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

Abstract

A support mechanism (30) for rotatably supporting both axial end portions of a screw shaft (21) is provided with: a bearing unit (41) having a moving-side bearing housing (51) and a pair of angular contact ball bearings (33B) embedded in the moving-side bearing housing (51); a support base (43) which is disposed closer to the axial center side than the bearing unit (41) and through which the screw shaft (21) passes; and a housing position adjustment mechanism (44) disposed between the bearing unit (41) and the support base (43). The housing position adjustment mechanism (44) is provided with: a support table-side member (61) provided on the support table (43) side; a bearing housing-side member (62) that is provided on the bearing housing (51) side and is relatively movable in the axial direction with respect to the support base-side member (61); a working fluid filled in a pressure chamber (66) formed between the support table-side member (61) and the bearing housing-side member (62); and 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). As a result, 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.

Description

Technical Field

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

[0002] In a ball screw feed device, high axial rigidity is required to maintain the feed accuracy of a screw shaft. Conventionally, as a method of imparting rigidity to the screw shaft of a ball screw device, generally, a plurality of angular contact bearings are combined and preloaded, and they are arranged at one end or both ends of the screw shaft, thereby fixing and supporting the screw shaft axially. In addition, in consideration of the thermal expansion of the screw shaft, a method of pre-applying a tensile force in the axial direction to the screw shaft to cause it to elongate by a specified amount is adopted. Patent Document 1 describes the following: By adjusting the axial dimension of a spacer, a tensile force is pre-applied to a feed screw (screw shaft), and moreover, a pre-tensioning mechanism is provided. When the feed screw elongates due to a temperature rise beyond the pre-tensioning force, this pre-tensioning mechanism uses a disc spring, the pressure of a fluid, etc. to move a bearing axially and impart a tensile force to the feed screw.

[0003] Prior Art Documents

[0004] Patent Documents

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

[0006] Technical Problem to be Solved by the Invention

[0007] However, if the load such as pre-tension and pre-tightening force applied to the feed screw is too large, it may impose a large load on the bearing, and the bearing may be damaged. Therefore, generally, within the range where an excessive load is not applied to the bearing axially, a disc spring, an externally supplied fluid, etc. as shown in the pre-tensioning mechanism described in Patent Document 1 are arranged. However, in the case of using a disc spring, the load weakens as the shaft elongates, so it is only possible to cope with elongation of 3 to 4 degrees Celsius in temperature rise. In a machining center, etc., the temperature rise of the ball screw often exceeds 4 degrees Celsius. In this case, the sufficient load based on the disc spring becomes an ineffective state, and there is a problem of reduced axial support rigidity.

[0008] In addition, in the method of supplying fluid from the outside and applying a load by hydraulic pressure, in addition to requiring external devices such as a hydraulic pump, there are also problems of enlargement of the ball screw feed device, resulting in increased costs and additional energy consumption.

[0009] Moreover, 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 using a pair of support mechanisms.

[0010] The present invention has been made in view of the above problems, and an object thereof 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 the problem

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

[0013] [1] A rotary support device, wherein:

[0014] It includes: a rotating shaft; and a pair of support mechanisms that respectively rotatably support both axial ends of the rotating shaft.

[0015] One of the pair of support mechanisms includes:

[0016] A bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft relative to the bearing housing and can support an axial load;

[0017] A support table that is penetrated by the rotating shaft or disposed around the rotating shaft; and

[0018] A housing position adjustment mechanism disposed between the bearing unit and the support table.

[0019] The housing position adjustment mechanism includes:

[0020] A support table side member disposed on the support table side and penetrated by the rotating shaft or disposed around the rotating shaft;

[0021] A bearing housing side member disposed on the bearing housing side and penetrated by the rotating shaft or disposed around the rotating shaft and capable of relatively moving axially with respect to the support table side member;

[0022] A working fluid filled in a pressure chamber formed between the support table side member and the bearing housing side member; and

[0023] An elastic member disposed in a compressed state in the pressure chamber between the opposed axial end faces of the support table side member and the bearing housing side member.

[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 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 for supporting the shaft.

[0025] One of the pair of support mechanisms has a support body that is penetrated by the shaft or disposed 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 disposed 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 disposed around the shaft, can move relative to the first component in the axial direction, and forms a receiving space between the second component and the first component;

[0029] A working fluid, which is filled in the receiving space; and

[0030] An elastic component, which is disposed in the receiving space in a compressed state between the opposing axial end faces of the first component and the second component.

[0031] Effects of the Invention

[0032] 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.

[0033] 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. Description of the Drawings

[0034] Figure 1 It is a cross-sectional view of a table feed system of a machine tool with a ball screw feed device according to a first embodiment of the present invention applied.

[0035] Figure 2 It is provided with Figure 1 An enlarged cross-sectional view of a support mechanism with the shown housing position adjustment mechanism.

[0036] Figure 3 It is Figure 2 A view in the direction A of

[0037] Figure 4It is a cross-sectional view showing a deformation example of a conical spring.

[0038] Figure 5 It is a diagram corresponding to the ball screw feed device according to the second embodiment of the present invention Figure 2 and is shown in the figure.

[0039] Figure 6 It is a diagram corresponding to the ball screw feed device according to the third embodiment of the present invention Figure 2 and is shown in the figure.

[0040] Figure 7 It is Figure 6 a magnified view of part VII.

[0041] Figure 8 (a) to (c) of this figure are main part magnified cross-sectional views showing examples in which wear-resistant members are applied to the seal grooves of the ball screw feed device according to the deformation example of the third embodiment.

[0042] Fig. 9 It is a diagram corresponding to the ball screw feed device according to the fourth embodiment of the present invention Figure 2 and is shown in the figure.

[0043] Fig.10 It is a diagram corresponding to the ball screw feed device according to the fifth embodiment of the present invention Figure 2 and is shown in the figure.

[0044] Fig.11 It is a diagram corresponding to a deformation example of a bearing unit in which a pair of angular contact ball bearings are arranged in a back-to-back combination in the first to fifth embodiments Figure 2 and is shown in the figure.

[0045] Fig.12 It is a diagram corresponding to another deformation example of a bearing unit in which a pair of angular contact ball bearings are arranged side by side in the first to fifth embodiments Figure 2 and is shown in the figure.

[0046] Fig.13 (a) of this figure is a schematic side view showing a first example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers, Fig.13 and (b) of this figure is a schematic side view showing a second example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers.

[0047] Fig.14 (a) of this figure is a schematic side view showing a third example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers, Fig.14 and (b) of this figure is a schematic side view showing a fourth example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers.

[0048] Fig.15It is a schematic side view showing a fifth example in which the housing position adjustment mechanism is composed of a plurality of pressure chambers.

[0049] Fig.16 It is a cross-sectional view taken along line XVI-XVI of 14(a).

[0050] Fig.17 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the sixth embodiment of the present invention.

[0051] Fig.18 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the first modification of the sixth embodiment.

[0052] Fig.19 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the second modification of the sixth embodiment.

[0053] Fig. 20 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the third modification of the sixth embodiment.

[0054] Fig.21 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the third modification of the sixth embodiment.

[0055] Fig. 22 It is Fig.21 an enlarged view of part XVIII.

[0056] Fig.23 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the fourth modification of the sixth embodiment.

[0057] Fig.24 It is a diagram corresponding to Figure 2 of the ball screw feed device according to the fifth modification of the sixth embodiment.

[0058] Fig.25 In (a), it is an enlarged cross-sectional view corresponding to Figure 2 the phase where the oil supply passage formed in the bearing housing side member is provided for filling the working fluid into the pressure chamber, and (b) is a cross-sectional view showing a modification example of the fixing bolt in (a).

[0059] Fig.26 In (a), it is instead of Fig.25Cross-sectional view of a fixing plug used for the fixing bolt in (a), (b) is a cross-sectional view showing an example of combining the fixing plug in (a) with a disc-shaped member, (c) is a cross-sectional view showing a modified example of the disc-shaped member in (b), and (d) is a cross-sectional view showing another modified example of the disc-shaped member in (b).

[0060] Fig. 27 Cross-sectional view of the table feed system of a machine tool with a ball screw feed device according to a modified example of the present invention applied thereto.

[0061] Fig.28 Cross-sectional view showing a first example of a housing position adjustment mechanism in which a support table is disposed on the axial end side with respect to a bearing unit.

[0062] Fig.29 Cross-sectional view showing a second example of a housing position adjustment mechanism in which a support table is disposed on the axial end side with respect to a bearing unit.

[0063] Fig.30 Cross-sectional view showing a third example of a housing position adjustment mechanism in which a support table is disposed on the axial end side with respect to a bearing unit.

[0064] Fig.31 Cross-sectional view showing a fourth example of a housing position adjustment mechanism in which a support table is disposed on the axial end side with respect to a bearing unit.

[0065] Fig.32 Cross-sectional view showing a rotary support device according to the present invention.

[0066] Fig.33 Cross-sectional view showing another rotary support device according to the present invention.

[0067] Fig.34 Cross-sectional view showing a shaft support device applying a support mechanism position adjustment mechanism according to the present invention.

[0068] Fig.35 is Fig.34 Enlarged view of part XXXV of Detailed Description of the Invention

[0069] Hereinafter, each embodiment of a ball screw feed device as an example of a rotary support device and a shaft support device according to the present invention will be described in detail with reference to the drawings.

[0070] (First Embodiment)

[0071] Figure 1 Shows the table feed system of a machine tool to which the ball screw feed device of the first embodiment is applied. In addition, for Figure 1 to Figure 3 , the axial direction of the screw shaft 21 of the ball screw feed device 20 ( Figure 1 The direction in the left - right direction (of the base 1) is set as the X - direction, and the direction parallel to the mounting surface 1a of the base 1 and orthogonal to the axial direction of the lead screw shaft 21 ( Figure 1 the direction perpendicular to the paper surface of the figure) 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. Additionally, in Figure 2 and in each figure corresponding to Figure 2 the dotted line indicates the bolt - fastening part.

[0072] The table feed system 10 is configured to include a moving table 11 fixed to a nut 23 of the ball screw feed device 20. By driving the lead screw shaft 21 of the ball screw feed device 20 with a drive motor 12, the moving table 11 can move freely in the X - direction. On the moving table 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 lead screw shaft 21 with a track mounting table 14 interposed therebetween; and two sliders 16 fixed to the lower surface of the moving table 11 and straddling the guide rail 15. Thus, by rotating the lead screw shaft 21 using the drive motor 12, the moving table 11 is guided by the pair of linear guides 13 and reciprocates linearly together with the nut 23.

[0073] The ball screw feed device 20 includes: a lead screw shaft 21 having a helical thread groove 21b formed on its outer peripheral surface; a nut 23 disposed around the lead screw shaft 21, having a helical thread groove (not shown) formed on its inner peripheral surface, and fitted with a nut housing 22 fixed to the lower surface of the moving table 11; and a plurality of balls (not shown) disposed between the thread groove of the nut 23 and the thread groove 21b of the lead screw shaft 21 so as to roll freely.

[0074] The lead screw shaft 21 includes: a large - diameter portion 24 formed at the axial center and having a thread groove 21b; 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. Additionally, a small - diameter shaft portion 27 is provided at the tip of one side (the right - hand side in the figure) of the lead screw shaft 21. The rotation shaft 12a of the drive motor 12 is connected to the small - diameter shaft portion 27 via a coupling 28.

[0075] In addition, one side of the lead screw shaft 21 to which the drive motor 12 is connected is rotatably supported by a first support mechanism 30, and the other side of the lead screw shaft 21 (the left - hand side in the figure) is rotatably supported by a second support mechanism 40.

[0076] 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 arranged in a face-to-face combination that rotatably supports the lead screw shaft 21 relative to the fixed-side bearing housing 31. 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 rollably disposed between the outer ring 34 and the inner ring 35 at a contact angle.

[0077] 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.

[0078] 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.

[0079] Also referring to Figure 2 and Figure 3 , the second support mechanism 40 has: a bearing unit 41 disposed at the other end of the lead screw shaft 21; a support table 43 fixed to the base 1 at a position axially closer to the center than 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.

[0080] 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.

[0081] 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 rollably disposed between the outer ring 54 and the inner ring 55 at a contact angle.

[0082] In a pair of angular contact ball bearings 53, 53, the outer ring 54 of the angular contact ball bearing 53 on the axially inner side is brought into contact with 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 axially outer side is fastened by an outer ring pressing member 47 fastened to the moving-side bearing housing 51. The outer rings 54, 54 are axially positioned with respect to the moving-side bearing housing 51. Further, the inner ring 55 of the angular contact ball bearing 53 disposed on the axially outer side is fastened by a fastening nut 38b screwed onto the external thread 25a via a spacer 48.

[0083] 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 on the lead screw shaft 21 and the housing position adjustment mechanism 60, respectively. In this structure, the moving-side bearing housing 51 may be integrated with the bearing housing side member 62 as needed.

[0084] The housing position adjustment 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 relatively moving axially with respect to the support table side member 61. The support table side member 61 and the bearing housing side member 62 face each other axially.

[0085] The annular portion 61a protruding toward the support table 43 side of the support table side member 61 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). The annular portion 62a protruding toward the moving-side bearing housing 51 side of the bearing housing side member 62 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 ).

[0086] Further, a bottomed annular recess 64 opening toward the support table side member 61 side (axially one side) is provided on the side surface of the bearing housing side member 62 on the support table side member 61 side. On the other hand, an annular protrusion 65 protruding into the annular recess 64 toward the bearing housing side member 62 side (axially the other side) is provided on the side surface of the support table side member 61 on the bearing housing side member 62 side. The annular recess 64 and the annular protrusion 65 are fitted so as to be able to slide 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.

[0087] Moreover, a working fluid, such as working oil 70, is filled in the pressure chamber 66 in a compressed state, and a plurality of disc springs 80 as elastic members are arranged in a compressed state between the opposed 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 recess 64 and the top surface of the annular projection 65.

[0088] The working oil 70 is a working fluid that has an elastic effect when an external force is applied and has been industrially confirmed to have rigidity, and is given rigidity when compressed.

[0089] Specifically, it is known that the bulk modulus of the working oil is affected by gas mixing, etc. (refer to Non-Patent Document (Junichi Oshimaru, Hirohisa Tanaka, "Measurement of the Bulk Modulus of Working Oil" Hydraulics and Pneumatics, Vol. 19, No. 7, 1988, p. 580 - 583)). In the present embodiment, the types of the working oil and the gas are appropriately selected so that even when there is a temperature rise of more than 4 degrees and the pressure chamber 66 expands axially according to the axial elongation of the lead screw shaft 21, a desired axial rigidity can be imparted to the lead screw shaft by the pressure acting on the bearing housing side member 62.

[0090] In addition, as the working fluid, it is not limited to oil, and any liquid such as water can be used as long as it has an elastic effect when compressed and can exhibit rigidity. Alternatively, it can also be a gas.

[0091] In addition, 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 by 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 by considering the volume expansion caused by the temperature rise of the working fluid due to the environmental change around the ball screw feed device 20 during the operation of the ball screw feed device 20.

[0092] When the plurality of disc springs 80 function as a series spring, as Figure 2 shown, they are axially overlapped and arranged such that the convex-side surfaces of adjacent disc springs 80 face each other and the concave-side surfaces face each other. In addition, when the plurality of disc springs 80 function as a parallel spring, although not shown, the disc springs 80 are arranged to overlap with the same orientation with respect to the axial direction.

[0093] Further, 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. Specifically, the O-ring 67 is disposed in an annular seal groove 68 formed on the outward-facing surface 65a and the inward-facing surface 65b of the annular convex portion 65, and is in sliding contact with the inward-facing surface 64a and the outward-facing surface 64b of the opposing annular concave portion 64, sealing the radial clearance 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 the radial clearance between the inward-facing surface 65b of the annular convex portion 65 and the outward-facing surface 64b of the annular concave portion 64. In addition, the seal groove 68 may also be formed on the inward-facing surface 64a and the outward-facing surface 64b of the annular concave portion 64. Further, one O-ring 67 and seal groove 68 are respectively disposed between each pair of opposing surfaces, but multiple ones may also be disposed. Thereby, the O-ring 67 prevents the working oil 70 filled in the pressure chamber 66 from leaking. From the viewpoint of preventing wear, a surface treatment such as wear resistance may also be applied to the O-ring 67.

[0094] In addition, a rotation prevention mechanism 75 for preventing relative rotation between the support base side member 61 and the bearing housing side member 62 is provided. Specifically, for example, in the bearing housing side member 62, a through hole 77 penetrating in the radial direction is formed at at least one portion in the circumferential direction, and the tip of the positioning pin 76 protrudes from the inward-facing surface 64a of the annular concave portion 64 through the through hole 77. Moreover, the tip of the positioning pin 76 is inserted into a long hole 78 formed axially on the outward-facing surface 65a of the annular convex portion 65 of the support base side member 61 in such a manner that the bearing housing side member 62 can move axially. In addition, the positioning pin 76 may be replaced by inserting a positioning key (not shown) in the rotational direction having the same rotation prevention function and capable of moving the bearing housing side member 62 axially into the long hole 78.

[0095] After the working oil 70 and the plurality of disc springs 80 are accommodated in the pressure chamber 66, such a housing position adjustment mechanism 60 presses the bearing housing side member 62 toward the support base side member 61 via a pair of angular contact ball bearings 53, 53 and the movable side bearing housing 51 by tightening the fastening nut 38b. Thereby, the working oil 70 is compressed and a pressure is applied to the working oil 70 in the direction of the lead screw shaft, and the plurality of disc springs 80 are compressed and a pressure is applied to the plurality of disc springs 80 in the direction of the lead screw shaft.

[0096] On the other hand, since the support base side member 61 is fixed to the base 1 via the support base 43, the bearing housing side member 62 and the movable side bearing housing 51 are pressed in the left direction in the figure by the pressure of the working oil 70 and the plurality of disc springs 80 accommodated in the pressure chamber 66 in a compressed state. Thereby, preloading is applied to the lead screw shaft 21 in the Figure 1 、 Figure 2 A state where tension is applied to the left side.

[0097] In addition, the pressures of the working oil 70 and the plurality of disc springs 80 housed in the pressure chamber 66 can be controlled to any size respectively by the tightening 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 size by the fastening nut 38b.

[0098] In addition, as described above, for the magnitude of the axial load applied to the lead screw shaft 21 by the working oil 70, in addition to considering the setting based on the tightening amount of the fastening nut 38b, it can also 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.

[0099] Next, the operation of the ball screw feed device 20 of the present embodiment will be described.

[0100] In the ball screw feed device 20, when the lead screw shaft 21 is rotationally driven by the drive motor 12 to cause the moving table 11 fixed to the nut 23 to perform a reciprocating linear motion, along with this motion, the drive motor 12, angular contact ball bearings 33, 53, the nut 23, etc. generate heat, and the temperature of the ball screw feed device 20 gradually rises, and the lead screw shaft 21 axially elongates due to thermal expansion.

[0101] When the lead screw shaft 21 axially elongates due to thermal expansion, in Figure 1 the ball screw feed device 20 of the present embodiment shown, 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, so the lead screw shaft 21 elongates leftward. When the lead screw shaft 21 axially elongates (leftward) 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 lead screw shaft 21 caused by thermal expansion by the pressures of the working oil 70 and the plurality of disc springs 80 housed in the pressure chamber 66.

[0102] In the present embodiment, it is designed that when the lead screw shaft 21 axially elongates, the working oil 70 and the plurality of disc springs 80 also continuously press the bearing unit 41 and the bearing housing side member 62 to the left. The design freedom of the working oil 70 and the pressure chamber 66 is large. By appropriately selecting the physical properties of the working fluid filled in the pressure chamber, the size and shape of the pressure chamber, in addition to the pressure of the plurality of disc springs 80, the pressure of the working oil 70 is also exerted, thereby being able to cope with a larger shaft elongation and applying a sufficient and appropriate load. 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.

[0103] In particular, even when the temperature rise is higher than 4 degrees, the pressure of the working oil 70 can vary corresponding to the axial elongation amount of the lead screw shaft 21. Therefore, during the period when the lead screw shaft 21 elongates axially, the state of using a 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.

[0104] In addition, the plurality of disc springs 80 used in the present embodiment are disc springs having an elastic coefficient such that even when the temperature rise of the ball screw feed device 20 is higher than 4 degrees, they can share the load with the working oil 70 and comprehensively maintain the compressed state between the bottom surface of the annular recess 64 and the top end surface of the annular projection 65 over a long distance in the axial direction.

[0105] In such a case of the present embodiment, an excessive load is not applied to the pair of angular contact ball bearings 33, 33 and 53, 53. Therefore, excessive wear, seizure, etc. caused by poor lubrication do not occur, and the service life of the pair of angular contact ball bearings 33, 33 and 53, 53 becomes longer.

[0106] That is, in the present embodiment, in the ball screw described in Patent Document 1, it is not necessary to apply a pre-tension of the magnitude applied by the spacer to the lead screw shaft 21. Therefore, an excessive load is not applied to the pair of angular contact ball bearings 33, 33 and 53, 53 either.

[0107] Moreover, in the ball screw feed device 20 of the present embodiment, it is not necessarily required to provide external devices such as an accumulator and a pump for supplying the working oil 70 to the pressure chamber 66, and the housing position adjustment mechanism 60 can be simplified. As a result, the energy supplied from the outside is not consumed, and the change in the pressure of the pressure chamber 66 can be minimized and continuously maintained.

[0108] In addition, the O-ring 67 of the present embodiment also functions as a damping mechanism. That is, when machining a workpiece placed on the moving table 11, due to the vibration generated by the moving table 11, the lead screw shaft 21 with low rigidity also vibrates. The vibration of the lead screw shaft 21 is 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 disorder of the machining surface quality of the workpiece placed on the moving table 11 can be suppressed.

[0109] At this time, the O-ring 67 disposed between the bearing housing side member 62 and the support table side member 61 can attenuate not only the axial vibration of the lead screw shaft 21 but also the radial vibration of the lead screw shaft 21.

[0110] In addition, the working oil 70 of the housing position adjustment mechanism 60 is stored not only in the pressure chamber 66, 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 on the pressure chamber 66 side of the O-ring 67. Therefore, by compressing the working oil 70, the pressure acts on the working oil 70 not only axially but also radially. As a result, the bearing housing side member 62 is supported by the support table side member 61 in a manner having a sufficient and appropriate radial load.

[0111] As a result, the housing position adjustment mechanism 60 can impart radial support rigidity to the lead screw shaft 21 via the pair of angular contact ball bearings 53, 53 and the bearing housing 51, and can also have a centering function for the lead screw shaft 21.

[0112] In addition, when the axial elongation of the lead screw shaft 21 as described above occurs, even when vibration is generated due to the elastic deformation when the disc spring 80 returns from the compressed state, the O-ring 67 can attenuate the vibration.

[0113] Moreover, the working oil 70 in the pressure chamber 66 exerts a damping effect when passing through the minute gaps generated at the contact portions between the disc springs 80 or between the disc spring 80 and the inner surface of the pressure chamber 66. Therefore, the vibration of the lead screw shaft 21 and the vibration of the plurality of disc springs 80 can be attenuated.

[0114] 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, 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.

[0115] It should be noted that, as Figure 4 shown, in the disc-shaped disc spring 80, a plurality of through holes 80a penetrating axially can be formed in the conical plate portion, and in addition, a plurality of slits (not shown) can also be formed. Thus, the disc spring 80 also functions as a damping hole, and the working oil 70 flows in the plurality of through holes 80a and slits, so that the attenuation effect can be further exerted.

[0116] In addition, although not shown, the support table side member 61 can also be integrally formed with the support table 43, and the bearing housing side member 62 can also be integrally formed with the moving side bearing housing 51.

[0117] (Second Embodiment)

[0118] Next, referring to Figure 5A ball screw feed device according to a second embodiment of the present invention will be described. In addition, in the present embodiment, the structure of the housing position adjustment mechanism 60 of the second support mechanism 40 is different from that of the first embodiment.

[0119] In the housing position adjustment mechanism 60 of the second embodiment, a storage chamber 71 is formed inside the annular convex portion 65. In addition, at least one portion in the circumferential direction (two portions in Figure 5 this case) is formed with a damping hole 72 along the axial direction so as to communicate the storage chamber 71 with the pressure chamber 66.

[0120] The storage chamber 71 opens to the outer surface 65a of the annular convex portion 65 at a position closer to the top surface of the annular convex portion 65 than the groove portion where the O-ring 67 is disposed, and is formed in a disk groove shape. Thus, in the present embodiment, the working oil 70 is stored not only in the pressure chamber 66 but also in the storage chamber 71 and the damping hole 72.

[0121] Accordingly, in the present embodiment, due to the vibration of the lead screw shaft 21, the bearing housing side member 62 vibrates together with the moving side bearing housing 51 and the pair of angular contact ball bearings 33, 33. As a result, the working oil 70 in the pressure chamber 66 and the storage chamber 71 passes through the damping hole 72 and 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, so that the vibration can be attenuated. Therefore, similar to the above-described 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 the disorder of the machining surface quality of the workpiece can be further improved.

[0122] 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.

[0123] In addition, the cross-sectional shape and length of the damping hole 72 may be arbitrarily formed as long as the attenuation function is effective.

[0124] Other structures and operations are the same as those of the first embodiment.

[0125] (Third Embodiment)

[0126] Next, with reference to Figure 6 and Figure 7 a ball screw feed device according to a third embodiment of the present invention will be described. In addition, in the present embodiment, the structure of the housing position adjustment mechanism 60 of the second support mechanism 40 is different from that of the first embodiment.

[0127] In the housing position adjustment mechanism 60 of the third embodiment, the seal grooves 68 formed in the outer facing surface 65a and the inner facing surface 65b of the annular convex portion 65 are composed of a tapered surface 69a whose groove depth becomes shallower as it moves away from the pressure chamber 66 side, and annular axially both side surfaces 69b, 69c that extend radially from the axially both end edges of the tapered surface 69a.

[0128] In addition, the axial distance between the axially both side surfaces 69b, 69c is wider than the axial width of the O-ring 67 in a state where it is elastically deformed and mounted in the seal groove 68. Thus, the working oil 70 that has passed through the gap g from the pressure chamber 66 is drawn into the vicinity of the boundary between the axially side surface 69b with a deeper groove depth and the tapered surface 69a.

[0129] Therefore, as the pressure of the working oil 70 in the pressure chamber 66 increases, as the O-ring 67 is pressed by the working oil 70 toward the atmospheric pressure side, 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 opposed inner facing surface 64a and outer facing surface 64b of the 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, thereby continuously maintaining the axial rigidity of the ball screw feed device 20.

[0130] In addition, as a modification of this embodiment, as shown in (a) to (c) of Figure 8 a wear-resistant member 59 may be interposed between at least one of the inner facing surface 64a of the annular concave portion 64 and the outer facing surface 65a of the annular convex portion 65 (in this embodiment, the tapered surface 69a of the seal groove 68 formed in the outer facing surface 65a) and the O-ring 67.

[0131] Specifically, as shown in (a) of Figure 8 the wear-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 facing 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 facing surface 65a of the annular convex portion 65.

[0132] In addition, as shown in (b) of Figure 8 the wear-resistant member 59 may also be formed as an annular member having a linear cross-section so as to be located between the inner peripheral surface of the O-ring 67 and the tapered surface 69a of the seal groove 68 formed in the outer facing surface 65a of the annular convex portion 65. And, as shown in (c) of Figure 8 the wear-resistant member 59 may also be formed as an annular member having a linear cross-section so as to be located between the outer peripheral surface of the O-ring 67 and the inner facing surface 64a of the annular concave portion 64.

[0133] As the wear-resistant member 59, for example, resin materials such as fluororesin, metal materials after appropriate surface treatment, etc. are used.

[0134] In Figure 8 In any of the modes (a) to (c), by using the wear-resistant member 59, it is possible to disperse the stress concentration applied to the O-ring 67, and suppress damages such as wear of the O-ring 67 and the contact surface in contact with the O-ring 67.

[0135] It should be noted that the wear-resistant member 59 may also be interposed between Figure 7 the O-ring 67 shown in and at least one of the outer surface 64b of the annular recess 64 and the inner surface 65b of the annular protrusion 65 (in Figure 7 it is the conical surface 69a of the seal groove 68 formed on the inner surface 65b).

[0136] In addition, in Figure 8 in (a) to (c), the wear-resistant member 59 is interposed between the O-ring 67 and the opposing surface opposing the O-ring 67 in the seal groove 68 having the conical surface 69a. On the other hand, even when the wear-resistant member 59 is interposed between the O-ring 67 and the opposing surface opposing the O-ring 67 in the seal groove 68 with a uniform groove depth as shown in Figure 2 , the above effects are also achieved.

[0137] Other structures and operations are the same as those of the first embodiment.

[0138] (Fourth Embodiment)

[0139] Next, with reference to Fig. 9 the ball screw feed device according to the fourth embodiment of the present invention will be described. In addition, in the present embodiment, the structure of the housing position adjustment mechanism 60 of the second support mechanism 40 is different from that of the first embodiment.

[0140] In the housing position adjustment mechanism 60 of the fourth embodiment, on the outer peripheral surfaces of the support table side member 61 and the bearing housing side member 62, heating elements 180, 181 such as electric heating wires and rubber heaters as the working fluid volume change part are arranged in a ring shape or discretely.

[0141] Thereby, the heat from the heating elements 180, 181 is transferred from the support table side member 61 and the bearing housing side member 62 to the working oil 70 in the pressure chamber 66, heating the working oil 70, so that the volume of the working oil 70 can be expanded. As a result, even when the lead screw shaft 21 elongates in the axial direction, since a load is generated in the pressure chamber 66 due to the volume expansion of the working oil 70, the axial support rigidity can be maintained.

[0142] In addition, in the present embodiment, heating elements 180 and 181 are installed on the outer peripheral surfaces of the support table side member 61 and the bearing housing side member 62 as the working fluid volume change portion, but a cooling jacket, a cooling element, or other cooling media 182 and 183 may be installed instead.

[0143] By using the cooling media 182 and 183, even when the load generated in the pressure chamber 66 due to the volume expansion of the working oil 70 becomes excessive, the working oil 70 can be cooled to contract the volume of the working oil 70. Thereby, it is possible to prevent the axial support rigidity of the ball screw feed device 20 from becoming excessive, and the axial support rigidity can be continuously maintained in a stable state.

[0144] In addition, in the present embodiment, the temperature of the working oil 70 is affected by the components of the ball screw feed device 20, the installation environment, the operation cycle, etc. Therefore, a feedback loop for the temperature of the components, the working oil 70, etc. may be formed by using the heating elements 180 and 181 and the cooling media 182 and 183, so as to control the working oil 70 to the target temperature. And, in the present embodiment, the operations of the heating elements 180 and 181 and the cooling media 182 and 183 may be feedback-controlled by considering the volume change of the working oil 70, the state of the pressure in the pressure chamber 66, the axial relative displacement between the support table side member 61 and the bearing housing side member 62, etc.

[0145] In addition, in the present embodiment, the working fluid volume change portion is installed on both the support table side member 61 and the bearing housing side member 62, but it may be installed on either the support table side member 61 or the bearing housing side member 62.

[0146] Moreover, in the present embodiment, the working fluid volume change portion is provided on the outer peripheral surfaces of the support table side member 61 and the bearing housing side member 62, but as long as it is a portion capable of expanding or contracting the volume of the working oil 70 in the pressure chamber 66, it may be installed at any position such as the axial side surface, the inner peripheral surface, the inside, etc.

[0147] 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. In addition, the heating element and the cooling medium may also be arranged side by side in either the support table side member 61 or the bearing housing side member 62.

[0148] Other structures and functions are the same as those of the first embodiment.

[0149] (Fifth Embodiment)

[0150] Next, refer to Fig.10A ball screw feed device according to a fifth embodiment of the present invention will be described. In addition, in the present embodiment, the second support mechanism 40 further has another housing position adjustment mechanism 160, which is different from the first embodiment in this respect.

[0151] That is, in the second support mechanism 40 of the fifth embodiment, another housing position adjustment mechanism 160 is further provided, which is disposed adjacent to the housing position adjustment mechanism 60 between the bearing unit 41 and the support table 43.

[0152] 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 move relative to the other support table side member 161 in the axial direction; and working oil 70 as another working fluid, which is filled in a pressure chamber 166 formed between the other support table side member 161 and the other bearing housing side member 162 in a compressed state; and a disc spring 80 as another elastic member, which is disposed in the pressure chamber 166 in a compressed state between the opposed axial end faces of the other support table side member 161 and the other bearing housing side member 162. That is, the second support mechanism 40 has two housing position adjustment mechanisms 60 and 160 with a series structure arranged in series in the axial direction.

[0153] As Fig.10 shown, in 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 fitted in the annular recess 164 so as to be able to slide in the axial direction, and the working oil 70 is filled in the pressure chamber 166 formed between the annular recess 164 and the annular protrusion 165 in a compressed state.

[0154] In addition, in the present embodiment, a circular ring portion 161a protruding toward the support table 43 side of the other support table side member 161 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). And 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 formed of one member or are integrally formed by connecting the two.

[0155] In this way, by arranging the two housing position adjustment mechanisms 60 and 160 in series in the axial direction, 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 axial centering property and coaxiality can be improved.

[0156] In addition, the other housing position adjustment mechanism 160 is not limited to Fig.10 The same structure as the housing position adjustment mechanism 60 as shown may also be other structures as long as it has a pressure generating unit housed in a compressed state in the 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, only working oil or only an elastic member may be disposed in the pressure chamber 166.

[0157] 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 structure is such that a plurality of housing position adjustment mechanisms are arranged in series along the axial direction.

[0158] Other structures and operations are the same as those of the first embodiment.

[0159] In addition, in the first to fifth embodiments, a pair of angular contact ball bearings of the bearing unit applicable 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 Fig.11 the back-to-back combination as shown, Fig.12 the side-by-side combination as shown, etc. in various support modes. In addition, as shown in Fig.11 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 angular contact ball bearing 53 on the axially inner side.

[0160] 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 modes such as back-to-back combination and side-by-side combination.

[0161] In addition, although not shown, the angular contact ball bearings 33, 53 do not necessarily consist of two angular contact ball bearings and may also consist of three or more angular contact ball bearings.

[0162] Moreover, in the above embodiments, 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 this is not limited thereto, and a structure in which they are arranged adjacent to each other in the radial direction and in parallel with the housing position adjustment mechanism 60 may also be adopted.

[0163] Thereby, the axial dimension of the ball screw feed device 20 can be suppressed, and the axial rigidity of the ball screw feed device 20 can be maintained in a state where an axial load larger than that when a single housing position adjustment mechanism is arranged is generated.

[0164] In addition, in the above-described embodiment, the annular recess is provided in the bearing housing side member, and the annular protrusion is provided in the support base side member. However, the present invention is not limited thereto, and the annular recess may be provided in the support base side member, and the annular protrusion may be provided in the bearing housing side member.

[0165] Moreover, although in the above-described embodiment, the pressure chamber 66 is formed in an annular shape by the annular recess 64 and the annular protrusion 65, a plurality of recesses and protrusions may be formed in the circumferential direction to form a plurality of pressure chambers. In this case, it may be configured such that working oil and elastic members are respectively arranged in the plurality of pressure chambers. In addition, an O-ring may be arranged between the inner circumferential surface of the recess and the outer circumferential surface of the protrusion, which has the functions of preventing leakage and damping of the working oil. Alternatively, it may be configured to provide a storage chamber opening to the outer circumferential surface of the protrusion and a damping hole communicating the storage chamber with the pressure chamber, which has an additional damping function.

[0166] For example, as shown in Fig.13 (a), the pressure chambers 66 at four positions are arranged around the lead screw shaft 21 in the circumferential direction. Alternatively, as shown in Fig.13 (b), two pressure chambers 66 connected in parallel adjacent to each other in the radial direction are provided at four positions in the circumferential direction, that is, a total of eight pressure chambers 66 are arranged around the lead screw shaft 21. Or, as shown in Fig.14 (a), the pressure chambers 66 at two positions in the circumferential direction, that is, the pressure chambers 66 located on both sides in the width direction (Y direction) with respect to the lead screw shaft 21, are arranged around the lead screw shaft 21. Alternatively, as shown in Fig.14 (b), three pressure chambers 66 arranged adjacent to each other in the radial direction (in this example, the width direction) are provided at two positions in the circumferential direction, that is, a total of six pressure chambers 66 are arranged around the lead screw shaft 21. In this case, the height dimensions of the support base side member 61 and the bearing housing side member 62 can be suppressed.

[0167] And, as shown in Fig.15 , the pressure chambers 66 at two positions in the circumferential direction, that is, the pressure chambers 66 located on both the upper and lower sides with respect to the lead screw shaft 21, may be arranged around the lead screw shaft 21. In this case, the width dimensions of the support base side member 61 and the bearing housing side member 62 can be suppressed.

[0168] Here, Fig.16 is a schematic cross-sectional view along the XVI-XVI line of Fig.14 (a). In this case, the pressure chambers 66 at two positions are respectively constituted by the recess 64x and the protrusion 65x.

[0169] In addition, in the figure, the protrusion 65x is integrally formed with the base of the support base side member 61, but it may be formed separately from the base and combined.

[0170] It should be noted that for multiple pressure chambers 66, as long as 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, any configuration is acceptable. Specifically, it is preferably arranged point-symmetrically or line-symmetrically in a plane orthogonal to the lead screw shaft 21. In addition, the multiple pressure chambers 66 can also be arranged with an offset in the axial direction.

[0171] Furthermore, adjacent pressure chambers 66 can be connected via a communication path as needed for purposes such as pressure equalization, and the working fluid inside can also flow between adjacent pressure chambers 66.

[0172] For example, in Fig.14 the (b) of Fig.15 adjacent pressure chambers 66 are connected to each other via a communication path 66x.

[0173] In addition, the support table side member 61 and the bearing housing side member 62 are not limited to being composed of a single component, and can also be divided and configured in a manner of surrounding the lead screw shaft 21 according to the layout of the pressure chambers 66. Moreover, the support table side member 61 and the bearing housing side member 62 as single components can also be configured to surround the lead screw shaft 21 and have a part of the circumference open and divided.

[0174] For example, in Fig.14 the (b) of

[0175] two support table side members 61 and bearing housing side members 62 are configured to be divided in the width direction with respect to the lead screw shaft 21.

[0176] In addition, similar to the above-mentioned another housing position adjustment mechanism 160, the pressure generating units in the multiple pressure chambers 66 are not limited to all having the same structure, that is, not limited to the structure having a working fluid and an elastic member. The pressure generating unit in any one of the pressure chambers 66 can also be other structures such as only using a working fluid or only using an elastic member.

[0177] (Sixth Embodiment)

[0178] In the housing position adjustment mechanism 60 of the above-mentioned embodiments and modification examples, when the lead screw shaft 21 elongates axially, the volume of the pressure chamber 66 becomes larger, and the working oil 70 and the disc spring 80 in the compressed state press the bearing unit 41 and the bearing housing side member 62 to the left while gradually decreasing the pressure. Thereby, the pair of angular contact ball bearings 53, 53 move axially, so as to maintain the axial support rigidity of the lead screw shaft 21.

[0179] However, in the sixth embodiment, the Fig.17 housing position adjustment mechanism 60 shown is used to maintain the axial support rigidity of the lead screw shaft 21. Specifically, when the lead screw shaft 21 elongates axially, the bearing unit 41 and the bearing housing side member 62 move leftward via a 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 becomes smaller. On the other hand, when the pressure generated by the working oil 70 and the disc spring 80 gradually rises, the bearing unit 41 and the bearing housing side member 62 are pressed rightward. Therefore, by adjusting the volume of the pressure chamber 66 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.

[0180] In this case, the support base 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 base 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 base 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.

[0181] The outer flange portion 61d of the support base 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 base 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 defined by the small-diameter cylindrical portion 61c and the outer flange portion 61d of the support base side member 61, and the large-diameter cylindrical portion 62c and the inner flange portion 62d of the bearing housing side member 62, and the working oil 70 and the disc spring 80 are filled in the pressure chamber 66 in a slightly compressed state.

[0182] In addition, in this case, the working oil 70 is also appropriately selected so that even when the temperature rise is more than 4 degrees and the pressure chamber 66 narrows axially according to the axial elongation of the lead screw shaft 21, the desired axial rigidity can be imparted to the lead screw shaft 21 by the pressure acting on the bearing housing side member 62.

[0183] Moreover, a plurality of disc springs 80 having a spring constant are used such that even when the temperature rise of the ball screw feed device 20 is more than 4 degrees and the plurality of disc springs 80 are compressed, the plurality of disc springs 80 share the load with the working oil 70 and comprehensively impart a desired axial rigidity to the screw shaft 21 over a long distance in the axial direction.

[0184] By forming the pressure chamber 66 in this way, when the 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 move leftward in the figure while compressing the working oil 70 and the disc springs 80 in the pressure chamber 66, thereby enabling the axial support rigidity of the screw shaft 21 to be maintained.

[0185] In addition, O-rings 67 are installed 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, thereby preventing the working oil 70 filled in the pressure chamber 66 from leaking. In addition, it also functions as a damping mechanism and can attenuate the vibration generated in the screw shaft 21.

[0186] Moreover, the working oil 70 in a compressed state is stored in the respective gaps 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. Therefore, the radial support rigidity and the centering property between the bearing housing side member 62 and the support table side member 61 can be improved by the radial pressure of the working oil 70 acting on the respective gaps. As a result, the housing position adjustment mechanism 60 can impart radial support rigidity to the screw shaft 21 and also has a centering function for the screw shaft 21.

[0187] In addition, the support table side member 61 and the bearing housing side member 62 may each be composed of a single member, but as Fig.17 shown, considering the assemblability, they may also be composed of two members 91, 92, 93, 94 in a state of sandwiching the O-ring 67.

[0188] In addition, one O-ring 67 and one sealing groove 68 are respectively arranged between the respective opposing surfaces, but multiple ones may also be arranged.

[0189] In addition, instead of Fig.17 , the support table side member 61 may have a large-diameter cylindrical portion and an inward flange portion, and the bearing housing side member 62 may have a small-diameter cylindrical portion and an outward flange portion to form a pressure chamber.

[0191] Moreover, as Fig.18As shown, such a housing position adjustment mechanism 60 may also be configured such that a storage chamber 71 and a damping hole 72 are provided in the outward flange portion 61d. Similar to the second embodiment, the working fluid 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, thereby having the function of attenuating the vibration of the lead screw shaft 21.

[0192] Alternatively, the storage chamber and the damping hole may be formed in the inward flange portion 62d, and the storage chamber may also open to the outer peripheral surface of the small-diameter cylindrical portion 61c.

[0193] In addition, in such a housing position adjustment mechanism 60, a pair of angular contact ball bearings 53, 53 may be arranged in a Fig.17 and Fig.18 front combination configuration as shown, or may be arranged in a Fig.19 and Fig. 20 back combination configuration as shown, or may be arranged in various support forms such as a side-by-side combination. In addition, although not shown, the pair of angular contact ball bearings do not necessarily consist of two angular contact ball bearings, and may also be composed of three or more ball bearings.

[0194] Moreover, as shown in Fig.21 and Fig. 22 , the housing position adjustment mechanism 60 of the sixth embodiment is the same as that of the third embodiment, and 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 may also be 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, 69c extending radially from the axial end edges of the tapered surface 69a.

[0195] Therefore, as the pressure of the working oil 70 in the pressure chamber 66 increases, the O-ring 67 is pressed toward the atmospheric pressure side. The O-ring 67 further improves the sealing performance through 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 and the inner peripheral surface of the large-diameter cylindrical portion 62c. As a result, even when relative movement occurs between the support base 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, thereby continuously maintaining the axial rigidity of the ball screw feed device 20.

[0196] In addition, in this modification, as shown in Fig. 22 , the sealing groove 68 formed on either of the opposed surfaces of the two members 91, 92 constituting the support base side member 61, and the sealing groove 68 formed on either of the opposed surfaces of the two members 93, 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.

[0197] In addition, in the case of this modification example, a wear-resistant member may be interposed between at least one of the inner circumferential surface of the O-ring 67 and the inward flange portion 62d and the outer circumferential surface of the small-diameter cylindrical portion 61c, and between at least one of the outer circumferential surface of the O-ring 67 and the outward flange portion 61d and the inner circumferential surface of the large-diameter cylindrical portion 62c.

[0198] In this case, the wear-resistant member 59 may also be interposed between the O-ring 67 and the opposing surface opposed to the O-ring 67 in the sealing groove 68 having the tapered surface 69a as shown in Fig. 22 or may be interposed between the O-ring 67 and the opposing surface opposed to the O-ring 67 in the sealing groove 68 having a uniform groove depth as shown in Fig.17

[0199] And, as shown in Fig.23 the housing position adjustment mechanism 60 of the sixth embodiment may be the same as that of the fourth embodiment, and working fluid volume change portions such as heating elements 180 and 181 and cooling media 182 and 183 may be provided in the support table side member 61 and the bearing housing side member 62.

[0200] Thus, as described in the fourth embodiment, according to the state of the ball screw feed device 20 used, the volume of the working oil 70 in the pressure chamber 66 is expanded by the heating elements 180 and 181, or the volume of the working oil 70 in the pressure chamber 66 is contracted by the cooling media 182 and 183, so that the axial support rigidity can be continuously maintained in a stable state.

[0201] In addition, in the housing position adjustment mechanism 60 of the sixth embodiment, as shown in Fig.24 the second support mechanism 40 may be formed in a series structure in which the housing position adjustment mechanism 60 and another housing position adjustment mechanism 160 are arranged in series in the axial direction between the bearing unit 41 and the support table 43, which is the same as that of the fifth embodiment.

[0202] In this case, the other support table side member 161 of the other housing position adjustment mechanism 160 also has an annular base portion 161b, a small-diameter cylindrical portion 161c, and an outward flange portion 161d, and the other bearing housing side member 162 of the other housing position adjustment mechanism 160 also has an annular base portion 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 body.

[0203] ​In addition, similar to the fifth embodiment, the second support mechanism 40 may be configured such that a plurality of housing position adjustment mechanisms are arranged in series along the axial direction, or may be configured in parallel along the radial direction.

[0204] Furthermore, the present invention is not limited to the above-described embodiments, and can be appropriately deformed, improved, etc. In addition, the embodiments and modification examples described in this specification can be combined and applied within the scope where they can be implemented.

[0205] For example, in the above-described pressure chamber, an auxiliary energy storage device and an external pump for supplying working oil can also be connected as needed. Also, 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 and the loads applied to the pair of angular contact bearings 53, 53.

[0206] In addition, in the above-described embodiment, a disc spring is used as the elastic member, but it is not limited thereto, and a helical spring may also be used.

[0207] In addition, in the first to fifth embodiments, an O-ring 67 is installed between the outer-facing surface 65a of the annular convex portion 65 and the inner-facing surface 64a of the annular concave portion 64, and between the inner-facing surface 65b of the annular convex portion 65 and the outer-facing surface 64b of the annular concave portion 64. However, it is not limited thereto, and as long as a sealing member for preventing the working oil 70 from leaking from the pressure chamber 66 is arranged.

[0208] Similarly, in the sixth embodiment, an O-ring 67 is 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, it is not limited thereto, and as long as a sealing member for preventing the working oil 70 from leaking from the pressure chamber 66 is arranged.

[0209] Moreover, more preferably, the sealing member not only prevents the working oil 70 from leaking from the pressure chamber 66, but also attenuates the vibration of the lead screw shaft 21 in the same manner as the O-ring 67.

[0210] In addition, in any of the embodiments, it is necessary to seal from the outside after the working oil 70 is filled in the pressure chamber 66. At this time, for example, in Figure 2 the housing position adjustment mechanism 60 shown, as Fig.25 shown in (a), an oil supply passage 109 for filling the working oil 70 into the pressure chamber 66 can be formed in the bearing housing side member 62 so as to penetrate radially between the inner-facing surface 64a of the annular concave portion 64 and the outer peripheral surface of the bearing housing side member 62.

[0211] Further, a fixing bolt 110 that is screwed into an internal thread portion 109a formed in the oil supply passage 109 may be installed on the outer peripheral surface of the bearing housing side member 62 to block the oil supply passage 109. Additionally, by winding a sealing tape (not shown), applying, or filling a leak-preventing agent, etc. around the external thread portion of the fixing bolt 110, the gap between the external thread and the internal thread portion 109a is filled, thereby enabling more reliable prevention of leakage of the hydraulic oil 70 filled in a compressed state.

[0212] Alternatively, an annular sealing groove 110a may be formed on the opposing surface of the head of the fixing bolt 110 that faces the outer peripheral surface of the bearing housing side member 62. Thereby, an O-ring 111 is installed in the sealing groove 110a, and the sealing performance of the fixing bolt 110 can be improved.

[0213] In addition, as shown in Fig.26 (b) thereof, the bottom surface of the sealing groove 110a of the fixing bolt 110 may also be formed in a conical shape to further improve the sealing performance.

[0214] Alternatively, as a component for blocking the oil supply passage 109, a fixing plug may be used instead of the fixing bolt 110. For example, as shown in Fig.26 (a) thereof, the oil supply passage 109 may be blocked by a conical fixing plug 112. In this case, the fixing plug 112 is screwed into an internal thread portion 109a formed on the outer diameter side of the oil supply passage 109 and fixed to the oil supply passage 109. Additionally, as shown in Fig.26 (b) thereof, the oil supply passage 109 has a conical internal thread portion 109a on the outer diameter side, and a straight portion 109b without an internal thread is continuous with the internal thread portion 109a via a stepped hole 109c. At this time, the fixing plug 112 may also be fastened to the internal thread portion 109a in a state where a disc-shaped member 113 is housed in the stepped hole 109c. In this case, the fixing plug 112 fastens to the internal thread portion 109a while deforming the disc-shaped member 113, so sealing performance is ensured between the contact surface of the disc-shaped member 113 and the stepped hole 109c.

[0215] Alternatively, a sealing tape (not shown) may also be wound around the external thread portion of the fixing plug 112, or the gap between the external thread and the internal thread portion 109a may be filled by coating or filling a leak-preventing agent, etc., thereby imparting good sealing performance.

[0216] In addition, as shown in Fig.26 (c) thereof, the disc-shaped member 113 may also be integrated with an elastic deformation member 114 that constitutes the contact surface in contact with the stepped hole 109c. Alternatively, as shown in Fig.26 (d) thereof, the disc-shaped member 113 may form an annular sealing groove 113a on the contact surface in contact with the stepped hole 109c and dispose an O-ring 115.

[0217] In addition, the oil supply passage 109 communicating with the pressure chamber 66 is not limited to a structure formed by penetrating in the radial direction, and may also be formed by penetrating any component constituting the pressure chamber 66 in the axial direction.

[0218] Furthermore, the support table only needs to be a structure that directly or indirectly supports the support table side component of the housing position adjustment mechanism, and is not limited to a structure penetrated by the rotating shaft as in the above-described embodiment. It may also be a structure arranged around the rotating shaft and can be designed in any shape.

[0219] (Applied to another ball screw feeding device)

[0220] In addition, in Figure 1 the ball screw feeding device 20, the drive motor 12 is connected to one side ( Figure 1 the right side in Fig. 27 ) of the screw shaft 21 supported by the first support mechanism 30, but the present invention is not limited thereto. That is, it may also be like Fig. 27 the ball screw feeding device 20 in

[0221] wherein the drive motor 12 is connected to the other side (

[0222] the left side in

[0223] For example, in Fig.28 and Fig.29 ) of the screw shaft 21 supported by the second support mechanism 40. In this case, the drive motor 12 is fixed to the base 1 and supported by another support table 85 penetrated by the screw shaft 21. In addition, the tip of the small-diameter shaft portion 27 is disposed separately from the rotating shaft 12a of the drive motor 12 within the coupling 28 so that the small-diameter shaft portion 27 can move axially when the screw shaft 21 expands axially due to thermal expansion. Therefore, the present invention can be used with high degrees of freedom, for example, as a ball screw feeding device used for positioning purposes in devices such as machine tools (machining centers, lathes, grinding machines, etc.), measuring machines (three-dimensional measuring devices), semiconductor manufacturing devices (stages for exposure devices, inspection probes, etc.), inspection devices, etc. that perform high-precision machining and measurement, and in semiconductor manufacturing.

[0222] 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 or the axially end side with respect to the bearing unit 41 according to the structure and function of the housing position adjustment mechanism 60.

[0223] For example, in Fig.28 and Fig.29In the manner shown, the support table 43 is provided at a position on the axial 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. Further, 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.

[0224] Further, in Fig.30 and Fig.31 In the manner shown, the support table 43 is disposed at a position on the axial 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 axial center side with respect to the bearing unit 41 by the outer cylinder portion 43b. The outer cylinder portion 43b extends axially from the main body portion having the through hole 43a and surrounds the periphery of the housing position adjustment mechanism 60. Also 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. Further, 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.

[0225] (Applications other than ball screw feed devices)

[0226] Further, in the above-described embodiment, the ball screw feed device has been described. However, the present invention can be applied not only to the ball screw feed device but also to a rotary support device that rotatably supports both axial end portions of a rotary shaft by a pair of support mechanisms. That is, in the case where the axial length of the rotary shaft changes due to the influence of heat, it can be configured to use the housing position adjustment mechanism as in the above-described embodiment to continuously and stably maintain the axial support rigidity of the rotary shaft. Further, by using the housing position adjustment mechanism of the above-described embodiment, vibration in the axial and radial directions can be attenuated.

[0227] For example, as Fig.32 shown, the rotary support device 120 includes a rotary shaft 121 and a pair of support mechanisms 30, 40 that rotatably support both axial end portions of the rotary shaft 121.

[0228] The support mechanism 30 includes: a bearing housing 31 fixed to the base 1; and bearings 33, 33 that rotatably support the rotary 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.

[0229] In addition, the support mechanism 40 includes: a bearing unit 41 having a bearing housing 51 and bearings 53, 53 that rotatably support the rotating shaft 121 relative to the bearing housing 51 and can support axial loads, i.e., a pair of angular contact ball bearings 53, 53 arranged in a face-to-face combination; a support table 43 disposed on the axially central side of 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.

[0230] 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 and capable of relatively moving axially with respect to the support table side member 61; a working oil (a working fluid having compression characteristics) 70 filled in a pressure chamber 66 formed between the support table side member 61 and the bearing housing side member 62; and a disc spring (elastic member) 80 disposed in a compressed state in the pressure chamber 66 between the opposed axial end faces of the support table side member 61 and the bearing housing side member 62.

[0231] In addition, in Fig.32 parts marked with the same reference numerals as those in the above-described embodiments are substantially the same, so the description thereof is omitted or simplified. In addition, various structures described in the ball screw feed device 20 can also be applied to the rotary support device and have the same effects.

[0232] In addition, each of the bearings 33, 53 of the support mechanisms 30, 40 of the rotary support device 120 described above may be an angular contact ball bearing as in the above-described embodiment, but is not limited thereto, and may also be a roller bearing or a sliding bearing capable of supporting axial loads. By using such bearings capable of supporting axial loads, particularly in the support mechanism 40, the working oil 70 and the elastic member 80 can be compressed via the bearings by tightening the fastening nut 38b as in the above-described embodiment.

[0233] In addition, in Fig.32 it is configured such that the second support mechanism 40 having the housing position adjustment mechanism 60 supports the end portion of the rotating shaft 121, but as Fig.33 shown, it may also be configured such that the second support mechanism 40 having the housing position adjustment mechanism 60 supports the rotating shaft 121 at a position closer to another support table 85 of the support drive motor 12.

[0234] For example, when Fig.33In the case where the rotary support device 120 shown is applied to a spindle device that rotates a tool in a machine tool, by mounting a tool at the end of the rotary shaft 121 supported by the support mechanism 30, it is possible to continuously and stably maintain the support rigidity in the axial direction of the rotary shaft 121, and reliably perform axial positioning of the tool, enabling high-precision machining.

[0235] In addition, in Fig.32 and Fig.33 in the rotary support device 120 shown, the drive motor 12 does not necessarily need to be arranged coaxially 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.

[0236] In addition, the drive motor 12 is not limited to a separate motor arranged coaxially with the rotary shaft 121. For example, a built-in motor can also be directly formed on the rotary shaft 121.

[0237] Furthermore, for the rotary support device 120, as the support body, it can also be a housing shell formed by integrating the bearing housing 31 of the first support mechanism 30 and the support table 43 of the second support mechanism 40.

[0238] In addition, in a rotary support device other than a ball screw feed device, as Figure 28 to Figure 31 shown, the support table can also be arranged on the axial end side with respect to the bearing unit.

[0239] In addition, in the above-described embodiment, 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 rotary shaft, but the present invention is not limited thereto, and it can be applied as a support mechanism position adjustment mechanism of a shaft support device. That is, the shaft is not limited to a rotary shaft, and in addition, the support mechanism is not limited to a structure having a bearing. The shaft support device only needs to have the following structure: having 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 having a support body (for example, the support table 43 in the above-described embodiment) through which the shaft passes or is arranged around the shaft.

[0240] Therefore, as the support mechanism position adjustment mechanism of the shaft support device, it is sufficient to have the following structure, which includes: a first component (for example, the support table side component 61 in the above embodiment), 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; a second component (for example, the bearing housing side component 62 in the above embodiment), 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, can move relatively axially with respect to the first component, and forms a receiving space (for example, the pressure chamber 66 in the above embodiment) between the second component and the first component; a working fluid, which is filled in the receiving space; and an elastic component, which is arranged in the receiving space in a compressed state between the opposing axial end faces of the first component and the second component.

[0241] The support mechanism position adjustment mechanism of such a shaft support device can apply the structure of the housing position adjustment mechanism described in the ball screw feed device 20 and achieve the same effect.

[0242] For example, Fig.34 and Fig.35 The rigid joint structure 200 as a shaft support device is shown, in which a support mechanism position adjustment mechanism is provided in one of a pair of support mechanisms for supporting the shaft. The rigid joint structure 200 includes two steel support bodies 231 and 243 that are vertically erected and fixed relative 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, and a shaft 221 constituting a beam member is inserted therethrough. In addition, the support bodies 231 and 243 can be columns, beams, support plates, etc., as long as they are composed of components of any shape and material that can support the shaft.

[0243] It should be noted that in this example, one end portion of the shaft 221 is positioned and fixed to the support body 231 by another support mechanism in which the flange portion 226 on the axial one end side of the shaft 221 abuts against the small-diameter step portion 231b of the through hole 231a of the support body 231 and a gland 232 is installed on the large-diameter step portion 231c of the through hole 231a.

[0244] In addition, the other axial end portion of the shaft 221 is inserted through the through hole 243a of the support body 243, protrudes to 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 adjustment mechanism 260 that constitute one support mechanism.

[0245] The cross-sectional shape of the central portion of the shaft 221 can be arbitrary and can be composed of a square steel pipe, an H-shaped steel, etc.

[0246] 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 side end portions thereof are clamped and integrated by the housing 251 and the pressing member 247 fixed to the housing 251.

[0247] In addition, similar to the above-described embodiment, the housing 251 is mounted on the support 243 via the support mechanism position adjustment mechanism 260. That is, the first member 261 corresponding to the support table side member 61 of the above-described embodiment is fitted into the through-hole 243a of the support 243 and fixed to the support 243, and the second member 262 corresponding to the bearing housing side member 62 of the above-described embodiment is fitted into the inward flange 251a of the housing 251 and fixed to the housing 251.

[0248] Therefore, when the shaft guiding member 250 is fastened by the fastening nut 38b screwed with the external thread 225a via the spacer 48, a reaction force acts on the shaft guiding member 250 to cause the shaft guiding member 250 to bear an axial load. Therefore, a predetermined rigidity is imparted between the supports 231 and 243 and the shaft 221.

[0249] In addition, in such a rigid joint structure 200, even when the shaft 221 undergoes axial elongation, the support mechanism position adjustment mechanism 260 also functions to follow the axial elongation of the shaft 221 and move 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 structure 200 can be maintained.

[0250] In addition, in this example, the housing 251 and the second member 262 of the support mechanism position adjustment mechanism 260 may be integrally formed, and the shaft guiding member 250 may be disposed with respect to the integrated member. Alternatively, 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 adjustment mechanism 260.

[0251] In addition, the shaft support device is not limited to the rigid joint structure as in this example, and may be a support structure in which the support mechanisms on the shaft side and the support side are pin joints. In this case, the shaft 221 may also be disposed obliquely according to the structure of the support structure.

[0252] Moreover, in a shaft support device such as a rigid body structure, the structure may be such that both support mechanisms have a support mechanism position adjustment mechanism.

[0253] As described above, the following matters are disclosed in this specification.

[0254] (A1)A ball screw feed device includes: 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 respectively rotatably support both axial ends of the screw shaft.

[0255] One of the pair of support mechanisms includes:

[0256] A bearing unit having a bearing housing; and an angular contact ball bearing having an outer ring embedded in the bearing housing, an inner ring fitted on the axial end of the screw shaft, and balls rotatably disposed between the outer ring and the inner ring.

[0257] A support table disposed at a position closer to the axial center than the bearing unit and penetrated by the screw shaft; and

[0258] A housing position adjustment mechanism disposed between the bearing unit and the support table.

[0259] The housing position adjustment mechanism includes:

[0260] A support table side member disposed on the support table side and penetrated by the screw shaft;

[0261] A bearing housing side member disposed on the bearing housing side, penetrated by the screw shaft, and capable of relatively moving axially with respect to the support table side member; and

[0262] A working fluid filled in a pressure chamber formed between the support table side member and the bearing housing side member; and

[0263] An elastic member disposed in a compressed state in the pressure chamber between the opposed axial end faces of the support table side member and the bearing housing side member.

[0264] According to this structure, 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 vibrations in the axial and radial directions can be attenuated.

[0265] (A2)According to the ball screw feed device described in (A1),

[0266] One of the support table side member and the bearing housing side member has an annular recess opening to one axial side,

[0267] The other of the support table side member and the bearing housing side member has an annular protrusion protruding toward the other axial side and fitting into the annular recess in a slidable manner along the axial direction.

[0268] The pressure chamber is formed between the annular concave portion and the annular convex portion.

[0269] According to this structure, since the pressure chamber is formed between the annular concave portion and the annular convex portion, the housing position adjustment mechanism can be compactly constituted around the lead screw shaft.

[0270] (A3) The ball screw feed device according to (A2), wherein

[0271] At least one sealing member is installed between the inner-facing surface of the annular concave portion and the outer-facing surface of the annular convex portion, and between the outer-facing surface of the annular concave portion and the inner-facing surface of the annular convex portion.

[0272] According to this structure, the working fluid filled in the pressure 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.

[0273] (A4) The ball screw feed device according to (A2) or (A3), wherein

[0274] The working fluid is stored in each gap between the inner-facing surface of the annular concave portion and the outer-facing surface of the annular convex portion, and between the outer-facing surface of the annular concave portion and the inner-facing surface of the annular convex portion.

[0275] According to this structure, the housing position adjustment mechanism can impart radial support rigidity to the lead screw shaft, and can also have a centering function for the lead screw shaft.

[0276] (A5) The ball screw feed device according to (A2) or (A3), wherein

[0277] The housing position adjustment mechanism includes: a storage chamber formed in the annular convex portion so as to open to the outer-facing surface or the inner-facing surface of the annular convex portion and storing the working fluid; and a damping hole formed in the annular convex portion so as to communicate the storage chamber with the pressure chamber.

[0278] According to this structure, the working fluid in the pressure chamber and the storage chamber passes through the damping hole and the gap between the outer-facing surface of the annular convex portion and the inner-facing surface of the annular concave portion, whereby its vibration can be attenuated.

[0279] (A6) The ball screw feed device according to any one of (A1) to (A5), wherein

[0280] The elastic member is a disc spring having a plurality of through holes or a plurality of slits penetrating in the axial direction in a conical plate portion.

[0281] According to this structure, the working fluid flows through a plurality of through holes or a plurality of slits, thereby being able to exert a damping effect.

[0282] (A7) The ball screw feed device according to (A3), wherein

[0283] the sealing member is an O-ring,

[0284] sealing grooves for arranging the O-ring are respectively formed on the inner-facing surface of the annular concave portion or the outer-facing surface of the annular convex portion, and the outer-facing surface of the annular concave portion or the inner-facing surface of the annular convex portion.

[0285] The sealing groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side.

[0286] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and can damp the vibration generated in the lead screw shaft. In addition, even when relative movement occurs between the support table side member and the bearing housing side member, it is possible to prevent the working oil from leaking to the atmospheric pressure side, thereby continuously maintaining the axial rigidity of the ball screw feed device.

[0287] (A8) The ball screw feed device according to (A3) or (A7), wherein

[0288] the sealing member is an O-ring,

[0289] a wear-resistant member is interposed between at least one of the inner-facing surface of the annular concave portion and the outer-facing surface of the annular convex portion and the O-ring, and between at least one of the outer-facing surface of the annular concave portion and the inner-facing surface of the annular convex portion and the O-ring.

[0290] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and can damp the vibration generated in the lead screw shaft. In addition, it is possible to disperse the stress concentration applied to the O-ring and suppress damage such as wear of the O-ring and the contact surface in contact with the O-ring.

[0291] (A9) The ball screw feed device according to (A1), wherein

[0292] one of the support table side member and the bearing housing side member has: a small-diameter cylindrical portion extending axially in one direction; and an outward flange portion extending radially outward from the tip of the small-diameter cylindrical portion.

[0293] The other of the support table side member and the bearing housing side member has: a large-diameter cylindrical portion that extends toward the other axial side and has an inner peripheral surface that slidably contacts the outer peripheral surface of the outward flange portion; and an inward flange portion that extends from the tip portion of the large-diameter cylindrical portion toward the inner diameter side and has an inner peripheral surface that slidably contacts the outer peripheral surface of the small-diameter cylindrical portion.

[0294] The pressure chamber is formed in an annular space defined by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion.

[0295] With this structure, 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.

[0296] (A10) The ball screw feed device according to (A9), wherein

[0297] At least one sealing member for preventing leakage of the working fluid filled in the pressure chamber is respectively assembled 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.

[0298] With this structure, it is possible to prevent the working fluid filled in the pressure chamber from leaking by means of the sealing member, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0299] (A11) The ball screw feed device according to (A9) or (A10), wherein

[0300] 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.

[0301] With this structure, the housing position adjustment mechanism can impart radial support rigidity to the lead screw shaft, and can also have a centering function for the lead screw shaft.

[0302] (A12) The ball screw feed device according to (A9) or (A10), wherein

[0303] The housing position adjustment mechanism includes: a storage chamber that 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 and stores the working fluid; and a damping hole that is formed in the outward flange portion or the inward flange portion so as to communicate the storage chamber with the pressure chamber.

[0304] According to this structure, the working fluid in the pressure chamber and the storage chamber can have its vibration attenuated 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 between the outer peripheral surface of the small-diameter cylindrical portion and the inner peripheral surface of the inward flange portion.

[0305] (A13) The ball screw feed device according to (A10), wherein,

[0306] The sealing member is an O-ring,

[0307] 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.

[0308] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0309] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and can attenuate the vibration generated in the screw shaft. In addition, even when relative movement occurs between the support table side component and the bearing housing side component, it can prevent the working oil from leaking to the atmospheric pressure side, thereby continuously maintaining the axial rigidity of the ball screw feed device.

[0310] (A14) The ball screw feed device according to (A10), wherein,

[0311] The sealing member is an O-ring,

[0312] 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.

[0313] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and can attenuate the vibration generated in the screw shaft. In addition, it can disperse the stress concentration applied to the O-ring, and suppress damages such as wear of the O-ring and the contact surface in contact with the O-ring.

[0314] (A15) The ball screw feed device according to (A1), wherein,

[0315] A working fluid volume changing portion is installed on at least one of the support table side component and the bearing housing side component, and the working fluid volume changing portion changes the volume of the working fluid by heating or cooling the working fluid.

[0316] According to this structure, by heating or cooling the working fluid to cause the volume of the working fluid to expand or contract, the axial support rigidity can be continuously maintained in a stable state.

[0317] (A16) The ball screw feed device according to (A1), wherein

[0318] One of the pair of support mechanisms further includes another housing position adjustment mechanism, and the another housing position adjustment mechanism is arranged in series or in parallel adjacent to the housing position adjustment mechanism between the bearing unit and the support table.

[0319] The another housing position adjustment mechanism includes:

[0320] Another support table side member, which is arranged on the support table side and is penetrated by the lead screw shaft;

[0321] Another bearing housing side member, which is arranged on the bearing housing side and is penetrated by the lead screw shaft, and can move relative to the another support table side member in the axial direction; and

[0322] A pressure generating unit, which 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.

[0323] According to this structure, in the case of series arrangement, even when the elongation of the lead screw shaft is larger, the axial rigidity of the ball screw feed device can be maintained. In addition, the centering and coaxiality of the lead screw shaft can be improved. Further, in the case of parallel arrangement, an axial load larger than that when a single housing position adjustment mechanism is arranged can be generated, and the axial rigidity can be maintained.

[0324] (A17) A ball screw feed device, wherein

[0325] It includes: a lead 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 rollably disposed between the thread groove of the lead screw shaft and the thread groove of the nut; and a pair of support mechanisms respectively rotatably supporting the axial ends of the lead screw shaft.

[0326] One of the pair of support mechanisms includes:

[0327] A bearing unit having a bearing housing; and an angular contact ball bearing respectively having an outer ring embedded in the bearing housing, an inner ring externally fitted to the axial end of the lead screw shaft, and balls rollably disposed between the outer ring and the inner ring;

[0328] A support table penetrated by the lead screw shaft; and

[0329] A housing position adjustment mechanism is installed on the bearing unit and the support table.

[0330] The housing position adjustment mechanism includes:

[0331] A support table side member is installed on the support table and penetrated by the lead screw shaft;

[0332] A bearing housing side member is installed on the bearing housing, penetrated by the lead screw shaft, and can move relatively axially with respect to the support table side member;

[0333] A working fluid is filled in a pressure chamber formed between the support table side member and the bearing housing side member; and

[0334] An elastic member is disposed in a compressed state in the pressure chamber between the opposing axial end faces of the support table side member and the bearing housing side member.

[0335] According to this structure, 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, and the vibration in the axial and radial directions can be attenuated.

[0336] (A18) A rotary support device, wherein,

[0337] It includes: a rotating shaft; and a pair of support mechanisms that respectively support the axial end portions of the rotating shaft rotatably.

[0338] One of the pair of support mechanisms includes:

[0339] A bearing unit that includes a bearing housing and a bearing, and can support the rotating shaft rotatably with respect to the bearing housing and can support an axial load;

[0340] A support table is disposed at a position axially central to the bearing unit and penetrated by the rotating shaft; and

[0341] A housing position adjustment mechanism is disposed between the bearing unit and the support table.

[0342] The housing position adjustment mechanism includes:

[0343] A support table side member is provided on the support table side and penetrated by the rotating shaft;

[0344] A bearing housing side member is provided on the bearing housing side, penetrated by the rotating shaft, and can move relatively axially with respect to the support table side member;

[0345] A working fluid is filled in a pressure chamber formed between the support table side member and the bearing housing side member; and

[0346] An elastic member, which is disposed in a compressed state in the pressure chamber between the opposing axial end faces of the support table side member and the bearing housing side member.

[0347] According to this structure, 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.

[0348] (A19) A rotary support device, wherein

[0349] it has: a rotating shaft and a pair of support mechanisms, and the pair of support mechanisms respectively support the axial end portions of the rotating shaft so as to be rotatable freely.

[0350] One of the pair of support mechanisms has:

[0351] a bearing unit, which has a bearing housing and a bearing, and the bearing supports the rotating shaft so as to be rotatable freely relative to the bearing housing and can support an axial load;

[0352] a support table, which is penetrated by the rotating shaft; and

[0353] a housing position adjustment mechanism, which is installed on the bearing unit and the support table,

[0354] the housing position adjustment mechanism has:

[0355] a support table side member, which is installed on the support table and is penetrated by the rotating shaft;

[0356] a bearing housing side member, which is installed on the bearing housing and is penetrated by the rotating shaft, and can move relative to the support table side member in the axial direction;

[0357] a working fluid, which is filled in a pressure chamber formed between the support table side member and the bearing housing side member; and

[0358] an elastic member, which is disposed in a compressed state in the pressure chamber between the opposing axial end faces of the support table side member and the bearing housing side member.

[0359] According to this structure, 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.

[0360] (A20)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 for supporting the shaft on a base.

[0361] The support mechanism position adjustment mechanism of the shaft support device includes:

[0362] A first component, which is provided on one of the support mechanism side and the base side and can be penetrated by the shaft;

[0363] A second component, which is provided on the other of the support mechanism side and the base side and can be penetrated by the shaft, can move relative to the first component axially, and forms a receiving space between the second component and the first component;

[0364] A working fluid, which is filled in the receiving space; and

[0365] An elastic component, which is disposed in the receiving space in a compressed state between the opposing axial end faces of the first component and the second component.

[0366] According to this structure, 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.

[0367] (A21)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 for supporting the shaft on a base.

[0368] The support mechanism position adjustment mechanism of the shaft support device includes:

[0369] A first component, which is mounted on one of the support mechanism and the base and can be penetrated by the shaft;

[0370] A second component, which is mounted on the other of the support mechanism and the base and can be penetrated by the shaft, can move relative to the first component axially, and forms a receiving space between the second component and the first component;

[0371] A working fluid, which is filled in the receiving space; and

[0372] An elastic component, which is disposed in the receiving space in a compressed state between the opposing axial end faces of the first component and the second component.

[0373] According to this structure, 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.

[0374] (A22) A rotational support device, wherein,

[0375] comprises: a rotating shaft; and a pair of support mechanisms that respectively support both axial end portions of the rotating shaft so as to be rotatable freely,

[0376] One of the pair of support mechanisms comprises:

[0377] a bearing unit that comprises a bearing housing and a bearing, which can support the rotating shaft so as to be rotatable freely relative to the bearing housing and the bearing can support an axial load;

[0378] a support table that is penetrated by the rotating shaft; and

[0379] a housing position adjustment mechanism that is disposed between the bearing unit and the support table,

[0380] The housing position adjustment mechanism comprises:

[0381] 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;

[0382] 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 can move axially relative to the support table side member;

[0383] a working fluid that is filled in a pressure chamber formed between the support table side member and the bearing housing side member; and

[0384] an elastic member that is disposed in a compressed state in the pressure chamber between the opposing axial end faces of the support table side member and the bearing housing side member.

[0385] According to this structure, 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.

[0386] (A23) The rotational support device according to (A22), wherein,

[0387] One of the support table side member and the bearing housing side member has a plurality of recesses that open to one axial side,

[0388] The other of the support table side member and the bearing housing side member has a plurality of convex portions, and the plurality of convex portions protrude toward the other axial side and are respectively fitted into the plurality of concave portions in a slidable manner along the axial direction.

[0389] A plurality of the pressure chambers are respectively formed between the plurality of concave portions and the plurality of convex portions.

[0390] According to this structure, the layout of the housing position adjustment mechanism can be freely constituted by the plurality of pressure chambers.

[0391] (A24) The rotary support device according to (A23), wherein

[0392] The plurality of pressure chambers are arranged on both sides in the width direction with respect to the rotation axis.

[0393] According to this structure, the height dimension of the housing position adjustment mechanism can be suppressed.

[0394] (A25) The rotary support device according to (A23), wherein

[0395] The working fluid and the elastic member are respectively arranged in the plurality of pressure chambers.

[0396] According to this structure, the plurality of pressure chambers can be commonly constituted.

[0397] (A26) The rotary support device according to (A22), wherein

[0398] The rotary support device is a ball screw feed device,

[0399] This ball screw feed device has the rotation axis as a screw shaft having a spiral thread groove formed on the outer peripheral surface, and further includes: a nut having a spiral thread groove formed on the inner peripheral surface; and a plurality of balls that are freely rollably arranged between the thread groove of the screw shaft and the thread groove of the nut.

[0400] According to this structure, a ball screw feed device can be constituted that can continuously and stably maintain the axial support rigidity even if the axial length of the rotation axis changes due to the influence of heat.

[0401] (A27) 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, and the shaft support device includes a shaft and a pair of the support mechanisms provided at both axial ends of the shaft for supporting the shaft on a base.

[0402] The support mechanism position adjustment mechanism of the shaft support device includes:

[0403] A first component, which is provided on one of the support mechanism side and the base side, can be penetrated by the shaft or can be arranged around the shaft;

[0404] A second component, which is provided on the other of the support mechanism side and the base side, can be penetrated by the shaft or can be arranged around the shaft, can move relatively axially with respect to the first component, and forms a receiving space between the second component and the first component;

[0405] A working fluid, which is filled in the receiving space; and

[0406] An elastic member, which is arranged in a compressed state in the receiving space between the opposing axial end faces of the first component and the second component.

[0407] According to this structure, 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.

[0408] (B1) A rotary support device,

[0409] comprising: a rotary shaft; and a pair of support mechanisms, which respectively support the axial end portions of the rotary shaft so as to be rotatable freely,

[0410] One of the pair of support mechanisms comprises:

[0411] A bearing unit, which comprises: a bearing housing; and a bearing, which can support the rotary shaft so as to be rotatable freely with respect to the bearing housing and can support an axial load;

[0412] A support table, which is penetrated by the rotary shaft or arranged around the rotary shaft; and

[0413] A housing position adjustment mechanism, which is disposed between the bearing unit and the support table,

[0414] The housing position adjustment mechanism comprises:

[0415] A support table side component, which is provided on the support table side, is penetrated by the rotary shaft or arranged around the rotary shaft;

[0416] A bearing housing side component, which is provided on the bearing housing side, is penetrated by the rotary shaft or arranged around the rotary shaft, and can move relatively axially with respect to the support table side component;

[0417] A working fluid, which is filled in a pressure chamber formed between the support table side component and the bearing housing side component; and

[0418] An elastic member, which is disposed in a compressed state between opposing axial end faces of the support table side member and the bearing housing side member within the pressure chamber.

[0419] According to this structure, 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 vibrations in the axial and radial directions can be attenuated.

[0420] (B2) The rotary support device according to (B1), wherein

[0421] 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,

[0422] 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 is fitted into the annular recess in a slidable manner along the axial direction.

[0423] The pressure chamber is formed between the annular recess and the annular protrusion.

[0424] According to this structure, 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 rotating shaft.

[0425] (B3) The rotary support device according to (B2), wherein

[0426] At least one sealing member is installed 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.

[0427] According to this structure, the sealing member can prevent the working fluid filled in the pressure chamber from leaking, and the function of the housing position adjustment mechanism can be maintained for a long time.

[0428] (B4) The rotary support device according to (B2) or (B3), wherein

[0429] The working fluid is stored in the gaps 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.

[0430] According to this structure, the housing position adjustment mechanism can impart radial support rigidity to the rotating shaft and can also have a centering function for the rotating shaft.

[0431] (B5) The rotary support device according to (B2) or (B3), wherein

[0432] The housing position adjustment mechanism includes: a storage chamber formed in the annular convex portion so as to open to the outer surface or the inner surface of the annular convex portion for storing the working fluid; and a damping hole formed in the annular convex portion so as to communicate the storage chamber with the pressure chamber.

[0433] According to this structure, the working fluid in the pressure chamber and the storage chamber 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, whereby its vibration can be attenuated.

[0434] (B6) The rotary bearing device according to any one of (B1) to (B5), wherein

[0435] The elastic member is a disc spring having a plurality of through holes or a plurality of slits penetrating in the axial direction in a conical plate portion.

[0436] According to this structure, the working fluid flows through the plurality of through holes or the plurality of slits, whereby an attenuation effect can be exerted.

[0437] (B7) The rotary bearing device according to (B3), wherein

[0438] The sealing member is an O-ring,

[0439] Sealing grooves for arranging the O-ring are respectively formed on the inner surface of the annular concave portion or the outer surface of the annular convex portion, and on the outer surface of the annular concave portion or the inner surface of the annular convex portion.

[0440] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0441] According to this structure, by using the O-ring as the sealing member, the O-ring also functions as an attenuation mechanism, and 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 thus the axial rigidity of the rotary bearing device can be continuously maintained.

[0442] (B8) The rotary bearing device according to (B3) or (B7), wherein

[0443] The sealing member is an O-ring,

[0444] A wear-resistant member is interposed between at least one of the inner surface of the annular concave portion and the outer surface of the annular convex portion and the O-ring, and between at least one of the outer surface of the annular concave portion and the inner surface of the annular convex portion and the O-ring.

[0445] According to this structure, by setting the sealing member as an O-ring, 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.

[0446] (B9) The rotary bearing device according to (B1), wherein

[0447] 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 outer flange portion extending from the tip portion of the small-diameter cylindrical portion toward the outer diameter side.

[0448] 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 the outer peripheral surface of the outer flange portion to slide in contact with; and an inner flange portion extending from the tip portion of the large-diameter cylindrical portion toward the inner diameter side and having an inner peripheral surface for the outer peripheral surface of the small-diameter cylindrical portion to slide in contact with.

[0449] The pressure chamber is formed in an annular space defined by the small-diameter cylindrical portion, the outer flange portion, the large-diameter cylindrical portion, and the inner flange portion.

[0450] According to this structure, 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.

[0451] (B10) The rotary bearing device according to (B9), wherein

[0452] At least one sealing member for preventing the working fluid filled in the pressure chamber from leaking is respectively installed between the inner peripheral surface of the inner flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outer flange portion and the inner peripheral surface of the large-diameter cylindrical portion.

[0453] According to this structure, the working fluid filled in the pressure 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.

[0454] (B11) The rotary bearing device according to (B9) or (B10), wherein

[0455] The working fluid is stored in each gap between the inner peripheral surface of the inner flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outer flange portion and the inner peripheral surface of the large-diameter cylindrical portion.

[0456] According to this structure, the housing position adjustment mechanism can impart radial support rigidity to the rotating shaft and can also have a centering function for the rotating shaft.

[0457] (B12) The rotational support device according to (B9) or (B10), wherein,

[0458] The housing position adjustment mechanism includes: a storage chamber 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, and stores the working fluid; and a damping hole formed in the outward flange portion or the inward flange portion so as to communicate the storage chamber with the pressure chamber.

[0459] According to this structure, the working fluid in the pressure chamber and the storage chamber can be attenuated in vibration 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 between the outer peripheral surface of the small-diameter cylindrical portion and the inner peripheral surface of the inward flange portion.

[0460] (B13) The rotational support device according to (B10), wherein,

[0461] The sealing member is an O-ring,

[0462] 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 the outer peripheral surface of the outward flange portion or the inner peripheral surface of the large-diameter cylindrical portion.

[0463] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0464] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and the vibration generated in the rotating shaft can be attenuated. 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 thus the axial rigidity of the rotational support device can be continuously maintained.

[0465] (B14) The rotational support device according to (B10), wherein,

[0466] The sealing member is an O-ring,

[0467] 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.

[0468] According to this structure, by setting the sealing member as an O-ring, 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.

[0469] (B15) The rotary bearing device according to (B1), wherein,

[0470] A working fluid volume changing portion is installed in at least one of the support table side member and the bearing housing side member, and the working fluid volume changing portion changes the volume of the working fluid by heating or cooling the working fluid.

[0471] According to this structure, by heating or cooling the working fluid to expand or contract the volume of the working fluid, the axial support rigidity can be continuously maintained in a stable state.

[0472] (B16) The rotary bearing device according to (B1), wherein,

[0473] One of the pair of support mechanisms further includes another housing position adjustment mechanism, and the another housing position adjustment mechanism is arranged in series or in parallel adjacent to the housing position adjustment mechanism between the bearing unit and the support table.

[0474] The another housing position adjustment mechanism includes:

[0475] Another support table side member, which is arranged on the support table side, is penetrated by the rotating shaft or arranged around the rotating shaft;

[0476] Another bearing housing side member, which is arranged on the bearing housing side, is 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; and

[0477] A pressure generating unit, which 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.

[0478] According to this structure, in the case of series arrangement, even when the elongation of the rotating shaft is larger, the axial rigidity of the rotary bearing device can be maintained. In addition, the centering property and coaxiality of the rotating shaft can 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.

[0479] (B17) The rotary bearing device according to (B1), wherein,

[0480] One of the support table side member and the bearing housing side member has a plurality of recesses opening to one axial side.

[0481] The other of the support table side member and the bearing housing side member has a plurality of protrusions that protrude toward the other axial side and are respectively fitted into the plurality of recesses in a slidable manner along the axial direction.

[0482] A plurality of the pressure chambers are respectively formed between the plurality of recesses and the plurality of protrusions.

[0483] According to this structure, the layout of the housing position adjustment mechanism can be freely constituted by the plurality of pressure chambers.

[0484] (B18) The rotary support device according to (B17), wherein

[0485] The plurality of pressure chambers are arranged on both sides in the width direction with respect to the rotary shaft.

[0486] According to this structure, the height dimension of the housing position adjustment mechanism can be suppressed.

[0487] (B19) The rotary support device according to (B17), wherein

[0488] The working fluid and the elastic member are respectively arranged in the plurality of pressure chambers.

[0489] According to this structure, the plurality of pressure chambers can be commonly constituted.

[0490] (B20) The rotary support device according to any one of (B1) to (B19), wherein

[0491] 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.

[0492] According to this structure, 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.

[0493] (B21) The rotary support device according to any one of (B1) to (B20), wherein

[0494] The rotary support device is a ball screw feed device.

[0495] The ball screw feed device has a lead screw shaft with a helical thread groove formed on its outer peripheral surface, 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.

[0496] According to this structure, a ball screw feed device can be constituted 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.

[0497] (B22) 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 support mechanisms provided at both axial ends of the shaft for supporting the shaft. Among them,

[0498] One of the pair of support mechanisms has a support body that is penetrated by the shaft or disposed around the shaft.

[0499] The support mechanism position adjustment mechanism of the shaft support device includes:

[0500] A first component, which is provided on one of the shaft side and the support body side, can be penetrated by the shaft or disposed around the shaft.

[0501] 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, can move relative to the first component axially, and forms a receiving space between the second component and the first component.

[0502] A working fluid, which is filled in the receiving space; and

[0503] An elastic component, which is disposed in the receiving space in a compressed state between the opposing axial end faces of the first component and the second component.

[0504] According to this structure, even when 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.

[0505] (B23) The support mechanism position adjustment mechanism of the shaft support device according to (B22), wherein,

[0506] The shaft is a rotating shaft.

[0507] One of the pair of support mechanisms further includes a bearing unit, which includes a bearing housing and a bearing. The bearing supports the rotating shaft to be rotatable relative to the bearing housing and can support an axial load.

[0508] The support mechanism position adjustment mechanism is a housing position adjustment mechanism disposed between the bearing unit and the support body.

[0509] The first component is a support body side component, which is disposed on the support body side and can be penetrated by the rotating shaft or can be arranged around the rotating shaft.

[0510] The second component is a bearing housing side component, which is disposed on the bearing housing side and can be penetrated by the rotating shaft or can be arranged around the rotating shaft, can move relative to the support body side component in the axial direction, and forms the accommodation space between the bearing housing side component and the support body side component.

[0511] According to this structure, 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.

[0512] (B24) The support mechanism position adjustment mechanism of the shaft support device according to (B22) or (B23), wherein,

[0513] One of the first component and the second component has an annular recess opening on one side in the axial direction.

[0514] The other of the first component and the second component has an annular protrusion, which protrudes toward the other side in the axial direction and is fitted into the annular recess in a slidable manner along the axial direction.

[0515] The pressure chamber is formed between the annular recess and the annular protrusion.

[0516] According to this structure, since the pressure chamber is formed between the annular recess and the annular protrusion, the support mechanism position adjustment mechanism can be compactly constituted around the shaft.

[0517] (B25) The support mechanism position adjustment mechanism of the shaft support device according to (B24), wherein,

[0518] At least one sealing member is installed 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 respectively.

[0519] According to this structure, the working fluid filled in the pressure chamber can be prevented from leaking by the sealing member, and the function of the support mechanism position adjustment mechanism can be maintained for a long time.

[0520] (B26) The support mechanism position adjustment mechanism of the shaft support device according to (B24) or (B25), wherein,

[0521] The working fluid is stored in each of the gaps 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.

[0522] According to this structure, the support mechanism position adjustment mechanism can impart radial support rigidity to the shaft and also has a centering function for the shaft.

[0523] (B27) The support mechanism position adjustment mechanism of the shaft support device according to (B24) or (B25), wherein,

[0524] The support mechanism position adjustment mechanism includes: a storage chamber formed in the annular protrusion so as to open to the outer-facing surface or the inner-facing surface of the annular protrusion for storing the working fluid; and a damping hole formed in the annular protrusion so as to communicate the storage chamber with the pressure chamber.

[0525] According to this structure, the working fluid in the pressure chamber and the storage chamber passes through the damping hole and the gap between the outer-facing surface of the annular protrusion and the inner-facing surface of the annular recess, whereby its vibration can be attenuated.

[0526] (B28) The support mechanism position adjustment mechanism of the shaft support device according to any one of (B22) to (B27), wherein,

[0527] The elastic member is a disc spring having a plurality of through holes or a plurality of slits penetrating in the axial direction in a conical plate portion.

[0528] According to this structure, the working fluid flows through the plurality of through holes or the plurality of slits, whereby an attenuation effect can be exerted.

[0529] (B29) The support mechanism position adjustment mechanism of the shaft support device according to (B25), wherein,

[0530] The sealing member is an O-ring,

[0531] 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,

[0532] The sealing groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side.

[0533] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as an attenuation 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, thereby continuously maintaining the axial rigidity of the shaft support device.

[0534] (B30) The support mechanism position adjustment mechanism of the shaft support device according to (B25) or (B29), wherein,

[0535] The sealing member is an O-ring,

[0536] 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.

[0537] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and the vibration generated in the 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 and the contact surface in contact with the O-ring can be suppressed.

[0538] (B31) The support mechanism position adjustment mechanism of the shaft support device according to (B22), wherein,

[0539] One of the first member and the second member has: a small-diameter cylindrical portion extending axially; and an outward flange portion extending radially outward from the tip of the small-diameter cylindrical portion,

[0540] The other of the first member and the second member has: a large-diameter cylindrical portion extending axially in the other direction, having an inner circumferential surface for the outer circumferential surface of the outward flange portion to slide in contact with; and an inward flange portion extending radially inward from the tip of the large-diameter cylindrical portion, having an inner circumferential surface for the outer circumferential surface of the small-diameter cylindrical portion to slide in contact with,

[0541] The pressure chamber is formed in the annular space defined by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion.

[0542] According to this structure, 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.

[0543] (B32) The support mechanism position adjustment mechanism of the shaft support device according to (B31), wherein,

[0544] At least one sealing member for preventing the working fluid filled in the pressure chamber from leaking is respectively installed between the inner circumferential surface of the inward flange portion and the outer circumferential surface of the small-diameter cylindrical portion, and between the outer circumferential surface of the outward flange portion and the inner circumferential surface of the large-diameter cylindrical portion.

[0545] According to this structure, the working fluid filled in the pressure chamber can be prevented from leaking by the sealing member, and the function of the support mechanism position adjustment mechanism can be maintained for a long time.

[0546] (B33) The support mechanism position adjustment mechanism of the shaft support device according to (B31) or (B32), wherein,

[0547] 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.

[0548] According to this structure, the support mechanism position adjustment mechanism can impart radial support rigidity to the shaft and also has a centering function for the shaft.

[0549] (B34) The support mechanism position adjustment mechanism of the shaft support device according to (B31) or (B32), wherein,

[0550] The support mechanism position adjustment mechanism includes: a storage chamber 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 and store the working fluid; and a damping hole formed in the outward flange portion or the inward flange portion so as to communicate the storage chamber with the pressure chamber.

[0551] According to this structure, the working fluid in the pressure chamber and the storage chamber can be attenuated in vibration 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 between the outer peripheral surface of the small-diameter cylindrical portion and the inner peripheral surface of the inward flange portion.

[0552] (B35) The support mechanism position adjustment mechanism of the shaft support device according to (B32), wherein the sealing member is an O-ring,

[0553] 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,

[0554] The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

[0555] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions 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, thereby continuously maintaining the axial rigidity of the shaft support device.

[0556] (B36) The support mechanism position adjustment mechanism of the shaft support device according to (B32), wherein,

[0557] The sealing member is an O-ring,

[0558] 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.

[0559] According to this structure, by setting the sealing member as an O-ring, the O-ring also functions as a damping mechanism, and the vibration generated in the 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 and the contact surface in contact with the O-ring can be suppressed.

[0560] (B37) The support mechanism position adjustment mechanism of the shaft support device according to (B22), wherein,

[0561] A working fluid volume change portion is installed on at least one of the first member and the second member, and the working fluid volume change portion changes the volume of the working fluid by heating or cooling the working fluid.

[0562] According to this structure, by heating or cooling the working fluid to expand or contract the volume of the working fluid, the axial support rigidity can be continuously maintained in a stable state.

[0563] (B38) The support mechanism position adjustment mechanism of the shaft support device according to (B22), wherein,

[0564] One of the pair of support mechanisms further includes another support mechanism position adjustment mechanism, and the another support mechanism position adjustment mechanism is arranged in series or parallel adjacent to the support mechanism position adjustment mechanism between the bearing unit and the support table.

[0565] The another support mechanism position adjustment mechanism includes:

[0566] Another first member, which is arranged on the support table side and is penetrated by the shaft or arranged around the shaft;

[0567] Another second member, which is arranged on the bearing housing side and is penetrated by the shaft or arranged around the shaft and can move axially relative to the another first member; and

[0568] A pressure generating unit, which is accommodated in a pressure chamber formed between the another first member and the another second member in a compressed state.

[0569] According to this structure, in the case of a series configuration, even when the elongation of the shaft is greater, the axial rigidity of the shaft support device can be maintained. In addition, the centering property and coaxiality of the shaft can be improved. Further, in the case of a parallel configuration, an axial load greater than that generated when a separate support mechanism position adjustment mechanism is arranged can be generated, and the axial rigidity can be maintained.

[0570] (B39) The support mechanism position adjustment mechanism of the shaft support device according to (B22), wherein,

[0571] One of the first component and the second component has a plurality of recesses opening to one side in the axial direction,

[0572] The other of the first component and the second component has a plurality of protrusions, and the plurality of protrusions protrude toward the other side in the axial direction and are respectively fitted into the plurality of recesses in a slidable manner along the axial direction.

[0573] A plurality of the pressure chambers are respectively formed between the plurality of recesses and the plurality of protrusions.

[0574] According to this structure, the layout of the support mechanism position adjustment mechanism can be freely constituted by the plurality of pressure chambers.

[0575] (B40) The support mechanism position adjustment mechanism of the shaft support device according to (B39), wherein,

[0576] The plurality of pressure chambers are arranged on both sides in the width direction with respect to the shaft.

[0577] According to this structure, the height dimension of the support mechanism position adjustment mechanism can be suppressed.

[0578] (B41) The support mechanism position adjustment mechanism of the shaft support device according to (B39), wherein,

[0579] The working fluid and the elastic member are respectively arranged in the plurality of pressure chambers.

[0580] According to this structure, the plurality of pressure chambers can be commonly constituted.

[0581] In addition, this application is based on the Japanese patent application filed on October 28, 2022 (Japanese Patent Application No. 2022-173761), the Japanese patent application filed on July 21, 2023 (Japanese Patent Application No. 2023-118995), and the Japanese patent application filed on August 22, 2023 (Japanese Patent Application No. 2023-134635), the contents of which are incorporated herein by reference.

[0582] Description of Reference Numerals

[0583] 20 Ball screw feed device (shaft support device, rotary support device)

[0584] 21 Lead screw shaft (shaft, rotary shaft)

[0585] 23 Nut

[0586] 30 First support mechanism (support mechanism)

[0587] 31 Fixed-side bearing housing

[0588] 33, 53 Angular contact ball bearings (bearings)

[0589] 34, 54 Outer rings

[0590] 35, 55 Inner rings

[0591] 36, 56 Ball bearings

[0592] 38a, 38b Lock nuts

[0593] 40 Second support mechanism (support mechanism)

[0594] 41 Bearing unit

[0595] 43 Support table (support body)

[0596] 51 Moving-side bearing housing (bearing housing)

[0597] 51a Inward flange

[0598] 59 Wear-resistant parts

[0599] 60 Housing position adjustment mechanism (support mechanism position adjustment mechanism)

[0600] 61 Support table side part (first part)

[0601] 62 Bearing housing side part (second part)

[0602] 64 Annular recess

[0603] 65 Annular protrusion

[0604] 66 Pressure chamber (accommodation space)

[0605] 67 O-ring (sealing part)

[0606] 68 Sealing groove

[0607] 69a Tapered surface

[0608] 70 Working oil (working fluid)

[0609] 80 Disc spring (elastic part)

[0610] 120 Rotary support device

[0611] 121 Rotating shaft

[0612] 160 Another housing position adjustment mechanism (another support mechanism position adjustment mechanism)

[0613] 161 Another support table side component (another support body side component)

[0614] 162 Another bearing housing side component

[0615] 180, 181 Heating element (working fluid volume change part)

[0616] 182, 183 Cooling medium (working fluid volume change part)

Claims

1. A rotary support device, characterized in that, it comprises: a rotary shaft; and a pair of support mechanisms that respectively support both axial end portions of the rotary shaft so as to be rotatable freely, one of the pair of support mechanisms comprises: a bearing unit that comprises a bearing housing and a bearing, the bearing supports the rotary shaft relative to the bearing housing so as to be rotatable freely, and the bearing can support an axial load; a support table that is penetrated by the rotary shaft or disposed around the rotary shaft; and a housing position adjustment mechanism that is disposed between the bearing unit and the support table, the housing position adjustment mechanism comprises: a support table side member that is disposed on the support table side and is penetrated by the rotary shaft or disposed around the rotary shaft; a bearing housing side member that is disposed on the bearing housing side and is penetrated by the rotary shaft or disposed around the rotary shaft, and can move axially relative to the support table side member; a working fluid that is filled in a pressure chamber formed between the support table side member and the bearing housing side member; and an elastic member that is disposed in a compressed state in the pressure chamber between the opposing axial end faces of the support table side member and the bearing housing side member.

2. 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 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 is fitted into the annular recess in a manner that can slide in the axial direction, the pressure chamber is formed between the annular recess and the annular protrusion.

3. The rotary support device according to claim 2, characterized in that, at least one sealing member is installed respectively 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.

4. The rotary support device according to claim 2 or 3, characterized in that, 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.

5. The rotary support device according to claim 2 or 3, characterized in that, the housing position adjustment mechanism comprises: a storage chamber that is formed in the annular protrusion in a manner that opens to the outer-facing surface or the inner-facing surface of the annular protrusion and stores the working fluid; and a damping hole that is formed in the annular protrusion in a manner that communicates the storage chamber with the pressure chamber.

6. The rotary support device according to claim 1, characterized in that, the elastic member is a disc spring that has a plurality of through holes or a plurality of slits penetrating in the axial direction in a conical plate portion.

7. The rotary support device according to claim 3, characterized in that, The sealing member is an O-ring. 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. The sealing groove has a tapered surface whose groove depth becomes shallower as it is farther from the pressure chamber side.

8. The rotary bearing device according to claim 3, characterized in that the sealing member is an O-ring, 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.

9. 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: a small-diameter cylindrical portion extending axially on one side; and an outward flange portion extending radially outward from the tip of the small-diameter cylindrical portion, the other of the support table side member and the bearing housing side member has: a large-diameter cylindrical portion extending axially on the other side, having an inner peripheral surface that slidably contacts the outer peripheral surface of the outward flange portion; and an inward flange portion extending radially inward from the tip of the large-diameter cylindrical portion, having an inner peripheral surface that slidably contacts the outer peripheral surface of the small-diameter cylindrical portion, the pressure chamber is formed in an annular space defined by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion.

10. The rotary bearing device according to claim 9, characterized in that at least one sealing member for preventing leakage of the working fluid filled in the pressure chamber 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.

11. The rotary bearing device according to claim 9 or 10, characterized in that 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.

12. The rotary bearing device according to claim 9 or 10, characterized in that the housing position adjustment mechanism includes: a storage chamber 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 and storing the working fluid; and a damping hole formed in the outward flange portion or the inward flange portion so as to communicate the storage chamber with the pressure chamber.

13. The rotary bearing device according to claim 10, characterized in that the sealing member is an O-ring, 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. The sealing groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side.

14. The rotary support device according to claim 10, wherein, the sealing member is an O-ring, 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.

15. The rotary support device according to claim 1, wherein, a working fluid volume changing portion is installed on at least one of the support table side member and the bearing housing side member, and the working fluid volume changing portion changes the volume of the working fluid by heating or cooling the working fluid.

16. The rotary support device according to claim 1, wherein, one of the pair of support mechanisms further includes another housing position adjustment mechanism, and the another housing position adjustment mechanism is arranged in series or in parallel adjacent to the housing position adjustment mechanism between the bearing unit and the support table, the another housing position adjustment mechanism includes: another support table side member, which is arranged on the support table side, is penetrated by the rotating shaft or arranged around the rotating shaft; another bearing housing side member, which is arranged 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 another support table side member; and a pressure generating unit, which 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.

17. The rotary support device according to claim 1, 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, the other of the support table side member and the bearing housing side member has a plurality of protrusions, and the plurality of protrusions protrude toward the other side in the axial direction and are respectively fitted into the plurality of recesses in a slidable manner along the axial direction, a plurality of the pressure chambers are respectively formed between the plurality of recesses and the plurality of protrusions.

18. The rotary support device according to claim 17, wherein, the plurality of pressure chambers are arranged on both sides in the width direction with respect to the rotating shaft.

19. The rotary support device according to claim 17, wherein, the working fluid and the elastic member are respectively arranged in the plurality of pressure chambers.

20. The rotary support device according to claim 1, wherein, 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 rotating shaft, and balls arranged between the outer ring and the inner ring so as to be able to roll freely.

21. The rotary support device according to claim 1, wherein, the rotary support device is a ball screw feed device, The ball screw feed device has a lead screw shaft with a helical thread groove formed on its outer peripheral surface, 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.

22. A support mechanism position adjustment mechanism for a shaft support device Characterized in that The support mechanism position adjustment mechanism of the shaft support device 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 support mechanisms provided at both axial ends of the shaft for supporting the shaft. One of the pair of support mechanisms has a support body that is penetrated by the shaft or disposed around the shaft. The support mechanism position adjustment mechanism of the shaft support device includes: A first component that 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 component that is provided on the other of the shaft side and the support body side and can be penetrated by the shaft or can be disposed around the shaft. The second component can move relative to the first component in the axial direction, and a receiving space is formed between the second component and the first component. A working fluid that fills the receiving space. And An elastic component that is disposed in a compressed state in the receiving space between the opposed axial end faces of the first component and the second component.

23. The support mechanism position adjustment mechanism of the shaft support device according to claim 22, Characterized in that The shaft is a rotating shaft. One of the pair of support mechanisms further includes a bearing unit. The bearing unit includes a bearing housing and a bearing. The bearing supports the rotating shaft so as to be rotatable relative to the bearing housing and can support an axial load. The support mechanism position adjustment mechanism is a housing position adjustment mechanism disposed between the bearing unit and the support body. The first component is a support body side component that is provided on the support body side and can be penetrated by the rotating shaft or can be disposed around the rotating shaft. The second component is a bearing housing side component that is provided on the bearing housing side and can be penetrated by the rotating shaft or can be disposed around the rotating shaft. The bearing housing side component can move relative to the support body side component in the axial direction, and the receiving space is formed between the bearing housing side component and the support body side component.

Images