rotary table

Abstract

The rotary table (1) of the present invention includes a base body (10), a worm gear (21), an inner ring (22), a plurality of rolling elements, and a worm unit (30). The worm unit (32) includes a worm (31) and a worm housing (32). The worm housing (32) has a facing surface that faces the outer peripheral surface (21B) of the worm gear (21). The worm housing (32) includes a flange (325) protruding from the facing surface, which covers the side surface (215A) of the first gear (215) facing the facing surface on the side opposite to the base body (10) in the axial direction of the worm gear (21).

Description

Technical Field

[0001] This invention relates to a rotary table. This application claims priority to Japanese Application No. 2020-005903, filed on January 17, 2020, and incorporates all the contents of that Japanese application. Background Technology

[0002] A rotary table is known to include a worm gear having a first gear formed over the entire circumference and a worm having a second gear meshing with the first gear (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2011-177841. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the aforementioned rotary table, it is preferable to reduce the entry of foreign objects into the area where the first gear and the second gear contact each other. Additionally, it is preferable to reduce the scattering of lubricating grease to the outside of the rotary table. Therefore, one object of the present invention is to provide a rotary table that can reduce the entry of foreign objects into the area where the gears in the worm gear and worm contact each other, and can also reduce the scattering of lubricating grease to the outside.

[0008] means for solving problems

[0009] The rotary table according to the present invention comprises: a base body having a planar retaining surface; a worm gear rotatably disposed on the base body and having an outer peripheral surface on which a first gear is formed in the entire circumferential direction; an inner ring disposed on the inner peripheral side of the worm gear and fixed to the base body; a plurality of rolling elements rotatably disposed on the inner peripheral surface of the worm gear and the outer peripheral surface of the inner ring; and a worm unit fixed to the retaining surface. The worm unit includes: a worm, held rotatably about an axis and having a second gear meshing with the first gear; and a worm housing surrounding and holding the worm, and fixed in such a way that it contacts the retaining surface on a planar contact surface. The worm housing has a facing surface facing the outer peripheral surface of the worm gear. A first through hole is formed on the facing surface, exposing the second gear. The worm housing includes a flange portion projecting from the facing surface, which covers the side of the first gear facing the facing surface on the side opposite to the base body in the axial direction of the worm gear.

[0010] The effects of the invention

[0011] The rotary table described above can reduce the amount of foreign matter entering the area where the gears in the worm gear and worm are in contact with each other, and can also reduce the amount of grease flying out of the rotary table. Attached Figure Description

[0012] Figure 1 It is a schematic three-dimensional diagram showing the structure of the rotary table.

[0013] Figure 2 It is a schematic plan view showing the structure of the rotary table.

[0014] Figure 3 It is a schematic plan view showing the structure of the rotary table.

[0015] Figure 4 It is a schematic plan view showing the structure of the base.

[0016] Figure 5 This is a schematic cross-sectional view showing the structure of the rotary table.

[0017] Figure 6 This is a schematic cross-sectional view showing the structure of the rotary table.

[0018] Figure 7 This is a schematic cross-sectional view showing the structure of the rotary table.

[0019] Figure 8 This is a schematic cross-sectional view showing the structure of the rotary table.

[0020] Figure 9 This is a schematic side view showing the construction of the worm gear unit.

[0021] Figure 10 This is a schematic three-dimensional diagram showing the structure of the worm gear housing.

[0022] Figure 11 This is a schematic cross-sectional view showing the structure of the rotary table.

[0023] Figure 12 This is a schematic plan view showing the structure of the rotary table with the cover and worm gear housing removed. Detailed Implementation

[0024] [Summary of Implementation Methods]

[0025] First, embodiments of the present invention will be described. The rotary table of the present invention includes: a base body having a planar retaining surface; a worm gear rotatably disposed on the base body and having an outer peripheral surface on which a first gear is formed in the entire circumferential direction; an inner ring disposed on the inner peripheral side of the worm gear and fixed to the base body; a plurality of rolling elements rotatably disposed on the inner peripheral surface of the worm gear and the outer peripheral surface of the inner ring; and a worm unit fixed to the retaining surface. The worm unit includes: a worm held rotatably about an axis and having a second gear meshing with the first gear; and a worm housing surrounding and holding the worm, and fixed in contact with the retaining surface on a planar contact surface. The worm housing has a facing surface facing the outer peripheral surface of the worm gear. A first through hole is formed on the facing surface, exposing the second gear. The worm housing includes a flange portion protruding from the facing surface and covering the axial side of the worm gear of the first gear facing the facing surface, opposite to the base body.

[0026] In the rotary table of the present invention, the second gear in the worm is surrounded by the worm housing. Furthermore, the side of the first gear facing the opposite surface is covered by a flange. By employing this structure, it is possible to reduce the ingress of foreign matter into the contact area between the first and second gears, and to reduce the scattering of lubricating grease to the outside of the rotary table. Thus, the rotary table according to the present invention reduces the ingress of foreign matter into the contact area between the gears in the worm wheel and the worm, and reduces the scattering of lubricating grease to the outside of the rotary table.

[0027] In the aforementioned rotary table, a grease supply hole may be formed on the worm housing, extending from the outer wall (excluding the opposing surface) to the opposing surface. The grease supply hole may also have a first opening on the opposing surface. The first opening may also be formed separately from the first through hole in the circumferential direction of the worm wheel. By forming the grease supply hole, grease can be supplied to the first gear and the second gear while the worm housing is fixed to the base body. Furthermore, by supplying grease while the worm wheel and worm are rotating, grease can be easily supplied to the contact area between the first gear and the second gear.

[0028] The rotary table described above may also have a cover component, which is configured to surround the first gear and fixed to the base body. By having such a cover component, it is possible to reduce the scattering of lubricating grease to the outside of the rotary table.

[0029] In the aforementioned rotary table, the rolling elements may also include a first roller and a second roller. The first roller and the second roller may also be arranged alternately in the circumferential direction. Alternatively, the central axis of the first roller may intersect with the central axis of the second roller. By including the first roller and the second roller as described above, a rolling bearing suitable for supporting loads applied in multiple directions by the worm gear and the inner ring can be constructed.

[0030] [Specific examples of implementation methods]

[0031] Next, an example of a specific embodiment of the rotary table of the present invention will be described with reference to the accompanying drawings. In the following drawings, the same or equivalent parts are labeled with the same reference numerals and repeated descriptions thereof are omitted.

[0032] Figure 1 This is a schematic perspective view showing the structure of a rotary table in one embodiment of the present disclosure. Figure 1 In this context, the Z-axis direction is the direction (axial) extending along the rotation axis R of the worm gear. Figure 2 It is a schematic plan view showing the structure of the rotary table. Figure 3 From and Figure 2 A plan view of the rotating platform as seen from the opposite side of the viewpoint. Figure 5 This indicates that the rotating edge of the stage will be rotated. Figure 2 A cross-sectional view of the AA section cut off. Figure 6 It is Figure 5 The enlarged cross-sectional view of region α in the figure. Figure 7 This indicates that the rotating edge of the stage will be rotated. Figure 2 A cross-sectional view of the BB cut-off state. Figure 8 This indicates that the rotating edge of the stage will be rotated. Figure 2 A cross-sectional view showing the state of CC cutoff. Figure 11 It is a cross-sectional view that enlarges the perimeter of the area where the first gear and the second gear are in contact. Figure 12 Is it related to unloading Figure 2 A plan view showing the state of the rotating stage's cover component and the worm gear housing.

[0033] Reference Figures 1-3 The rotary table 1 has a base body 10, a rolling bearing unit 20, a worm gear unit 30, and screws 51, 52, and 53.

[0034] Reference Figure 1 The base 10 has a flat plate shape. (See reference...) Figure 4 The base body 10 has a first surface 101, a second surface 102 serving as a retaining surface, and a third surface 103. When viewed from above in the Z-axis direction, the first surface 101 and the second surface 102 are aligned in the Y-axis direction. (Refer to...) Figure 1 The thickness of the region corresponding to the first surface 101 is greater than the thickness of the region corresponding to the second surface 102. That is, the height of the second surface 102 in the Z-axis direction is lower than the height of the first surface 101. The first surface 101 and the second surface 102 are connected by a third surface 103. (Refer to...) Figure 4The first surface 101 has a planar shape. When viewed from above in the Z-axis direction, the first surface 101 has a rectangular shape. Four through holes 105 extending along the thickness direction are formed at the corners of the first surface 101. A through hole 107 extending along the thickness direction is formed in the first surface 101. When viewed from above in the Z-axis direction, the through hole 107 has a circular shape. When viewed from above in the Z-axis direction, an annular recess 101B is formed in the first surface 101 surrounding the through hole 107. Furthermore, an annular recess 101A is formed surrounding the recess 101B. (See reference...) Figure 7 The thickness of the region of the first surface 101 corresponding to the recess 101A is greater than the thickness of the region of the first surface 101 corresponding to the recess 101B. (Refer to...) Figure 4 The recesses 101A and 101B respectively have the worm gear 21 and inner ring 22 described later (see reference). Figure 1 The corresponding shape. A plurality of threaded holes 106 are formed at equal intervals in the circumferential direction in the recess 101B. A plurality of threaded holes 104 are formed at intervals in the circumferential direction on the outer peripheral side of the first surface 101, in the recess 101A.

[0035] Reference Figure 4 Viewed from above along the Z-axis, the second surface 102 has a rectangular shape. The length L3 of the second surface 102 along the X-axis is shorter than the length L4 of the first surface 101 along the X-axis. The second surface 102 has a planar shape. Four through holes 108A, 108B, 108C, and 108D are formed on the second surface 102, extending along the thickness direction. The inner diameter of the through holes 108A, 108B, 108C, and 108D is greater than that of the screw 53 described later (see reference). Figure 3 The outer diameter of the threaded portion on the second surface 102 is large. A first recess 11 is formed between the through hole 108C and the through hole 108D. When viewed from above in the Z-axis direction, the first recess 11 is formed in the region in the Y-axis direction closer to the long side opposite to the first surface 101 than the center of the second surface 102. In the X-axis direction, when viewed from the through hole 108C, a through hole 109 extending along the thickness direction is formed on the side opposite to the first recess 11. (Refer to...) Figure 4 and Figure 6 A first threaded hole 12 communicating with the first recess 11 is formed on the base body 10. The first threaded hole 12 extends along the Y-axis direction.

[0036] Reference Figure 7 and Figure 8The rolling bearing unit 20 includes a worm gear 21 as an outer ring, an inner ring 22, a plurality of first rollers 23 and a plurality of second rollers 24 as multiple rolling elements, and a cover member 25. The worm gear 21 is disposed on a first surface 101 of the base body 10. The worm gear 21 is configured to correspond to a position on the first surface 101 where a recess 101A is formed. The worm gear 21 is configured such that the direction along the rotation axis R of the worm gear 21 is aligned with the direction perpendicular to the first surface 101 (Z-axis direction). The worm gear 21 has an annular shape.

[0037] The worm gear 21 includes an inner circumferential surface 21A, an outer circumferential surface 21B, an axial end face 21D, and an axial end face 21E opposite to the end face 21D. A first gear 215 is formed along the entire circumference of the outer circumferential surface 21B. The inner circumferential surface 21A includes a first region 211 and a second region 212. The first region 211 is located axially closer to the end face 21D than the center of the inner circumferential surface 21A. The second region 212 is located axially closer to the end face 21E than the center of the inner circumferential surface 21A. In the Z-axis direction, an annular recessed space 21C is formed between the first region 211 and the second region 212. The space 21C is surrounded by an annular first rolling surface 213 and an annular second rolling surface 214. The first rolling surface 213 and the second rolling surface 214 intersect (orthogonalize). The space 21C is formed along the rolling path of a plurality of first rollers 23 and a plurality of second rollers 24. (Refer to...) Figure 1 and Figure 2 On the worm gear 21, a plurality of threaded holes 216 (eight in this embodiment) are formed at equal intervals in the circumferential direction.

[0038] Reference Figure 7 and Figure 8The inner ring 22 has an annular shape. The inner ring 22 is disposed on the inner circumferential side of the worm gear 21. The inner ring 22 is configured to correspond to the position of the first surface 101 where a recess 101B is formed. The inner ring 22 includes an outer circumferential surface 22A, an inner circumferential surface 22B, an axial end face 22D, and an axial end face 22E opposite to the end face 22D. The outer circumferential surface 22A includes a third region 221 and a fourth region 222. The third region 221 is disposed axially closer to the end face 22D than the center of the outer circumferential surface 22A. The fourth region 222 is disposed axially closer to the end face 22E than the center of the outer circumferential surface 22A. An annular recessed space 22C is formed between the third region 221 and the fourth region 222 in the Z-axis direction. The space 22C is surrounded by an annular third rolling surface 223 and an annular fourth rolling surface 224. The third rolling surface 223 and the fourth rolling surface 224 intersect (or are orthogonal). Space 22C is formed along the rolling paths of the plurality of first rollers 23 and the plurality of second rollers 24. The first rolling surface 213 and the fourth rolling surface 224 face each other. In this embodiment, in a section including the rotation axis R, the first rolling surface 213 and the fourth rolling surface 224 are arranged in parallel. The second rolling surface 214 and the fourth rolling surface 224 face each other. In this embodiment, in a section including the rotation axis R, the second rolling surface 214 and the fourth rolling surface 224 are arranged in parallel.

[0039] Reference Figure 1 On the inner ring 22, a plurality of threaded holes 225 (eight in this embodiment) are formed at equal intervals in the circumferential direction. (Refer to...) Figure 2 and Figure 4 The position where the threaded hole 225 is formed is aligned with the position where the threaded hole 106 is formed on the base body 10, and the screw 52 (refer to) is installed. Figure 3 Screw it into the threaded holes 106 and 225. In this way, the inner ring 22 is fixed on the base body 10.

[0040] Reference Figure 7 and Figure 8The first roller 23 and the second roller 24 have a cylindrical shape. The first roller 23 and the second roller 24 are alternately arranged in the circumferential direction. The first roller 23 is configured to contact and roll on its outer circumferential surface 23A with the second rolling surface 214 and the third rolling surface 223. The second roller 24 is configured to contact and roll on its outer circumferential surface 24A with the first rolling surface 213 and the fourth rolling surface 224. The central axis P1 of the first roller 23 intersects (or is orthogonal to) the central axis P2 of the second roller 24. Specifically, the intersection of the central axis P1 of the first roller 23 and the central axis P2 of the second roller 24 occurs when the worm gear 21 rotates and the centers of gravity of the first roller 23 and the second roller 24 pass through a predetermined point. In this way, the worm gear 21 can rotate relative to the base body 10 about the rotation axis R.

[0041] Reference Figure 7 A cover member 25 is disposed on the first surface 101. The cover member 25 is disposed on the outer peripheral side of the worm gear 21. The cover member 25 has an annular shape. The cover member 25 surrounds the first gear 215. In this embodiment, the first gear 215 is exposed from a portion of the cover member 25. (Refer to...) Figure 2 The cover component 25 has a plurality of threaded holes 251 spaced apart in the circumferential direction (four in this embodiment). See reference... Figure 2 and Figure 4 The positions where threaded holes 251 and 104 are formed on the base body 10 are aligned, and screws 51 are screwed into the threaded holes 104 and 251. In this way, the cover component 25 is fixed on the base body 10.

[0042] Reference Figure 1 The worm gear unit 30 is mounted on the second surface 102. (Refer to...) Figure 9 and Figure 12 The worm gear unit 30 includes a worm 31, a worm housing 32, a pin 33, a motor 34, a coupling 35, a cover 36, a first support bearing 37, and a second support bearing 38. The worm 31 has a cylindrical shape. A second gear 31A is formed on the outer circumferential surface of the worm 31. The second gear 31A meshes with a first gear 215. A cover 36 is disposed at one end of the worm 31. The worm 31 is rotatably supported relative to the cover 36 by the first support bearing 37. A coupling 35 is disposed at the other end of the worm 31. The motor 34 is fixed to the motor housing 35A by screws. As the motor 34 in this embodiment, a synchronous motor or an AC servo motor can be used, for example. The worm 31 is rotatably supported relative to the coupling 35 by the second support bearing 38. The worm 31 is connected to the motor 34 via the coupling 35. The motor 34 is electrically connected to an external power source (not shown). The motor 34 has a ring 34A for manual rotation.

[0043] Reference Figure 10 The worm housing 32 has a cuboid shape with an internal space S. The worm housing 32 includes a first outer wall surface 32A, a second outer wall surface 32B serving as a contact surface, a third outer wall surface 32C, a fourth outer wall surface 32D, a fifth outer wall surface 32E, and a sixth outer wall surface 32F. The first outer wall surface 32A, second outer wall surface 32B, third outer wall surface 32C, fourth outer wall surface 32D, and sixth outer wall surface 32F have a planar shape. The first outer wall surface 32A and second outer wall surface 32B are arranged side-by-side in the Z-axis direction. The first outer wall surface 32A and second outer wall surface 32B are arranged in parallel. The third outer wall surface 32C and fourth outer wall surface 32D are arranged side-by-side in the X-axis direction. The third outer wall surface 32C and fourth outer wall surface 32D are arranged in parallel. The fifth outer wall surface 32E and sixth outer wall surface 32F are arranged side-by-side in the Y-axis direction.

[0044] Reference Figure 6 A recess 321 is formed on the second outer wall surface 32B. (Refer to...) Figure 10 An opening 324A communicating with the internal space S is formed on the third outer wall surface 32C. Four threaded holes 327 are formed around the opening 324A. An opening 324B communicating with the internal space S is formed on the fourth outer wall surface 32D. The fifth outer wall surface 32E has a curved (arc-shaped) facing surface 322 recessed in the Y-axis direction. A first through hole 323 communicating with the internal space S is formed on the facing surface 322. The worm gear housing 32 includes a flange portion 325 protruding from the facing surface 322 in the Y-axis direction. The front end portion 325A in the protruding direction of the flange portion 325 has a curved (arc-shaped) shape. The front end portion 325A constitutes a part of the fifth outer wall surface 32E.

[0045] A grease supply hole 326 is formed on the worm housing, extending from the third outer wall surface 32C to the opposing surface 322. The grease supply hole 326 has a first opening 326A on the opposing surface 322 and a second opening 326B on the third outer wall surface 32C. The first opening 326A is formed spaced apart from the first through hole 323 in the X-axis direction. A grease nipple 328 is pressed in by closing the second opening 326B (see reference). Figure 11 The grease supply can be easily adjusted by installing the grease nipple 328.

[0046] Reference Figure 6 A cylindrical pin 33 is disposed protruding from the second outer wall surface 32B. The pin 33 is embedded in a recess 321 on the second outer wall surface 32B. In this embodiment, the pin 33 has a width L5 in the X-axis direction greater than that of the first recess 11 (see reference). Figure 4 Slightly smaller outer diameter.

[0047] Reference Figure 9 and Figure 10 The worm housing 32 with its threaded hole 327 is aligned with the cover 36 with its threaded hole (not shown), and screws 54 are screwed in. This secures the worm housing 32 to the cover 36. (See reference...) Figure 9 and Figure 11 The worm housing 32 surrounds the worm 31. The worm 31 is housed within the internal space S formed by the worm housing 32. The second gear 31A of the worm 31 protrudes from the first through hole 323 on the worm housing. (Refer to...) Figure 6 The second outer wall surface 32B of the worm housing 32 contacts the second surface 102 of the base body 10. The facing surface 322 of the worm housing 32 faces the outer peripheral surface 21B of the worm wheel 21. The second gear 31A exposed from the first through hole 323 of the facing surface 322 meshes with the first gear 215 of the worm wheel 21.

[0048] Reference Figure 6 The flange portion 325 covers the side surface 215A of the first gear 215 facing the opposing surface 322 in the Z-axis direction, opposite to the base body 10. In this embodiment, the distance L1 between the side surface 325A of the flange portion 325 and the outer peripheral surface 21B of the worm gear 21 facing the side surface 325A is 1 mm or less. The distance L1 is preferably 0.5 mm or more and 1 mm or less. The distance L2 between the wall surface 325B of the flange portion 325 facing the side surface 215A of the first gear 215 and the side surface 215A of the first gear 215 is 1 mm or less. The distance L2 is preferably 0.5 mm or more and 1 mm or less. By setting the distances L1 and L2 within the above range, the scattering of grease to the outside of the rotary table 1 can be reduced. In addition, the labyrinth structure can reduce the entry of foreign objects from the outside.

[0049] Reference Figure 6 The pin 33 is inserted into the elongated first recess 11 of the base body 10. The rotary table 1 also has an internal hexagonal headstock retainer screw 40, which serves as a first screw screwed into the first threaded hole 12 of the base body 10. The front end 40A of the internal hexagonal headstock retainer screw 40 contacts the outer peripheral surface 33A of the pin 33. (Refer to...) Figure 3 and Figure 4 The positions of the through holes 108A, 108B, 108C, and 108D on the base body 10 are aligned with the positions of the threaded holes (not shown) formed on the worm housing 32, and screws 53 are screwed in. In this way, the worm housing 32 is fixed to the base body 10.

[0050] In this embodiment of the rotary table 1, the second gear 31A is surrounded by the worm housing 32. Furthermore, the side 215A of the first gear 215 is covered by the flange 325. This structure reduces the amount of foreign matter entering the area where the first gear 215 contacts the second gear 31A, and also reduces the amount of grease scattering to the outside of the rotary table 1. Additionally, it reduces leakage of grease supplied from the grease supply hole 326 to the end face 21D of the worm gear 21. Furthermore, because the worm housing 32 has the flange 325, grease scattering can be reduced even without additional cover components.

[0051] In the above embodiment, a grease supply hole 326 is formed on the worm housing 32. The grease supply hole 326 has a first opening 326A on the facing surface 322. The first opening 326A is formed separately from the first through hole 323 in the circumferential direction of the worm gear 21. The grease supply hole 326 extends along the X-axis direction. By forming the grease supply hole 326, grease supply can be performed while the worm housing 32 is fixed on the base body 10. In addition, by performing grease supply from the upper side of the area where the first gear 215 and the second gear 31A are in contact while the worm gear 21 and the worm 31 are rotating, grease supply can be easily performed on the area where the first gear 215 and the second gear 31A are in contact.

[0052] In the above embodiments, refer to Figure 9 and Figure 11 When viewed from the area where the first gear 215 contacts the second gear 31A, the first opening 326A in the grease supply hole 326 is formed on the side of the first outer wall surface 32A in the Z-axis direction. (Refer to...) Figure 9 and Figure 11 The first opening 326A is formed in the Z-axis direction slightly closer to the first outer wall surface 32A than the center of the facing surface 322. When viewed from the first through hole 323, the first opening 326A is formed in the X-axis direction on the side of the third outer wall surface 32C. With this structure, grease can be supplied to the area where the first gear 215 and the second gear 31A contact while the grease is moved by gravity. Therefore, grease supply to the area where the first gear 215 and the second gear 31A contact is easily achieved.

[0053] In the above embodiment, the rotary table 1 has a cover member 25. By having a cover member 25, it is possible to reduce the scattering of lubricating grease to the outside of the rotary table 1.

[0054] In the above embodiment, a first roller 23 and a second roller 24 are used as rolling elements. The first roller 23 and the second roller 24 may also be arranged alternately in the circumferential direction. The central axis P1 of the first roller 23 intersects the central axis P2 of the second roller 24. By using the first roller 23 and the second roller 24, a rolling bearing suitable for supporting loads applied in multiple directions by the worm gear 21 and the inner ring 22 can be constructed. By using such a crossed rolling bearing, the rotary table 1 can be compactly constructed with a small cross section. In addition, the first roller 23 and the second roller 24 are inserted after the cover (not shown) of the inner ring 22 is removed. In the above embodiment, the case where the first roller 23 and the second roller 24 are used as rolling elements has been described, but it is not limited to this, and balls may also be used as rolling elements. In the above embodiment, the case where a grease supply hole 326 is formed on the worm housing 32 has been described, but it is not limited to this, and the grease supply hole 326 may not be formed on the worm housing 32.

[0055] The embodiments disclosed herein are illustrative in all respects and should be understood as not being limiting in any way. The scope of the invention is not limited by the foregoing description, but is defined by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

[0056] Explanation of reference numerals in the attached figures

[0057] 1 Rotary stage; 10 Base body; 11 First recess; 12 First threaded hole; 20 Unit; 21 Worm gear; 21A, 22B Inner peripheral surfaces; 21B, 22A, 23A, 24A, 33A Outer peripheral surfaces; 21C, 22C Spaces; 21D, 21E, 22D, 22E End faces; 22 Inner ring; 23 First roller; 24 Second roller; 25 Cover component; 30 Worm gear unit; 31 Worm; 31A First threaded hole Two gears; 32 worm housing; 32A first outer wall surface; 32B second outer wall surface; 32C third outer wall surface; 32D fourth outer wall surface; 32E fifth outer wall surface; 32F sixth outer wall surface; 33 pin; 34 motor; 34A ring; 35 coupling; 35A motor housing; 36 cover; 37 first support bearing; 38 second support bearing; 40 socket head cap screw; 40A, 325A front end; 51, 52, 53, 54 Screws; 101 First surface; 101A, 101B, 321 Recesses; 102 Second surface; 103 Third surface; 104, 106, 216, 225, 251, 327 Threaded holes; 105, 107, 108A, 108B, 108C, 108D, 109 Through holes; 211 First region; 212 Second region; 213 First rolling surface; 2 14 Second rolling surface; 215 First gear; 215A, 325A side surface; 221 Third region; 222 Fourth region; 223 Third rolling surface; 224 Fourth rolling surface; 322 Opposing surface; 323 First through hole; 324A, 324B openings; 325 Flange; 325B Wall; 326 Grease supply hole; 326A First opening; 326B Second opening; 328 Grease nipple.

Claims

1. A rotary table, wherein, have: The base has a planar retaining surface; The worm gear is rotatably mounted on the base body and has an outer circumferential surface on which a first gear is formed throughout the circumference; The inner ring is disposed on the inner circumferential side of the worm gear and fixed to the base body; Multiple rolling elements are rotatably disposed on the inner circumferential surface of the worm gear and the outer circumferential surface of the inner ring; as well as The worm gear unit is fixed to the retaining surface. The worm gear unit includes: The worm gear is kept rotatable about an axis and has a second gear that meshes with the first gear; as well as A worm housing surrounds and holds the worm, and is configured and fixed to the retaining surface of the base body in such a way that its planar contact surface contacts the retaining surface. The worm housing has a facing surface that faces the outer peripheral surface of the worm wheel. A first through hole is formed on the facing surface to expose the second gear. The worm housing includes a flange protruding from the opposing surface, the flange covering the side of the first gear facing the opposing surface on the axial direction of the worm wheel opposite to the base body.

2. The rotary table according to claim 1, wherein, A grease supply hole is formed on the worm housing, and the grease supply hole extends from the outer wall other than the facing surface to the facing surface. The grease supply port has a first opening on the opposing surface. The first opening is formed separately from the first through hole in the circumferential direction of the worm gear.

3. The rotary table according to claim 1 or 2, wherein, The rotary table also has a cover component, which is configured to surround the first gear and fixed to the base body.

4. The rotary table according to claim 1 or 2, wherein, The rolling element includes a first roller and a second roller. The first roller and the second roller are arranged alternately in the circumferential direction. The central axis of the first roller intersects with the central axis of the second roller.

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