storage chambers 71 are respectively constituted by the concave portions 64x and the convex portions 65x.

[0191] In addition, in the figure, the convex portion 65x is integrally formed with the base portion of the support table side member 61, but it may also be formed separately from the base portion and combined.

[0192] In addition, as long as the plurality of pressure chambers 66 and the storage chambers 71 are configured such that the bearing unit 41 and the bearing housing side member 62 can stably move in the same direction following the axial elongation of the lead screw shaft 21 caused by thermal expansion, they can be arbitrarily arranged. Specifically, it is preferably point-symmetric or line-symmetrically arranged in a plane orthogonal to the lead screw shaft 21. In addition, the plurality of pressure chambers 66 and the plurality of storage chambers 71 may also be arranged offset in the axial direction.

[0193] Furthermore, adjacent pressure chambers 66 and storage chambers 71 may be connected via a communication path as needed for the purpose of equalizing pressure, etc., and the working fluid inside can also flow between the adjacent pressure chambers 66 and storage chambers 71.

[0194] For example, Figure 20 in (b) of Figure 21 , the adjacent pressure chambers 66 are connected via the communication path 66x.

[0195] In addition, the support table side member 61 and the bearing housing side member 62 are not limited to being constituted by a single member, and may also be divided and constituted in a manner of surrounding the lead screw shaft 21 according to the layout of the pressure chambers 66 and the storage chambers 71. Further, the single members, that is, the support table side member 61 and the bearing housing side member 62, may also be formed with a part of the circumference opened or divided in a manner of surrounding the lead screw shaft 21.

[0196] For example, Figure 20 in (b) of

[0197] In addition, similar to the above-described another housing position adjustment mechanism 160, the pressure generating units in the plurality of pressure chambers 66 and the storage chambers 71 are not limited to having the same configuration throughout. That is, it is not limited to a configuration in which a working fluid and an elastic member are disposed in the pressure chamber 66 and a working fluid and a hollow member are disposed in the storage chamber 71. The pressure generating unit in any one of the pressure chambers 66 may also have other configurations such as using an elastic member such as a spring. Therefore, it is sufficient to form the storage chamber 71 and the damping hole 72 in at least one of the plurality of convex portions 65x, and convex portions 65x that do not have the storage chamber 71 and the damping hole 72 may also be provided.

[0198] In addition, the concave and convex portions constituting the pressure chamber 66 and the storage chamber 71 are not limited to having a circular cross section, and may be formed in any shape such as a rectangle. Further, the cross-sectional dimensions and the axial dimensions of the plurality of pressure chambers 66 and the storage chambers 71 may also be arbitrarily configured.

[0199] (Fifth Embodiment)

[0200] In the housing position adjustment mechanism 60 of the above-described embodiment and the modification, when the lead screw shaft 21 extends in the axial direction, the volume of the pressure chamber 66 increases, and the working oil 70 and the disc spring 80 in a compressed state in the pressure chamber 66 and the working oil 70 and the hollow member 90 in a compressed state in the storage chamber 71 gradually reduce the pressure while pressing the bearing unit 41 and the bearing housing side member 62 to the left. As a result, the pair of angular contact ball bearings 53, 53 move axially to maintain the axial support rigidity of the lead screw shaft 21.

[0201] However, in the fifth embodiment, the housing position adjustment mechanism 60 as shown in Figure 23 is used to maintain the axial support rigidity of the lead screw shaft 21. Specifically, when the lead screw shaft 21 extends in the axial direction, the bearing unit 41 and the bearing housing side member 62 move to the left via the pair of angular contact ball bearings 53, 53 that move together with the lead screw shaft 21, and the volume of the pressure chamber 66 decreases. On the other hand, if the pressures of the working oil 70, the disc spring 80, and the hollow member 90 gradually increase, the bearing unit 41 and the bearing housing side member 62 are pressed to the right. Therefore, by adjusting the volume of the pressure chamber 66 and the pressures of the disc spring 80 and the hollow member 90 in a manner that allows the axial elongation of the lead screw shaft 21, the axial support rigidity of the lead screw shaft 21 can be maintained.

[0202] In this case, the support table side member 61 has: a small-diameter cylindrical portion 61c that extends from the small-diameter portion of the annular base 61b mounted on the support table 43 toward the bearing housing 51 side; and an outer flange portion 61d that extends from the tip of the small-diameter cylindrical portion 61c toward the outer diameter side. The bearing housing side member 62 has: a large-diameter cylindrical portion 62c that extends from the large-diameter portion of the annular base 62b mounted on the moving-side bearing housing 51 toward the support table 43 side; and an inner flange portion 62d that extends from the tip of the large-diameter cylindrical portion 62c toward the inner diameter side.

[0203] The outer flange portion 61d of the support table side member 61 can move axially relative between the annular base 62b and the inner flange portion 62d of the bearing housing side member 62, and its outer peripheral surface is in sliding contact with the inner peripheral surface of the large-diameter cylindrical portion 62c via an O-ring 67. In addition, the inner flange portion 62d of the bearing housing side member 62 can move axially relative between the annular base 61b and the outer flange portion 61d of the support table side member 61, and its inner peripheral surface is in sliding contact with the outer peripheral surface of the small-diameter cylindrical portion 61c via an O-ring 67. Therefore, the pressure chamber 66 is formed by an annular space separated by the small-diameter cylindrical portion 61c and the outer flange portion 61d of the support table side member 61, and the large-diameter cylindrical portion 62c and the inner flange portion 62d of the bearing housing side member 62. In this pressure chamber 66, the working oil 70 and the disc spring 80 are filled in a slightly compressed state.

[0204] Furthermore, in the outer flange portion 61d, a storage chamber 71 that opens to the inner peripheral surface of the large-diameter cylindrical portion 62c and a damping hole 72 that communicates the pressure chamber 66 and the storage chamber 71 are formed. A hollow member 90 is arranged in the storage chamber 71.

[0205] In this case, when the lead screw shaft 21 axially elongates due to thermal expansion, the pair of angular contact ball bearings 53, 53, the bearing housing 51, and the bearing housing side member 62 compress the working oil 70 and the disc spring 80 in the pressure chamber 66, and the working oil 70 and the hollow member 90 in the storage chamber 71 while moving to the left in the figure by the interaction of this pressure, thereby enabling the maintenance of the axial support rigidity of the lead screw shaft 21.

[0206] In particular, since the working oil 70 can flow between the pressure chamber 66 and the storage chamber 71 via the damping hole, the plurality of disc springs 80, the hollow members 90, and the working oil 70 can be designed to share the load pressing on the bearing unit 41 and the bearing housing side member 62, and can also change corresponding to the axial elongation amount of the lead screw shaft 21 when the temperature rise amount is higher than 4 degrees. Thus, during the axial elongation of the lead screw shaft 21, the state of using the pair of angular contact ball bearings 33, 33 as fixed support portions is maintained, and the axial rigidity of the ball screw feed device 20 is stabilized.

[0207] In addition, by installing the O-ring 67 between the inner peripheral surface of the inward flange portion 62d and the outer peripheral surface of the small-diameter cylindrical portion 61c, and between the outer peripheral surface of the outward flange portion 61d and the inner peripheral surface of the large-diameter cylindrical portion 62c, leakage of the working oil 70 filled in the pressure chamber 66 and the storage chamber 71 can be prevented. In addition, it also functions as a damping mechanism, and can attenuate the vibration generated in the lead screw shaft 21.

[0208] In addition, the working oil 70 in the pressure chamber 66 and the storage chamber 71 passes through the damping hole 72 and the gap between the inner peripheral surface of the large-diameter cylindrical portion 62c and the outer peripheral surface of the outward flange portion 61d, so that the vibration of the lead screw shaft 21 can be attenuated.

[0209] Furthermore, in each gap between the inner peripheral surface of the inward flange portion 62d and the outer peripheral surface of the small-diameter cylindrical portion 61c, and between the outer peripheral surface of the outward flange portion 61d and the inner peripheral surface of the large-diameter cylindrical portion 62c, the working oil 70 in a compressed state is stored. Therefore, through the radial pressure of the working oil 70 acting on each gap, the radial support rigidity and the centering property between the bearing housing side member 62 and the support base side member 61 can be improved. As a result, the housing position adjustment mechanism 60 can impart radial support rigidity to the lead screw shaft 21. Furthermore, it can also have a centering function for the lead screw shaft 21.

[0210] In addition, the support base side member 61 and the bearing housing side member 62 can also be respectively composed of single components, but as Figure 23 shown, considering the assemblability, they can also be respectively composed of two components 91, 92, 93, 94 in a state of sandwiching the O-ring 67.

[0211] In addition, one O-ring 67 and one seal groove 68 are respectively arranged between each pair of opposing surfaces, but multiple ones can also be arranged.

[0212] In addition, instead of Figure 23 , the support base side member 61 can be made to have a large-diameter cylindrical portion and an inward flange portion, and the bearing housing side member 62 can be made to have a small-diameter cylindrical portion and an outward flange portion, so as to form a pressure chamber.

[0213] Furthermore, the storage chamber and the damping hole can also be formed in the inward flange portion 62d, and the storage chamber can also be opened on the outer peripheral surface of the small-diameter cylindrical portion 61c.

[0214] In addition, in such a housing position adjustment mechanism 60, a pair of angular contact ball bearings 53, 53 can be arranged in a face-to-face combination as Figure 23 shown, or in a back-to-back combination as Figure 24 shown, or in various support forms such as a side-by-side combination. In addition, although not shown, a pair of angular contact ball bearings do not necessarily consist of two angular contact ball bearings, and can also consist of three or more angular contact ball bearings.

[0215] Furthermore, as shown in Figure 25 and Figure 26 , the housing position adjustment mechanism 60 of the fifth embodiment may also be the same as that of the second embodiment. The sealing groove 68 formed on the inner peripheral surface of the inward flange portion 62d and the outer peripheral surface of the outward flange portion 61d is composed of a tapered surface 69a whose groove depth becomes shallower as it moves away from the pressure chamber side, and annular axial side surfaces 69b and 69c extending radially from the axial end edges of the tapered surface 69a.

[0216] Therefore, as the pressure of the working oil 70 in the pressure chamber 66 increases, as the O-ring 67 is pressed toward the atmospheric pressure side, the O-ring 67 utilizes the wedge structure between the tapered surface 69a of the sealing groove 68 and the outer peripheral surface of the opposed small-diameter cylindrical portion 61c or the inner peripheral surface of the large-diameter cylindrical portion 62c to further improve the sealing performance. As a result, even when relative movement occurs between the support base side member 61 and the bearing housing side member 62, leakage of the working oil 70 to the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device 20 can be continuously maintained.

[0217] In addition, in this modification, as shown in Figure 26 , the sealing groove 68 formed on either one of the opposed surfaces of the two members 91 and 92 constituting the support base side member 61, and the sealing groove 68 formed on either one of the opposed surfaces of the two members 93 and 94 constituting the bearing housing side member 62 may also have a tapered surface 69a whose groove depth becomes shallower as it moves away from the pressure chamber side.

[0218] In addition, in the case of this modification, a wear-resistant member may be interposed between at least one of the inner peripheral surface of the inward flange portion 62d and the outer peripheral surface of the small-diameter cylindrical portion 61c and the O-ring 67, and between at least one of the outer peripheral surface of the outward flange portion 61d and the inner peripheral surface of the large-diameter cylindrical portion 62c and the O-ring 67.

[0219] In this case, the wear-resistant member 59 may be interposed between the O-ring 67 and the opposed surface opposed to the O-ring 67 in the sealing groove 68 having the tapered surface 69a as shown in Figure 26 , or may be interposed between the O-ring 67 and the opposed surface opposed to the O-ring 67 in the sealing groove 68 having a uniform groove depth as shown in Figure 23 .

[0220] Furthermore, as shown in Figure 27 , the housing position adjustment mechanism 60 of the fifth embodiment may also be the same as that of the third embodiment, and a working medium volume change portion such as heating elements 180 and 181 or cooling media 182 and 183 may be provided between the support base side member 61 and the bearing housing side member 62.

[0221] Thus, as described in the third embodiment, according to the state of the ball screw feed device 20 in use, the volume of the hollow member 90 and the working oil 70 in the pressure chamber 66 can be expanded by the heating elements 180 and 181, or the volume of the hollow member 90 and the working oil 70 in the pressure chamber 66 can be contracted by the cooling media 182 and 183, so as to continuously maintain the axial support rigidity in a stable state.

[0222] In addition, in the housing position adjustment mechanism 60 of the fifth embodiment, as Figure 28 shown, similar to the fourth embodiment, the second support mechanism 40 can also be configured such that the housing position adjustment mechanism 60 and another housing position adjustment mechanism 160 are arranged in series axially between the bearing unit 41 and the support table 43.

[0223] In this case, the other support table side member 161 of the other housing position adjustment mechanism 160 has an annular base 161b, a small-diameter cylindrical portion 161c, and an outward flange portion 161d, and the other bearing housing side member 162 has an annular base 162b, a large-diameter cylindrical portion 162c, and an inward flange portion 162d. In addition, the other support table side member 161 and the other bearing housing side member 162 of the other housing position adjustment mechanism 160 are each composed of two members 191, 192, 193, and 194. In addition, the support table side member 61 of the housing position adjustment mechanism 60 and the other bearing housing side member 162 of the other housing position adjustment mechanism 160 are connected to each other to form an integral structure.

[0224] In addition, similar to the fourth embodiment, the second support mechanism 40 can be configured such that a plurality of housing position adjustment mechanisms are arranged in series axially, or can be arranged side by side radially.

[0225] In addition, the present invention is not limited to the above embodiments, and can be appropriately changed, improved, etc. In addition, the various embodiments and various modification examples described in this specification can be combined and applied within the scope of feasibility.

[0226] For example, an auxiliary accumulator or an external pump for supplying working oil can be connected to the above pressure chamber or storage chamber as needed. Further, the state of the ball screw feed device can be diagnosed or corrected by monitoring the pressure of the working oil in the pressure chamber or storage chamber or the load applied to the pair of angular contact bearings 53, 53.

[0227] In addition, in the above embodiments, a disc spring is used as the elastic member, but it is not limited thereto, and a helical spring can also be used.

[0228] In addition, in the first to fourth embodiments, an O-ring 67 is installed between the outward-facing surface 65a of the annular convex portion 65 and the inward-facing surface 64a of the annular concave portion 64, and between the inward-facing surface 65b of the annular convex portion 65 and the outward-facing surface 64b of the annular concave portion 64. However, this is not limiting, and any sealing member configured to prevent the working oil 70 from leaking out of the pressure chamber 66 may be used.

[0229] Similarly, in the fifth embodiment, an O-ring 67 is also installed between the outer peripheral surface of the outward-facing flange portion 61d and the inner peripheral surface of the large-diameter cylindrical portion 62c, and between the inner peripheral surface of the inward-facing flange portion 62d and the outer peripheral surface of the small-diameter cylindrical portion 61c. However, this is not limiting, and any sealing member configured to prevent the working oil 70 from leaking out of the pressure chamber 66 may be used.

[0230] Furthermore, it is preferable that the sealing member not only prevents the working oil 70 from leaking out of the pressure chamber 66 but also attenuates the vibration of the lead screw shaft 21, similar to the O-ring 67.

[0231] In addition, in any of the embodiments, the working oil 70 needs to be sealed from the outside on the basis of being filled in the pressure chamber 66. At this time, for example Figure 2 in the housing position adjustment mechanism 60 shown, as Figure 29 shown in (a), in the bearing housing side member 62, an oil supply passage 109 for filling the working oil 70 into the pressure chamber 66 may be formed by penetrating radially between the inward-facing surface 64a of the annular concave portion 64 and the outer peripheral surface of the bearing housing side member 62.

[0232] Also, a set bolt 110 screwed into an internal thread portion 109a formed in the oil supply passage 109 and blocking the oil supply passage 109 may be installed on the outer peripheral surface of the bearing housing side member 62. In addition, by winding a sealing tape (not shown), or applying or filling a leak-proof agent, etc., to the external thread portion of the set bolt 110, the gap between the external thread and the internal thread 109a is filled, thereby more reliably preventing the working oil 70 filled in a compressed state from leaking.

[0233] Also, an annular sealing groove 110a may be formed on the opposing surface of the head of the set bolt 110 opposing the outer peripheral surface of the bearing housing side member 62. Thus, by installing an O-ring 111 in the sealing groove 110a, the sealing performance of the set bolt 110 can be improved.

[0234] In addition, as Figure 29 shown in (b), the bottom surface of the sealing groove 110a of the set bolt 110 is formed in a tapered shape in order to further improve the sealing performance.

[0235] In addition, as a member for blocking the oil supply passage 109, a set plug may be used instead of the set bolt 110. For example, it may also be used as Figure 30The conical stop plug 112 shown in (a) plugs the oil supply passage 109. In this case, the stop plug 112 is screwed into the internal thread portion 109a formed on the outer diameter side of the oil supply passage 109 and fixed to the oil supply passage 109. In addition, as shown in Figure 30 (b), the oil supply passage 109 has a conical internal thread portion 109a on the outer diameter side, and the straight portion 109b without the internal thread portion is continuous with the internal thread portion 109a via the stepped hole 109c. At this time, the stop plug 112 can also be fastened to the internal thread portion 109a in a state where the disk-shaped member 113 is accommodated in the stepped hole 109c. In this case, the stop plug 112 deforms the disk-shaped member 113 while fastening to the internal thread portion 109a, so that a seal can be ensured between the contact surface of the disk-shaped member 113 and the stepped hole 109c.

[0236] In addition, by winding a sealing tape (not shown) around the external thread portion of the stop plug 112, or applying or filling a leak-proof agent, etc., the gap between the external thread and the internal thread portion 109a is filled, and thus good sealing performance can also be imparted.

[0237] In addition, as shown in Figure 30 (c), the disk-shaped member 113 can also be integrated with the elastic deformation member 114 that constitutes the contact surface in contact with the stepped hole 109c. Or, as shown in Figure 30 (d), the disk-shaped member 113 can also form an annular seal groove 113a on the contact surface in contact with the stepped hole 109c and arrange an O-ring 115.

[0238] In addition, the oil supply passage 109 communicating with the pressure chamber 66 is not limited to a configuration formed by penetrating in the radial direction, and can also be formed by penetrating any component constituting the pressure chamber 66 in the axial direction.

[0239] Furthermore, the support base only needs to be configured to directly or indirectly support the support base side component of the housing position adjustment mechanism, and is not limited to the configuration penetrated by the rotating shaft as in the above-described embodiment. It can also be a configuration arranged around the rotating shaft, and can be designed into any shape.

[0240] (Application to Another Ball Screw Feeding Device)

[0241] In addition, Figure 1 in the ball screw feeding device 20, a drive motor 12 is connected to one side of the screw shaft 21 supported by the first support mechanism 30 ( Figure 1 the right side in), but the present invention is not limited thereto. That is, it can also be like the ball screw feeding device 20 shown in Figure 31 , and a drive motor 12 is connected to the other side of the screw shaft 21 supported by the second support mechanism 40 ( Figure 31 the left side in).

[0242] In this case, the drive motor 12 is supported by another support table 85 that is fixed to the base 1 and penetrated by the lead screw shaft 21. In addition, the tip of the small-diameter shaft portion 27 is disposed at a distance from the rotary shaft 12a of the drive motor 12 within the coupling 28 so that when the lead screw shaft 21 axially elongates due to thermal expansion, the small-diameter shaft portion 27 can move axially.

[0243] Therefore, the present invention can be highly flexibly used, for example, as a positioning application for devices that perform high-precision machining and measurement such as machine tools (machining centers, lathes, grinders, etc.), measuring machines (3D measuring devices), semiconductor manufacturing devices (stages for exposure devices, inspection probes, etc.), inspection devices, etc., or as a ball screw feed device for semiconductor manufacturing or the like.

[0244] In addition, in the above-described embodiment, the support table 43 is disposed on the axially central side with respect to the bearing unit 41, but the present invention is not limited thereto, and it may also be disposed on the axially end side with respect to the bearing unit 41. That is, the support table 43 can be disposed on the axially central side with respect to the bearing unit 41 or on the axially end side according to the configuration or action of the housing position adjustment mechanism 60.

[0245] For example, Figure 32 and Figure 33 In the form shown, the support table 43 is provided on the axially end side with respect to the bearing unit 41. In this case, the support table side member 61 may be directly or indirectly mounted on the support table 43, and the bearing housing side member 62 may be directly or indirectly mounted on the bearing housing 51. In addition, the spacer 48a disposed between the inner ring 55 and the fastening nut 38b passes through the through-hole 43a of the support table 43, the inside of the support table side member 61, and the bearing housing side member 62.

[0246] In addition, Figure 34 and 31 In the form shown, the support table 43 is disposed on the axially end side with respect to the bearing unit 41. On the other hand, the support table 43 is fixed to the support table side member 61 disposed on the axially central side with respect to the bearing unit 41 through an outer cylinder portion 43b that axially extends from the main body portion having the through-hole 43a and surrounds the housing position adjustment mechanism 60. In this case, the support table side member 61 may be directly or indirectly mounted on the support table 43, and the bearing housing side member 62 may be directly or indirectly mounted on the bearing housing 51. In addition, the spacer 48a disposed between the inner ring 55 and the fastening nut 38b passes through the through-hole 43a of the support table 43.

[0247] (For applications other than ball screw feed devices)

[0248] In addition, in the above-described embodiments, the ball screw feed device has been described. However, the present invention can also be applied to a rotary support device that rotatably supports both axial ends of a rotating shaft by a pair of support mechanisms. That is, in a case where the axial length of the rotating shaft changes due to the influence of heat, a housing position adjustment mechanism as in the above-described embodiments can be used to configure the support rigidity in the axial direction of the rotating shaft to be continuously and stably maintained. In addition, by using the housing position adjustment mechanism of the above-described embodiments, vibration in the axial and radial directions can be attenuated.

[0249] For example, as Figure 36 shown, the rotary support device 120 includes a rotating shaft 121 and a pair of support mechanisms 30 and 40 that rotatably support both axial ends of the rotating shaft 121, respectively.

[0250] The support mechanism 30 includes: a bearing housing 31 fixed to the base 1; and bearings 33, 33 that rotatably support the rotating shaft 121 with respect to the bearing housing 31, that is, a pair of angular contact ball bearings 33, 33 arranged in a face-to-face combination.

[0251] In addition, the support mechanism 40 includes: a bearing unit 41; a support table 43 disposed on the axially central side with respect to the bearing unit 41 and penetrated by the rotating shaft 121; and a housing position adjustment mechanism 60 disposed between the bearing unit 41 and the support table 43. The bearing unit 41 includes: a bearing housing 51; and bearings 53, 53 that rotatably support the rotating shaft 121 in the bearing housing 51 and can support an axial load, that is, a pair of angular contact ball bearings 53, 53 arranged in a face-to-face combination.

[0252] Moreover, the housing position adjustment mechanism 60 includes: a support table side member 61 disposed on the support table 43 side and penetrated by the rotating shaft 121; a bearing housing side member 62 disposed on the bearing housing 51 side and penetrated by the rotating shaft 121, capable of relatively moving axially with respect to the support table side member 61; a working oil (working fluid) 70 filled in a pressure chamber 66 formed between the support table side member 61 and the bearing housing side member 62, a storage chamber 71 formed in either the support table side member 61 or the bearing housing side member 62, and a damping hole 72 that communicates the pressure chamber 66 and the storage chamber 71; a disc spring (elastic member) 80 disposed in the pressure chamber 66 in a compressed state between the opposing axial end faces of the support table side member 61 and the bearing housing side member 62; and a hollow member 90 accommodated in the storage chamber 71.

[0253] In addition, Figure 36Components marked with the same reference numerals as those in the above-described embodiments are substantially the same components, and thus their descriptions are omitted or simplified. In addition, various structures described in the ball screw feed device 20 can also be applied to the rotary support device, achieving the same effects.

[0254] In addition, each of the bearings 33 and 53 of the support mechanisms 30 and 40 of the rotary support device 120 described above may be an angular contact ball bearing as in the above-described embodiments, but is not limited thereto, and may also be a roller bearing or a sliding bearing capable of supporting an axial load. By using such a bearing capable of supporting an axial load, particularly in the support mechanism 40, the working oil 70 and the elastic member 80 can be compressed via the bearing by tightening a fastening nut 38b as in the above-described embodiments.

[0255] In addition, Figure 36 in, it is configured such that the second support mechanism 40 having the housing position adjustment mechanism 60 supports the end of the rotary shaft 121. However, as Figure 37 shown, the second support mechanism 40 having the housing position adjustment mechanism 60 may also be configured to support the rotary shaft 121 at a position closer to another support table 85 of the support drive motor 12.

[0256] For example, when the rotary support device 120 as Figure 37 shown is applied to a spindle device that rotates a tool in a machine tool, by installing a tool at the end of the rotary shaft 121 supported by the support mechanism 30, the axial support rigidity of the rotary shaft 121 can be continuously and stably maintained, and the axial positioning of the tool can be reliably performed, achieving high-precision machining.

[0257] In addition, in Figure 36 and Figure 37 shown in the rotary support device 120, the drive motor 12 does not necessarily need to be coaxially arranged with the rotary shaft 121. For example, the power of the drive motor can also be transmitted to the rotary shaft 121 via a pulley, a gear train, etc.

[0258] In addition, the drive motor 12 is not limited to a separate component coaxially arranged with the rotary shaft 121. For example, a built-in motor can also be directly formed on the rotary shaft 121.

[0259] In addition, as the rotary support device 120, as a support body, a housing in which the bearing housing 31 of the first support mechanism 30 and the support table 43 of the second support mechanism 40 are integrated can also be provided.

[0260] In addition, in a rotary support device other than the ball screw feed device, as Figures 32 - 35 shown, the support table can be arranged on the axial end side with respect to the bearing unit.

[0261] In addition, in the above-described embodiments, the housing position adjustment mechanism has been described as a mechanism for adjusting the axial position of the bearing housing of the bearing that supports the rotating shaft. However, the present invention is not limited thereto, and it can also be applied as a support mechanism position adjustment mechanism of the shaft support device. That is, the shaft is not limited to a rotating shaft, and the support mechanism is not limited to a configuration having a bearing, as long as the configuration is as follows: the shaft support device includes: a shaft and a pair of support mechanisms provided at both axial ends of the shaft for supporting the shaft, and one of the pair of support mechanisms has a support body (for example, the support table 43 in the above-described embodiment) that is penetrated by the shaft or disposed around the shaft.

[0262] Therefore, as the support mechanism position adjustment mechanism of the shaft support device, as long as the configuration is as follows: it includes: a first member (for example, the support table side member 61 in the above-described embodiment), which is provided on one of the shaft side and the support body side, and can be penetrated by the shaft or disposed around the shaft; a second member (for example, the bearing housing side member 62 in the above-described embodiment), which is provided on the other of the shaft side and the support body side, can be penetrated by the shaft or disposed around the shaft, and can move relative to the first member in the axial direction; a working fluid, which is filled in a pressure chamber formed between the first member and the second member, a storage chamber formed in either the first member or the second member, and a damping hole that communicates the pressure chamber with the storage chamber; an elastic member, which is disposed in the pressure chamber in a compressed state between the opposing axial end faces of the first member and the second member; and a hollow member, which is housed in the storage chamber.

[0263] Such a support mechanism position adjustment mechanism of the shaft support device can apply the structure of the housing position adjustment mechanism described in the ball screw feed device 20 and exhibit the same effect.

[0264] For example, FIGS. 42 and 43 show a rigid joint structure 200 of a shaft support device in which a support mechanism position adjustment mechanism is provided in one of a pair of support mechanisms for supporting a shaft. The rigid joint structure 200 includes two steel support bodies 231 and 243 that are erected and fixed vertically with respect to the base 1 and are parallel to each other. Concentric through holes 231a and 243a are formed in the support bodies 231 and 243 for inserting the shaft 221 that constitutes the beam member. In addition, the support bodies 231 and 243 may be columns, beams, support plates, etc., as long as they are composed of components of any material and shape that can support the shaft.

[0265] In addition, in this example, the shaft 221 abuts the flange portion 226 on one axial end side against the small-diameter step portion 231b of the through hole 231a of the support body 231, and the other support mechanism that presses the cover 232 is installed on the large-diameter step portion 231c of the through hole 231a to position and fix one end portion of the shaft 221 to the support body 231.

[0266] Further, the axially opposite end of the shaft 221 is inserted through the through hole 243a of the support body 243 and protrudes toward the side opposite to the support body 231, and is supported by the support body 243 via a shaft guiding member 250, a housing 251, and a support mechanism position adjusting mechanism 260 that constitute a support mechanism.

[0267] The cross-sectional shape of the central portion of the shaft 221 is arbitrary and can be formed of a square steel pipe, an H-shaped steel pipe, or the like.

[0268] The shaft guiding member 250 is a member configured to surround the shaft 221, guides the small-diameter portion 225 of the shaft 221, and both outer diameter ends thereof are clamped and integrated by the housing 251 and a pressing member 247 fixed to the housing 251.

[0269] Further, the housing 251 is mounted on the support body 243 via the support mechanism position adjusting mechanism 260 in the same manner as in the above-described embodiment. That is, a first member 261 corresponding to the support table side member 61 in the above-described embodiment is fitted into the through hole 243a of the support body 243 and fixed to the support body 243, and a second member 262 corresponding to the bearing housing side member 62 in the above-described embodiment is fitted into the inward flange 251a of the housing 251 and fixed to the housing 251.

[0270] Therefore, when the shaft guiding member 250 is fastened by a fastening nut 38b screwed onto the external thread 225a via a spacer 48, a reaction force acts on the shaft guiding member 250, and an axial load is borne. Therefore, a predetermined rigidity is imparted between the support bodies 231 and 243 and the shaft 221.

[0271] Further, in such a rigid joint structure 200, even when axial elongation occurs in the shaft 221, the support mechanism position adjusting mechanism 260 also functions, follows the axial elongation of the shaft 221, and moves the shaft guiding member 250 and the housing 251 in the same direction. Therefore, the axial force acting on the shaft 221 can be maintained, and the rigidity of the rigid joint structure 200 can be ensured.

[0272] Further, in this example, the housing 251 and the second member 262 of the support mechanism position adjusting mechanism 260 may be integrally formed, and the shaft guiding member 250 may be disposed in the integrated member. Further, the housing 251 may not be provided, and the shaft guiding member 250 may be directly fixed to the second member 262 of the support mechanism position adjusting mechanism 260.

[0273] Further, the shaft support device is not limited to the rigid joint structure as in the present embodiment, and may be a support structure in which the support mechanisms on the shaft side and the support body side are pin-connected. In this case, the shaft 221 may also be disposed obliquely according to the configuration of the support structure.

[0274] Further, in a shaft support device such as a rigid joint structure, the configuration may be such that both support mechanisms have support mechanism position adjustment mechanisms.

[0275] As described above, the following matters are disclosed in this specification.

[0276] (A1) A ball screw feed device, comprising: a screw shaft having a helical thread groove formed on its outer peripheral surface; a nut having a helical thread groove formed on its inner peripheral surface; a plurality of balls rotatably disposed between the thread groove of the screw shaft and the thread groove of the nut; and a pair of support mechanisms that rotatably support both axial end portions of the screw shaft.

[0277] One of the pair of support mechanisms includes:

[0278] A bearing unit including a bearing housing and an angular contact ball bearing, the angular contact ball bearing having an outer ring embedded in the bearing housing, an inner ring fitted onto the axial end portion of the screw shaft, and balls rotatably disposed between the outer ring and the inner ring;

[0279] A support table disposed on the axially central side of the bearing unit and penetrated by the screw shaft; and

[0280] A housing position adjustment mechanism disposed between the bearing unit and the support table.

[0281] The housing position adjustment mechanism includes:

[0282] A support table side member disposed on the support table side and penetrated by the screw shaft;

[0283] A bearing housing side member disposed on the bearing housing side and penetrated by the screw shaft, capable of moving axially relative to the support table side member;

[0284] A working fluid housed in a pressure chamber formed between the support table side member and the bearing housing side member, a storage chamber formed in either the support table side member or the bearing housing side member, and a damping hole communicating the pressure chamber and the storage chamber;

[0285] An elastic member disposed in the pressure chamber in a compressed state between the opposed axial end faces of the support table side member and the bearing housing side member; and

[0286] A hollow member housed in the storage chamber.

[0287] According to this configuration, even if the axial length of the screw shaft changes due to thermal influence, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be attenuated.

[0288] (A2) The ball screw feed device as described in (A1), wherein one of the support table side member and the bearing housing side member has an annular recess opening toward one side in the axial direction.

[0289] The other of the support table side member and the bearing housing side member has an annular protrusion protruding toward the other side in the axial direction and slidably fitted in the axial direction within the annular recess.

[0290] The pressure chamber is formed between the annular recess and the annular protrusion.

[0291] The storage chamber is formed within the annular protrusion so as to open to the outer surface or the inner surface of the annular protrusion.

[0292] The damping hole is formed within the annular protrusion.

[0293] According to this configuration, since the pressure chamber is formed between the annular recess and the annular protrusion, the housing position adjustment mechanism can be compactly configured around the screw shaft. In addition, since the working fluid passes through the damping hole and the gap between the outer surface of the annular protrusion and the inner surface of the annular recess, its vibration can be attenuated.

[0294] (A3) The ball screw feed device as described in (A2), wherein at least one sealing member is installed between the inner surface of the annular recess and the outer surface of the annular protrusion, and between the outer surface of the annular recess and the inner surface of the annular protrusion.

[0295] According to this configuration, the sealing member can prevent the working fluid filled in the pressure chamber and the storage chamber from leaking, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0296] (A4) The ball screw feed device as described in (A2) or (A3), wherein the working fluid is stored in each gap between the inner surface of the annular recess and the outer surface of the annular protrusion, and between the outer surface of the annular recess and the inner surface of the annular protrusion.

[0297] According to this configuration, the housing position adjustment mechanism can impart radial support rigidity to the screw shaft, and further, it can also have a centering function for the screw shaft.

[0298] (A5) The ball screw feed device as described in (A3), wherein the sealing member is an O-ring.

[0299] Sealing grooves for arranging the O-ring are respectively formed on the inner surface of the annular recess or the outer surface of the annular protrusion, and on the outer surface of the annular recess or the inner surface of the annular protrusion.

[0300] The above-mentioned seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side.

[0301] According to this configuration, by using an O-ring as the sealing member, the O-ring also acts as a damping mechanism, enabling the vibration generated in the lead screw shaft to be damped. In addition, even when relative movement occurs between the support base side member and the bearing housing side member, leakage of the working oil to the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device can be continuously maintained.

[0302] (A6) The ball screw feed device as described in (A3) or (A5), wherein the sealing member is an O-ring.

[0303] A wear-resistant member is interposed between at least one of the inner-facing surface of the annular recess and the outer-facing surface of the annular protrusion and the O-ring, and between at least one of the outer-facing surface of the annular recess and the inner-facing surface of the annular protrusion and the O-ring.

[0304] According to this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, enabling the vibration generated in the lead screw shaft to be damped. In addition, the stress concentration applied to the O-ring can be dispersed, suppressing damage such as wear of the O-ring or the contact surface in contact with the O-ring.

[0305] (A7) The ball screw feed device as described in any one of (A1) to (A4), wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits that axially penetrate a conical plate portion.

[0306] According to this configuration, since the working fluid flows through the plurality of through holes or the plurality of slits, a damping effect can be exerted.

[0307] (A8) The ball screw feed device as described in (A1), wherein the hollow member has at least one rib protruding from its inner peripheral surface.

[0308] According to this configuration, when the hollow member is compressed and deformed, excessive deformation of the hollow member can be prevented.

[0309] (A9) The ball screw feed device as described in (A1), wherein a plurality of the above-mentioned hollow members are arranged in the storage chamber.

[0310] By utilizing the total pressure generated by the plurality of hollow members, even when the axial length of the lead screw shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

[0311] (A10) The ball screw feed device as described in (A1), wherein the surface of the hollow member is covered by an outer layer.

[0312] According to this configuration, the rigidity of the hollow member can be changed, and in addition, the hollow member can be protected from the influence of liquid.

[0313] (A11) The ball screw feed device as described in (A1), wherein the hollow member has an integrally formed seamless hollow cross-section.

[0314] According to this configuration, local stress concentration is not likely to occur, and a deformable hollow member can be easily manufactured.

[0315] (A12) The ball screw feed device as described in (A1), wherein the hollow member is an assembly having a hollow cross-section, and is formed by integrating the above-mentioned two or more members via the edge portions of the two or more members.

[0316] According to this configuration, a deformable hollow member can be easily manufactured.

[0317] (A13) The ball screw feed device as described in (A1), wherein the hollow member is formed by bending a member and joining the edge portions of the member to form a hollow cross-section.

[0318] According to this configuration, a deformable hollow member can be easily manufactured.

[0319] (A14) The ball screw feed device as described in (A1), wherein one of the support table side member and the bearing housing side member has a small-diameter cylindrical portion extending toward one side in the axial direction and an outward flange portion protruding toward the outer diameter side from the tip of the small-diameter cylindrical portion,

[0320] The other of the support table side member and the bearing housing side member has: a large-diameter cylindrical portion extending toward the other side in the axial direction and having an inner peripheral surface for slidably contacting the outer peripheral surface of the outward flange portion; and an inward flange portion extending toward the inner diameter side from the tip of the large-diameter cylindrical portion and having an inner peripheral surface for slidably contacting the outer peripheral surface of the small-diameter cylindrical portion,

[0321] The pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion,

[0322] The storage chamber is formed in the outward flange portion or the inward flange portion so as to open to the inner peripheral surface of the large-diameter cylindrical portion or the outer peripheral surface of the small-diameter cylindrical portion,

[0323] The damping hole is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed.

[0324] According to this configuration, even if the axial length of the lead screw shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained. In addition, since the working fluid passes through the damping holes and the gaps between the inner peripheral surface of the large-diameter cylindrical portion and the outer peripheral surface of the outward flange portion, or between the outer peripheral surface of the small-diameter cylindrical portion and the inner peripheral surface of the inward flange portion, its vibration can be attenuated.

[0325] (A15) The ball screw feed device as described in (A14), wherein at least one sealing member is respectively installed between the inner peripheral surface of the above-mentioned inward flange portion and the outer peripheral surface of the above-mentioned small-diameter cylindrical portion, and between the outer peripheral surface of the above-mentioned outward flange portion and the inner peripheral surface of the above-mentioned large-diameter cylindrical portion.

[0326] According to this configuration, the sealing member can prevent the working fluid stored in the pressure chamber and the storage chamber from leaking, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0327] (A16) The ball screw feed device as described in (A14) or (A15), wherein the working fluid is stored in the respective gaps between the inner peripheral surface of the above-mentioned inward flange portion and the outer peripheral surface of the above-mentioned small-diameter cylindrical portion, and between the outer peripheral surface of the above-mentioned outward flange portion and the inner peripheral surface of the above-mentioned large-diameter cylindrical portion.

[0328] According to this configuration, the housing position adjustment mechanism can impart radial support rigidity to the lead screw shaft. Further, it can also have a centering function for the lead screw shaft.

[0329] (A17) The ball screw feed device as described in (A15), wherein the above-mentioned sealing member is an O-ring.

[0330] Sealing grooves for arranging the above-mentioned O-rings are respectively formed on the inner peripheral surface of the above-mentioned inward flange portion or the outer peripheral surface of the above-mentioned small-diameter cylindrical portion, and on the outer peripheral surface of the above-mentioned outward flange portion or the inner peripheral surface of the above-mentioned large-diameter cylindrical portion.

[0331] The above-mentioned sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0332] According to this configuration, by setting the sealing member as an O-ring, the O-ring also acts as a damping mechanism, and the vibration generated in the lead screw shaft can be attenuated. In addition, even when relative movement occurs between the support table side component and the bearing housing side component, leakage of the working oil to the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device can be continuously maintained.

[0333] (A18) The ball screw feed device as described in (A15), wherein the above-mentioned sealing member is an O-ring.

[0334] A wear-resistant member is interposed between at least one of the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion and the O-ring, and between at least one of the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion and the O-ring.

[0335] According to this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, and the vibration generated in the lead screw shaft can be damped. In addition, the stress concentration applied to the O-ring can be dispersed, and damage such as wear of the O-ring or the contact surface in contact with the O-ring can be suppressed.

[0336] (A19) The ball screw feed device according to (A1), wherein a working medium volume changing portion that changes the volumes of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid is installed in at least one of the support table side member and the bearing housing side member.

[0337] According to this configuration, the hollow member and the working fluid can be heated or cooled to expand or contract the volumes of the hollow member and the working fluid, and the axial support rigidity can be continuously maintained in a stable state.

[0338] (A20) The ball screw feed device according to (A1), wherein one of the pair of support mechanisms further includes:

[0339] Another housing position adjusting mechanism that is arranged in series or in parallel adjacent to the housing position adjusting mechanism between the bearing unit and the support table;

[0340] The another housing position adjusting mechanism includes:

[0341] Another support table side member that is provided on the support table side and penetrated by the lead screw shaft;

[0342] Another bearing housing side member that is provided on the bearing housing side and penetrated by the lead screw shaft and can relatively move axially with respect to the another support table side member;

[0343] A pressure generating unit that is housed in a state of being compressed in a pressure chamber formed between the another support table side member and the another bearing housing side member.

[0344] According to this configuration, in the case of series arrangement, even when the elongation of the lead screw shaft is larger, in addition to maintaining the axial rigidity of the ball screw feed device, the centering property or coaxiality of the lead screw shaft can be improved. In addition, in the case of parallel arrangement, an axial load larger than that when a single housing position adjusting mechanism is arranged is generated, and the axial rigidity can be maintained.

[0345] (A21)A ball screw feed device, comprising: a screw shaft having a helical thread groove formed on its outer peripheral surface; a nut having a helical thread groove formed on its inner peripheral surface; a plurality of balls rotatably disposed between the thread groove of the screw shaft and the thread groove of the nut; and a pair of support mechanisms rotatably supporting the axial end portions of the screw shaft respectively,

[0346] One of the pair of support mechanisms includes:

[0347] A bearing unit, which includes a bearing housing and an angular contact ball bearing, and the angular contact ball bearing respectively includes an outer ring embedded in the bearing housing, an inner ring externally fitted to the axial end portion of the screw shaft, and balls rotatably disposed between the outer ring and the inner ring;

[0348] A support table penetrated by the screw shaft; and

[0349] A housing position adjustment mechanism installed on the bearing unit and the support table,

[0350] The housing position adjustment mechanism includes:

[0351] A support table side member installed on the support table and penetrated by the screw shaft;

[0352] A bearing housing side member installed on the bearing housing and penetrated by the screw shaft, capable of relatively moving axially with respect to the support table side member;

[0353] A working fluid housed in a pressure chamber formed between the support table side member and the bearing housing side member, a storage chamber formed in either the support table side member or the bearing housing side member, and a damping hole communicating the pressure chamber and the storage chamber;

[0354] An elastic member disposed in a compressed state between the opposing axial end faces of the support table side member and the bearing housing side member in the pressure chamber; and

[0355] A hollow member housed in the storage chamber.

[0356] According to this configuration, even if the axial length of the screw shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibration in the axial and radial directions can be attenuated.

[0357] (A22)A rotary support device, comprising a rotating shaft and a pair of support mechanisms rotatably supporting the axial end portions of the rotating shaft respectively,

[0358] One of the pair of support mechanisms includes:

[0359] A bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft with respect to the bearing housing and can support an axial load.

[0360] A support table disposed on the axially central side relative to the bearing unit and penetrated by the lead screw shaft; and

[0361] A housing position adjustment mechanism disposed between the bearing unit and the support table,

[0362] The housing position adjustment mechanism includes:

[0363] A support table side member disposed on the support table side and penetrated by the rotating shaft;

[0364] A bearing housing side member disposed on the bearing housing side and penetrated by the rotating shaft, capable of axially moving relative to the support table side member;

[0365] A working fluid housed in a pressure chamber formed between the support table side member and the bearing housing side member, a storage chamber formed in either the support table side member or the bearing housing side member, and a damping hole communicating the pressure chamber and the storage chamber;

[0366] An elastic member disposed in the pressure chamber in a compressed state between the opposed axial end faces of the support table side member and the bearing housing side member; and

[0367] A hollow member housed in the storage chamber.

[0368] According to this configuration, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibration in the axial and radial directions can be attenuated.

[0369] (A23)A rotary support device including a rotating shaft and a pair of support mechanisms that rotatably support the axially opposite end portions of the rotating shaft,

[0370] One of the pair of support mechanisms includes:

[0371] A bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft with respect to the bearing housing and can support an axial load;

[0372] A support table penetrated by the rotating shaft; and

[0373] A housing position adjustment mechanism mounted on the bearing unit and the support table,

[0374] The above-described housing position adjustment mechanism includes:

[0375] A support table side member that is mounted on the above-described support table and penetrated by the above-described rotating shaft;

[0376] A bearing housing side member that is mounted on the above-described bearing housing, penetrated by the above-described rotating shaft, and capable of relatively moving axially with respect to the above-described support table side member;

[0377] A working fluid that is accommodated in a pressure chamber formed between the above-described support table side member and the above-described bearing housing side member, a storage chamber formed in either the above-described support table side member or the above-described bearing housing side member, and a damping hole that communicates the above-described pressure chamber and the above-described storage chamber;

[0378] An elastic member that is disposed in a compressed state between opposing axial end faces of the above-described support table side member and the above-described bearing housing side member in the above-described pressure chamber; and

[0379] A hollow member that is accommodated in the above-described storage chamber.

[0380] According to this configuration, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0381] (A24) A support mechanism position adjustment mechanism of a shaft support device, which is provided in one of a pair of the above-described support mechanisms in the shaft support device. The shaft support device includes a shaft and a pair of support mechanisms provided at both axial ends of the shaft for supporting the shaft on a base, and the support mechanism position adjustment mechanism of the shaft support device includes:

[0382] A first member that is provided on one of the above-described support mechanism side and the base side and can be penetrated by the above-described shaft;

[0383] A second member that is provided on the other of the above-described support mechanism side and the base side, can be penetrated by the above-described shaft, and can move axially with respect to the above-described first member;

[0384] A working fluid that is accommodated in a pressure chamber formed between the above-described first member and the above-described second member, a storage chamber formed in either the above-described first member or the above-described second member, and a damping hole that communicates the above-described pressure chamber and the above-described storage chamber;

[0385] An elastic member that is disposed in a compressed state between opposing axial end faces of the above-described first member and the above-described second member in the above-described pressure chamber; and

[0386] A hollow member that is accommodated in the above-described storage chamber.

[0387] According to this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0388] (A25) A support mechanism position adjustment mechanism for a shaft support device, which is provided in one of a pair of the above-mentioned support mechanisms in the shaft support device. The shaft support device includes a shaft and a pair of support mechanisms provided at both axial ends of the shaft for supporting the shaft on a base, and the support mechanism position adjustment mechanism of the shaft support device includes:

[0389] A first component, which is mounted on one of the support mechanism and the base and can be penetrated by the shaft;

[0390] A second component, which is mounted on the other of the support mechanism and the base and can be penetrated by the shaft and can move relative to the first component in the axial direction;

[0391] A working fluid, which is housed in a pressure chamber formed between the first component and the second component, a storage chamber formed in either the first component or the second component, and a damping hole connecting the pressure chamber and the storage chamber;

[0392] An elastic component, which is disposed in a compressed state between the opposing axial end faces of the first component and the second component in the pressure chamber; and

[0393] A hollow component, which is housed in the storage chamber.

[0394] According to this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0395] (A26) A rotary support device, which includes a rotary shaft and a pair of support mechanisms that rotatably support both axial end portions of the rotary shaft respectively,

[0396] One of the pair of the above-mentioned support mechanisms includes:

[0397] A bearing unit, which includes a bearing housing and a bearing. The bearing rotatably supports the rotary shaft relative to the bearing housing and can support an axial load;

[0398] A support table, which is penetrated by the rotary shaft; and

[0399] A housing position adjustment mechanism, which is disposed between the bearing unit and the support table,

[0400] The housing position adjustment mechanism includes:

[0401] A support table side member, which is provided on the support table side, is penetrated by the rotating shaft or arranged around the rotating shaft;

[0402] A bearing housing side member, which is provided on the bearing housing side, is penetrated by the rotating shaft or arranged around the rotating shaft, and can move relatively axially with respect to the support table side member;

[0403] A working fluid, which is accommodated in a pressure chamber formed between the support table side member and the bearing housing side member, a storage chamber formed in the support table side member and the bearing housing side member, and a damping hole communicating the pressure chamber with the storage chamber;

[0404] An elastic member, which is arranged in a compressed state between the opposing axial end faces of the support table side member and the bearing housing side member in the pressure chamber; and

[0405] A hollow member, which is accommodated in the storage chamber.

[0406] According to this configuration, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0407] (A27) The rotary support device as described in (A26), wherein one of the support table side member and the bearing housing side member has a plurality of recesses opening axially on one side,

[0408] The other of the support table side member and the bearing housing side member has a plurality of protrusions protruding axially on the other side, and are slidably fitted into the plurality of recesses respectively in the axial direction,

[0409] A plurality of the pressure chambers are respectively formed between the plurality of recesses and the plurality of protrusions,

[0410] In at least one of the plurality of protrusions, the storage chamber and the damping hole are formed in such a manner that the storage chamber communicates with the pressure chamber via the damping hole.

[0411] According to this configuration, the layout of the housing position adjustment mechanism can be freely formed by a plurality of pressure chambers.

[0412] (A28) The rotary support device as described in (A27), wherein the plurality of pressure chambers are arranged on both sides in the width direction with respect to the rotating shaft.

[0413] According to this configuration, the height dimension of the housing position adjustment mechanism can be suppressed.

[0414] (A29) The rotary bearing device as described in (A27), wherein in a plurality of the above-mentioned convex portions, the above-mentioned storage chambers and the above-mentioned damping holes are respectively formed.

[0415] The above-mentioned elastic members are respectively arranged in a state of being compressed in a plurality of the above-mentioned pressure chambers.

[0416] The above-mentioned hollow members are respectively housed in a plurality of the above-mentioned storage chambers.

[0417] According to this configuration, a plurality of pressure chambers and a plurality of storage chambers can be commonly configured.

[0418] (A30) The rotary bearing device as described in (A26), wherein the rotary bearing device is a ball screw feed device, and in this ball screw feed device, the above-mentioned rotary shaft is a lead screw shaft having a spiral thread groove formed on its outer peripheral surface, and further includes: a nut having a spiral thread groove formed on its inner peripheral surface, and a plurality of balls rotatably disposed between the thread groove of the above-mentioned lead screw shaft and the thread groove of the above-mentioned nut.

[0419] According to this configuration, a ball screw feed device can be configured such that even if the axial length of the rotary shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

[0420] (A31) A support mechanism position adjustment mechanism of a shaft support device, which is provided in one of a pair of support mechanisms in the shaft support device. The shaft support device includes a shaft and a pair of the above-mentioned support mechanisms provided at both axial ends of the above-mentioned shaft for supporting the above-mentioned shaft on a base, and the support mechanism position adjustment mechanism of the shaft support device includes:

[0421] A first member, which is provided on one of the above-mentioned support mechanism side and the above-mentioned base side, and can be penetrated by the above-mentioned shaft or can be arranged around the above-mentioned shaft;

[0422] A second member, which is provided on the other of the above-mentioned support mechanism side and the above-mentioned base side, can be penetrated by the above-mentioned shaft or can be arranged around the above-mentioned shaft, and can relatively move axially with respect to the above-mentioned first member;

[0423] A working fluid, which is housed in a pressure chamber formed between the above-mentioned first member and the above-mentioned second member, a storage chamber formed in the above-mentioned first member or the above-mentioned second member, and a damping hole communicating the above-mentioned pressure chamber and the above-mentioned storage chamber;

[0424] An elastic member, which is arranged in a compressed state between the opposing axial end faces of the above-mentioned first member and the above-mentioned second member in the above-mentioned pressure chamber; and

[0425] A hollow member, which is housed in the above-mentioned storage chamber.

[0426] According to this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0427] (B1) A rotary support device including a rotating shaft and a pair of support mechanisms that rotatably support both axial end portions of the rotating shaft, and

[0428] One of the pair of support mechanisms includes:

[0429] a bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft relative to the bearing housing and that can support an axial load;

[0430] a support table that is penetrated by the rotating shaft or disposed around the rotating shaft; and

[0431] a housing position adjustment mechanism disposed between the bearing unit and the support table,

[0432] The housing position adjustment mechanism includes:

[0433] a support table side member that is disposed on the support table side and is penetrated by the rotating shaft or disposed around the rotating shaft;

[0434] a bearing housing side member that is disposed on the bearing housing side and is penetrated by the rotating shaft or disposed around the rotating shaft and that can move axially relative to the support table side member;

[0435] a working fluid that is housed in a pressure chamber formed between the support table side member and the bearing housing side member, a storage chamber formed in the support table side member or the bearing housing side member, and a damping hole that connects the pressure chamber and the storage chamber;

[0436] an elastic member that is disposed in a compressed state in the pressure chamber between opposing axial end faces of the support table side member and the bearing housing side member; and

[0437] a hollow member that is housed in the storage chamber.

[0438] According to this configuration, even if the axial length of the shaft rotationally changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibrations in the axial and radial directions can be attenuated.

[0439] (B2) The rotary support device according to (B1), wherein one of the support table side member and the bearing housing side member has an annular recess that opens to one side in the axial direction,

[0440] The other of the above-mentioned support table side member and the above-mentioned bearing housing side member has an annular convex portion that protrudes toward the other axial side and can slide axially and fit into the above-mentioned annular concave portion.

[0441] The above-mentioned pressure chamber is formed between the above-mentioned annular concave portion and the above-mentioned annular convex portion.

[0442] The above-mentioned storage chamber is formed in the above-mentioned annular convex portion so as to open to the outer surface or the inner surface of the above-mentioned annular convex portion.

[0443] The above-mentioned damping hole is formed in the above-mentioned annular convex portion.

[0444] According to this configuration, since the pressure chamber is formed between the annular concave portion and the annular convex portion, the housing position adjustment mechanism can be compactly configured around the lead screw shaft. In addition, since the working fluid passes through the damping hole and the gap between the outer surface of the annular convex portion and the inner surface of the annular concave portion, its vibration can be attenuated.

[0445] (B3) The rotary support device as described in (B2), wherein at least one sealing member is installed between the inner surface of the above-mentioned annular concave portion and the outer surface of the above-mentioned annular convex portion, and between the outer surface of the above-mentioned annular concave portion and the inner surface of the above-mentioned annular convex portion.

[0446] According to this configuration, the sealing member can prevent the working fluid filled in the pressure chamber and the storage chamber from leaking, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0447] (B4) The rotary support device as described in (B2) or (B3), wherein the working fluid is stored in each gap between the inner surface of the above-mentioned annular concave portion and the outer surface of the above-mentioned annular convex portion, and between the outer surface of the above-mentioned annular concave portion and the inner surface of the above-mentioned annular convex portion.

[0448] According to this configuration, the housing position adjustment mechanism can impart radial support rigidity to the rotating shaft, and further can also have a centering function for the rotating shaft.

[0449] (B5) The rotary support device as described in (B3), wherein the above-mentioned sealing member is an O-ring.

[0450] Sealing grooves for arranging the above-mentioned O-ring are respectively formed on the inner surface of the above-mentioned annular concave portion or the outer surface of the above-mentioned annular convex portion, and on the outer surface of the above-mentioned annular concave portion or the inner surface of the above-mentioned annular convex portion.

[0451] The above-mentioned sealing groove has a tapered surface whose groove depth becomes shallower as it moves away from the above-mentioned pressure chamber side.

[0452] According to this configuration, by using an O-ring as the sealing member, even if the O-ring functions as a damping mechanism, the vibration generated in the rotating shaft can be attenuated. In addition, even when relative movement occurs between the support base side member and the bearing housing side member, leakage of the working oil to the atmospheric pressure side can be prevented, and the axial rigidity of the rotary support device can be continuously maintained.

[0453] (B6) The rotary support device according to (B3) or (B5), wherein the sealing member is an O-ring.

[0454] A wear-resistant member is interposed between at least one of the inner-facing surface of the annular recess and the outer-facing surface of the annular protrusion and the O-ring, and between at least one of the outer-facing surface of the annular recess and the inner-facing surface of the annular protrusion and the O-ring.

[0455] According to this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, and the vibration generated in the rotating shaft can be attenuated. In addition, the stress concentration applied to the O-ring can be dispersed, and damage such as wear of the O-ring or the contact surface in contact with the O-ring can be suppressed.

[0456] (B7) The rotary support device according to any one of (B1) to (B4), wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits that axially penetrate a conical plate portion.

[0457] According to this configuration, by allowing the working fluid to flow through the plurality of through holes or the plurality of slits, a damping effect can be exerted.

[0458] (B8) The rotary support device according to (B1), wherein the hollow member has at least one rib protruding from its inner peripheral surface.

[0459] According to this configuration, excessive deformation of the hollow member can be prevented when the hollow member is compressed and deformed.

[0460] (B9) The rotary support device according to (B1), wherein a plurality of the hollow members are arranged in the storage chamber.

[0461] According to this configuration, by using the total pressure generated by the plurality of hollow members, the axial support rigidity can be continuously and stably maintained even when the axial length of the rotating shaft changes due to the influence of heat.

[0462] (B10) The rotary support device according to (B1), wherein the surface of the hollow member is covered with an outer layer.

[0463] According to this configuration, the rigidity of the hollow member can be changed, and in addition, the hollow member can be protected from the influence of liquid.

[0464] (B11) The rotary bearing device according to (B1), wherein the hollow member is a structure having an integrally formed seamless hollow cross section.

[0465] According to this configuration, local stress concentration is not likely to occur, and a deformable hollow member can be easily manufactured.

[0466] (B12) The rotary bearing device according to (B1), wherein the hollow member is an assembly having a hollow cross section, and is formed by integrating the two or more members via the edge portions of the two or more members.

[0467] According to this configuration, a deformable hollow member can be easily manufactured.

[0468] (B13) The rotary bearing device according to (B1), wherein the hollow member is formed by bending a member and joining the edge portions of the member to form a hollow cross section.

[0469] According to this configuration, a deformable hollow member can be easily manufactured.

[0470] (B14) The rotary bearing device according to (B1), wherein one of the support base side member and the bearing housing side member has a small-diameter cylindrical portion extending toward one side in the axial direction and an outward flange portion extending from the tip end portion of the small-diameter cylindrical portion toward the outer diameter side.

[0471] The other of the support base side member and the bearing housing side member has: a large-diameter cylindrical portion extending toward the other side in the axial direction and having an inner circumferential surface for slidably contacting the outer circumferential surface of the outward flange portion; and an inward flange portion extending from the tip end portion of the large-diameter cylindrical portion toward the inner diameter side and having an inner circumferential surface for slidably contacting the outer circumferential surface of the small-diameter cylindrical portion.

[0472] The pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion.

[0473] The storage chamber is formed in the outward flange portion or the inward flange portion so as to open to the inner circumferential surface of the large-diameter cylindrical portion or the outer circumferential surface of the small-diameter cylindrical portion.

[0474] The damping hole is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed.

[0475] According to this configuration, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained. In addition, since the working fluid passes through the damping hole and the gap between the inner circumferential surface of the large-diameter cylindrical portion and the outer circumferential surface of the outward flange portion, or between the outer circumferential surface of the small-diameter cylindrical portion and the inner circumferential surface of the inward flange portion, its vibration can be attenuated.

[0476] (B15) The rotary support device according to (B14), wherein at least one sealing member is installed between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion, respectively.

[0477] According to this configuration, the working fluid accommodated in the pressure chamber and the storage chamber can be prevented from leaking by the sealing member, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0478] (B16) The rotary support device according to (B14) or (B15), wherein the working fluid is stored in each gap between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion.

[0479] According to this configuration, the housing position adjustment mechanism can impart radial support rigidity to the rotating shaft, and further can also have a centering function for the rotating shaft.

[0480] (B17) The rotary support device according to (B15), wherein the sealing member is an O-ring.

[0481] Sealing grooves for arranging the O-ring are respectively formed on the inner peripheral surface of the inward flange portion or the outer peripheral surface of the small-diameter cylindrical portion, and on the outer peripheral surface of the outward flange portion or the inner peripheral surface of the large-diameter cylindrical portion.

[0482] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0483] According to this configuration, by setting the sealing member as an O-ring, the O-ring also acts as a damping mechanism, and the vibration generated in the rotating shaft can be damped. In addition, even when relative movement occurs between the support table side member and the bearing housing side member, leakage of the working oil to the atmospheric pressure side can be prevented, and the axial rigidity of the rotary support device can be continuously maintained.

[0484] (B18) The rotary support device according to (B15), wherein the sealing member is an O-ring.

[0485] A wear-resistant member is interposed between at least one of the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion and the O-ring, and between at least one of the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion and the O-ring.

[0486] According to this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, enabling the vibration generated in the rotating shaft to be damped. In addition, the stress concentration applied to the O-ring can be dispersed, suppressing damage such as wear of the O-ring and the contact surface in contact with the O-ring.

[0487] (B19) The rotary bearing device according to (B1), wherein a working medium volume change unit that changes the volumes of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid is installed in at least one of the support table side member and the bearing housing side member.

[0488] According to this configuration, the hollow member and the working fluid can be heated or cooled to expand or contract the volumes of the hollow member and the working fluid, and the axial support rigidity can be continuously maintained in a stable state.

[0489] (B20) The rotary bearing device according to (B1), wherein one of the pair of support mechanisms further includes:

[0490] Another housing position adjustment mechanism that is arranged in series or in parallel adjacent to the housing position adjustment mechanism between the bearing unit and the support table;

[0491] The above-mentioned another housing position adjustment mechanism includes:

[0492] Another support table side member that is arranged on the support table side and is penetrated by the rotating shaft or arranged around the rotating shaft;

[0493] Another bearing housing side member that is arranged on the bearing housing side and is penetrated by the rotating shaft or arranged around the rotating shaft and can move relatively axially with respect to the another support table side member;

[0494] A pressure generation unit that is housed in a pressure chamber formed between the another support table side member and the another bearing housing side member in a compressed state.

[0495] According to this configuration, in the case of series arrangement, even when the elongation of the rotating shaft is larger, in addition to maintaining the axial rigidity of the rotary bearing device, the centering property and coaxiality of the rotating shaft can also be improved. In addition, in the case of parallel arrangement, an axial load larger than that when a single housing position adjustment mechanism is arranged is generated, and the axial rigidity can be maintained.

[0496] (B21) The rotary bearing device according to (B1), wherein one of the support table side member and the bearing housing side member has a plurality of recesses opening to one side in the axial direction,

[0497] The other of the above-mentioned support table side member and the above-mentioned bearing housing side member has a plurality of convex portions that protrude toward the other axial side and are slidably fitted into the plurality of above-mentioned concave portions in the axial direction respectively.

[0498] A plurality of the above-mentioned pressure chambers are respectively formed between the plurality of above-mentioned concave portions and the plurality of above-mentioned convex portions.

[0499] In at least one of the plurality of above-mentioned convex portions, the above-mentioned storage chamber and the above-mentioned damping hole are formed in such a manner that the above-mentioned storage chamber communicates with the above-mentioned pressure chamber via the above-mentioned damping hole.

[0500] According to this configuration, the layout of the housing position adjustment mechanism can be freely configured by a plurality of pressure chambers.

[0501] (B22) The rotary support device as described in (B21), wherein the plurality of above-mentioned pressure chambers are arranged on both sides in the width direction with respect to the above-mentioned rotary shaft.

[0502] According to this configuration, the height dimension of the housing position adjustment mechanism can be suppressed.

[0503] (B23) The rotary support device as described in (B21), wherein the above-mentioned storage chamber and the above-mentioned damping hole are respectively formed in the plurality of above-mentioned convex portions.

[0504] The above-mentioned elastic members are respectively arranged in a state of being compressed in the plurality of above-mentioned pressure chambers.

[0505] The above-mentioned hollow members are respectively housed in the plurality of above-mentioned storage chambers.

[0506] According to this configuration, the plurality of pressure chambers and the plurality of storage chambers can be commonly configured.

[0507] (B24) The rotary support device as described in any one of (B1) to (B23), wherein the above-mentioned bearing of the above-mentioned bearing unit includes a pair of angular contact ball bearings, and each of the angular contact ball bearings includes an outer ring embedded in the above-mentioned bearing housing, an inner ring externally fitted to the axial end of the above-mentioned rotary shaft, and balls rotatably arranged between the above-mentioned outer ring and the above-mentioned inner ring.

[0508] According to this configuration, in the case where the bearing unit has a pair of angular contact ball bearings, even if the axial length of the rotary shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

[0509] (B25) The rotary support device as described in any one of (B1) to (B24), wherein the rotary support device is a ball screw feed device, and the ball screw feed device has a lead screw shaft with a helical thread groove formed on its outer peripheral surface as the rotary shaft, and further includes: a nut with a helical thread groove formed on its inner peripheral surface; and a plurality of balls that are rotatably disposed between the thread groove of the lead screw shaft and the thread groove of the nut.

[0510] According to this configuration, a ball screw feed device can be configured such that even if the axial length of the rotary shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

[0511] (B26) A support mechanism position adjustment mechanism for a shaft support device, which is provided in one of a pair of support mechanisms in the shaft support device. The shaft support device includes a shaft and a pair of the support mechanisms provided at both axial ends of the shaft to support the shaft.

[0512] One of the pair of support mechanisms has a support body that is penetrated by the shaft or disposed around the shaft, and the support mechanism position adjustment mechanism of the shaft support device includes:

[0513] A first component, which is provided on one of the shaft side and the support body side, and can be penetrated by the shaft or disposed around the shaft;

[0514] A second component, which is provided on the other of the shaft side and the support body side, can be penetrated by the shaft or disposed around the shaft, and can move axially relative to the first component;

[0515] A working fluid, which is accommodated in a pressure chamber formed between the first component and the second component, a storage chamber formed in the first component or the second component, and a damping hole that communicates the pressure chamber and the storage chamber;

[0516] An elastic component, which is disposed in a compressed state between the opposing axial end faces of the first component and the second component in the pressure chamber; and

[0517] A hollow component, which is accommodated in the storage chamber.

[0518] According to this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and the vibration in the axial and radial directions can be attenuated.

[0519] (B27) The support mechanism position adjustment mechanism for a shaft support device as described in (B26), wherein the shaft is a rotary shaft.

[0520] One of the pair of the above-described support mechanisms further includes a bearing unit, which includes: a bearing housing and a bearing. The bearing rotatably supports the rotating shaft with respect to the bearing housing, and the bearing can support an axial load.

[0521] The support mechanism position adjustment mechanism is a housing position adjustment mechanism disposed between the bearing unit and the support body.

[0522] The first component is disposed on the support body side and is a support body side component that can be penetrated by the rotating shaft or can be arranged around the rotating shaft.

[0523] The second component is a bearing housing side component that is disposed on the bearing housing side, can be penetrated by the rotating shaft or can be arranged around the rotating shaft, can relatively move axially with respect to the support body side component, and forms the accommodation space between it and the support body side component.

[0524] According to this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

[0525] (B28) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein one of the first component and the second component has an annular recess that opens toward one side in the axial direction.

[0526] The other of the first component and the second component has an annular protrusion that protrudes toward the other side in the axial direction and can slide axially and fit into the annular recess.

[0527] The storage chamber is formed in the annular protrusion so as to open to the outer surface or the inner surface of the annular protrusion.

[0528] The damping hole is formed in the annular protrusion.

[0529] According to this configuration, since the pressure chamber is formed between the annular recess and the annular protrusion, the support mechanism position adjustment mechanism can be compactly configured around the shaft. In addition, since the working fluid passes through the damping hole and the gap between the outer surface of the annular protrusion and the inner surface of the annular recess, its vibration can be attenuated.

[0530] (B29) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein at least one sealing member is installed between the inner surface of the annular recess and the outer surface of the annular protrusion, and between the outer surface of the annular recess and the inner surface of the annular protrusion, respectively.

[0531] According to this configuration, the working fluid filled in the pressure chamber and the storage chamber can be prevented from leaking by the sealing member, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0532] (B30) The support mechanism position adjustment mechanism of the shaft support device as described in (B28) or (B29), wherein the working fluid is stored in each gap between the inner-facing surface of the annular recess and the outer-facing surface of the annular protrusion, and between the outer-facing surface of the annular recess and the inner-facing surface of the annular protrusion.

[0533] According to this configuration, the support mechanism position adjustment mechanism can impart radial support rigidity to the shaft, and further, it can also have a centering function for the shaft.

[0534] (B31) The support mechanism position adjustment mechanism of the shaft support device as described in (B29), wherein the sealing member is an O-ring.

[0535] Sealing grooves for arranging the O-ring are respectively formed on the inner-facing surface of the annular recess or the outer-facing surface of the annular protrusion, and on the outer-facing surface of the annular recess or the inner-facing surface of the annular protrusion.

[0536] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0537] According to this configuration, by setting the sealing member as an O-ring, the O-ring also acts as a damping mechanism, and the vibration generated in the shaft can be attenuated. In addition, even when relative movement between the first component and the second component occurs, leakage of the working oil to the atmospheric pressure side can be prevented, and the axial rigidity of the shaft support device can be continuously maintained.

[0538] (B32) The support mechanism position adjustment mechanism of the shaft support device as described in (B29) or (B31), wherein the sealing member is an O-ring.

[0539] A wear-resistant member is interposed between at least one of the inner-facing surface of the annular recess and the outer-facing surface of the annular protrusion and the O-ring, and between at least one of the outer-facing surface of the annular recess and the inner-facing surface of the annular protrusion and the O-ring.

[0540] According to this configuration, by setting the sealing member as an O-ring, the O-ring also acts as a damping mechanism, and the vibration generated in the shaft can be attenuated. In addition, the stress concentration applied to the O-ring can be dispersed, and damage such as wear of the O-ring or the contact surface in contact with the O-ring can be suppressed.

[0541] (B33) The support mechanism position adjustment mechanism of the shaft support device as described in any one of (B26) to (B30), wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits that axially penetrate a conical plate portion.

[0542] According to this configuration, since the working fluid flows through the plurality of through holes or the plurality of slits, a damping effect can be exerted.

[0543] (B34) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein the hollow member has at least one rib protruding from its inner peripheral surface.

[0544] According to this configuration, when the hollow member is compressed and deformed, excessive deformation of the hollow member can be prevented.

[0545] (B35) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein a plurality of the hollow members are arranged in the storage chamber.

[0546] According to this configuration, by utilizing the total pressure generated by the plurality of hollow members, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained.

[0547] (B36) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein the surface of the hollow member is covered by an outer layer.

[0548] According to this configuration, the rigidity of the hollow member can be changed, and in addition, the hollow member can be protected from the influence of liquid.

[0549] (B37) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein the hollow member is a structure having an integrally formed seamless hollow cross-section.

[0550] According to this configuration, local stress concentration is not likely to occur, and a deformable hollow member can be easily manufactured.

[0551] (B38) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein the hollow member is an assembly having a hollow cross-section, and is formed by integrating the above-mentioned two or more members via the edge portions of the two or more members.

[0552] According to this configuration, a deformable hollow member can be easily manufactured.

[0553] (B39) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein the hollow member is formed by bending the member and joining the edge portions of the member to form a hollow cross-section.

[0554] According to this configuration, a deformable hollow member can be easily manufactured.

[0555] (B40) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein one of the first member and the second member has a small-diameter cylindrical portion extending long in the axial direction and an outward flange portion extending from the tip of the small-diameter cylindrical portion toward the outer diameter side.

[0556] The other of the first member and the second member has: a large-diameter cylindrical portion extending toward the other side in the axial direction and having an inner peripheral surface for sliding contact with the outer peripheral surface of the outward flange portion; and an inward flange portion extending from the tip of the large-diameter cylindrical portion toward the inner diameter side and having an inner peripheral surface for sliding contact with the outer peripheral surface of the small-diameter cylindrical portion.

[0557] The pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion.

[0558] The storage chamber is formed in the outward flange portion or the inward flange portion so as to open on the inner peripheral surface of the large-diameter cylindrical portion or the outer peripheral surface of the small-diameter cylindrical portion.

[0559] The damping hole is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed.

[0560] According to this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained. In addition, since the working fluid passes through the damping hole and the gap between the inner peripheral surface of the large-diameter cylindrical portion and the outer peripheral surface of the outward flange portion, or the outer peripheral surface of the small-diameter cylindrical portion and the inner peripheral surface of the inward flange portion, the vibration can be attenuated.

[0561] (B41) The support mechanism position adjustment mechanism of the shaft support device as described in (B40), wherein at least one sealing member is installed between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion, respectively.

[0562] According to this configuration, the working fluid accommodated in the pressure chamber and the storage chamber can be prevented from leaking through the sealing member, and the function of the support mechanism position adjustment mechanism can be maintained for a long time.

[0563] (B42) The support mechanism position adjustment mechanism of the shaft support device as described in (B40) or (B41), wherein the working fluid is stored in each clearance between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion.

[0564] According to this configuration, the support mechanism position adjustment mechanism can impart radial support rigidity to the shaft. Further, it can also have a centering function for the shaft.

[0565] (B43) The support mechanism position adjustment mechanism of the shaft support device as described in (B41), wherein the sealing member is an O-ring.

[0566] Sealing grooves for arranging the O-ring are respectively formed on the inner peripheral surface of the inward flange portion or the outer peripheral surface of the small-diameter cylindrical portion, and on the outer peripheral surface of the outward flange portion or the inner peripheral surface of the large-diameter cylindrical portion.

[0567] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0568] According to this configuration, by setting the sealing member as an O-ring, the O-ring also acts as a damping mechanism, and the vibration generated in the shaft can be attenuated. In addition, even when relative movement between the first component and the second component occurs, leakage of the working oil to the atmospheric pressure side can be prevented, and the axial rigidity of the shaft support device can be continuously maintained.

[0569] (B44) The support mechanism position adjustment mechanism of the shaft support device as described in (B41), wherein the sealing member is an O-ring.

[0570] A wear-resistant member is interposed between at least one of the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion and the O-ring, and between at least one of the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion and the O-ring.

[0571] According to this configuration, by setting the sealing member as an O-ring, the O-ring also acts as a damping mechanism, and the vibration generated in the shaft can be attenuated. In addition, the stress concentration applied to the O-ring can be dispersed, and damage such as wear of the O-ring and the contact surface in contact with the O-ring can be suppressed.

[0572] (B45) The support mechanism position adjustment mechanism of the shaft support device as described in (B26) or (B27), wherein a working medium volume change portion for changing the volume of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid is installed on at least one of the first component and the second component.

[0573] According to this configuration, the hollow member and the working fluid can be heated or cooled, causing the volume of the hollow member and the working fluid to expand or contract, and continuously maintaining the axial support rigidity in a stable state.

[0574] (B46) A support mechanism position adjustment mechanism for a shaft support device as described in (B26) or (B27), wherein one of the pair of the support mechanisms further includes:

[0575] Another support mechanism position adjustment mechanism, which is arranged in series or in parallel adjacent to the support mechanism position adjustment mechanism between the bearing unit and the support table;

[0576] The above another support mechanism position adjustment mechanism includes:

[0577] Another first component, which is arranged on the side of the support table, is penetrated by the shaft or arranged around the rotation axis;

[0578] Another second component, which is arranged on the side of the bearing housing, is penetrated by the shaft or arranged around the rotation axis and can move relative to the another first component in the axial direction;

[0579] A pressure generating unit, which is accommodated in a compressed state in a pressure chamber formed between the another first component and the another second component.

[0580] According to this configuration, in the case of series arrangement, in addition to being able to maintain the axial rigidity of the shaft support device even when the shaft elongation is greater, the centering property or coaxiality of the shaft can also be improved. In addition, in the case of parallel arrangement, an axial load larger than that when a single support mechanism position adjustment mechanism is arranged is generated, and the axial rigidity can be maintained.

[0581] (B47) A support mechanism position adjustment mechanism for a shaft support device as described in (B26) or (B27), wherein one of the first component and the second component has a plurality of recesses opening to one side in the axial direction,

[0582] The other of the first component and the second component has a plurality of protrusions protruding toward the other side in the axial direction, and can slide in the axial direction and be fitted into the plurality of recesses respectively,

[0583] A plurality of the above pressure chambers are respectively formed between the plurality of the recesses and the plurality of the protrusions,

[0584] In at least one of the plurality of the protrusions, the storage chamber and the damping hole are formed in such a way that the storage chamber communicates with the pressure chamber via the damping hole.

[0585] According to this configuration, the layout of the support mechanism position adjustment mechanism can be freely constituted by a plurality of pressure chambers.

[0586] (B48) The support mechanism position adjustment mechanism of the shaft support device as described in (B47), wherein a plurality of the pressure chambers are arranged on both sides in the width direction with respect to the shaft.

[0587] According to this configuration, the height dimension of the support mechanism position adjustment mechanism can be suppressed.

[0588] (B49) The support mechanism position adjustment mechanism of the shaft support device as described in (B47), wherein the storage chamber and the damping hole are respectively formed in each of the plurality of convex portions.

[0589] The elastic members are respectively arranged in a state of being compressed in the plurality of pressure chambers.

[0590] The hollow members are respectively housed in the plurality of storage chambers.

[0591] According to this configuration, the plurality of pressure chambers and the plurality of storage chambers can be commonly configured.

[0592] In addition, this application is based on Japanese Patent Application No. 2022-173763 filed on October 28, 2022, Japanese Patent Application No. 2023-118997 filed on July 21, 2023, and Japanese Patent Application No. 2023-134637 filed on August 22, 2023, the contents of which are incorporated herein by reference.

[0593] Description of Reference Numerals

[0594] 20: Ball screw feed device (shaft support device, rotary support device)

[0595] 21: Lead screw shaft (shaft, rotary shaft)

[0596] 23: Nut

[0597] 30: First support mechanism (support mechanism)

[0598] 31: Fixed side bearing housing

[0599] 33, 53: Angular contact ball bearings (bearings)

[0600] 34, 54: Outer rings

[0601] 35, 55: Inner rings

[0602] 36, 56: Balls

[0603] 38a, 38b: Lock nuts

[0604] 40: Second support mechanism (support mechanism)

[0605] 41: Bearing unit

[0606] 43: Support table (support body)

[0607] 51: Moving side bearing housing (bearing housing)

[0608] 51a: Inward flange

[0609] 59: Wear-resistant component

[0610] 60: Housing position adjustment mechanism (support mechanism position adjustment mechanism)

[0611] 61: Support table side component (first component)

[0612] 62: Bearing housing side component (second component)

[0613] 64: Annular recess

[0614] 65: Annular protrusion

[0615] 66: Pressure chamber

[0616] 67: O-ring (sealing component)

[0617] 68: Sealing groove

[0618] 69a: Tapered surface

[0619] 70: Working oil (working fluid)

[0620] 71: Storage chamber

[0621] 72: Damping hole

[0622] 80: Belleville spring (elastic component)

[0623] 90: Hollow component

[0624] 120: Rotating support device

[0625] 121: Rotating shaft

[0626] 160: Another housing position adjustment mechanism (another support mechanism position adjustment mechanism)

[0627] 161: Another support table side component (another support body side component)

[0628] 162: Another bearing housing side component

[0629] 170: Another working fluid

[0630] 180, 181: Heating element (working medium volume change part)

[0631] 182, 183: Cooling medium (working medium volume change section)

Claims

1. A rotary bearing device, characterized in that, it has a rotary shaft and a pair of bearing mechanisms that rotatably support both axial end portions of the rotary shaft, one of the pair of bearing mechanisms includes: a bearing unit, the bearing unit includes a bearing housing and a bearing, the bearing rotatably supports the rotary shaft relative to the bearing housing, and the bearing can support an axial load; a support table, the support table is penetrated by the rotary shaft or disposed around the rotary shaft; and a housing position adjustment mechanism, the housing position adjustment mechanism is disposed between the bearing unit and the support table, the housing position adjustment mechanism has: a support table side member, the support table side member is disposed on the support table side, penetrated by the rotary shaft or disposed around the rotary shaft; a bearing housing side member, the bearing housing side member is disposed on the bearing housing side, penetrated by the rotary shaft or disposed around the rotary shaft, and can relatively move axially with respect to the support table side member; a working fluid, the working fluid is accommodated in a pressure chamber, a storage chamber, and a damping hole, the pressure chamber is formed between the support table side member and the bearing housing side member, the storage chamber is formed in the support table side member or the bearing housing side member, and the damping hole communicates the pressure chamber with the storage chamber; an elastic member, the elastic member is disposed in the pressure chamber in a compressed state between the opposing axial end faces of the support table side member and the bearing housing side member; and a hollow member, the hollow member is accommodated in the storage chamber.

2. The rotary bearing device according to claim 1, characterized in that, one of the support table side member and the bearing housing side member has an annular recess that opens to one side in the axial direction, the other of the support table side member and the bearing housing side member has an annular protrusion that protrudes toward the other side in the axial direction and can be slidably fitted into the annular recess in the axial direction, the pressure chamber is formed between the annular recess and the annular protrusion, the storage chamber is formed in the annular protrusion so as to open to the outer surface or the inner surface of the annular protrusion, the damping hole is formed in the annular protrusion.

3. The rotary bearing device according to claim 2, characterized in that, at least one sealing member is respectively installed between the inner surface of the annular recess and the outer surface of the annular protrusion, and between the outer surface of the annular recess and the inner surface of the annular protrusion.

4. The rotary bearing device according to claim 2 or 3, characterized in that, the working fluid is stored in each gap between the inner surface of the annular recess and the outer surface of the annular protrusion, and between the outer surface of the annular recess and the inner surface of the annular protrusion.

5. The rotary bearing device according to claim 3, characterized in that, the sealing member is an O-ring, sealing grooves for disposing the O-ring are respectively formed on the inner surface of the annular recess or the outer surface of the annular protrusion, and on the outer surface of the annular recess or the inner surface of the annular protrusion. The sealing groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side.

6. The rotary bearing device according to claim 3, characterized in that the sealing member is an O-ring, and at least one of the inner-facing surface of the annular recess and the outer-facing surface of the annular protrusion and the O-ring, and at least one of the outer-facing surface of the annular recess and the inner-facing surface of the annular protrusion and the O-ring are interposed with wear-resistant members.

7. The rotary bearing device according to claim 1, characterized in that the elastic member is a disc spring having a plurality of through holes or a plurality of slits that axially penetrate a conical plate portion.

8. The rotary bearing device according to claim 1, characterized in that the hollow member has at least one rib protruding from its inner peripheral surface.

9. The rotary bearing device according to claim 1, characterized in that a plurality of the hollow members are arranged in the storage chamber.

10. The rotary bearing device according to claim 1, characterized in that the surface of the hollow member is covered by an outer layer.

11. The rotary bearing device according to claim 1, characterized in that the hollow member is a structure having an integrally formed seamless hollow cross-section.

12. The rotary bearing device according to claim 1, characterized in that the hollow member is an assembly having a hollow cross-section, and is formed by integrating two or more members via the edge portions of the two or more members.

13. The rotary bearing device according to claim 1, characterized in that the hollow member is formed by bending a member and joining the edge portions of the member to form a hollow cross-section.

14. The rotary bearing device according to claim 1, characterized in that one of the support base side member and the bearing housing side member has a small-diameter cylindrical portion extending toward one side in the axial direction and an outward flange portion extending from the tip of the small-diameter cylindrical portion toward the outer diameter side, the other of the support base side member and the bearing housing side member has: a large-diameter cylindrical portion extending toward the other side in the axial direction and having an inner peripheral surface for slidably contacting the outer peripheral surface of the outward flange portion; and an inward flange portion extending from the tip of the large-diameter cylindrical portion toward the inner diameter side and having an inner peripheral surface for slidably contacting the outer peripheral surface of the small-diameter cylindrical portion, the pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion, the storage chamber is formed in the outward flange portion or the inward flange portion so as to open on the inner peripheral surface of the large-diameter cylindrical portion or the outer peripheral surface of the small-diameter cylindrical portion, the damping hole is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed.

15. The rotary bearing device according to claim 14, characterized in that at least one sealing member is respectively installed between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion.

16. The rotary bearing device according to claim 14 or 15, characterized in that Between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion, each gap stores the working fluid.

17. The rotary support device according to claim 15, characterized in that, the sealing member is an O-ring, on the inner peripheral surface of the inward flange portion or the outer peripheral surface of the small-diameter cylindrical portion, and on the outer peripheral surface of the outward flange portion or the inner peripheral surface of the large-diameter cylindrical portion, sealing grooves for arranging the O-ring are respectively formed, the sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

18. The rotary support device according to claim 15, characterized in that, the sealing member is an O-ring, between at least one of the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion and the O-ring, and between at least one of the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion and the O-ring, wear-resistant members are interposed.

19. The rotary support device according to claim 1, characterized in that, a working medium volume changing portion is installed on at least one of the support table side member and the bearing housing side member, and the working medium volume changing portion changes the volumes of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid.

20. The rotary support device according to claim 1, characterized in that, one of the pair of support mechanisms further includes: another housing position adjusting mechanism, the another housing position adjusting mechanism is arranged in series or in parallel adjacent to the housing position adjusting mechanism between the bearing unit and the support table; the another housing position adjusting mechanism includes: another support table side member, the another support table side member is arranged on the support table side, penetrated by the rotating shaft or arranged around the rotating shaft; another bearing housing side member, the another bearing housing side member is arranged on the bearing housing side, penetrated by the rotating shaft or arranged around the rotating shaft, and can relatively move axially with respect to the another support table side member; a pressure generating unit, the pressure generating unit is accommodated in a pressure chamber formed between the another support table side member and the another bearing housing side member in a compressed state.

21. The rotary support device according to claim 1, characterized in that, one of the support table side member and the bearing housing side member has a plurality of recesses opening to one side in the axial direction, the other of the support table side member and the bearing housing side member has a plurality of protrusions, the plurality of protrusions protrude toward the other side in the axial direction, and can be slidably fitted into the plurality of recesses respectively in the axial direction, the plurality of pressure chambers are respectively formed between the plurality of recesses and the plurality of protrusions, in at least one of the plurality of protrusions, the storage chamber and the damping hole are formed in such a way that the storage chamber communicates with the pressure chamber via the damping hole.

22. The rotary support device according to claim 21, characterized in that, the plurality of pressure chambers are arranged on both sides in the width direction with respect to the rotating shaft.

23. The rotary bearing device according to claim 21, characterized in that, the storage chambers and the damping holes are respectively formed in the plurality of convex portions, the elastic members are respectively arranged in a compressed state in the plurality of pressure chambers, the hollow members are respectively received in the plurality of storage chambers.

24. The rotary bearing device according to claim 1, characterized in that, the bearing of the bearing unit includes a pair of angular contact ball bearings, and each of the pair of angular contact ball bearings includes an outer ring embedded in the bearing housing, an inner ring externally fitted to the axial end of the rotary shaft, and balls rotatably arranged between the outer ring and the inner ring.

25. The rotary bearing device according to claim 1, characterized in that, the rotary bearing device is a ball screw feed device, the ball screw feed device has the rotary shaft as a screw shaft formed with a spiral thread groove on the outer peripheral surface, and further has: a nut formed with a spiral thread groove on the inner peripheral surface, and a plurality of balls rotatably arranged between the thread groove of the screw shaft and the thread groove of the nut.

26. A support mechanism position adjustment mechanism for a shaft support device, characterized in that, it is provided in one of a pair of support mechanisms in the shaft support device, the shaft support device includes a shaft and a pair of the support mechanisms provided at the axial ends of the shaft for supporting the shaft, one of the pair of support mechanisms includes a support body penetrated by the shaft or arranged around the shaft, the support mechanism position adjustment mechanism of the shaft support device has: a first member, the first member is provided on one of the shaft side and the support body side, and can be penetrated by the shaft or can be arranged around the shaft; a second member, the second member is provided on the other of the shaft side and the support body side, can be penetrated by the shaft or can be arranged around the shaft, and can relatively move axially with respect to the first member; a working fluid, the working fluid is received in a pressure chamber, a storage chamber, and a damping hole, the pressure chamber is formed between the first member and the second member, the storage chamber is formed in the first member or the second member, and the damping hole communicates the pressure chamber with the storage chamber; an elastic member, the elastic member is in the pressure chamber and is arranged in a compressed state between the opposing axial end faces of the first member and the second member; and a hollow member, the hollow member is received in the storage chamber.

27. The support mechanism position adjustment mechanism of the shaft support device according to claim 26, characterized in that, the shaft is a rotary shaft, one of the pair of support mechanisms further has a bearing unit, the bearing unit has a bearing housing and a bearing, the bearing rotatably supports the rotary shaft with respect to the bearing housing, and the bearing can support an axial load; the support mechanism position adjustment mechanism is a housing position adjustment mechanism arranged between the bearing unit and the support body, the first member is provided on the support body side and is a support body side member that can be penetrated by the rotary shaft or can be arranged around the rotary shaft, The second component is a bearing housing side component, which is arranged on the bearing housing side, can be penetrated by the rotating shaft or can be arranged around the rotating shaft, can move axially relative to the support body side component, and forms the accommodation space between it and the support body side component.

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