Rotation support device and support mechanism position adjustment mechanism for shaft support device

Abstract

A support mechanism (30) for rotatably supporting both axial end portions of a screw shaft (21) comprises: a bearing unit (41) having a moving-side bearing housing (51) and a pair of angular ball bearings (33B); a support base (43); and a housing position adjustment mechanism (44) disposed between the bearing unit (41) and the support base (43). The housing position adjustment mechanism (44) comprises: a support-base-side member (61) provided on the support base (43) side; a bearing-housing-side member (62) provided on the bearing housing (51) side, and capable of relative movement in the axial direction with respect to the support-base-side member (61); a working fluid accommodated in a pressure chamber (66) formed between the support-base-side member (61) and the bearing-housing-side member (62), in a storage chamber (71) formed in either the support-base-side member or the bearing-housing-side member, and in an orifice (72) establishing communication between the pressure chamber (66) and the storage chamber (71); a disc spring (80) disposed inside the pressure chamber (66) in a state compressed between the opposing axial end surfaces of the support-base-side member (61) and the bearing-housing-side member (62); and a hollow member (90) accommodated in the storage chamber (71). Consequently, the support rigidity in the axial direction can be continuously and stably maintained, even if the axial length of a screw shaft or a rotary shaft changes owing to the effect of heat.

Description

[Technical Field]

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

[0002] In a ball screw feed device, high axial rigidity is required to maintain the feed accuracy of the screw shaft. Conventionally, a method of providing rigidity to the screw shaft of a ball screw device has been to combine multiple angular bearings to apply preload and place them at one or both ends of the screw shaft. A common method is to fix and support the screw shaft in the axial direction. In addition, when thermal expansion of the screw shaft is taken into consideration, a method is used in which tension is applied to the screw shaft in the axial direction in advance to elongate it by a predetermined amount. Patent Document 1 describes a method in which tension is applied to the feed screw (screw shaft) in advance by adjusting the axial dimension of the spacer, and when the feed screw elongates beyond the amount of pretension due to a temperature rise, It is described that the device is provided with a pretensioning mechanism that applies tension to the feed screw by moving the bearing in the axial direction using a disc spring or fluid pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Registration No. 2573982 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the load applied to the feed screw, known as pretension or pretension, is excessive, a large load is placed on the bearing, potentially damaging it. For this reason, a disc spring or an externally supplied fluid, as seen in the pretension mechanism described in Patent Document 1, is typically used to prevent excessive axial load from being placed on the bearing. However, disc springs weaken the load as the shaft elongates, and can only handle a temperature rise of 3 to 4 degrees. In machining centers, the temperature rise of ball screws often exceeds 4 degrees, which means that the disc springs are no longer able to apply sufficient load, resulting in a problem of reduced axial support rigidity. Furthermore, the method of applying a load by supplying fluid from an external source using hydraulic pressure requires external devices such as a hydraulic pump, and also has the problem of increasing the size of the ball screw feed device, resulting in increased costs and additional energy consumption. Furthermore, this problem exists not only in ball screw feed devices, but also in rotation support devices such as spindle devices in which both axial ends of a rotation shaft are rotatably supported by a pair of support mechanisms.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a rotation support device and a support mechanism position adjustment mechanism for a shaft support device that can continuously and stably maintain axial support rigidity even if the axial length of the rotating shaft changes due to the effects of heat. [Means for solving the problem]

[0006] The above object of the present invention can be achieved by the following configuration. [1] A rotary support device comprising a rotary shaft and a pair of support mechanisms that rotatably support both axial ends of the rotary shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing and a bearing that rotatably supports the rotary shaft relative to the bearing housing and is capable of supporting an axial load; a support base through which the rotation shaft passes or which is arranged around the rotation shaft; a housing position adjustment mechanism disposed between the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: a support base side member that is provided on the support base side and through which the rotation shaft passes or that is arranged around the rotation shaft; a bearing housing side member provided on the bearing housing side, through which the rotation shaft passes or which is disposed around the rotation shaft, and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A rotary support device comprising: [2] A shaft support device including a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft, the support mechanism position adjustment mechanism of the shaft support device being provided on one of the pair of support mechanisms, one of the pair of support mechanisms has a support body through which the shaft passes or which is disposed around the shaft; a first member provided on one of the shaft side and the support side, through which the shaft can pass or which can be arranged around the shaft; a second member provided on the other of the shaft side and the support side, through which the shaft can pass or which can be arranged around the shaft, and which is movable in the axial direction relative to the first member; a pressure chamber formed between the first member and the second member, a reservoir chamber formed in the first member or the second member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the first member and the second member within the pressure chamber; a hollow member accommodated in the storage chamber; A support mechanism position adjustment mechanism for a shaft support device. [Effects of the Invention]

[0007] According to the rotary support device of the present invention, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0008] Furthermore, according to the support mechanism position adjustment mechanism of the shaft support device of the present invention, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a table feed system of a machine tool to which a ball screw feed device according to a first embodiment of the present invention is applied. [Figure 2] 2 is an enlarged cross-sectional view of a support mechanism including a housing position adjustment mechanism shown in FIG. 1. FIG. [Figure 3] FIG. 3 is a view taken along the arrow A in FIG. 2. [Figure 4] FIG. 10 is a cross-sectional view showing a modified example of the disc spring. [Figure 5] 10(a) to 10(c) are cross-sectional views showing first to third modified examples of a hollow member disposed in a pressure chamber. [Figure 6] 10(a) and 10(b) are cross-sectional views showing fourth and fifth modified examples of the hollow member. [Figure 7] FIG. 10 is a cross-sectional view showing a sixth modified example of the hollow member. [Figure 8] 10(a) to 10(c) are cross-sectional views of hollow members according to seventh to ninth modified examples of the first embodiment. [Figure 9] 10(a) to 10(c) are cross-sectional views of hollow members according to tenth to twelfth modified examples of the first embodiment. [Figure 10] 10(a) and 10(b) are cross-sectional views of hollow members according to thirteenth and fourteenth modifications of the first embodiment. [Figure 11] 10(a) to 10(c) are cross-sectional views of hollow members according to fifteenth to seventeenth modifications of the first embodiment. [Figure 12] 10 is a view corresponding to FIG. 2 of a ball screw feed device according to a second embodiment of the present invention. FIG. [Figure 13] FIG. 13 is an enlarged view of a portion XIII in FIG. [Figure 14] 10(a) to 10(c) are enlarged cross-sectional views of a main part showing an example in which a wear-resistant member is applied to a seal groove of a ball screw feed device according to a modified example of the second embodiment. [Figure 15] 2. FIG. 6 is a view corresponding to FIG. 2 of a ball screw feed device according to a third embodiment of the present invention. [Figure 16] FIG. 10 is a view corresponding to FIG. 2 of a ball screw feed device according to a fourth embodiment of the present invention. [Figure 17] 10 is a view corresponding to FIG. 2, showing a pair of angular contact ball bearings of a bearing unit arranged back to back, according to a second modified example of the present invention. FIG. [Figure 18] 10 is a view corresponding to FIG. 2, showing a pair of angular contact ball bearings of a bearing unit combined in parallel according to a third modified example of the present invention. FIG. [Figure 19] (a) is a schematic side view showing a first example in which the housing position adjustment mechanism is composed of multiple pressure chambers, and (b) is a schematic side view showing a second example in which the housing position adjustment mechanism is composed of multiple pressure chambers. [Figure 20] (a) is a schematic side view showing a third example in which the housing position adjustment mechanism is composed of multiple pressure chambers, and (b) is a schematic side view showing a fourth example in which the housing position adjustment mechanism is composed of multiple pressure chambers. [Figure 21] FIG. 10 is a schematic side view showing a fifth example in which the housing position adjustment mechanism is configured by a plurality of pressure chambers. [Figure 22] FIG. 22 is a cross-sectional view taken along line XXII-XXII in FIG. 20(a). [Figure 23] FIG. 10 is a view corresponding to FIG. 2 of a ball screw feed device according to a fifth embodiment of the present invention. [Figure 24]FIG. 10 is a view corresponding to FIG. 2 of a ball screw feed device according to a first modified example of the fifth embodiment of the present invention. [Figure 25] FIG. 10 is a view corresponding to FIG. 2 of a ball screw feed device according to a second modified example of the fifth embodiment. [Figure 26] FIG. 26 is an enlarged view of part XXVI in FIG. 25. [Figure 27] FIG. 13 is a view corresponding to FIG. 2 of a ball screw feed device according to a third modified example of the fifth embodiment. [Figure 28] FIG. 10 is a view corresponding to FIG. 2 of a ball screw feed device according to a fourth modified example of the fifth embodiment. [Figure 29] 1(a) is an enlarged cross-sectional view corresponding to FIG. 2 in a phase where an oil supply passage formed in a bearing housing side member is provided to fill the pressure chamber with working fluid, and FIG. 1(b) is a cross-sectional view showing a modified example of the locking plug bolt of FIG. [Figure 30] 29(a) is a cross-sectional view of a stopper plug used in place of the stopper bolt of FIG. 29(a), (b) is a cross-sectional view showing an example in which the stopper plug of (a) is combined with a disk-shaped member, (c) is a cross-sectional view showing a modified example of the disk-shaped member of (b), and (d) is a cross-sectional view showing another modified example of the disk-shaped member of (b). [Figure 31] FIG. 10 is a cross-sectional view of a table feed system of a machine tool to which a ball screw feed device according to a modified example of the present invention is applied. [Figure 32] 10 is a cross-sectional view showing a first example of a housing position adjustment mechanism in which a support base is disposed on the axial end side of a bearing unit. FIG. [Figure 33] 10 is a cross-sectional view showing a second example of a housing position adjustment mechanism in which a support base is disposed on the axial end side of a bearing unit. FIG. [Figure 34] 10 is a cross-sectional view showing a third example of a housing position adjustment mechanism in which a support base is disposed on the axial end side of a bearing unit. FIG. [Figure 35] FIG. 10 is a cross-sectional view showing a fourth example of a housing position adjusting mechanism in which a support base is disposed on the axial end side of a bearing unit. [Figure 36] 1 is a cross-sectional view showing a rotation support device according to the present invention. [Figure 37] FIG. 10 is a cross-sectional view showing another rotation support device according to the present invention. [Figure 38] 1 is a cross-sectional view showing a shaft support device to which a support mechanism position adjustment mechanism according to the present invention is applied. [Figure 39] FIG. 39 is an enlarged view of part XXXIX in FIG. 38. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a ball screw feed device, which is an example of a rotation support device or a shaft support device according to the present invention, will be described in detail with reference to the drawings.

[0011] (First embodiment) Fig. 1 shows a table feed system of a machine tool to which a ball screw feed device of the first embodiment is applied. With respect to Figs. 1 to 3, the axial direction of a screw shaft 21 of a ball screw feed device 20 (the left-right direction in Fig. 1) is defined as the X direction, the direction parallel to the mounting surface 1a of a base 1 and perpendicular to the axial direction of the screw shaft 21 (the direction perpendicular to the plane of the paper in Fig. 1) is defined as the Y direction, and the direction perpendicular to the mounting surface 1a of the base 1 (the up-down direction in Fig. 1) is defined as the Z direction. In Fig. 2 and the figures corresponding to Fig. 2, dotted lines indicate bolt fastening locations.

[0012] The table feed system 10 includes a moving table 11 fixed to a nut 23 of a ball screw feed device 20, and is configured so that the moving table 11 is movable in the X direction by driving a screw shaft 21 of the ball screw feed device 20 with a drive motor 12. The moving table 11 is provided with a pair of linear guides 13 (only one of which is shown in FIG. 1) on both sides of the ball screw feed device 20 in the Y direction. Each linear guide 13 includes a guide rail 15 disposed parallel to the screw shaft 21 on the base 1 via a rail mounting base 14, and two sliders 16 fixed to the underside of the moving table 11 and mounted across the guide rails 15. When the screw shaft 21 is rotated by the drive motor 12, the moving table 11 is guided by the pair of linear guides 13 and moves back and forth linearly together with the nut 23.

[0013] The ball screw feed device 20 comprises a screw shaft 21 having a spiral screw groove 21b formed on its outer peripheral surface, a nut 23 arranged around the screw shaft 21, having a spiral screw groove (not shown) formed on its inner peripheral surface, and fitted into a nut housing 22 fixed to the underside of the moving table 11, and a plurality of balls (not shown) arranged so as to roll freely between the screw groove of the nut 23 and the screw groove 21b of the screw shaft 21.

[0014] The screw shaft 21 includes a large diameter portion 24 formed in the axial center and having a screw groove 21b, and small diameter portions 25 formed at both axial ends of the large diameter portion 24. A male thread 25a is formed on the outer peripheral surface of the tip end of the small diameter portion 25, and a small diameter shaft portion 27 is provided at the tip end of one side (the right side in the figure) of the screw shaft 21. The small diameter shaft portion 27 is connected to the rotating shaft 12a of the drive motor 12 via a coupling 28.

[0015] In addition, one side of the 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 screw shaft 21 (the left side in the figure) is rotatably supported by a second support mechanism 40.

[0016] 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 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 fitted inside the fixed-side bearing housing 31, an inner ring 35 fitted outside the small diameter portion 25 of the screw shaft 21, and a plurality of balls 36 rollably disposed between the outer ring 34 and the inner ring 35 with a contact angle therebetween.

[0017] The pair of angular contact ball bearings 33, 33 has the outer ring 34 of the axially inner angular contact ball bearing 33 abutting against the inward flange 31a of the fixed-side bearing housing 31, and the outer ring 34 of the axially outer angular contact ball bearing 33 fixed by an outer ring holder 37 fastened to the fixed-side bearing housing 31. The inner ring 35 of the axially inner angular contact ball bearing 33 abuts against the step 21a between the large-diameter portion 24 and the small-diameter portion 25 of the screw shaft 21, and the inner ring 35 of the axially outer angular contact ball bearing 33 is fastened by a fastening nut 38a that screws onto the male thread 25a. Therefore, the first support mechanism 30 supports the screw shaft 21 in a state where the axial position of the screw shaft 21 is fixed.

[0018] 2 and 3, the second support mechanism 40 includes a bearing unit 41 arranged at the other end of the screw shaft 21, a support base 43 fixed to the base 1 axially centrally of the bearing unit 41, and a housing position adjustment mechanism 60 disposed between the bearing unit 41 and the support base 43. The support base 43 is provided with a through-hole 43a through which the screw shaft 21 passes.

[0019] The bearing unit 41 includes a moving-side bearing housing 51 and a pair of angular contact ball bearings 53, 53 that support the screw shaft 21 rotatably relative to the moving-side bearing housing 51. The pair of angular ball bearings 53, 53 comprises an outer ring 54 fitted inside the moving side bearing housing 51, an inner ring 55 fitted outside the small diameter portion 25 of the screw shaft 21, and a plurality of balls 56 arranged between the outer ring 54 and the inner ring 55 so as to be able to roll freely with a contact angle.

[0020] In the 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 retainer 47 fastened and fixed to the moving-side bearing housing 51, so that each outer ring 54, 54 is positioned in the axial direction relative to the moving-side bearing housing 51. In addition, the inner ring 55 of the angular contact ball bearing 53 arranged on the axially outer side is fastened via a spacer 48 by a fastening nut 38b that threads onto the male thread 25a. That is, the pair of angular contact ball bearings 53, 53, the moving-side bearing housing 51, and the outer ring holder 47 can be unitized as the bearing unit 41 with a predetermined preload applied to the pair of angular contact ball bearings 53, 53 arranged in face-to-face combination, and this bearing unit 41 can be easily attached to the screw shaft 21 and the housing position adjustment mechanism 60. In this configuration, the moving-side bearing housing 51 can also be integrated with the bearing housing side member 62, if necessary.

[0021] The housing position adjustment mechanism 60 is provided on the support base 43 side and includes a support base side member 61 through which the screw shaft 21 passes, and a bearing housing side member 62 provided on the movable-side bearing housing 51 side and movable in the axial direction relative to the support base side member 61. The support base side member 61 and the bearing housing side member 62 face each other in the axial direction.

[0022] The support base side member 61 has an annular portion 61a protruding toward the support base 43 side, which fits into a through hole 43a of the support base 43, and is fixed to the support base 43 with a plurality of bolts (not shown). The bearing housing side member 62 has an annular portion 62a protruding toward the moving-side bearing housing 51 side, which fits into the inward flange 51a, and is fixed to the moving-side bearing housing 51 with a plurality of bolts 63 (see FIG. 3).

[0023] Furthermore, a bottomed annular recess 64 that opens toward the support base side member 61 (one axial side) is provided on the side surface of the bearing housing side member 62 facing the support base side member 61. Meanwhile, a ring-shaped protrusion 65 that protrudes into the annular recess 64 toward the bearing housing side member 62 (the other axial side) is provided on the side surface of the support base side member 61 facing the bearing housing side member 62. The ring-shaped recess 64 and the ring-shaped protrusion 65 are slidably fitted together in the axial direction, and an annular pressure chamber 66 is formed between the bottom surface, inward surface 64a, and outward surface 64b of the ring-shaped recess 64 and the tip surface of the ring-shaped protrusion 65.

[0024] In addition, an annular storage chamber 71 is formed within the annular protrusion 65, and an orifice 72 is formed along the axial direction at at least one location (two locations in Figure 2) in the circumferential direction to connect the storage chamber 71 to the pressure chamber 66.

[0025] The reservoir chamber 71 is formed in the shape of a disk groove, opening on the outward surface 65a of the annular protrusion 65 closer to the tip surface of the annular protrusion 65 than the groove in which the O-ring 67 described below is disposed.

[0026] The pressure chamber 66, the storage chamber 71, and the orifice 72 contain a working fluid, for example, hydraulic oil 70, in a compressed state, and the hydraulic oil 70 flows through the pressure chamber 66, the storage chamber 71, and the orifice 72, including the gap g between the outward surface 65a of the annular convex portion 65 and the inward surface 64a of the annular recess 64.

[0027] Additionally, in the pressure chamber 66, a plurality of disc springs 80, which are elastic members, are arranged in a compressed state between the opposing axial end faces of the support base side member 61 and the bearing housing side member 62, i.e., between the bottom surface of the annular recess 64 and the tip surface of the annular protrusion 65. Therefore, the space in the pressure chamber 66 other than the space occupied by the plurality of disc springs 80 is filled with hydraulic oil 70. Furthermore, a hollow member 90 configured to have a sealed structure is disposed in the storage chamber 71, In the reservoir chamber 71, the space other than the hollow member 90 is filled with the hydraulic oil 70.

[0028] The hydraulic oil 70 is a hydraulic fluid that has an elastic effect when an external force is applied, and whose rigidity has been confirmed industrially, and is given rigidity when compressed.

[0029] Specifically, it is known that the bulk modulus of hydraulic oil is affected by the inclusion of gas, etc. (see non-patent document (Deshimaru Junichi and Tanaka Hirohisa, "Measurement of the Bulk Modulus of Hydraulic Oil," Hydraulics and Pneumatics, Vol. 19, No. 7, 1988, pp. 580-583)). In this embodiment, even if the temperature rises by more than 4 degrees, when the pressure chamber 66 expands in the axial direction in response to the axial elongation of the screw shaft 21, the type of hydraulic oil and gas are appropriately selected so that the desired axial rigidity is imparted to the screw shaft by the pressure acting on the bearing housing side member 62.

[0030] The working fluid is not limited to oil, but may be any liquid such as water, or may be a gas, as long as it has an elastic effect and exhibits rigidity when compressed. Furthermore, the magnitude of the axial load applied by the working fluid to the screw shaft 21 may be set not only by the tightening amount of the fastening nut 38b but also by taking into consideration volume expansion due to a temperature rise of the working fluid, which occurs in conjunction with a temperature rise of the angular contact ball bearings 53, 53 and the screw shaft 21 during operation of the ball screw feed device 20. In addition, the magnitude of the axial load applied by the working fluid to the screw shaft 21 may also be set by taking into consideration volume expansion due to a temperature rise of the working fluid, which is caused by a change in the environment around the ball screw feed device 20 during operation of the ball screw feed device 20.

[0031] When the plurality of disc springs 80 function as series springs, they are arranged so that the convex surfaces of adjacent disc springs 80 face each other and the concave surfaces of adjacent disc springs 80 face each other, as shown in Fig. 2. When the plurality of disc springs 80 function as parallel springs, they are arranged so that the disc springs 80 face each other and face each other in the same direction in the axial direction, although this is not shown.

[0032] The hollow member 90 is a life-ring-like structure formed in an annular shape and having an elliptical cross section with an inner diameter larger than the outward surface 64b of the annular recess 64 and an outer diameter smaller than the inward surface 64a of the annular recess 64, and is made of elastically deformable rubber, resin, metal, etc., or a combination of these. The hollow member 90 contains an arbitrary liquid or gas that has an elastic effect when an external force is applied and whose rigidity has been industrially confirmed. However, from the viewpoint of ease of assembly, it is preferable that the hollow member 90 be structured so as to be divided into a plurality of parts in the circumferential direction.

[0033] Furthermore, O-rings 67 are fitted between the outward surface 65a of the annular convex portion 65 and the inward surface 64a of the annular recessed portion 64, and between the inward surface 65b of the annular convex portion 65 and the outward surface 64b of the annular recessed portion 64. Specifically, the O-rings 67 are arranged in annular seal grooves 68 formed in the outward surface 65a and the inward surface 65b of the annular convex portion 65 and come into sliding contact with the opposing inward surface 64a and the outward surface 64b of the annular recessed portion 64 to seal the radial gap between the outward surface 65a of the annular convex portion 65 and the inward surface 64a of the annular recessed portion 64, and the radial gap between the inward surface 65b of the annular convex portion 65 and the outward surface 64b of the annular recessed portion 64. Note that the seal grooves 68 may also be formed in the inward surface 64a and the outward surface 64b of the annular recessed portion 64. Furthermore, although one O-ring 67 and one seal groove 68 are respectively arranged between the opposing surfaces, multiple O-rings 67 and multiple seal grooves 68 may also be arranged. As a result, the O-ring 67 prevents leakage of the hydraulic oil 70 filled in the pressure chamber 66 and the reservoir chamber 71. From the viewpoint of preventing wear, the O-ring 67 may be subjected to a surface treatment that provides wear resistance or the like.

[0034] An anti-rotation mechanism 75 is provided between the support base side member 61 and the bearing housing side member 62 to prevent relative rotation therebetween. Specifically, for example, the bearing housing side member 62 has a through-hole 77 formed in at least one location in the circumferential direction, which penetrates radially so that the tip of a positioning pin 76 protrudes from the inward surface 64a of the annular recess 64. The tip of the positioning pin 76 is inserted into an elongated hole 78 formed along the axial direction in the outward surface 65a of the annular protrusion 65 of the support base side member 61 so that the bearing housing side member 62 can move in the axial direction. Note that the positioning pin 76 may be replaced by a rotational positioning key (not shown) or the like having a similar anti-rotation function, which is inserted into the elongated hole 78 so that the bearing housing side member 62 can move in the axial direction.

[0035] In this housing position adjustment mechanism 60, after storing hydraulic oil 70 and a plurality of disc springs 80 in the pressure chamber 66 and storing hydraulic oil 70 and a hollow member 90 in the reservoir chamber 71, the fastening nut 38b is tightened to press the bearing housing side member 62 toward the support base side member 61 via the pair of angular ball bearings 53, 53 and the moving side bearing housing 51. The hydraulic oil 70 is compressed, and pressure in the screw axis direction is applied to the hydraulic oil 70; the multiple disc springs 80 are compressed, and pressure in the screw axis direction is applied to the multiple disc springs 80; and further, the hollow member 90 is compressed, and pressure in the screw axis direction is also applied to the hollow member 90.

[0036] Meanwhile, because 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 leftward in the figure by the pressure of the hydraulic oil 70 stored in a compressed state in the pressure chamber 66 and the plurality of disc springs 80, and by the pressure of the hydraulic oil 70 stored in a compressed state in the storage chamber 71 and the hollow member 90. This brings about a state in which tension is applied to the screw shaft 21 in advance to the left in Figures 1 and 2.

[0037] Furthermore, the pressure of the hydraulic oil 70 and the plurality of disc springs 80 contained in the pressure chamber 66, and the pressure of the hydraulic oil 70 and the hollow member 90 contained in the reservoir chamber 71 can each be controlled to any desired magnitude by the amount of tightening of the fastening nut 38b. That is, the magnitude of the axial load applied to the screw shaft 21 can be set to any desired magnitude by the fastening nut 38b.

[0038] Furthermore, the magnitude of the axial load applied to the screw shaft 21 by the hydraulic oil 70 can be set not only by the amount of tightening of the fastening nut 38b, as described above, but also by taking into consideration the volume expansion of the hydraulic oil 70 due to a rise in temperature when the ball screw feed device 20 is in operation.

[0039] Next, the operation of the ball screw feed device 20 of this embodiment will be described. In the ball screw feed device 20, when the screw shaft 21 is driven to rotate by the drive motor 12 and the moving table 11 fixed to the nut 23 is caused to move back and forth in a linear motion, the drive motor 12, angular contact ball bearings 33, 53, nut 23, etc. generate heat as a result of this motion, the temperature of the ball screw feed device 20 gradually rises, and the screw shaft 21 extends in the axial direction due to thermal expansion.

[0040] 1, when the screw shaft 21 expands in the axial direction due to thermal expansion, the right end of the screw shaft 21 extends leftward because the right end of the screw shaft 21 is fixed to the fixed-side bearing housing 31 via the angular contact ball bearings 33, 33. When the screw shaft 21 expands in the axial direction (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 expansion of the screw shaft 21 due to thermal expansion due to the interaction between the pressure of the hydraulic oil 70 and the plurality of disc springs 80 contained in the pressure chamber 66 and the pressure of the hydraulic oil 70 and the hollow member 90 contained in the reservoir chamber 71.

[0041] In this embodiment, the hydraulic oil 70, the plurality of disc springs 80, and the hollow member 90 are designed to continue to press the bearing unit 41 and the bearing housing side member 62 to the left even when the screw shaft 21 extends in the axial direction. The hydraulic oil 70, the pressure chamber 66, and the reservoir chamber 71 have a high degree of design freedom. By appropriately selecting the physical properties of the hydraulic oil 70 filled in the pressure chamber and the size and shape of the pressure chamber and the reservoir chamber, the pressure of the hydraulic oil 70 can be exerted in addition to the pressure of the plurality of disc springs 80 and the hollow member 90, thereby applying a sufficient and appropriate load in response to greater axial extension. Therefore, even if the temperature of the ball screw feed device 20 rises above 4 degrees, the pair of angular contact ball bearings 53 can be moved axially to maintain axial support rigidity, and the axial rigidity of the ball screw feed device 20 is stabilized.

[0042] In particular, because the hydraulic oil 70 can flow through the pressure chamber 66 and the reservoir chamber 71 via an orifice, the load pressing the bearing unit 41 and the bearing housing side member 62 is shared among the multiple disc springs 80, hollow member 90, and hydraulic oil 70, and the design can be such that the load can change in response to the axial elongation of the screw shaft 21 even in the event of a temperature rise of more than 4 degrees. As a result, while the screw shaft 21 is elongating in the axial direction, the pair of angular contact ball bearings 33, 33 remains as a fixed support, and the axial rigidity of the ball screw feed device 20 is stabilized.

[0043] In this embodiment, excessive loads are not applied to the pair of angular ball bearings 33, 33 and 53, 53, so there is no risk of excessive wear or seizure due to poor lubrication, and the life of the pair of angular ball bearings 33, 33 and 53, 53 is extended. In other words, in this embodiment, there is no need to apply pretension to the screw shaft 21 of the magnitude that was applied by the spacer in the ball screw described in Patent Document 1, so excessive loads will no longer act on the pair of angular ball bearings 33, 33 and 53, 53.

[0044] Furthermore, in the ball screw feed device 20 of this embodiment, it is not necessary to install external devices such as an accumulator or a pump for supplying the hydraulic oil 70 to the pressure chamber 66 and the reservoir chamber 71, thereby simplifying the housing position adjustment mechanism 60. As a result, the pressures in the pressure chamber 66 and the reservoir chamber 71 can be maintained with as little change as possible without consuming energy supplied from the outside.

[0045] The O-ring 67 in this embodiment also functions as a damping mechanism. That is, when a workpiece placed on the movable table 11 is machined, vibrations generated in the movable table 11 tend to cause the screw shaft 21, which has a relatively low rigidity, to vibrate. This vibration of the screw shaft 21 is propagated to the bearing housing side member 62 via the pair of angular contact ball bearings 33, 33 and the movable-side bearing housing 51, but the vibration of the bearing housing side member 62 is damped by the O-ring 67 between the bearing housing side member 62 and the support base side member 61. Therefore, the vibration of the screw shaft 21 can also be damped, and disturbances in the machined surface quality of the workpiece placed on the movable table 11 can be suppressed. In this case, the O-ring 67 arranged between the bearing housing side member 62 and the support base side member 61 can not only damp vibrations in the axial direction of the screw shaft 21, but also damp vibrations in the radial direction of the screw shaft 21.

[0046] Furthermore, the hydraulic oil 70 of the housing position adjustment mechanism 60 is stored not only in the pressure chamber 66, the reservoir chamber 71, and the orifice 72, but also in the gaps between the outward surface 65a of the annular convex portion 65 and the inward surface 64a of the annular recessed portion 64, and between the inward surface 65b of the annular convex portion 65 and the outward surface 64b of the annular recessed portion 64, and in each gap on the pressure chamber 66 side of the O-ring 67. Therefore, when the hydraulic oil 70 is compressed, pressure acts on the hydraulic oil 70 not only in the axial direction but also in the radial direction. As a result, the bearing housing side member 62 is supported by the support base side member 61 with a sufficient and appropriate radial load. As a result, the housing position adjustment mechanism 60 can provide radial support rigidity to the screw shaft 21 via the pair of angular ball bearings 53, 53 and the bearing housing 51, and can also have an aligning function for the screw shaft 21.

[0047] Furthermore, when the axial elongation of the screw shaft 21 described above occurs, even if vibration occurs due to elastic deformation when the disc spring 80 or the hollow member 90 recovers from a compressed state, the O-ring 67 can damp this vibration.

[0048] Furthermore, when the disc spring 80 and the hollow member 90 are restored from their compressed state, the hydraulic oil 70 passes through the orifice 72 and the gap g between the outward surface 65a of the annular protrusion 65 and the inward surface 64a of the annular recess 64, thereby damping the vibration. Therefore, similar to the O-ring 67 described above, when a workpiece placed on the moving table 11 is machined, the vibration transmitted to the screw shaft 21 is damped, and the quality of the machined surface of the workpiece can be further improved.

[0049] In addition, the hydraulic oil 70 in the pressure chamber 66 exerts an orifice effect by passing through the tiny gaps that form at the contact points between the disc springs 80 or between the disc springs 80 and the inner surface of the pressure chamber 66, thereby damping the vibrations of the screw shaft 21 and the multiple disc springs 80 mentioned above.

[0050] Therefore, in the ball screw feed device 20 of this embodiment, hydraulic oil 70 and multiple disc springs 80 are contained in the pressure chamber 66, hydraulic oil 70 and a hollow member 90 are contained in the storage chamber 71, and the pressure chamber 66 and the storage chamber 71 are circulated through an orifice 72.This makes it possible to continuously and stably maintain axial support rigidity even if the axial length of the screw shaft 21 changes due to the influence of heat, and to damp vibrations in the axial and radial directions.

[0051] 4, the disc-shaped disc spring 80 may have a plurality of through holes 80a penetrating the conical plate portion in the axial direction, or may have a plurality of slits (not shown). This allows the disc spring 80 to function as an orifice, and the hydraulic oil 70 to flow through the plurality of through holes 80a and slits, thereby further enhancing the damping effect.

[0052] Furthermore, in the above embodiment, the hollow member 90 has an elliptical cross section, but is not limited to this, and may have a rectangular cross section as shown in Fig. 5(a) or a triangular cross section as shown in Fig. 5(b). Furthermore, in the above embodiment, the hollow member 90 is formed in an annular shape, but is not limited to this, and may be formed in one or more spherical shapes, semicircular arc shapes (not shown), or the like as shown in Fig. 5(c).

[0053] 6(a) and 6(b) are cross-sectional views of a hollow member 90 formed in an annular shape according to a modified example of this embodiment. As in these modified examples, the hollow member 90 may be configured to have at least one rib 90a protruding from its inner circumferential surface. The rib 90a may be formed in an annular shape around the entire circumference of the hollow member 90, or may be formed partially in the circumferential direction of the hollow member 90. Furthermore, the rib 90a may be formed only partially in the circumferential direction of the ring-shaped cross section.

[0054] By providing the hollow member 90 with such ribs 90a, when the hollow member 90 is compressed and deformed due to the pressure generated in the storage chamber 71, the ribs 90a come into contact with the inner peripheral surface facing the ribs 90a, thereby preventing the hollow member 90 from being excessively deformed, such as by plastic deformation. This also prevents the liquid or gas contained in the hollow member 90 from leaking into the storage chamber 71. The rib 90a can also be applied to hollow members having shapes other than annular, and may be formed inside the above-mentioned spherical or semicircular hollow members, for example.

[0055] 7, the hollow member 90 may be provided with at least one outer layer 100 that covers (molds) the entire surface. This allows the rigidity of the hollow member 90 to be changed and also protects the surface of the hollow member 90 from working fluids such as the working oil 70. The outer layer 100 may be made of the same material as the hollow member, but may also be made of a different material.

[0056] Furthermore, in the above embodiment, the hollow member 90 is molded seamlessly as a single piece, which makes it difficult for localized stress concentrations to occur and allows for easy manufacturing. However, the hollow member 90 is not limited to being molded as a single piece, and may be, for example, a combined body having a hollow cross section formed by integrating two or more members via their edges. Alternatively, the hollow member 90 may be formed by bending members and joining their edges to form a hollow cross section.

[0057] 8 to 10, the hollow member 90 is a combined body having a hollow cross section, which is formed by combining two or more ring-shaped members 101, 102 together via ribs 101a, 102a formed on both peripheries of these ring-shaped members 101, 102. The ring-shaped members 101, 102 may be combined by any suitable method selected from among adhesive bonding, fusion bonding, connection using a mechanical locking mechanism, and the like.

[0058] For example, as shown in Figures 8(a) to 8(c), the hollow member 90 is composed of an outer diameter side ring-shaped member 101 and an inner diameter side ring-shaped member 102, which are divided into two in the radial direction, and the circular arc-shaped portions 101b, 102b of the ring-shaped members 101, 102 form a hollow cross section. Also, in Figures 8(a) and 8(b), one of the ribs 101a, 102a is made longer than the other and joined to each other by adhesive or fusion welding. In particular, as shown in Figure 8(b), the tip of the longer rib 102a may be bent so that the rib 102a covers the side of the shorter rib 101a. Furthermore, as shown in Figure 8(c), the ribs may be joined to each other by a continuous or discontinuous U-shaped fastening structure, with the tip of the longer rib 102a covering the tip of the shorter rib 101a, to seal the interior.

[0059] Alternatively, as shown in Figures 9(a) to 9(c), the hollow member 90 is composed of a left ring-shaped member 101 and a right ring-shaped member 102 that are divided in two axial directions, and the circular arc-shaped portions 101b and 102b of the ring-shaped members 101 and 102 form a hollow cross section. Also, in Figures 9(a) and 9(b), one of the ribs 101a and 102a may be made longer than the other and joined to each other by adhesive or fusion welding. In particular, as shown in Figure 9(b), the tip of the longer rib 102a may be bent so that the rib 102a covers the side of the shorter rib 101a. Furthermore, as shown in Figure 9(c), the ribs may be joined to each other by a continuous or discontinuous U-shaped fastening structure, with the tip of the longer rib 102a covering the tip of the shorter rib 101a, to seal the interior.

[0060] Furthermore, as shown in Figures 10(a) and (b), the hollow member 90 may have seal grooves 101a1, 102a1 formed near the edges on at least one of the opposing surfaces of the ribs 101a, 102a of the two divided ring-shaped members 101, 102 (rib 101a in Figure 10(a) and ribs 101a, 102a in Figure 10(b)), and a seal member such as an O-ring 103 may be placed therein to improve internal sealing performance.

[0061] 11(a) to (c), the hollow member 90 is formed by bending a ring-shaped member 104 having a strip-like cross section so as to form a hollow cross section all around, and joining ribs 104a and 104b formed on the periphery of the ring-shaped member 104. In this case, the ring-shaped member 104 can be joined by adhesion, fusion bonding, An appropriate method may be selected from among connection using a mechanical locking mechanism, etc.

[0062] 11(a) and 11(b), one of the ribs 104a, 104b is longer than the other and joined to each other by adhesive or melt-bonding. In particular, as shown in Fig. 11(b), the tip of the long rib 104b may be bent so that the rib 104b covers the side of the short rib 104a. Furthermore, as shown in Fig. 11(c), the ribs may be joined to seal the interior with a continuous or discontinuous U-shaped fastening structure so that the tip of the long rib 104b covers the tip of the short rib 104a.

[0063] In this way, by using the configurations shown in FIGS. 8 to 11, the deformable hollow member 90 can be easily manufactured by methods other than integral molding. The peripheral portions of the ring-shaped members 101, 102, and 104 are as shown in FIGS. The ribs 101a, 102a, 104a, and 104b may not be included. That is, the hollow member 90 may be formed by joining the peripheral edges of the arc-shaped portions 101b and 102b of the ring-shaped members 101 and 102 by an appropriate joining method, or the hollow member 90 may be formed by joining the peripheral edge of the curved portion of the ring-shaped member 104 by an appropriate joining method. Furthermore, the configurations shown in Figures 8 to 11 are not limited to those that are based on ring-shaped members, but can also be applied to planar or curved members for constructing spherical or semicircular arc shapes, as shown in Figure 4(c).

[0064] In addition, in the above embodiment, the storage chamber 71 is formed on the outer diameter side so as to open to the outward 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 inward surface 65b of the annular convex portion 65. Furthermore, the cross-sectional shape and length of the orifice 72 may be arbitrarily formed as long as they provide a damping function.

[0065] Although not shown, the support base side member 61 may be configured integrally with the support base 43, and the bearing housing side member 62 may be configured integrally with the moving side bearing housing 51.

[0066] (Second embodiment) Next, a ball screw feed device according to a second embodiment of the present invention will be described with reference to Figures 12 and 13. Note that in this embodiment, the configuration of the housing position adjustment mechanism 60 of the second support mechanism 40 is different from that of the first embodiment.

[0067] In the housing position adjustment mechanism 60 of the second embodiment, the seal groove 68 formed on the outward surface 65a and the inward surface 65b of the annular protrusion 65 is composed of a tapered surface 69a whose groove depth becomes shallower as it moves away from the pressure chamber 66 side, and circular ring-shaped axial side surfaces 69b, 69c extending radially from both axial end edges of the tapered surface 69a.

[0068] Furthermore, the axial distance between both axial side surfaces 69b, 69c is wider than the axial width of the O-ring 67 when it is elastically deformed and attached to the seal groove 68. As a result, the hydraulic oil 70 that has passed through the gap g from the pressure chamber 66 flows around to the vicinity of the boundary between the axial side surface 69b, which has a deep groove, and the tapered surface 69a.

[0069] Therefore, as the pressure of the hydraulic oil 70 inside the pressure chamber 66 increases and the O-ring 67 is pushed toward the atmospheric pressure side by the hydraulic oil 70, the O-ring 67 further improves the sealing performance due to the wedge structure between the tapered surface 69a of the seal groove 68 and the inward surface 64a and outward surface 64b of the opposing annular recess 64. As a result, even if relative movement occurs between the support base side member 61 and the bearing housing side member 62, leakage of the hydraulic oil 70 toward the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device 20 can be continuously maintained.

[0070] As a modification of this embodiment, as shown in Figures 14(a) to (c), a wear-resistant member 59 may be interposed between the O-ring 67 and at least one of the inward surface 64a of the annular recess 64 and the outward surface 65a of the annular protrusion 65 (in this embodiment, the tapered surface 69a of the seal groove 68 formed on the outward surface 65a).

[0071] Specifically, as shown in FIG. 14(a), the wear-resistant member 59 may be formed as an annular member having a U-shaped cross section so as to be positioned between the outer peripheral surface of the O-ring 67 and the inward surface 64a of the annular recess 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 outward surface 65a of the annular protrusion 65.

[0072] 14(b), the wear-resistant member 59 may be formed as an annular member having a straight cross section so as to be positioned between the inner peripheral surface of the O-ring 67 and the tapered surface 69a of the seal groove 68 formed in the outward surface 65a of the annular protrusion 65. Furthermore, as shown in FIG. 14(c), the wear-resistant member 59 may be formed as an annular member having a straight cross section so as to be positioned between the outer peripheral surface of the O-ring 67 and the inward surface 64a of the annular recess 64.

[0073] The wear-resistant member 59 may be made of, for example, a resin material such as a fluorine-based resin, or a metal material that has been subjected to an appropriate surface treatment.

[0074] In any of the embodiments shown in Figures 14(a) to (c), the use of the wear-resistant member 59 can disperse the stress concentration on the O-ring 67, thereby suppressing damage such as wear to the O-ring 67 and the contact surface with the O-ring 67.

[0075] In addition, the wear-resistant member 59 may also be interposed between the O-ring 67 and at least one of the outward surface 64b of the annular recess 64 and the inward surface 65b of the annular protrusion 65 (in FIG. 13, the tapered surface 69a of the seal groove 68 formed on the inward surface 65b), as shown in FIG.

[0076] 14(a) to 14(c), the wear-resistant member 59 is interposed between the O-ring 67 and the opposing surface of the O-ring 67 in the seal groove 68 having a tapered surface 69a. On the other hand, the above effect can also be achieved by interposing the wear-resistant member 59 between the O-ring 67 and the opposing surface of the O-ring 67 in the seal groove 68 having a uniform groove depth as shown in FIG. The other configurations and operations are the same as those of the first embodiment.

[0077] (Third embodiment) Next, a ball screw feed device according to a third embodiment of the present invention will be described with reference to Fig. 15. In this embodiment, the configuration of the housing position adjustment mechanism 60 of the second support mechanism 40 differs from that of the first embodiment.

[0078] In the housing position adjustment mechanism 60 of the third embodiment, heating elements 180, 181, such as heating wires or rubber heaters, serving as working medium volume change parts, are arranged in a ring shape or discretely on the outer circumferential surfaces of the support base side member 61 and the bearing housing side member 62.

[0079] As a result, heat from the heating elements 180, 181 is transmitted from the support base side member 61 and the bearing housing side member 62 to the hollow member 90 and the hydraulic oil 70 in the pressure chamber 66, and by heating the hollow member 90 and the hydraulic oil 70, the volumes of the hollow member 90 and the hydraulic oil 70 can be expanded. As a result, even if the screw shaft 21 elongates in the axial direction, a load is excited in the pressure chamber 66 due to the volume expansion of the hollow member 90 and the hydraulic oil 70, so that the support rigidity in the axial direction can be maintained.

[0080] In this embodiment, heating elements 180, 181 are attached to the outer peripheral surfaces of the support base side member 61 and the bearing housing side member 62 as working medium volume change units, but cooling media 182, 183 such as a cooling jacket or a cooling element may be attached instead.

[0081] By using the cooling media 182, 183, even if the load excited in the pressure chamber 66 becomes excessive due to the volume expansion of the hollow member 90 and the hydraulic oil 70, it is possible to cool the hollow member 90 and the hydraulic oil 70 and contract the volumes of the hollow member 90 and the hydraulic oil 70. This prevents the axial support stiffness of the ball screw feed device 20 from becoming excessively large, and makes it possible to continuously maintain the axial support stiffness in a stable state.

[0082] In addition, in this embodiment, the temperatures of the hollow member 90 and the hydraulic oil 70 are affected by the components, installation environment, operation cycle, etc. of the ball screw feed device 20, and therefore the hollow member 90 and the hydraulic oil 70 may be controlled to a target temperature by forming a feedback loop for the temperatures of the components, hollow member 90, hydraulic oil 70, etc. using the heating elements 180, 181 and the cooling media 182, 183. Furthermore, in this embodiment, the operation of the heating elements 180, 181 and the cooling media 182, 183 may be feedback-controlled by taking into consideration the change in volume of the hydraulic oil 70, the pressure state within the pressure chamber 66, the relative axial displacement between the support base side member 61 and the bearing housing side member 62, etc.

[0083] In addition, in this embodiment, the working medium volume change unit is attached to both the support base side member 61 and the bearing housing side member 62, but it may also be attached to either the support base side member 61 or the bearing housing side member 62.

[0084] Furthermore, in this embodiment, the working medium volume change unit is provided on the outer peripheral surface of the support base side member 61 and the outer peripheral surface of the bearing housing side member 62, but it can be attached at any position, such as the axial side, inner peripheral surface, or interior, as long as it is a location where the volume of the hollow member 90 and working oil 70 in the pressure chamber 66 can be expanded or contracted. In addition, a heating element may be attached to either the support base side member 61 or the bearing housing side member 62, and a cooling medium may be attached to the other. Also, the heating element and the cooling medium may be arranged so as to coexist in either the support base side member 61 or the bearing housing side member 62. The other configurations and operations are the same as those of the first embodiment.

[0085] (Fourth embodiment) Next, a ball screw feed device according to a sixth embodiment of the present invention will be described with reference to Fig. 16. This embodiment differs from the first embodiment in that the second support mechanism 40 further includes another housing position adjustment mechanism 160.

[0086] That is, the second support mechanism 40 of the fourth embodiment further includes another housing position adjustment mechanism 160 disposed adjacent to the housing position adjustment mechanism 60 between the bearing unit 41 and the support base 43 . The other housing position adjustment mechanism 160 includes: another support base side member 161 provided on the support base 43 side and through which the screw shaft 21 passes; another bearing housing side member 162 provided on the bearing housing 51 side and through which the screw shaft 21 passes and which is movable axially relative to the other support base side member 161; another pressure chamber 166 formed between the other support base side member 161 and the other bearing housing side member 162; another storage chamber 171 formed in either the other support base side member 161 or the other bearing housing side member 162; another working fluid 170 contained in an orifice 172 communicating between the other pressure chamber 166 and the other storage chamber 171; an elastic member 80 arranged in a compressed state within the other pressure chamber 166 between the opposing axial end faces of the other support base side member 161 and the other bearing housing side member 162; and a hollow member 90 contained within the other storage chamber 171. That is, the second support mechanism 40 has two housing position adjustment mechanisms 60, 160 arranged in tandem in the axial direction.

[0087] 16, in another housing position adjustment mechanism 160, another bearing housing side member 162 has an annular recess 164, and another support base side member 161 has an annular protrusion 165 that is axially slidably fitted within the annular recess 164. Furthermore, multiple disc springs 80 and another working fluid 170 are disposed in another pressure chamber 166 formed between the annular recess 164 and the annular protrusion 165. As the other working fluid 170, the one exemplified as the working oil 70 is applied.

[0088] In this embodiment, the other support base side member 161 has an annular portion 161a protruding toward the support base 43 side, which fits into a through hole 43a of the support base 43, and is fixed to the support base 43 with a plurality of bolts (not shown). Furthermore, the support base side member 61 of the housing position adjustment mechanism 60 and the other bearing housing side member 162 of the other housing position adjustment mechanism 160 are integrally configured as a single member or by connecting the two.

[0089] In this way, by arranging the two housing position adjustment mechanisms 60, 160 in series in the axial direction, it is possible to stably maintain the axial rigidity of the ball screw feed device 20 even when the extension of the screw shaft is even greater, and it is also possible to improve axial alignment and coaxiality.

[0090] 16, the other housing position adjustment mechanism 160 is not limited to having the same configuration as the housing position adjustment mechanism 60, and may have any other configuration as long as it has pressure generating means housed in a compressed state in a pressure chamber 166 formed between the other support base side member 161 and the other bearing housing side member 162. For example, as the pressure generating means, a hollow member 90 may be disposed in the other pressure chamber 166 instead of an elastic member such as a spring. In addition, the second support mechanism 40 may have two housing position adjustment mechanisms 60, 160, or may have three or more housing position adjustment mechanisms, as long as the multiple housing position adjustment mechanisms are arranged in series in the axial direction. The other configurations and operations are the same as those of the first embodiment.

[0091] In the first to fourth embodiments, the pair of angular contact ball bearings applied to the bearing unit of the second support mechanism are arranged in a face-to-face arrangement, but the arrangement is not limited to this. That is, the pair of angular contact ball bearings 53, 53 may be arranged in various support configurations, such as a back-to-back arrangement as shown in Fig. 17 or a parallel arrangement as shown in Fig. 18. When the pair of angular contact ball bearings 53, 53 are arranged in a back-to-back arrangement as shown in Fig. 17, an inner ring spacer 49 may be arranged between the step between the large diameter portion 24 and the small diameter portion 25 of the screw shaft 21 and the inner ring 55 of the angular contact ball bearing 53 on the axially inner side. Furthermore, 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 be arranged in various support configurations such as a back-to-back combination or a parallel combination. Furthermore, although not shown, the angular contact ball bearings 33, 53 do not necessarily have to be made up of two angular contact ball bearings, but can also be made up of three or more angular contact ball bearings.

[0092] Furthermore, in the above embodiment, the other housing position adjustment mechanism 160 is arranged adjacent to the housing position adjustment mechanism 60 in the axial direction, but this is not limited to this, and it may also be configured to be arranged adjacent to the housing position adjustment mechanism 60 in parallel in the radial direction. This makes it easier to maintain the axial rigidity of the ball screw feed device 20 while reducing the axial dimension of the ball screw feed device 20 and generating a larger axial load than when a single housing position adjustment mechanism is installed.

[0093] Furthermore, in the above embodiment, the annular recess is provided on the bearing housing side member and the annular protrusion is provided on the support base side member, but the present invention is not limited to this, and the annular recess may be provided on the support base side member and the annular protrusion may be provided on the bearing housing side member.

[0094] Furthermore, in the above embodiment, the pressure chamber 66 and the storage chamber 71 are formed in an annular shape by the annular recess 64 and the annular protrusion 65, but a plurality of recesses and protrusions may be formed in the circumferential direction to form a plurality of pressure chambers and a plurality of storage chambers. In this case, hydraulic oil and an elastic member may be disposed in the plurality of pressure chambers, and hydraulic oil and a hollow member may be disposed in the storage chamber, respectively, and an O-ring may be disposed between the inner circumferential surface of the recess and the outer circumferential surface of the protrusion, to provide a configuration having a function of preventing hydraulic oil leakage and attenuating the pressure. In this case, an orifice that connects the reservoir chamber and the pressure chamber is also provided in each protrusion.

[0095] For example, as shown in FIG. 19(a), four pressure chambers 66 and reservoir chambers 71 may be arranged around the screw shaft 21 in the circumferential direction. Alternatively, as shown in FIG. 19(b), two pressure chambers 66 and reservoir chambers 71 arranged side by side adjacent to each other in the radial direction may be arranged at four circumferential positions, i.e., a total of eight pressure chambers 66 and reservoir chambers 71 may be arranged around the screw shaft 21. Alternatively, as shown in FIG. 20(a), two pressure chambers 66 and reservoir chambers 71 may be arranged around the screw shaft 21 in the circumferential direction, i.e., pressure chambers 66 and reservoir chambers 71 on both sides of the screw shaft 21 in the width direction (Y direction). Alternatively, as shown in FIG. 20(b), three pressure chambers 66 and reservoir chambers 71 arranged side by side adjacent to each other in the radial direction (width direction in this example) may be arranged at two circumferential positions, i.e., a total of six pressure chambers 66 and reservoir chambers 71 may be arranged around the 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 reduced.

[0096] 21, the pressure chambers 66 and the storage chambers 71 may be arranged at two locations in the circumferential direction, i.e., the pressure chambers 66 and the storage chambers 71 on both the upper and lower sides of the screw shaft 21, around the 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 reduced.

[0097] Here, Figure 22 is a schematic cross-sectional view taken along line XXII-XXII in Figure 20(a) In this case, the two pressure chambers 66 and the storage chambers 71 are each formed of a recessed portion 64x and a protruding portion 65x. In the drawing, the protrusion 65x is configured integrally with the base of the support base side member 61, but it may be configured separately from the base and then joined.

[0098] The multiple pressure chambers 66 and the multiple reservoir chambers 71 can be arranged arbitrarily as long as the bearing unit 41 and the bearing housing side member 62 can move stably in the same direction following the axial extension of the screw shaft 21 due to thermal expansion, and specifically, they are preferably arranged point-symmetrically or line-symmetrically on a plane perpendicular to the screw shaft 21. The multiple pressure chambers 66 and the multiple reservoir chambers 71 may also be arranged offset in the axial direction.

[0099] Furthermore, adjacent pressure chambers 66 or reservoir chambers 71 may be connected via a communication passage as necessary for purposes such as pressure equalization, and the working fluid inside may circulate through adjacent pressure chambers 66 and reservoir chambers 71. For example, in FIGS. 20(b) and 21, adjacent pressure chambers 66 communicate with each other via a communication passage 66x.

[0100] Furthermore, the support base side member 61 and the bearing housing side member 62 are not limited to being configured as a single member, but may be configured as separate members arranged around the screw shaft 21 according to the layout of the pressure chamber 66 and the storage chamber 71. Furthermore, the support base side member 61 and the bearing housing side member 62, which are single members, may also be configured as being arranged around the screw shaft 21 with a portion of the circumferential direction opened or divided. For example, in FIG. 20(b), two support base side members 61 and two bearing housing side members 62 are configured to be separated in the width direction of the screw shaft 21.

[0101] Additionally, similar to the other housing position adjustment mechanisms 160 described above, the pressure generating means in the multiple pressure chambers 66 and the reservoir chamber 71 are not limited to all having the same configuration, i.e., a configuration in which a working fluid and an elastic member are disposed in the pressure chamber 66, and a working fluid and a hollow member are disposed in the reservoir chamber 71, and the pressure generating means in any of the pressure chambers 66 may have another configuration, such as using an elastic member such as a spring. Therefore, it is sufficient that at least one of the multiple protrusions 65x has a reservoir chamber 71 and an orifice 72, and a protrusion 65x that does not have a reservoir chamber 71 or an orifice 72 may be provided.

[0102] Furthermore, the recesses and protrusions that make up the pressure chambers 66 and the storage chambers 71 are not limited to being circular in cross section, but may be any shape, such as rectangular. Furthermore, the cross-sectional dimensions and axial dimensions of the multiple pressure chambers 66 and the storage chambers 71 can each be configured as desired.

[0103] (Fifth embodiment) In the housing position adjustment mechanism 60 of the above-described embodiment and modified example, when the screw shaft 21 extends in the axial direction, the volume of the pressure chamber 66 increases, and the hydraulic oil 70 and disc spring 80 compressed in the pressure chamber 66 and the hydraulic oil 70 and hollow member 90 compressed in the storage chamber 71 gradually reduce pressure while pressing the bearing unit 41 and the bearing housing side member 62 to the left. This causes the pair of angular contact ball bearings 53, 53 to move axially, maintaining the axial support rigidity of the screw shaft 21.

[0104] However, in the fifth embodiment, the axial support rigidity of the screw shaft 21 is maintained by using a housing position adjustment mechanism 60 as shown in Fig. 23. Specifically, when the screw shaft 21 extends in the axial direction, the bearing unit 41 and the bearing housing side member 62 move to the left via the pair of angular contact ball bearings 53, 53 that move together with the screw shaft 21, and the volume of the pressure chamber 66 decreases. Meanwhile, as the pressure of the hydraulic oil 70, the disc spring 80, and the hollow member 90 gradually increases, the bearing unit 41 and the bearing housing side member 62 are pressed to the right. Therefore, by adjusting the volume of the pressure chamber 66 and the pressure of the disc spring 80 and the hollow member 90 so as to allow the screw shaft 21 to extend in the axial direction, the axial support rigidity of the screw shaft 21 can be maintained.

[0105] In this case, the support base side member 61 has a small diameter cylindrical portion 61c extending from the small diameter portion of the annular base portion 61b attached to the support base 43 toward the bearing housing 51, and an outward flange portion 61d extending 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 extending from the large diameter portion of the annular base portion 62b attached to the moving-side bearing housing 51 toward the support base 43, and an inward flange portion 62d extending from the tip of the large diameter cylindrical portion 62c toward the inner diameter side.

[0106] The outward flange portion 61d of the support base side member 61 is movable axially relative to the annular base portion 62b and the inward 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. The inward flange portion 62d of the bearing housing side member 62 is movable axially relative to the annular base portion 61b and the outward 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 partitioned by the small-diameter cylindrical portion 61c and the outward flange portion 61d of the support base side member 61 and the large-diameter cylindrical portion 62c and the inward flange portion 62d of the bearing housing side member 62, and this pressure chamber 66 is filled with hydraulic oil 70 and a disc spring 80 in a slightly compressed state.

[0107] Furthermore, the outward flange portion 61d is formed with a storage chamber 71 that opens to the inner circumferential surface of the large-diameter cylindrical portion 62c, and an orifice 72 that connects the pressure chamber 66 and the storage chamber 71. A hollow member 90 is arranged in the storage chamber 71.

[0108] In this case too, when the screw shaft 21 stretches in the axial direction due to thermal expansion, the pair of angular ball bearings 53, 53, the bearing housing 51, and the bearing housing side member 62 compress the hydraulic oil 70 and the disc spring 80 in the pressure chamber 66, and the hydraulic oil 70 and the hollow member 90 in the storage chamber 71, and move to the left in the figure due to the interaction of these pressures, thereby maintaining the axial support rigidity of the screw shaft 21.

[0109] In particular, because the hydraulic oil 70 can flow through the pressure chamber 66 and the reservoir chamber 71 via an orifice, the load pressing the bearing unit 41 and the bearing housing side member 62 is shared among the multiple disc springs 80, hollow member 90, and hydraulic oil 70, and the design can be such that the load can change in response to the axial elongation of the screw shaft 21 even in the event of a temperature rise of more than 4 degrees. As a result, while the screw shaft 21 is elongating in the axial direction, the pair of angular contact ball bearings 33, 33 remains as a fixed support, and the axial rigidity of the ball screw feed device 20 is stabilized.

[0110] In addition, by installing an O-ring 67 between the inner surface of the inward flange portion 62d and the outer surface of the small diameter cylindrical portion 61c, and between the outer surface of the outward flange portion 61d and the inner surface of the large diameter cylindrical portion 62c, leakage of the hydraulic oil 70 filled in the pressure chamber 66 and the storage chamber 71 can be prevented, and the O-ring 67 also functions as a damping mechanism to damp vibrations occurring in the screw shaft 21.

[0111] In addition, the hydraulic oil 70 in the pressure chamber 66 and the storage chamber 71 passes through the orifice 72 and the gap between the inner surface of the large diameter cylindrical portion 62c and the outer surface of the outward flange portion 61d, thereby damping vibrations of the screw shaft 21.

[0112] Furthermore, compressed hydraulic oil 70 is stored in each gap between the inner circumferential surface of the inward flange portion 62d and the outer circumferential surface of the small-diameter cylindrical portion 61c, and between the outer circumferential surface of the outward flange portion 61d and the inner circumferential surface of the large-diameter cylindrical portion 62c. Therefore, the radial pressure of the hydraulic oil 70 acting on each gap can improve the radial support rigidity and alignment ability between the bearing housing side member 62 and the support base side member 61. As a result, the housing position adjustment mechanism 60 can provide radial support rigidity to the screw shaft 21, and can also have an alignment function for the screw shaft 21.

[0113] The support base side member 61 and the bearing housing side member 62 may each be constructed from a single member, but as shown in Figure 23, in consideration of ease of assembly, they can also be constructed with two members 91, 92 and 93, 94 sandwiching an O-ring 67 between them. Furthermore, one O-ring 67 and one seal groove 68 are disposed between each opposing surface, but a plurality of them may be disposed.

[0114] Also, instead of Figure 23, the support base 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. Furthermore, the storage chamber and the orifice may be formed within the inward flange portion 62d, and the storage chamber may be open to the outer circumferential surface of the small diameter cylindrical portion 61c.

[0115] Also, in such a housing position adjustment mechanism 60, the pair of angular contact ball bearings 53, 53 may be arranged in a face-to-face configuration as shown in Fig. 23, a back-to-back configuration as shown in Fig. 24, a parallel configuration, or any other supporting configuration. In addition, although not shown, the pair of angular contact ball bearings does not necessarily have to be made up of two angular contact ball bearings, and can also be made up of three or more ball bearings.

[0116] Furthermore, as shown in Figures 25 and 26, in the housing position adjustment mechanism 60 of the fifth embodiment, similar to the second embodiment, the seal groove 68 formed on the inner surface of the inward flange portion 62d and the outer surface of the outward flange portion 61d may be configured by a tapered surface 69a whose groove depth becomes shallower as it moves away from the pressure chamber side, and circular axial side surfaces 69b, 69c extending radially from both axial end edges of the tapered surface 69a.

[0117] Therefore, as the pressure of the hydraulic oil 70 in the pressure chamber 66 increases and the O-ring 67 is pushed toward the atmospheric pressure side, the O-ring 67 further improves the sealing performance due to the wedge structure between the tapered surface 69a of the seal groove 68 and the outer peripheral surface of the opposing small-diameter cylindrical portion 61c and the inner peripheral surface of the large-diameter cylindrical portion 62c. As a result, even if relative movement occurs between the support base side member 61 and the bearing housing side member 62, leakage of the hydraulic oil 70 toward the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device 20 can be continuously maintained.

[0118] In this modified example, as shown in Figure 26, the seal groove 68 formed on either of the opposing surfaces of the two members 91, 92 that make up the support base side member 61, and the seal groove 68 formed on either of the opposing surfaces of the two members 93, 94 that make up the bearing housing side member 62 may also have a tapered surface 69a in which the groove depth becomes shallower as it moves away from the pressure chamber side.

[0119] Also, in this modified example, a wear-resistant member may be interposed between the O-ring 67 and at least one of the inner surface of the inward flange portion 62d and the outer surface of the small-diameter cylindrical portion 61c, and between the O-ring 67 and at least one of the outer surface of the outward flange portion 61d and the inner surface of the large-diameter cylindrical portion 62c.

[0120] In this case, the wear-resistant member 59 may be interposed between the O-ring 67 and the opposing surface of the O-ring 67 in a seal groove 68 having a tapered surface 69a as shown in FIG. 26, or may be interposed between the O-ring 67 and the opposing surface of the O-ring 67 in a seal groove 68 having a uniform groove depth as shown in FIG. 23.

[0121] Furthermore, as shown in FIG. 27, the housing position adjustment mechanism 60 of the fifth embodiment may be configured such that the support base side member 61 and the bearing housing side member 62 are provided with working medium volume change units such as heating elements 180, 181 and cooling media 182, 183, similar to the third embodiment.

[0122] As a result, as described in the third embodiment, depending on the state of the ball screw feed device 20 being used, the heating elements 180, 181 can expand the volume of the hollow member 90 and the hydraulic oil 70 in the pressure chamber 66, and the cooling media 182, 183 can contract the volume of the hollow member 90 and the hydraulic oil 70 in the pressure chamber 66, thereby continuously maintaining the axial support rigidity in a stable state.

[0123] Furthermore, in the housing position adjustment mechanism 60 of the fifth embodiment, as shown in FIG. 28, similar to the fourth embodiment, the second support mechanism 40 may have a tandem configuration 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 base 43.

[0124] In this case, the other support base side member 161 of the other housing position adjustment mechanism 160 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 has an annular base portion 162b, a large-diameter cylindrical portion 162c, and an inward flange portion 162d. The other support base 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. The support base side member 61 of the housing position adjustment mechanism 60 and the other bearing housing side member 162 of the other housing position adjustment mechanism 160 are connected to each other and configured as a single unit.

[0125] As in the fourth embodiment, the second support mechanism 40 may be configured such that a plurality of housing position adjustment mechanisms are arranged in series in the axial direction, or may be configured such that they are arranged in parallel in the radial direction.

[0126] The present invention is not limited to the above-described embodiment, and various modifications and improvements are possible. The embodiments and modifications described in this specification can be combined and applied within the scope of feasibility. For example, an auxiliary accumulator or an external pump for supplying hydraulic oil can be connected to the pressure chamber or reservoir chamber as needed. Furthermore, the condition of the ball screw feed device can be diagnosed or corrected by monitoring the pressure of the hydraulic oil in the pressure chamber or reservoir chamber or the load applied to the pair of angular bearings 53, 53. In the above embodiment, a disc spring is used as the elastic member, but the elastic member is not limited to this and may be a coil spring.

[0127] Furthermore, in the first to fourth embodiments, O-rings 67 are attached between the outward surface 65a of the annular convex portion 65 and the inward surface 64a of the annular recess 64, and between the inward surface 65b of the annular convex portion 65 and the outward surface 64b of the annular recess 64, but this is not limited thereto, and any sealing member may be arranged to prevent the hydraulic oil 70 from leaking from inside the pressure chamber 66. Similarly, in the fifth embodiment, O-rings 67 are fitted between the outer peripheral surface of the outward flange portion 61d and the inner peripheral surface of the large diameter cylindrical portion 62c, and between the inner peripheral surface of the inward flange portion 62d and the outer peripheral surface of the small diameter cylindrical portion 61c, but this is not limited thereto and any sealing member may be arranged to prevent the hydraulic oil 70 from leaking from inside the pressure chamber 66. Furthermore, it is more preferable that the seal member not only prevents the hydraulic oil 70 from leaking from the pressure chamber 66 but also damps vibrations of the screw shaft 21 in the same way as the O-ring 67 .

[0128] In any of the embodiments, the hydraulic oil 70 needs to be sealed from the outside after being filled into the pressure chamber 66. In this case, for example, in the housing position adjustment mechanism 60 shown in Fig. 2, an oil supply passage 109 for filling the pressure chamber 66 with the hydraulic oil 70 may be formed in the bearing housing side member 62 so as to penetrate radially between the inward surface 64a of the annular recess 64 and the outer peripheral surface of the bearing housing side member 62, as shown in Fig. 29(a).

[0129] A stopper bolt 110 may be attached to the outer peripheral surface of the bearing housing side member 62, threadedly engaging with a female thread portion 109a formed in the oil supply passage 109 to close the oil supply passage 109. The male thread portion of the stopper bolt 110 may be wrapped with sealing tape (not shown) or may be coated or filled with a leak prevention agent, thereby filling the gap between the male thread and the female thread portion 109a, and thereby more reliably preventing leakage of the hydraulic oil 70 filled in a compressed state.

[0130] Furthermore, an annular seal groove 110a may be formed on the surface of the head of the stopper bolt 110 that faces the outer circumferential surface of the bearing housing side member 62. This allows an O-ring 111 to be attached to the seal groove 110a, thereby improving the sealing performance of the stopper bolt 110. As shown in FIG. 29(b), the bottom surface of the seal groove 110a of the stopper bolt 110 is To further improve the sealing performance, the opening may be tapered.

[0131] Furthermore, the member blocking the oil supply passage 109 may be a stopper plug instead of the stopper bolt 110. For example, the oil supply passage 109 may be blocked by a tapered stopper plug 112 as shown in FIG. 30( a). In this case, the stopper plug 112 is threaded into a female thread portion 109a formed on the outer diameter side of the oil supply passage 109 and fixed to the oil supply passage 109. Furthermore, as shown in FIG. 30( b), the oil supply passage 109 has a tapered female thread portion 109a on the outer diameter side, and a straight portion 109b without a female thread portion is continuous with the female thread portion 109a via a stepped hole 109c. In this case, the stopper plug 112 may be fastened to the female thread portion 109a with a disk-shaped member 113 accommodated in the stepped hole 109c. In this case, the stopper plug 112 is fastened to the female thread portion 109a while deforming the disk-shaped member 113, so that a tight seal is ensured between the contact surface of the disk-shaped member 113 and the stepped hole 109c. In addition, the male thread portion of the stopper plug 112 may be wrapped with sealing tape (not shown) or a leak prevention agent may be applied or filled to fill the gap between the male thread and the female thread portion 109a, thereby providing good sealing properties.

[0132] As shown in Figure 30(c), the disk-shaped member 113 may be integrated with an elastically deformable member 114 that forms the contact surface with the stepped hole 109c. Alternatively, as shown in Figure 30(d), the disk-shaped member 113 may have an annular seal groove 113a formed in the contact surface with the stepped hole 109c, and an O-ring 115 may be disposed therein.

[0133] Furthermore, the oil supply passage 109 communicating with the pressure chamber 66 is not limited to a configuration in which it is formed so as to penetrate in the radial direction, but may be formed so as to penetrate in the axial direction through any of the members that constitute the pressure chamber 66 .

[0134] Furthermore, the support base may be configured to directly or indirectly support the support base side member of the housing position adjustment mechanism, and is not limited to a configuration in which the rotation axis passes through it as in the above embodiment, but may also be configured to be arranged around the rotation axis, and can be designed into any shape.

[0135] (Applicable to other ball screw feeders) 1, the drive motor 12 is coupled to one side (the right side in FIG. 1) of the screw shaft 21 supported by the first support mechanism 30, but the present invention is not limited to this. That is, as in the ball screw feed device 20 of FIG. 31, the drive motor 12 may be coupled to the other side (the left side in FIG. 31) 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 base 85 through which the screw shaft 21 passes. In addition, the tip of the small diameter shaft portion 27 is disposed within the coupling 28 away from the rotary shaft 12a of the drive motor 12 so that the small diameter shaft portion 27 can move in the axial direction when the screw shaft 21 expands axially due to thermal expansion.

[0136] Therefore, the present invention can be used with a high degree of freedom as a ball screw feed device for positioning devices that perform high-precision processing and measurement, such as machine tools (machining centers, lathes, grinders, etc.), measuring machines (3D measuring devices), semiconductor manufacturing equipment (tables for exposure devices, inspection probes, etc.), inspection equipment, etc., and for use in semiconductor manufacturing, etc.

[0137] In the above embodiment, the support base 43 is disposed on the axial center side relative to the bearing unit 41, but the present invention is not limited to this, and the support base 43 may be disposed on the axial end side relative to the bearing unit 41. That is, the support base 43 may be disposed on the axial end side relative to the bearing unit 41 depending on the configuration and operation of the housing position adjustment mechanism 60. It may be disposed on the axial center side of the bearing unit 41 or on the axial end side.

[0138] 32 and 33, the support base 43 is provided closer to the axial end than the bearing unit 41. In this case, the support base side member 61 may be attached directly or indirectly to the support base 43, and the bearing housing side member 62 may be attached directly or indirectly to the bearing housing 51. In addition, a spacer 48a disposed between the inner ring 55 and the fastening nut 38b passes through the through hole 43a of the support base 43, the support base side member 61, and the bearing housing side member 62.

[0139] 34 and 31, the support base 43 is disposed closer to the axial end than the bearing unit 41, and is fixed to a support base side member 61 disposed closer to the axial center than the bearing unit 41 by an outer cylinder part 43b that extends axially from a main body part having a through hole 43a and surrounds the periphery of the housing position adjustment mechanism 60. In this case as well, the support base side member 61 only needs to be attached directly or indirectly to the support base 43, and the bearing housing side member 62 is It may be attached directly or indirectly to the bearing housing 51. A spacer 48a disposed between the inner ring 55 and the fastening nut 38b passes through the through hole 43a of the support base 43.

[0140] (Application to devices other than ball screw feeders) Furthermore, although the above-described embodiment describes a ball screw feed device, the present invention can be applied to a rotation support device in which both axial ends of a rotating shaft are rotatably supported by a pair of support mechanisms, in addition to the ball screw feed device. That is, when the axial length of the rotating shaft changes due to the influence of heat, a housing position adjustment mechanism such as that in the above-described embodiment can be used to continuously and stably maintain the axial support rigidity of the rotating shaft. Furthermore, by using the housing position adjustment mechanism of the above embodiment, vibrations in the axial and radial directions can be damped.

[0141] For example, as shown in FIG. 36, a rotary support device 120 includes a rotary shaft 121 and a pair of support mechanisms 30, 40 that rotatably support both axial ends of the rotary shaft 121, respectively. The support mechanism 30 includes a bearing housing 31 fixed to the base 1, and bearings 33, 33 that rotatably support the rotating shaft 121 relative to the bearing housing 31, i.e., a pair of angular contact ball bearings 33, 33 arranged in a face-to-face combination.

[0142] The support mechanism 40 also includes a bearing housing 51, a bearing unit 41 that supports the rotating shaft 121 rotatably relative to the bearing housing 51 and is equipped with bearings 53, 53 that can support axial loads, i.e., a pair of angular ball bearings 53, 53 arranged in a face-to-face combination, a support base 43 that is arranged axially toward the center of the bearing unit 41 and through which the rotating shaft 121 passes, and a housing position adjustment mechanism 60 that is arranged between the bearing unit 41 and the support base 43.

[0143] The housing position adjustment mechanism 60 comprises a support base side member 61 provided on the support base 43 side and through which the rotating shaft 121 passes, a bearing housing side member 62 provided on the bearing housing 51 side and through which the rotating shaft 121 passes and which is movable axially relative to the support base side member 61, a pressure chamber 66 formed between the support base side member 61 and the bearing housing side member 62, a storage chamber 71 formed in either the support base side member 61 or the bearing housing side member 62, and hydraulic oil (working fluid) 70 filled in an orifice 72 communicating between the pressure chamber 66 and the storage chamber 71, a disc spring (elastic member) 80 arranged in a compressed state between the opposing axial end faces of the support base side member 61 and the bearing housing side member 62 within the pressure chamber 66, and a hollow member 90 accommodated in the storage chamber 71. 36, the same reference numerals as those in the above embodiment are used to denote substantially the same components, and the description thereof will be omitted or simplified. In addition, the various structures described in the ball screw feed device 20 can also be applied to the rotation support device, and similar effects can be achieved.

[0144] Furthermore, the bearings 33, 53 of the support mechanisms 30, 40 of the rotation support device 120 may be angular contact ball bearings as in the above embodiment, but are not limited to these and may be roller bearings or plain bearings capable of supporting axial loads. By using such bearings capable of supporting axial loads, particularly in the support mechanism 40, the hydraulic oil 70 and the elastic member 80 can be compressed via the bearings by tightening the fastening nut 38b as in the above embodiment.

[0145] In addition, in Figure 36, the second support mechanism 40 having the housing position adjustment mechanism 60 is configured to support the end of the rotating shaft 121, but as shown in Figure 37, the second support mechanism 40 having the housing position adjustment mechanism 60 may also be configured to support the rotating shaft 121 at a position closer to another support base 85 that supports the drive motor 12.

[0146] For example, when a rotary support device 120 such as that shown in FIG. 37 is applied to a spindle device that rotates a tool in a machine tool, by attaching a tool to the end of a rotating shaft 121 supported by the support mechanism 30, the axial support rigidity of the rotating shaft 121 is continuously and stably maintained while the axial positioning of the tool is reliably performed, thereby enabling high-precision machining.

[0147] In the rotary support device 120 shown in Figures 36 and 37, the drive motor 12 does not necessarily have to be arranged coaxially with the rotating shaft 121, and the power of the drive motor may be transmitted to the rotating shaft 121 via, for example, a pulley or a gear train.

[0148] In addition, the drive motor 12 is not necessarily limited to a separate motor arranged coaxially with the rotary shaft 121, but may be a built-in motor directly configured on the rotary shaft 121, for example. Furthermore, the rotation support device 120 may be configured as a support body in the form of a housing case in which the bearing housing 31 of the first support mechanism 30 and the support base 43 of the second support mechanism 40 are integrated.

[0149] In a rotation support device other than a ball screw feed device, the support base may also be disposed on the axial end side of the bearing unit as shown in FIGS.

[0150] Furthermore, in the above embodiment, the housing position adjustment mechanism is described as a mechanism for adjusting the axial position of the bearing housing of the bearing that supports the rotating shaft, but the present invention is not limited to this and can be applied as a support mechanism position adjustment mechanism for a shaft support device. That is, the shaft is not limited to a rotating shaft, and the support mechanism is not limited to a configuration including a bearing. The shaft support device may be configured to include a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft, one of the pair of support mechanisms including a support body (for example, support base 43 in the above embodiment) through which the shaft passes or around which the shaft is disposed.

[0151] Therefore, the support mechanism position adjustment mechanism of the shaft support device may be configured to include a first member (e.g., support base side member 61 in the above embodiment) that is provided on either the shaft side or the support side and through which the shaft can pass or that can be arranged around the shaft, a second member (e.g., bearing housing side member 62 in the above embodiment) that is provided on the other of the shaft side or the support side and through which the shaft can pass or that can be arranged around the shaft and that can move axially relative to the first member, a pressure chamber formed between the first member and the second member, a storage chamber formed in either the first member or the second member, and a working fluid that is filled in an orifice that connects the pressure chamber and the storage chamber, an elastic member that is arranged in a compressed state between the opposing axial end faces of the first member and the second member within the pressure chamber, and a hollow member that is accommodated in the storage chamber. The support mechanism position adjustment mechanism of such a shaft support device can be applied with the structure of the housing position adjustment mechanism described in the ball screw feed device 20, and will have the same effects.

[0152] 42 and 43 show a rigid-jointed structure 200 as a shaft support device in which a support mechanism position adjustment mechanism is provided on one of a pair of support mechanisms that support a shaft. The rigid-jointed structure 200 includes two parallel steel supports 231, 243 that are fixed vertically to a base 1. Concentric through-holes 231a, 243a are formed in the supports 231, 243, and a shaft 221 that constitutes a beam member is inserted through these holes. The supports 231, 243 may be pillars, beams, support plates, or the like, and may be made of any material and shape that can support a shaft.

[0153] In this example, the flange portion 226 on one axial end of the shaft 221 is abutted against the small diameter step portion 231b of the through hole 231a of the support body 231, and one end of the shaft 221 is positioned and fixed to the support body 231 by the other support mechanism that attaches the pressing lid 232 to the large diameter step portion 231c of the through hole 231a.

[0154] In addition, the other axial end of the shaft 221 passes through a through hole 243a of the support body 243, protrudes to the opposite side of the support body 231, and is supported by the support body 243 via a shaft guide member 250, a housing 251, and a support mechanism position adjustment mechanism 260, which constitute one of the support mechanisms. The cross-sectional shape of the center portion of the shaft 221 is arbitrary, and may be made of a square steel pipe, an H-shaped steel, or the like.

[0155] The shaft guide member 250 is a member configured to surround the shaft 221, guides the small diameter portion 225 of the shaft 221, and has both ends on the outer diameter side thereof clamped and integrated between the housing 251 and a pressing member 247 fixed to the housing 251.

[0156] Furthermore, the housing 251 is attached to the support body 243 via a support mechanism position adjustment mechanism 260, as in the above embodiment. That is, a first member 261, which corresponds to the support base side member 61 in the above embodiment, is fitted into a through hole 243a of the support body 243 and fixed to the support body 243, and a second member 262, which corresponds to the bearing housing side member 62 in the above embodiment, is fitted into an inward flange 251a of the housing 251 and fixed to the housing 251.

[0157] Therefore, when the shaft guide member 250 is tightened by the fastening nut 38b that is threaded onto the male screw 225a via the spacer 48, a reaction force acts on the shaft guide member 250, and the shaft guide member 250 is subjected to an axial load. Therefore, a predetermined rigidity is provided between the supports 231, 243 and the shaft 221.

[0158] Furthermore, in such a rigid-jointed structure 200, even if axial elongation occurs in the shaft 221, the support mechanism position adjustment mechanism 260 operates to move the shaft guide member 250 and the housing 251 in the same direction in response to the axial elongation of the shaft 221. Therefore, the axial force acting on the shaft 221 can be maintained, and the rigidity of the rigid-jointed structure 200 can be maintained.

[0159] In this example, the housing 251 and the second member 262 of the support mechanism position adjustment mechanism 260 may be integrally configured, and the shaft guide member 250 may be disposed on the integrated member. Also, the shaft guide member 250 may be directly fixed to the second member 262 of the support mechanism position adjustment mechanism 260 without providing the housing 251. Furthermore, the shaft support device is not limited to a rigid structure as in this example, but may be a brace structure in which the support mechanisms on the shaft side and the support side are pin-jointed. In this case, the shaft 221 may be arranged at an angle depending on the configuration of the brace structure. Furthermore, in a shaft support device such as a rigid structure, both support mechanisms may have a support mechanism position adjustment mechanism.

[0160] As described above, the present specification discloses the following: (A1) A ball screw feed device comprising: a screw shaft having a helical thread groove formed on its outer peripheral surface; a nut having a helical thread groove formed on its inner peripheral surface; a plurality of balls rollably disposed between the thread groove of the screw shaft and the thread groove of the nut; and a pair of support mechanisms rotatably supporting both axial ends of the screw shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing, an angular contact ball bearing including an outer ring fitted inside the bearing housing, an inner ring fitted externally onto an axial end of the screw shaft, and balls disposed so as to roll between the outer ring and the inner ring; a support base disposed axially centrally of the bearing unit and through which the screw shaft passes; a housing position adjustment mechanism disposed between the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: A support base side member provided on the support base side and through which the screw shaft passes; a bearing housing side member provided on the bearing housing side, through which the screw shaft passes and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in either the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A ball screw feed device comprising: With this configuration, even if the axial length of the screw shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0161] (A2) One of the support base member and the bearing housing member has an annular recess that opens to one axial side, the other of the support base member and the bearing housing member has an annular protrusion that protrudes toward the other axial side and is axially slidably fitted within the annular recess, the pressure chamber is formed between the annular recess and the annular protrusion, The storage chamber is formed in the annular convex portion so as to open to an outward surface or an inward surface of the annular convex portion, The orifice is formed within the annular protrusion. The ball screw feed device according to (A1). According to this configuration, the pressure chamber is formed between the annular recess and the annular protrusion, so that the housing position adjustment mechanism can be configured compactly around the screw shaft. Furthermore, the vibration can be damped by passing through the gap between the outward surface of the annular convex portion and the inward surface of the annular concave portion.

[0162] (A3) The ball screw feed device described in (A2), wherein at least one seal member is attached between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion. According to this configuration, the seal member can prevent leakage of the working fluid filled in the pressure chamber and the reservoir chamber, and the function of the housing position adjustment mechanism can be maintained for a long period of time.

[0163] (A4) A ball screw feed device according to (A2) or (A3), wherein the working fluid is stored in each gap between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion. According to this configuration, the housing position adjustment mechanism can provide radial support rigidity to the screw shaft, and further has an aligning function for the screw shaft.

[0164] (A5) The sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inward surface of the annular recess or an outward surface of the annular protrusion, and on an outward surface of the annular recess or an inward surface of the annular protrusion, The ball screw feed device according to (A3), wherein the seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the screw shaft. Furthermore, even if relative movement occurs between the support base member and the bearing housing member, leakage of hydraulic oil to the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device can be continuously maintained.

[0165] (A6) The sealing member is an O-ring, A ball screw feed device as described in (A3) or (A5), wherein a wear-resistant member is interposed between the O-ring and at least one of the inward surface of the annular recess and the outward surface of the annular protrusion, and between the O-ring and at least one of the outward surface of the annular recess and the inward surface of the annular protrusion. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the screw shaft. It also disperses stress concentration on the O-ring, suppressing wear and other damage to the O-ring and the contact surface with the O-ring.

[0166] (A7) The ball screw feed device according to any one of (A1) to (A4), wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits penetrating through a conical plate portion in the axial direction. According to this configuration, the working fluid flows through the plurality of through holes or the plurality of slits, It is possible to exert a damping effect.

[0167] (A8) The ball screw feed device according to (A1), wherein the hollow member has at least one rib protruding from its inner peripheral surface. According to this configuration, when the hollow member is compressed and deformed, the hollow member can be prevented from being deformed excessively.

[0168] (A9) The ball screw feed device according to (A1), wherein a plurality of the hollow members are disposed in the storage chamber. The total pressure generated by the multiple hollow members makes it possible to continuously and stably maintain axial support rigidity even if the axial length of the screw shaft changes due to the influence of heat.

[0169] (A10) The ball screw feed device according to (A1), wherein the surface of the hollow member is covered with an outer layer. According to this configuration, the rigidity of the hollow member can be changed, and the hollow member can be protected from liquids.

[0170] (A11) The ball screw feed device according to (A1), wherein the hollow member is an integrally molded structure having a seamless hollow cross section. According to this configuration, localized stress concentration is unlikely to occur, and a deformable hollow member can be easily manufactured.

[0171] (A12) The ball screw feed device according to (A1), wherein the hollow member is a combined body having a hollow cross section, which is formed by integrating two or more members via the edges of the two or more members. According to this configuration, the deformable hollow member can be easily manufactured.

[0172] (A13) The ball screw feed device according to (A1), wherein the hollow member has a hollow cross section formed by bending the member and joining edges of the member. According to this configuration, the deformable hollow member can be easily manufactured.

[0173] (A14) One of the support base side member and the bearing housing side member has a small diameter cylindrical portion extending to one axial side and an outward flange portion extending from a tip end of the small diameter cylindrical portion toward an outer diameter side, the other of the support base side member and the bearing housing side member has a large-diameter cylindrical portion extending toward the other axial side and having an inner peripheral surface with which the outer peripheral surface of the outward flange portion slides, and an inward flange portion extending from a tip end of the large-diameter cylindrical portion toward an inner diameter side and having an inner peripheral surface with which the outer peripheral surface of the small-diameter cylindrical portion slides, the pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion, The storage chamber is formed in the outward flange portion or the inward flange portion so as to open to the inner circumferential surface of the large diameter cylindrical portion or the outer circumferential surface of the small diameter cylindrical portion, The orifice is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed. The ball screw feed device according to (A1). With this configuration, even if the axial length of the screw shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained. Furthermore, the working fluid passes through the orifice and the gap between the inner circumferential surface of the large-diameter cylindrical portion and the outer circumferential surface of the outward flange portion, or between the outer circumferential surface of the small-diameter cylindrical portion and the inner circumferential surface of the inward flange portion, thereby damping the vibration.

[0174] (A15) The ball screw feed device according to (A14), wherein at least one seal member is fitted 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. According to this configuration, the seal member can prevent leakage of the working fluid contained in the pressure chamber and the reservoir chamber, and the function of the housing position adjustment mechanism can be maintained for a long period of time.

[0175] (A16) A ball screw feed device according to (A14) or (A15), wherein the working fluid is stored in each gap between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large diameter cylindrical portion. According to this configuration, the housing position adjustment mechanism can provide radial support rigidity to the screw shaft, and further has an aligning function for the screw shaft.

[0176] (A17) The sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inner peripheral surface of the inward flange portion or an outer peripheral surface of the small-diameter cylindrical portion, and on an outer peripheral surface of the outward flange portion or an inner peripheral surface of the large-diameter cylindrical portion, The ball screw feed device according to (A15), wherein the seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the screw shaft. Furthermore, even if relative movement occurs between the support base member and the bearing housing member, leakage of hydraulic oil to the atmospheric pressure side can be prevented, and the axial rigidity of the ball screw feed device can be continuously maintained.

[0177] (A18) The sealing member is an O-ring, A ball screw feed device as described in (A15), wherein a wear-resistant member is interposed between the O-ring and 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 between the O-ring and at least one of the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large diameter cylindrical portion. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the screw shaft. It also disperses stress concentration on the O-ring, suppressing wear and other damage to the O-ring and the contact surface with the O-ring.

[0178] (A19) A ball screw feed device as described in (A1), in which a working medium volume change unit is attached to at least one of the support base side member and the bearing housing side member, and changes the volume of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid. According to this configuration, the hollow member and the working fluid can be heated or cooled to expand or contract the volumes of the hollow member and the working fluid, thereby continuously maintaining the axial support rigidity in a stable state.

[0179] (A20) One of the pair of support mechanisms is Further, another housing position adjustment mechanism is disposed adjacent to the housing position adjustment mechanism in series or in parallel between the bearing unit and the support base, The other housing position adjustment mechanism is Another support base side member provided on the support base side and through which the screw shaft passes; another bearing housing side member provided on the bearing housing side, through which the screw shaft passes and which is movable in the axial direction relative to the other support base side member; a pressure generating means accommodated in a compressed state in a pressure chamber formed between the other support base side member and the other bearing housing side member; The ball screw feed device according to (A1) is provided with: According to this configuration, in the case of a series arrangement, it is possible to maintain the axial rigidity of the ball screw feed device even when the screw shaft elongates more, and it is possible to improve the alignment and coaxiality of the screw shaft. Furthermore, in the case of a parallel arrangement, it is possible to generate a larger axial load than when a single housing position adjustment mechanism is arranged, and the axial rigidity can be maintained.

[0180] (A21) A ball screw feed device comprising: a screw shaft having a helical screw groove formed on its outer peripheral surface; a nut having a helical screw groove formed on its inner peripheral surface; a plurality of balls rollably disposed between the screw groove of the screw shaft and the screw groove of the nut; and a pair of support mechanisms rotatably supporting both axial ends of the screw shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing, an angular contact ball bearing including an outer ring fitted inside the bearing housing, an inner ring fitted externally onto an axial end of the screw shaft, and balls disposed so as to roll between the outer ring and the inner ring; A support base through which the screw shaft passes; a housing position adjustment mechanism attached to the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: A support base side member attached to the support base and through which the screw shaft passes; a bearing housing side member attached to the bearing housing, through which the screw shaft passes and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in either the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A ball screw feed device comprising: With this configuration, even if the axial length of the screw shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0181] (A22) A rotary support device comprising a rotary shaft and a pair of support mechanisms that rotatably support both axial ends of the rotary shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing and a bearing that rotatably supports the rotary shaft relative to the bearing housing and is capable of supporting an axial load; a support base disposed axially centrally of the bearing unit and through which the rotating shaft passes; a housing position adjustment mechanism disposed between the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: a support base side member provided on the support base side and through which the rotation shaft passes; a bearing housing side member provided on the bearing housing side, through which the rotation shaft passes and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in either the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A rotary support device comprising: With this configuration, even if the axial length of the rotating shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0182] (A23) A rotary support device comprising a rotary shaft and a pair of support mechanisms that rotatably support both axial ends of the rotary shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing and a bearing that rotatably supports the rotary shaft relative to the bearing housing and is capable of supporting an axial load; a support base through which the rotation shaft passes; a housing position adjustment mechanism attached to the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: a support base side member attached to the support base and through which the rotation shaft passes; a bearing housing side member attached to the bearing housing, through which the rotation shaft passes and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in either the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A rotary support device comprising: With this configuration, even if the axial length of the rotating shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0183] (A24) In a shaft support device including a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft on a base, a support mechanism position adjustment mechanism for the shaft support device provided on one of the pair of support mechanisms, a first member provided on one of the support mechanism side and the base side, through which the shaft can pass; a second member provided on the other of the support mechanism side and the base side, through which the shaft can pass and which is movable in the axial direction relative to the first member; a pressure chamber formed between the first member and the second member, a reservoir chamber formed in either the first member or the second member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the first member and the second member within the pressure chamber; a hollow member accommodated in the storage chamber; A support mechanism position adjustment mechanism for a shaft support device. With this configuration, even if the axial length of the shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0184] (A25) In a shaft support device including a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft on a base, a support mechanism position adjustment mechanism for the shaft support device provided on one of the pair of support mechanisms, a first member attached to one of the support mechanism and the base, through which the shaft can pass; a second member attached to the other of the support mechanism and the base, through which the shaft can pass and which is movable in the axial direction relative to the first member; a pressure chamber formed between the first member and the second member, a reservoir chamber formed in either the first member or the second member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the first member and the second member within the pressure chamber; a hollow member accommodated in the storage chamber; A support mechanism position adjustment mechanism for a shaft support device. With this configuration, even if the axial length of the shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0185] (A26) A rotary support device comprising a rotary shaft and a pair of support mechanisms that rotatably support both axial ends of the rotary shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing and a bearing that rotatably supports the rotary shaft relative to the bearing housing and is capable of supporting an axial load; a support base through which the rotation shaft passes; a housing position adjustment mechanism disposed between the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: a support base side member that is provided on the support base side and through which the rotation shaft passes or that is arranged around the rotation shaft; a bearing housing side member provided on the bearing housing side, through which the rotation shaft passes or which is disposed around the rotation shaft, and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A rotary support device comprising: With this configuration, even if the axial length of the rotating shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0186] (A27) One of the support base member and the bearing housing member has a plurality of recesses that open to one axial side, the other of the support base side member and the bearing housing side member has a plurality of protrusions that protrude toward the other axial side and are fitted into the plurality of recesses so as to be slidable in the axial direction, the pressure chambers are formed between the recesses and the protrusions, respectively; The storage chamber and the orifice are formed in at least one of the plurality of protrusions so that the storage chamber communicates with the pressure chamber via the orifice. A rotary support device according to (A26). According to this configuration, the layout of the housing position adjustment mechanism can be freely configured using a plurality of pressure chambers.

[0187] (A28) The rotation support device according to (A27), wherein the plurality of pressure chambers are arranged on both sides of the rotation shaft in the width direction. With this configuration, the height dimension of the housing position adjustment mechanism can be reduced.

[0188] (A29) The plurality of protrusions are each formed with the storage chamber and the orifice, the elastic members are disposed in a compressed state within the plurality of pressure chambers, The rotary support device according to (A27), wherein the hollow members are housed in each of the plurality of storage chambers. According to this configuration, a plurality of pressure chambers and a plurality of storage chambers can be configured in common.

[0189] (A30) The rotation support device is The rotating shaft is a screw shaft having a spiral thread groove formed on its outer peripheral surface, and further includes a nut having a spiral thread groove formed on its inner peripheral surface, and a plurality of balls arranged so as to roll between the screw groove of the screw shaft and the screw groove of the nut. The rotary support device according to (A26), which is a ball screw feed device. According to this configuration, a ball screw feed device can be configured that can continuously and stably maintain axial support rigidity even if the axial length of the rotary shaft changes due to the influence of heat.

[0190] (A31) In a shaft support device including a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft on a base, a support mechanism position adjustment mechanism for the shaft support device provided on one of the pair of support mechanisms, a first member provided on one of the support mechanism side and the base side, through which the shaft can pass or which can be arranged around the shaft; a second member provided on the other of the support mechanism side and the base side, through which the shaft can pass or which can be arranged around the shaft, and which is movable in the axial direction relative to the first member; a pressure chamber formed between the first member and the second member, a reservoir chamber formed in the first member or the second member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the first member and the second member within the pressure chamber; a hollow member accommodated in the storage chamber; A support mechanism position adjustment mechanism for a shaft support device. With this configuration, even if the axial length of the shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0191] (B1) A rotary support device including a rotary shaft and a pair of support mechanisms that rotatably support both axial ends of the rotary shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing and a bearing that rotatably supports the rotary shaft relative to the bearing housing and is capable of supporting an axial load; a support base through which the rotation shaft passes or which is arranged around the rotation shaft; a housing position adjustment mechanism disposed between the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: a support base side member that is provided on the support base side and through which the rotation shaft passes or that is arranged around the rotation shaft; a bearing housing side member provided on the bearing housing side, through which the rotation shaft passes or which is disposed around the rotation shaft, and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A rotary support device comprising: With this configuration, even if the axial length of the rotating shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0192] (B2) One of the support base member and the bearing housing member has an annular recess that opens to one axial side, the other of the support base member and the bearing housing member has an annular protrusion that protrudes toward the other axial side and is axially slidably fitted within the annular recess, the pressure chamber is formed between the annular recess and the annular protrusion, The storage chamber is formed in the annular convex portion so as to open to an outward surface or an inward surface of the annular convex portion, The orifice is formed within the annular protrusion. (B1) The rotary support device according to (B1). With this configuration, the pressure chamber is formed between the annular recess and the annular protrusion, allowing the housing position adjustment mechanism to be configured compactly around the rotation shaft. Furthermore, the working fluid passes through the orifice and the gap between the outward surface of the annular protrusion and the inward surface of the annular recess, thereby damping the vibration.

[0193] (B3) A rotation support device described in (B2), in which at least one seal member is installed between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion. According to this configuration, the seal member can prevent leakage of the working fluid filled in the pressure chamber and the reservoir chamber, and the function of the housing position adjustment mechanism can be maintained for a long period of time.

[0194] (B4) A rotation support device described in (B2) or (B3), in which the working fluid is stored in each gap between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion. According to this configuration, the housing position adjustment mechanism can provide radial support rigidity to the rotating shaft, and can also have an aligning function with respect to the rotating shaft.

[0195] (B5) The sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inward surface of the annular recess or an outward surface of the annular protrusion, and on an outward surface of the annular recess or an inward surface of the annular protrusion, The rotation support device according to (B3), wherein the seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the rotating shaft. Furthermore, even if relative movement occurs between the support base member and the bearing housing member, leakage of hydraulic oil to the atmospheric pressure side is prevented, and the axial rigidity of the rotation support device can be continuously maintained.

[0196] (B6) The sealing member is an O-ring, A rotation support device as described in (B3) or (B5), in which a wear-resistant member is interposed between the O-ring and at least one of the inward surface of the annular recess and the outward surface of the annular protrusion, and between the O-ring and at least one of the outward surface of the annular recess and the inward surface of the annular protrusion. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the rotating shaft. It also disperses stress concentration on the O-ring, suppressing wear and other damage to the O-ring and the contact surface with the O-ring.

[0197] (B7) A rotation support device according to any one of (B1) to (B4), wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits penetrating axially through a conical plate portion. According to this configuration, the working fluid flows through the plurality of through holes or the plurality of slits, thereby achieving a damping effect.

[0198] (B8) The rotation support device according to (B1), wherein the hollow member has at least one rib protruding from its inner peripheral surface. According to this configuration, when the hollow member is compressed and deformed, the hollow member can be prevented from being deformed excessively.

[0199] (B9) The rotation support device according to (B1), wherein a plurality of the hollow members are arranged in the storage chamber. With this configuration, the total pressure generated by the multiple hollow members makes it possible to continuously and stably maintain axial support rigidity even if the axial length of the rotating shaft changes due to the influence of heat.

[0200] (B10) The rotary support device according to (B1), wherein the surface of the hollow member is covered with an outer layer. According to this configuration, the rigidity of the hollow member can be changed, and the hollow member can be protected from liquids.

[0201] (B11) The rotary support device according to (B1), wherein the hollow member is a structure having a seamless hollow cross section that is integrally molded. According to this configuration, localized stress concentration is unlikely to occur, and a deformable hollow member can be easily manufactured.

[0202] (B12) The rotary support device according to (B1), wherein the hollow member is a combined body having a hollow cross section, which is formed by integrating two or more members via the edges of the two or more members. According to this configuration, the deformable hollow member can be easily manufactured.

[0203] (B13) The rotary support device according to (B1), wherein the hollow member has a hollow cross section formed by bending the member and joining edges of the member. According to this configuration, the deformable hollow member can be easily manufactured.

[0204] (B14) One of the support base side member and the bearing housing side member has a small diameter cylindrical portion extending to one axial side and an outward flange portion extending from a tip end of the small diameter cylindrical portion toward an outer diameter side, the other of the support base side member and the bearing housing side member has a large-diameter cylindrical portion extending toward the other axial side and having an inner peripheral surface with which the outer peripheral surface of the outward flange portion slides, and an inward flange portion extending from a tip end of the large-diameter cylindrical portion toward an inner diameter side and having an inner peripheral surface with which the outer peripheral surface of the small-diameter cylindrical portion slides, the pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion, The storage chamber is formed in the outward flange portion or the inward flange portion so as to open to the inner circumferential surface of the large diameter cylindrical portion or the outer circumferential surface of the small diameter cylindrical portion, The orifice is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed. (B1) The rotary support device according to (B1). With this configuration, even if the axial length of the rotating shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained. Furthermore, the working fluid passes through the orifice and the gap between the inner circumferential surface of the large-diameter cylindrical portion and the outer circumferential surface of the outward flange portion, or between the outer circumferential surface of the small-diameter cylindrical portion and the inner circumferential surface of the inward flange portion, thereby damping the vibration.

[0205] (B15) The rotation support device according to (B14), wherein at least one seal member is fitted 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. According to this configuration, the seal member can prevent leakage of the working fluid contained in the pressure chamber and the reservoir chamber, and the function of the housing position adjustment mechanism can be maintained for a long period of time.

[0206] (B16) A rotation support device according to (B14) or (B15), wherein the working fluid is stored in each gap between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large diameter cylindrical portion. According to this configuration, the housing position adjustment mechanism can provide radial support rigidity to the rotating shaft, and can also have an aligning function with respect to the rotating shaft.

[0207] (B17) The sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inner peripheral surface of the inward flange portion or an outer peripheral surface of the small-diameter cylindrical portion, and on an outer peripheral surface of the outward flange portion or an inner peripheral surface of the large-diameter cylindrical portion, The rotation support device according to (B15), wherein the seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the rotating shaft. Furthermore, even if relative movement occurs between the support base member and the bearing housing member, leakage of hydraulic oil to the atmospheric pressure side is prevented, and the axial rigidity of the rotation support device can be continuously maintained.

[0208] (B18) The sealing member is an O-ring, A rotation support device as described in (B15), wherein a wear-resistant member is interposed between the O-ring and 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 between the O-ring and at least one of the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large diameter cylindrical portion. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations generated in the rotating shaft. It also disperses stress concentration on the O-ring, suppressing wear and other damage to the O-ring and the contact surface with the O-ring.

[0209] (B19) A rotary support device as described in (B1), in which a working medium volume change unit is attached to at least one of the support base side member and the bearing housing side member, and changes the volume of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid. According to this configuration, the hollow member and the working fluid can be heated or cooled to expand or contract the volumes of the hollow member and the working fluid, thereby continuously maintaining the axial support rigidity in a stable state.

[0210] (B20) One of the pair of support mechanisms is Further, another housing position adjustment mechanism is disposed adjacent to the housing position adjustment mechanism in series or in parallel between the bearing unit and the support base, The other housing position adjustment mechanism is Another support-base-side member is provided on the support base side and passes through the rotation shaft or is arranged around the rotation shaft; another bearing housing side member provided on the bearing housing side, through which the rotation shaft passes or arranged around the rotation shaft, and movable in the axial direction relative to the other support base side member; a pressure generating means accommodated in a compressed state in a pressure chamber formed between the other support base side member and the other bearing housing side member; The rotary support device according to (B1) comprises: With this configuration, in the case of a series arrangement, the axial rigidity of the rotation support device can be maintained even when the elongation of the rotating shaft is greater, and the alignment and coaxiality of the rotating shaft can be improved. Furthermore, in the case of a parallel arrangement, a larger axial load can be generated than when a single housing position adjustment mechanism is arranged, and the axial rigidity can be maintained.

[0211] (B21) One of the support base member and the bearing housing member has a plurality of recesses that open to one axial side, the other of the support base side member and the bearing housing side member has a plurality of protrusions that protrude toward the other axial side and are fitted into the plurality of recesses so as to be slidable in the axial direction, the pressure chambers are formed between the recesses and the protrusions, respectively; The storage chamber and the orifice are formed in at least one of the plurality of protrusions so that the storage chamber communicates with the pressure chamber via the orifice. (B1) The rotary support device according to (B1). According to this configuration, the layout of the housing position adjustment mechanism can be freely configured using a plurality of pressure chambers.

[0212] (B22) The rotation support device according to (B21), wherein the plurality of pressure chambers are arranged on both sides of the rotation shaft in the width direction. With this configuration, the height dimension of the housing position adjustment mechanism can be reduced.

[0213] (B23) The plurality of protrusions are each formed with the storage chamber and the orifice, the elastic members are disposed in a compressed state within the plurality of pressure chambers, The rotary support device according to (B21), wherein the hollow members are housed in the plurality of storage chambers, respectively. According to this configuration, a plurality of pressure chambers and a plurality of storage chambers can be configured in common.

[0214] (B24) A rotary support device described in any one of (B1) to (B23), wherein the bearing of the bearing unit includes a pair of angular contact ball bearings each having an outer ring fitted inside the bearing housing, an inner ring fitted outside the axial end of the rotating shaft, and balls arranged freely rollable between the outer ring and the inner ring. With this configuration, when the bearing unit has a pair of angular ball bearings, the axial support rigidity can be continuously and stably maintained even if the axial length of the rotating shaft changes due to the influence of heat.

[0215] (B25) The rotation support device is The rotating shaft is a screw shaft having a spiral thread groove formed on its outer peripheral surface, and further includes a nut having a spiral thread groove formed on its inner peripheral surface, and a plurality of balls arranged so as to roll between the screw groove of the screw shaft and the screw groove of the nut. The rotation support device according to any one of (B1) to (B24), which is a ball screw feed device. According to this configuration, a ball screw feed device can be configured that can continuously and stably maintain axial support rigidity even if the axial length of the rotary shaft changes due to the influence of heat.

[0216] (B26) In a shaft support device including a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft, a support mechanism position adjustment mechanism for the shaft support device provided on one of the pair of support mechanisms, one of the pair of support mechanisms has a support body through which the shaft passes or which is disposed around the shaft; a first member provided on one of the shaft side and the support side, through which the shaft can pass or which can be arranged around the shaft; a second member provided on the other of the shaft side and the support side, through which the shaft can pass or which can be arranged around the shaft, and which is movable in the axial direction relative to the first member; a pressure chamber formed between the first member and the second member, a reservoir chamber formed in the first member or the second member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the first member and the second member within the pressure chamber; a hollow member accommodated in the storage chamber; A support mechanism position adjustment mechanism for a shaft support device. With this configuration, even if the axial length of the shaft changes due to the effects of heat, the axial support rigidity can be continuously and stably maintained, and vibrations in the axial and radial directions can be damped.

[0217] (B27) The axis is a rotation axis, one of the pair of support mechanisms further includes a bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft relative to the bearing housing and is capable of supporting 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 member is a support-side member that is provided on the support side and through which the rotation shaft can pass or that can be arranged around the rotation shaft, The second member is a bearing housing side member that is provided on the bearing housing side, through which the rotating shaft can pass or that can be arranged around the rotating shaft, that is movable axially relative to the support side member, and that forms the accommodation space between itself and the support side member. (B26) A support mechanism position adjustment mechanism for a shaft support device described in With this configuration, even if the axial length of the shaft changes due to the influence of heat, the support rigidity in the axial direction can be continuously and stably maintained.

[0218] (B28) One of the first member and the second member has an annular recess that opens to one side in the axial direction, the other of the first member and the second member has an annular protrusion that protrudes toward the other axial side and is axially slidably fitted within the annular recess, the pressure chamber is formed between the annular recess and the annular protrusion, The storage chamber is formed in the annular convex portion so as to open to an outward surface or an inward surface of the annular convex portion, The orifice is formed within the annular protrusion. A support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27). With this configuration, the pressure chamber is formed between the annular recess and the annular protrusion, allowing the support mechanism position adjustment mechanism to be configured compactly around the shaft. Furthermore, the working fluid passes through the orifice and the gap between the outward surface of the annular protrusion and the inward surface of the annular recess, thereby damping the vibration.

[0219] (B29) A support mechanism position adjustment mechanism for a shaft support device described in (B26) or (B27), in which at least one seal member is installed between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion. According to this configuration, the seal member can prevent leakage of the working fluid filled in the pressure chamber and the reservoir chamber, and the function of the support mechanism position adjustment mechanism can be maintained for a long period of time.

[0220] (B30) A support mechanism position adjustment mechanism for a shaft support device described in (B28) or (B29), in which the working fluid is stored in each gap between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion. According to this configuration, the support mechanism position adjustment mechanism can provide radial support rigidity to the shaft, and can also have an aligning function with respect to the shaft.

[0221] (B31) The sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inward surface of the annular recess or an outward surface of the annular protrusion, and on an outward surface of the annular recess or an inward surface of the annular protrusion, The support mechanism position adjustment mechanism for a shaft support device according to (B29), wherein the seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations that occur in the shaft. Furthermore, even if relative movement occurs between the first and second members, leakage of hydraulic oil to the atmospheric pressure side is prevented, and the axial rigidity of the shaft support device can be continuously maintained.

[0222] (B32) The sealing member is an O-ring, A support mechanism position adjustment mechanism for a shaft support device described in (B29) or (B31), in which a wear-resistant member is interposed between the O-ring and at least one of the inward surface of the annular recess and the outward surface of the annular convex portion, and between the O-ring and at least one of the outward surface of the annular recess and the inward surface of the annular convex portion. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations that occur in the shaft. It also disperses stress concentrations on the O-ring, suppressing wear and other damage to the O-ring and the contact surface with the O-ring.

[0223] (B33) A support mechanism position adjustment mechanism for a shaft support device described in any one of (B26) to (B30), wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits penetrating axially through a conical plate portion. According to this configuration, the working fluid flows through the plurality of through holes or the plurality of slits, thereby achieving a damping effect.

[0224] (B34) The support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27), wherein the hollow member has at least one rib protruding from its inner peripheral surface. According to this configuration, when the hollow member is compressed and deformed, the hollow member can be prevented from being deformed excessively.

[0225] (B35) The support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27), wherein a plurality of the hollow members are arranged in the storage chamber. With this configuration, the total pressure generated by the multiple hollow members makes it possible to continuously and stably maintain axial support rigidity even if the axial length of the shaft changes due to the influence of heat.

[0226] (B36) A support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27), wherein the surface of the hollow member is covered with an outer layer. According to this configuration, the rigidity of the hollow member can be changed, and the hollow member can be protected from liquids.

[0227] (B37) The support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27), wherein the hollow member is a structure having a seamless hollow cross section that is integrally molded. According to this configuration, localized stress concentration is unlikely to occur, and a deformable hollow member can be easily manufactured.

[0228] (B38) A support mechanism position adjustment mechanism for a shaft support device described in (B26) or (B27), wherein the hollow member is a combined body having a hollow cross section formed by integrating two or more members via the edges of the two or more members. According to this configuration, the deformable hollow member can be easily manufactured.

[0229] (B39) The support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27), wherein the hollow member has a hollow cross section formed by bending the member and joining the edges of the member. According to this configuration, the deformable hollow member can be easily manufactured.

[0230] (B40) One of the first member and the second member has a small-diameter cylindrical portion extending to one side in the axial direction and an outward flange portion extending from a tip end of the small-diameter cylindrical portion toward an outer diameter side, the other of the first member and the second member has a large-diameter cylindrical portion extending toward the other axial side and having an inner peripheral surface with which the outer peripheral surface of the outward flange portion slides, and an inward flange portion extending from a tip end of the large-diameter cylindrical portion toward an inner diameter side and having an inner peripheral surface with which the outer peripheral surface of the small-diameter cylindrical portion slides, the pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion, The storage chamber is formed in the outward flange portion or the inward flange portion so as to open to the inner circumferential surface of the large diameter cylindrical portion or the outer circumferential surface of the small diameter cylindrical portion, The orifice is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed. A support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27). With this configuration, even if the axial length of the shaft changes due to the influence of heat, the axial support rigidity can be continuously and stably maintained. Also, the working fluid passes through the orifice and the gap between the inner circumferential surface of the large-diameter cylindrical portion and the outer circumferential surface of the outward flange portion, or between the outer circumferential surface of the small-diameter cylindrical portion and the inner circumferential surface of the inward flange portion, thereby damping the vibration.

[0231] (B41) A support mechanism position adjustment mechanism for a shaft support device described in (B40), in which at least one seal member is installed between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large diameter cylindrical portion. According to this configuration, the seal member can prevent leakage of the working fluid contained in the pressure chamber and the reservoir chamber, and the function of the support mechanism position adjustment mechanism can be maintained for a long period of time.

[0232] (B42) A support mechanism position adjustment mechanism for a shaft support device described in (B40) or (B41), in which the working fluid is stored in each gap between the inner surface of the inward flange portion and the outer surface of the small diameter cylindrical portion, and between the outer surface of the outward flange portion and the inner surface of the large diameter cylindrical portion. According to this configuration, the support mechanism position adjustment mechanism can provide radial support rigidity to the shaft, and can also have an aligning function with respect to the shaft.

[0233] (B43) The sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inner peripheral surface of the inward flange portion or an outer peripheral surface of the small-diameter cylindrical portion, and on an outer peripheral surface of the outward flange portion or an inner peripheral surface of the large-diameter cylindrical portion, The support mechanism position adjustment mechanism for a shaft support device according to (B41), wherein the seal groove has a tapered surface whose groove depth becomes shallower as it moves away from the pressure chamber side. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations that occur in the shaft. Furthermore, even if relative movement occurs between the first and second members, leakage of hydraulic oil to the atmospheric pressure side is prevented, and the axial rigidity of the shaft support device can be continuously maintained.

[0234] (B44) The sealing member is an O-ring, A support mechanism position adjustment mechanism for a shaft support device described in (B41), in which a wear-resistant member is interposed between the O-ring and at least one of the inner surface of the inward flange portion and the outer surface of the small diameter cylindrical portion, and between the O-ring and at least one of the outer surface of the outward flange portion and the inner surface of the large diameter cylindrical portion. With this configuration, by using an O-ring as the sealing member, the O-ring also functions as a damping mechanism, damping vibrations that occur in the shaft. It also disperses stress concentrations on the O-ring, suppressing wear and other damage to the O-ring and the contact surface with the O-ring.

[0235] (B45) A support mechanism position adjustment mechanism for a shaft support device described in (B26) or (B27), in which a working medium volume change unit is attached to at least one of the first member and the second member, which changes the volume of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid. According to this configuration, the hollow member and the working fluid can be heated or cooled to expand or contract the volumes of the hollow member and the working fluid, thereby continuously maintaining the axial support rigidity in a stable state.

[0236] (B46) One of the pair of support mechanisms is further comprising another support mechanism position adjustment mechanism disposed adjacent to the support mechanism position adjustment mechanism in series or in parallel between the bearing unit and the support base; The other support mechanism position adjustment mechanism is Another first member is provided on the support base side, through which the shaft passes or which is arranged around the rotation axis; another second member provided on the bearing housing side, through which the shaft passes or which is arranged around the rotation axis, and which is movable in the axial direction relative to the another first member; a pressure generating means accommodated in a compressed state in a pressure chamber formed between the other first member and the other second member; The support mechanism position adjustment mechanism for the shaft support device according to (B26) or (B27) is provided with: With this configuration, in the case of a series arrangement, it is possible to maintain the axial rigidity of the shaft support device even when the shaft elongation is greater, and it is possible to improve the alignment and coaxiality of the shaft. Furthermore, in the case of a parallel arrangement, it is possible to generate a larger axial load than when a single support mechanism position adjustment mechanism is arranged, and the axial rigidity can be maintained.

[0237] (B47) One of the first member and the second member has a plurality of recesses that open to one side in the axial direction, the other of the first member and the second member has a plurality of protrusions that protrude toward the other axial side and are fitted into the plurality of recesses so as to be slidable in the axial direction, the pressure chambers are formed between the recesses and the protrusions, respectively; The storage chamber and the orifice are formed in at least one of the plurality of protrusions so that the storage chamber communicates with the pressure chamber via the orifice. A support mechanism position adjustment mechanism for a shaft support device according to (B26) or (B27). According to this configuration, the layout of the support mechanism position adjustment mechanism can be freely configured using a plurality of pressure chambers.

[0238] (B48) The support mechanism position adjustment mechanism for a shaft support device according to (B47), wherein the plurality of pressure chambers are arranged on both sides of the shaft in the width direction. According to this configuration, the height dimension of the support mechanism position adjustment mechanism can be reduced.

[0239] (B49) The plurality of protrusions are each formed with the storage chamber and the orifice, the elastic members are disposed in a compressed state within the plurality of pressure chambers, The support mechanism position adjustment mechanism for a shaft support device according to (B47), wherein the hollow members are housed in the plurality of storage chambers, respectively. According to this configuration, a plurality of pressure chambers and a plurality of storage chambers can be configured in common.

[0240] This application is based on a Japanese patent application filed on October 28, 2022 (Patent Application No. 2022-173763), a Japanese patent application filed on July 21, 2023 (Patent Application No. 2023-118997), and a Japanese patent application filed on August 22, 2023 (Patent Application No. 2023-134637), the contents of which are incorporated by reference into this application. [Explanation of symbols]

[0241] 20 Ball screw feed device (shaft support device, rotation support device) 21 Screw shaft (shaft, rotating shaft) 23 Nut 30 First support mechanism (support mechanism) 31 Fixed side bearing housing 33,53 Angular contact ball bearings (bearings) 34,54 outer ring 35,55 Inner circle 36,56 balls 38a, 38b Fastening nuts 40 Second support mechanism (support mechanism) 41 Bearing unit 43 Support stand (support body) 51 Moving side bearing housing (bearing housing) 51a Inward flange 59 Wear-resistant materials 60 Housing position adjustment mechanism (support mechanism position adjustment mechanism) 61 support base side member (first member) 62 Bearing housing side member (second member) 64 Annular recess 65 Annular convex part 66 Pressure Chamber 67 O-ring (sealing material) 68 Seal groove 69a Tapered surface 70 Hydraulic oil (working fluid) 71 Storage chamber 72 Orifice 80 Disc spring (elastic member) 90 Hollow Member 120 Rotating support device 121 Rotation axis 160 Other housing position adjustment mechanism (other support mechanism position adjustment mechanism) 161 Other support base side member (other support side member) 162 Other bearing housing side members 170 Other working fluids 180, 181 Heating element (working medium volume change part) 182, 183 Cooling medium (working medium volume change unit)

Claims

1. A rotary support device including a rotary shaft and a pair of support mechanisms that rotatably support both axial end portions of the rotary shaft, One of the pair of support mechanisms is a bearing unit including a bearing housing and a bearing that rotatably supports the rotary shaft relative to the bearing housing and is capable of supporting an axial load; a support base through which the rotation shaft passes or which is arranged around the rotation shaft; a housing position adjustment mechanism disposed between the bearing unit and the support base; Equipped with The housing position adjustment mechanism includes: a support base side member that is provided on the support base side and through which the rotation shaft passes or that is arranged around the rotation shaft; a bearing housing side member provided on the bearing housing side, through which the rotation shaft passes or which is disposed around the rotation shaft, and which is movable in the axial direction relative to the support base side member; a pressure chamber formed between the support base side member and the bearing housing side member, a reservoir chamber formed in the support base side member or the bearing housing side member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the support base member and the bearing housing member within the pressure chamber; a hollow member accommodated in the storage chamber; A rotary support device comprising:

2. one of the support base member and the bearing housing member has an annular recess that opens to one axial side, the other of the support base member and the bearing housing member has an annular protrusion that protrudes toward the other axial side and is axially slidably fitted within the annular recess, the pressure chamber is formed between the annular recess and the annular protrusion, The storage chamber is formed in the annular convex portion so as to open to an outward surface or an inward surface of the annular convex portion, The orifice is formed within the annular protrusion. The rotary support device according to claim 1 .

3. At least one seal member is fitted between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion, respectively. The rotary support device according to claim 2 .

4. 4. The rotation support device according to claim 2, wherein the working fluid is stored in each gap between the inward surface of the annular recess and the outward surface of the annular protrusion, and between the outward surface of the annular recess and the inward surface of the annular protrusion.

5. the sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inward surface of the annular recess or an outward surface of the annular protrusion, and on an outward surface of the annular recess or an inward surface of the annular protrusion, 4. The rotation support device according to claim 3, wherein the seal groove has a tapered surface whose depth decreases with increasing distance from the pressure chamber.

6. the sealing member is an O-ring, 4. The rotation support device according to claim 3, wherein a wear-resistant member is interposed between the O-ring and at least one of the inward surface of the annular recess and the outward surface of the annular protrusion, and between the O-ring and at least one of the outward surface of the annular recess and the inward surface of the annular protrusion.

7. 2. The rotation support device according to claim 1, wherein the elastic member is a disc spring having a plurality of through holes or a plurality of slits that pass through a conical plate portion in the axial direction.

8. The rotary support device according to claim 1 , wherein the hollow member has at least one rib protruding from its inner circumferential surface.

9. The rotation support device according to claim 1 , wherein a plurality of the hollow members are disposed within the storage chamber.

10. The rotary support device according to claim 1 , wherein the surface of the hollow member is covered with an outer layer.

11. 2. The rotary support device according to claim 1, wherein the hollow member is a structure having a hollow cross section that is integrally molded without joints.

12. The rotary support device according to claim 1 , wherein the hollow member is a combined body having a hollow cross section, which is formed by integrating two or more members via their edges.

13. The rotary support device according to claim 1 , wherein the hollow member has a hollow cross section formed by bending the member and joining edges of the member.

14. one of the support base side member and the bearing housing side member has a small diameter cylindrical portion extending to one axial side and an outward flange portion extending from a tip end of the small diameter cylindrical portion toward an outer diameter side, the other of the support base side member and the bearing housing side member has a large-diameter cylindrical portion extending toward the other axial side and having an inner peripheral surface with which the outer peripheral surface of the outward flange portion slides, and an inward flange portion extending from a tip end of the large-diameter cylindrical portion toward an inner diameter side and having an inner peripheral surface with which the outer peripheral surface of the small-diameter cylindrical portion slides, the pressure chamber is formed in an annular space partitioned by the small-diameter cylindrical portion, the outward flange portion, the large-diameter cylindrical portion, and the inward flange portion, The storage chamber is formed in the outward flange portion or the inward flange portion so as to open to the inner circumferential surface of the large diameter cylindrical portion or the outer circumferential surface of the small diameter cylindrical portion, The orifice is formed in the outward flange portion or the inward flange portion in which the storage chamber is formed. The rotary support device according to claim 1 .

15. 15. The rotation support device according to claim 14, wherein at least one seal member is installed between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large diameter cylindrical portion.

16. 16. The rotation support device according to claim 14, wherein the working fluid is stored in each gap between the inner peripheral surface of the inward flange portion and the outer peripheral surface of the small-diameter cylindrical portion, and between the outer peripheral surface of the outward flange portion and the inner peripheral surface of the large-diameter cylindrical portion.

17. the sealing member is an O-ring, a seal groove in which the O-ring is disposed is formed on an inner peripheral surface of the inward flange portion or an outer peripheral surface of the small-diameter cylindrical portion, and on an outer peripheral surface of the outward flange portion or an inner peripheral surface of the large-diameter cylindrical portion, 16. The rotation support device according to claim 15, wherein the seal groove has a tapered surface whose depth decreases with increasing distance from the pressure chamber.

18. the sealing member is an O-ring, 16. The rotation support device according to claim 15, wherein a wear-resistant member is interposed between the O-ring and at least one of the inner circumferential surface of the inward flange portion and the outer circumferential surface of the small-diameter cylindrical portion, and between the O-ring and at least one of the outer circumferential surface of the outward flange portion and the inner circumferential surface of the large-diameter cylindrical portion.

19. A rotary support device as described in claim 1, wherein a working medium volume change unit is attached to at least one of the support base side member and the bearing housing side member, and changes the volume of the hollow member and the working fluid by heating or cooling the hollow member and the working fluid.

20. One of the pair of support mechanisms is Further, another housing position adjustment mechanism is disposed adjacent to the housing position adjustment mechanism in series or in parallel between the bearing unit and the support base, The other housing position adjustment mechanism is Another support-base-side member is provided on the support base side and passes through the rotation shaft or is arranged around the rotation shaft; another bearing housing side member provided on the bearing housing side, through which the rotation shaft passes or arranged around the rotation shaft, and movable in the axial direction relative to the other support base side member; a pressure generating means accommodated in a compressed state in a pressure chamber formed between the other support base side member and the other bearing housing side member; The rotary support device of claim 1 , comprising:

21. One of the support base member and the bearing housing member has a plurality of recesses that open to one axial side, the other of the support base side member and the bearing housing side member has a plurality of protrusions that protrude toward the other axial side and are fitted into the plurality of recesses so as to be slidable in the axial direction, the pressure chambers are formed between the recesses and the protrusions, respectively; The storage chamber and the orifice are formed in at least one of the plurality of protrusions so that the storage chamber communicates with the pressure chamber via the orifice. The rotary support device according to claim 1 .

22. The rotation support device according to claim 21 , wherein the plurality of pressure chambers are arranged on both sides of the rotation shaft in the width direction.

23. The plurality of protrusions each have the storage chamber and the orifice formed therein, the elastic members are disposed in a compressed state within the plurality of pressure chambers, The rotary support device according to claim 21 , wherein the hollow members are housed in the plurality of storage chambers, respectively.

24. 2. The rotary support device according to claim 1, wherein the bearing of the bearing unit includes a pair of angular contact ball bearings, each of which has an outer ring fitted inside the bearing housing, an inner ring fitted outside the axial end of the rotating shaft, and balls arranged freely rollable between the outer ring and the inner ring.

25. The rotation support device is The rotating shaft is a screw shaft having a spiral thread groove formed on its outer peripheral surface, and further includes a nut having a spiral thread groove formed on its inner peripheral surface, and a plurality of balls arranged so as to roll between the screw groove of the screw shaft and the screw groove of the nut.

2. The rotary support device according to claim 1, which is a ball screw feed device.

26. A shaft support device including a shaft and a pair of support mechanisms provided at both axial ends of the shaft to support the shaft, the support mechanism position adjustment mechanism of the shaft support device being provided on one of the pair of support mechanisms, one of the pair of support mechanisms has a support body through which the shaft passes or which is disposed around the shaft; a first member provided on one of the shaft side and the support side, through which the shaft can pass or which can be arranged around the shaft; a second member provided on the other of the shaft side and the support side, through which the shaft can pass or which can be arranged around the shaft, and which is movable in the axial direction relative to the first member; a pressure chamber formed between the first member and the second member, a reservoir chamber formed in the first member or the second member, and a working fluid accommodated in an orifice communicating between the pressure chamber and the reservoir chamber; an elastic member disposed in a compressed state between opposing axial end surfaces of the first member and the second member within the pressure chamber; a hollow member accommodated in the storage chamber; A support mechanism position adjustment mechanism for a shaft support device.

27. the axis is a rotation axis, one of the pair of support mechanisms further includes a bearing unit including a bearing housing and a bearing that rotatably supports the rotating shaft relative to the bearing housing and is capable of supporting 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 member is a support-side member that is provided on the support side and through which the rotation shaft can pass or that can be arranged around the rotation shaft, 27. The support mechanism position adjustment mechanism for a shaft support device according to claim 26, wherein the second member is a bearing housing side member that is provided on the bearing housing side, through which the rotation shaft can pass or that can be arranged around the rotation shaft, that is movable axially relative to the support side member, and that forms the pressure chamber between itself and the support side member.

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