Flexible meshing type gear device
By introducing a double row of rolling elements and spacer components into the vibrating body bearing, the problem of lubricant not being able to properly lubricate the rolling elements is solved, the lubrication effect is improved, the normal operation of the gear device is ensured, and friction loss is reduced.
Patent Information
- Application Number
- CN202510593210.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-05-23
- Filing Date
- 2025-05-09
- Publication Date
- 2025-11-25
AI Technical Summary
In existing flexural gear systems, the lubricant only remains in the space between the rolling elements, which is insufficient to properly lubricate the rolling elements.
A vibrating bearing structure was designed, comprising a double row of rolling elements and a spacer component. By configuring the spacer component between the first and second rolling element rows, the lubricant can be effectively supplied to the track surface of the rolling elements.
Proper lubrication of the vibrating body bearings was achieved, improving the lubrication effect, ensuring the normal operation of the gear unit, and reducing frictional loss.
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Figure CN121007201A_ABST
Abstract
Description
[0001] This application claims priority based on Japanese Patent Application No. 2024-083784 filed on May 23, 2024. The entire contents of this Japanese application are incorporated herein by reference. TECHNICAL FIELD
[0002] The present application relates to a flexspline gear device. BACKGROUND
[0003] Conventionally, a flexspline gear device is known, which includes an external gear that is flexibly deformed by a vibration body, and a vibration body bearing that is disposed between the vibration body and the external gear (for example, refer to Patent Literature 1).
[0004] In such a flexspline gear device, in a case where the vibration body bearing is double-rowed, for example, a space is sometimes ensured between the two rows of rolling elements, and a lubricant (grease) is sometimes held in this space.
[0005] Patent Literature 1: International Publication No. 2017 / 006442
[0006] However, simply filling the lubricant in the space between the rows of rolling elements sometimes causes the lubricant to stay in the space and fail to properly lubricate the rolling elements. SUMMARY
[0007] The present application has been achieved in view of the above-described circumstances, and aims to properly lubricate a vibration body bearing.
[0008] The present application is a flexspline gear device including a vibration body, a flex gear that is flexibly deformed by the vibration body, and a vibration body bearing that is disposed between the vibration body and the flex gear,
[0009] The vibration body bearing includes a first row of rolling elements in which a plurality of first rolling elements are arranged in a circumferential direction, a first retainer that retains the plurality of first rolling elements, a second row of rolling elements that is disposed at a position offset in an axial direction from the first row of rolling elements and in which a plurality of second rolling elements are arranged in the circumferential direction, and a second retainer that retains the plurality of second rolling elements.
[0010] The first retainer includes a plurality of first pockets that respectively accommodate the plurality of first rolling elements, the first pockets being open toward the second row of rolling elements in the axial direction.
[0011] The second retainer includes a plurality of second pockets that respectively accommodate the plurality of second rolling elements, the second pockets being open toward the first row of rolling elements in the axial direction.
[0012] A spacing member is disposed between the first row of rolling elements and the second row of rolling elements.
[0013] Inventive Effects
[0014] According to the present application, the vibration generator shaft bearing can be appropriately lubricated. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is a sectional view showing a flexspline type gear device according to an embodiment.
[0016] Figure 2 is an enlarged view of the E portion of Figure 1
[0017] Figure 3 is a view showing positional relationships of a rolling element row, a retainer, and a spacer member in a vibration generator shaft bearing according to an embodiment.
[0018] Figure 4 is a view showing a modification of the vibration generator shaft bearing according to an embodiment, and is a partial sectional view showing the same portion as Figure 3
[0019] In the drawing: 1 - flexspline type gear device, 10 - vibration generator shaft, 10a - vibration generator, 12 - external gear (flexspline), 15 - vibration generator shaft bearing, 40A - first rolling element, 40B - second rolling element, 42A - first rolling element row, 42B - second rolling element row, 44 - inner ring, 44A - first inner ring, 44B - second inner ring, 46 - outer ring, 46A - first outer ring, 46B - second outer ring, 48A - first retainer, 48B - second retainer, 54A - first rolling surface, 54B - second rolling surface, 60A - first ring portion, 60B - second ring portion, 62A - first column portion, 62B - second column portion, 64A - first pocket, 64B - second pocket, 66A - first opening portion, 66B - second opening portion, 68A - first anti-falling portion, 68B - second anti-falling portion, 70 - spacer member, S - bearing inner space. DETAILED DESCRIPTION
[0020] Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings.
[0021] [Structure of flexspline type gear device]
[0022] Figure 1 is a sectional view showing a flexspline type gear device 1 according to an embodiment.
[0023] Hereinafter, the direction along the rotation axis O1 in the figure is defined as "axial direction", the direction perpendicular to the rotation axis O1 is defined as "radial direction", and the rotation direction centered on the rotation axis O1 is defined as "circumferential direction". Furthermore, in the axial direction, the side connected to the external driven component (the left side in the figure) is called the "load side", and the side opposite to the load side (the right side in the figure) is called the "load opposite side".
[0024] like Figure 1 As shown, the flexural meshing gear device 1 is a cylindrical flexural meshing gear device in which the external gear 12 flexes and deforms to transmit rotational motion around the rotating shaft O1.
[0025] Specifically, the flexural meshing gear device 1 includes: a vibrating body shaft 10; an external gear 12, which is flexed and deformed by the vibrating body shaft 10; a first internal gear 22g and a second internal gear 23g, which mesh with the external gear 12; and a vibrating body bearing 15. The flexural meshing gear device 1 also includes a first housing 22, an internal gear component 23, a second housing 24, a first cover 26, a second cover 27, and a main bearing 33.
[0026] The vibrating shaft 10 has: a hollow vibrating body 10a, whose cross-sectional shape (outer periphery) perpendicular to the rotation axis O1 is elliptical (having mutually orthogonal major and minor axes); and shaft portions 10b and 10c, located on both sides of the vibrating body 10a along its axial direction, whose cross-sectional shape perpendicular to the rotation axis O1 is circular. Furthermore, the elliptical shape is not limited to a strictly geometrically elliptical shape, but also includes approximately elliptical shapes. The vibrating shaft 10 rotates around the rotation axis O1, and the center of the cross-sectional shape of the vibrating body 10a perpendicular to the rotation axis O1 coincides with the rotation axis O1. This vibrating shaft 10 is an input shaft connected to a drive source such as a motor (not shown) to input driving force. Furthermore, the vibrating shaft 10 can also be a solid shaft.
[0027] The external gear 12 is a flexible cylindrical metal with teeth on its outer periphery. The external gear 12 is an example of a flexible gear according to the present invention.
[0028] The first internal gear 22g and the second internal gear 23g are configured such that the axis of rotation is aligned with the axis of rotation O1.
[0029] These first internal gears 22g and second internal gears 23g are arranged axially and mesh with the external gear 12. Specifically, one of the first internal gears 22g and 23g meshes with a tooth portion of the external gear 12 that is further to one side than the axial center, and the other meshes with a tooth portion of the external gear 12 that is further to the other side than the axial center. The first internal gear 22g is configured such that internal teeth are provided at corresponding positions on the inner periphery of the first housing 22. The second internal gear 23g is configured such that internal teeth are provided at corresponding positions on the inner periphery of the internal gear component 23.
[0030] The vibrator bearing 15 is positioned between the vibrator 10a and the external gear 12.
[0031] The specific structure of the vibrating body bearing 15 will be described later.
[0032] Spacer rings 36 and 37 are provided on both sides of the external gear 12 in the axial direction to act as limiting members that abut against it to restrict axial movement.
[0033] The first housing 22 and the second housing 24 are connected to each other by bolts 57, thereby covering the radially outer sides of the first internal gear 22g, the second internal gear 23g, and the external gear 12. As described above, the first housing 22 has internal teeth on a portion of its inner circumference and is integrally formed with the first internal gear 22g. Furthermore, when the flexural gear assembly 1 is connected to an external object device, the first housing 22 and the second housing 24 are connected by being fastened together with the object device.
[0034] At least a portion of the internal gear component 23 is disposed radially inside the second housing 24 and radially outside the vibrating body shaft 10. Furthermore, as described above, the internal gear component 23 has internal teeth on a portion of its inner circumference and is integrally formed with the second internal gear 23g.
[0035] The first cover 26 is connected to the first housing 22 by bolts 51, thereby covering the meshing portion of the external gear 12 and the first internal gear 22g from the opposite side of the load. An input bearing 31 (e.g., a ball bearing) is disposed between the first cover 26 and the shaft portion 10b of the vibrator shaft 10, via which the first cover 26 supports the vibrator shaft 10 for free rotation.
[0036] The second cover 27 is connected to the internal gear component 23 by bolts 52, thereby covering the meshing portion of the external gear 12 and the second internal gear 23g from the load side. An input bearing 32 (e.g., a ball bearing) is disposed between the second cover 27 and the shaft portion 10c of the vibrator shaft 10, through which the second cover 27 supports the vibrator shaft 10 for free rotation. When the flexural meshing gear device 1 is connected to an external object device, the second cover 27 and the internal gear component 23 are connected together with the driven component of the object device by fastening together, and output decelerated rotation to the driven component.
[0037] The main bearing 33, for example, is a ball bearing, disposed between the internal gear component 23 and the second housing 24. The second housing 24 supports the internal gear component 23 for free rotation via the main bearing 33. Furthermore, the main bearing 33 is not limited to a ball bearing; for example, it can be a crossed roller bearing. Also, the main bearing 33 may not have a dedicated inner or outer ring. Furthermore, the main bearing 33 can also be a sealed bearing with internal lubricant.
[0038] [Action Description]
[0039] In the flexural gear assembly 1, if the rotation of the vibrator shaft 10 is driven by a drive source such as a motor, the motion of the vibrator 10a is transmitted to the external gear 12 via the vibrator bearing 15. At this time, the external gear 12 is constrained to flex into an elliptical shape with a major axis and a minor axis when viewed axially, following the shape of the outer circumferential surface of the vibrator 10a. Furthermore, the external gear 12 meshes with the fixed first internal gear 22g at the major axis position of the vibrator 10a, and therefore does not rotate at the same speed as the vibrator 10a, but rather moves the major axis position of the vibrator 10a by means of flexural deformation.
[0040] For example, when the external gear 12 has 100 teeth and the first internal gear 22g has 102 teeth, the external gear 12 rotates (rotates) by the amount of the difference in the number of teeth between itself and the first internal gear 22g when rotating one revolution at the meshing position. If the number of teeth is as described above, the rotational motion of the vibrating body shaft 10 will be reduced in speed by a reduction ratio of 100:2 and transmitted to the external gear 12.
[0041] On the other hand, the external gear 12 also meshes with the second internal gear 23g. Therefore, for example, if we assume that the number of teeth of the second internal gear 23g is the same as the number of teeth of the external gear 12, the external gear 12 and the second internal gear 23g will rotate at the same speed. As a result, the rotational motion of the vibrating body shaft 10 will be reduced by a reduction ratio of 100:2 and transmitted to the internal gear component 23 and the second cover 27, so that the rotational motion will be output to the driven component.
[0042] [Materials of each component]
[0043] The materials of the components other than the vibrating body bearing 15 are not particularly limited, but in this embodiment, they are configured as follows.
[0044] The vibrating body shaft 10, external gear 12, and spacer rings 36 and 37 are made of metal materials such as steel. While not specifically limited, more specifically, the vibrating body shaft 10 is made of steel materials such as chromium-molybdenum steel. Alternatively, the vibrating body shaft 10 may also be made of aluminum alloy. The external gear 12 is made of steel materials such as nickel-chromium-molybdenum steel. The spacer rings 36 and 37 are made of steel materials such as high-carbon chromium bearing steel.
[0045] The inner and outer rings and rolling elements of the input bearings 31 and 32 and the main bearing 33 are made of metal (e.g., high carbon chromium bearing steel).
[0046] Each bolt 51, 52, and 57 is made of metal (e.g., rolled steel for general structures, cold-headed carbon steel wire, carbon steel for mechanical structures, etc.).
[0047] On the other hand, the first outer shell 22, the internal gear component 23, the second outer shell 24, the first cover 26 and the second cover 27 are not particularly limited, but are made of resin (resin-based materials).
[0048] In this embodiment, a resin containing reinforcing fibers in its resin matrix is used as the resin for the second outer shell 24, the first cover 26, and the second cover 27. Alternatively, a resin without reinforcing fibers may also be used.
[0049] The base resin can be an engineering plastic (general-purpose engineering plastic) with a heat resistance of around 50–60°C. Specifically, examples include polyamide (PA), polycarbonate (PC), polyacetal (POM), modified polyphenylene ether (m-PPE), and polybutylene terephthalate (PBT). The heat resistance mentioned here does not refer to the temperature at which the shape can be statically maintained, but rather to the temperature at which the gear's performance can be maintained.
[0050] Examples of reinforcing fibers include glass fiber, aramid fiber, polyethylene fiber, ZYLON fiber, and boron fiber.
[0051] In this embodiment, a resin containing reinforcing fibers in its resin matrix is used as the resin for the first housing 22 and the internal gear component 23.
[0052] The matrix resin is preferably a resin with heat resistance of 70°C or higher, for example, a super engineering plastic (special engineering plastic) with heat resistance of 100°C or higher. Specifically, examples include polyetheretherketone (PEEK), polyamide-imide (PAI), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), aromatic polyamide (PPA), liquid crystal polymer (LCP), polysulfone (PSU), polyethersulfone (PES), polyetherimide (PEI), polyarylate (PAR), thermoplastic polyimide (TPI), etc.
[0053] As reinforcing fibers, examples include fibers with higher thermal conductivity than the aforementioned reinforcing fibers (e.g., carbon fiber).
[0054] In addition, regarding the resin and reinforcing fiber used for the first housing 22 and the internal gear component 23, considering heat dissipation, it is preferable to use materials with higher thermal conductivity or heat resistance than the second housing 24, the first cover 26 and the second cover 27, but the same materials as those exemplified for the second housing 24, the first cover 26 and the second cover 27 may also be used.
[0055] [Specific structure of the vibrator bearing]
[0056] Figure 2 yes Figure 1 An enlarged view of part E. Figure 3 This is a cross-sectional view of the vibratory bearing 15 displayed at a certain radial position, showing the positional relationship of the rolling elements, retainer, and spacer components described later in the vibratory bearing 15.
[0057] like Figure 2 and Figure 3 As shown, in this embodiment, the vibrating body bearing 15 is a double-row ball bearing, having two rows of rolling elements and an inner ring 44 and an outer ring 46 shared by these rows.
[0058] Specifically, the vibrating bearing 15 includes: a first rolling element row 42A, which is composed of a plurality of first rolling elements 40A arranged circumferentially; a first retainer 48A, which holds the plurality of first rolling elements 40A; a second rolling element row 42B, which is disposed at a position offset axially relative to the first rolling element row 42A and is composed of a plurality of second rolling elements 40B arranged circumferentially; a second retainer 48B, which holds the plurality of second rolling elements 40B; and an inner ring 44 and an outer ring 46.
[0059] <Rolling Body>
[0060] In this embodiment, the first rolling element 40A is a sphere, but it can also be a roller or other rolling element. The first rolling element row 42A overlaps with the first internal gear 22g in the axial direction.
[0061] In this embodiment, the second rolling element 40B is a ball, but it can also be a roller or other rolling element, and it can be a different type of rolling element than the first rolling element 40A (e.g., a ball and a roller). The axial position of the second rolling element row 42B overlaps with the second internal gear 23g.
[0062] The first rolling element 40A and the second rolling element 40B are made of metal (e.g., high carbon chromium bearing steel).
[0063] <Inner and Outer Circles>
[0064] The inner ring 44 is fixed to the vibrator 10a, for example, by bonding or pressing. The inner ring 44 is flexible and is fixed in an elliptical flexed state by being fitted into the vibrator 10a. On both axial sides of the inner ring 44 and between it and the input bearings 31 and 32, limiting members 38 and 39 are arranged to restrict their axial movement, which are externally fitted into the vibrator shaft 10.
[0065] Alternatively, the inner ring 44 can also be integrally formed with the vibrator 10a from the same components. That is, the outer circumferential surface of the vibrator 10a can form the inner ring of the vibrator bearing 15.
[0066] The outer ring 46 is embedded in the inner circumference of the external gear 12. The outer ring 46 is flexible and flexes and deforms through the inner ring 44 and the rolling elements 42A and 42B as the vibrating body 10a rotates.
[0067] Alternatively, the outer ring 46 can also be integrally formed with the external gear 12 using the same components. That is, the inner circumferential surface of the external gear 12 can form the outer ring of the vibrating body bearing 15.
[0068] The inner ring 44 has a first rolling surface 54A on which the first rolling element 40A rolls and a second rolling surface 54B on which the second rolling element 40B rolls.
[0069] The outer ring 46 has a first rolling surface 54A on which the first rolling element 40A rolls and a second rolling surface 54B on which the second rolling element 40B rolls.
[0070] The first rolling surface 54A and the second rolling surface 54B are grooves into which a portion of the rolling elements 40A and 40B are embedded. However, the shape of the rolling surfaces 54A and 54B is not particularly limited; for example, they may be rectangular grooves that match the rolling elements 40A and 40B as rollers, or they may not be grooves. The first rolling surface 54A restricts the axial movement of the first rolling element 40A, and the second rolling surface 54B restricts the axial movement of the second rolling element 40B.
[0071] The inner ring 44 and the outer ring 46 are made of metal (e.g., high carbon chromium bearing steel).
[0072] <Retainer>
[0073] The first retainer 48A revolves around the rotation axis O1 (reference) Figure 1 The first retainer 48A holds multiple first rolling elements 40A in a rotatable manner and is able to rotate together with the first rolling element row 42A about the rotation axis O1. The first retainer 48A is not particularly limited, but is made of resin (resin-based material).
[0074] The first retainer 48A includes: a first ring portion 60A disposed on the opposite side of the load than the first rolling element row 42A; a plurality of first column portions 62A protruding axially from the first ring portion 60A toward the load side; and a plurality of first pockets 64A formed between adjacent first column portions 62A in the circumferential direction to respectively accommodate a plurality of first rolling elements 40A.
[0075] The first retainer 48A is formed in a comb shape by a first ring portion 60A and a plurality of first column portions 62A. The comb-shaped first retainer 48A does not have a ring portion disposed on the load side relative to the first row of rolling elements 42A.
[0076] The first column portion 62A is arranged at intervals in the circumferential direction. The first column portion 62A is cantilevered by the first ring portion 60A, and the load side is the free end.
[0077] The first pocket 64A opens axially toward the load side (the side of the second rolling element row 42B), and the opening portion of the first pocket 64A forms a first opening 66A.
[0078] The first retainer 48A has a first anti-drop portion 68A that prevents the first rolling element 40A from falling out of the first pocket 64A through the first opening 66A.
[0079] The first anti-detachment part 68A is composed of a protrusion (claw part) protruding inward from the end of each of the adjacent first post parts 62A in the circumferential direction toward the first pocket 64A. In this embodiment, the first anti-detachment part 68A and the first post part 62A are integrally formed from the same component, but they can also be separately provided.
[0080] The second retainer 48B revolves around the rotation axis O1 (reference) Figure 1 The second retainer 48B holds multiple second rolling elements 40B in a rotatable manner and is able to rotate together with the second rolling element row 42B about the rotation axis O1. The second retainer 48B is not particularly limited, but is made of resin (resin-based material).
[0081] The second retainer 48B includes: a second ring portion 60B disposed on the load side further than the second rolling element row 42B; a plurality of second pillar portions 62B protruding axially from the second ring portion 60B toward the load-opposite side; and a plurality of second pockets 64B formed between adjacent second pillar portions 62B in the circumferential direction to respectively accommodate the plurality of second rolling elements 40B. In this embodiment, the positional relationship between the constituent elements (second ring portion 60B, second pillar portion 62B, second pocket 64B) of the second retainer 48B when viewed axially is the same as the positional relationship between the constituent elements (first ring portion 60A, first pillar portion 62A, first pocket 64A) of the first retainer 48A when viewed axially.
[0082] The second retainer 48B is formed in a comb shape by a second ring portion 60B and a plurality of second column portions 62B. The comb-shaped second retainer 48B does not have a ring portion disposed on the opposite side of the load relative to the second row of rolling elements 42B.
[0083] The second column portions 62B are arranged at intervals in the circumferential direction. The second column portions 62B are cantilevered by the second ring portions 60B, with the free end on the opposite side of the load.
[0084] The second pocket 64B opens axially toward the side opposite to the load (the side of the first rolling element row 42A), and the opening portion of the second pocket 64B forms a second opening 66B.
[0085] The second retainer 48B has a second anti-detachment portion 68B that prevents the second rolling element 40B from falling out of the second pocket 64B through the second opening 66B.
[0086] The second anti-detachment part 68B is composed of a protrusion (claw) that protrudes inward toward the circumferential side of the end portion of each of the adjacent second post portions 62B in the circumferential direction. In this embodiment, the second detachment prevention part 68B and the second post portion 62B are integrally formed from the same component, but they can also be separately provided.
[0087] <Spacer Components>
[0088] A spacer 70 is disposed in the bearing space S between the first rolling element row 42A and the second rolling element row 42B inside the vibrating bearing 15.
[0089] The spacer 70 is formed in a generally cylindrical shape and is configured to move radially and axially within the bearing inner space S.
[0090] Specifically, the spacer 70 is configured to move radially between the outer circumference of the inner ring 44 and the inner circumference of the outer ring 46. That is, the inner diameter of the spacer 70 has a predetermined gap relative to the outer diameter of the inner ring 44, and the outer diameter of the spacer 70 has a predetermined gap relative to the inner diameter of the outer ring 46. The "inner ring" or "outer ring" here can be replaced by these components if they are integrated as an integral part of the vibrator 10a or the external gear 12.
[0091] Furthermore, the spacer member 70 is configured to be axially movable between the first rolling element 40A and the second rolling element 40B. The ends of the first rolling element 40A and the second rolling element 40B protrude axially inward from the retainers 48A and 48B that hold them. Therefore, the axial position of the spacer member 70 differs from the axial positions of the first retainer 48A and the second retainer 48B. That is, the spacer member 70 does not contact either the first retainer 48A or the second retainer 48B.
[0092] The material of the spacer 70 is not particularly limited; for example, it can be metal or resin. However, from the viewpoints of being able to come into contact with metal rolling elements 40A and 40B, being lightweight, and having self-lubricating properties, it is preferable to be made of resin (resin-based material).
[0093] The vibrating bearing 15 contains a lubricant (not shown). From the viewpoint of retaining the lubricant within the bearing's internal space S, the lubricant is preferably a grease with a certain degree of hardness. From this viewpoint, the consistency number of the grease is preferably 1 or higher, more preferably 1 to 2. Here, the consistency number refers to the number after classifying the greases specified in JIS K2220 according to the range of mixed consistency.
[0094] However, lubricants are not limited to greases; they can also be lubricating oils, etc.
[0095] [Technical Effects of This Embodiment]
[0096] As described above, according to this embodiment, a spacer 70 is disposed in the bearing inner space S between the first rolling element row 42A and the second rolling element row 42B in the vibrating body bearing 15.
[0097] As a result, the bearing internal space S becomes narrower, and the lubricant filling the bearing internal space S can be easily supplied to the raceway surfaces (rolling surfaces 54A, 54B) of the rolling elements 40A, 40B. Therefore, for example, even if the lubricant is a relatively hard grease, the vibrating bearing 15 can be properly lubricated.
[0098] Furthermore, according to this embodiment, the spacer member 70 is configured to be able to move radially between the outer periphery of the inner ring 44 and the inner periphery of the outer ring 46.
[0099] As a result, the spacer 70 moves within the bearing inner space S, accompanied by the movement or posture change of the flexural meshing gear device 1 itself. Consequently, the grease in the bearing inner space S can be easily supplied to the raceway surfaces (rolling surfaces 54A, 54B) of the rolling elements 40A, 40B.
[0100] [other]
[0101] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.
[0102] For example, in the above embodiment, the case where the vibrating element bearing 15 is a double-row bearing is illustrated. However, as long as the vibrating element bearing 15 has at least two rows of rolling elements, its inner and outer rings do not necessarily have to be shared among these rolling element rows.
[0103] Specifically, such as Figure 4 As shown, the vibrating body bearing 15 can also be a structure consisting of two rows of single-row bearings. That is, the vibrating body bearing 15 can also be a structure in which the first inner ring 44A and the first outer ring 46A supporting the first rolling element 40A are separate from the second inner ring 44B and the second outer ring 46B supporting the second rolling element 40B.
[0104] Furthermore, the vibratory bearing can also have three or more rows of rolling elements. In this case, spacers can also be arranged between adjacent rows of rolling elements in the axial direction.
[0105] Furthermore, in the above embodiment, a cylindrical flexural gear device is exemplified as the flexural gear device 1. However, the present invention is not limited to this; for example, it can also be applied to so-called cup-shaped or top-hat-shaped flexural gear devices.
[0106] Furthermore, the detailed structure shown in the above embodiments can be appropriately modified without departing from the spirit of the invention.
Claims
1. A flexural meshing gear device, comprising: a vibrating body; a flexural gear that flexes and deforms with the vibrating body; and a vibrating body bearing disposed between the vibrating body and the flexural gear. The vibrating bearing comprises: a first rolling element row, consisting of a plurality of first rolling elements arranged circumferentially; a first retainer for retaining the plurality of first rolling elements; a second rolling element row, disposed axially offset from the first rolling element row, and consisting of a plurality of second rolling elements arranged circumferentially; and a second retainer for retaining the plurality of second rolling elements. The first retainer has a plurality of first pockets that respectively accommodate the plurality of first rolling elements, the first pockets opening axially toward the second row of rolling elements. The second retainer has a plurality of second pockets for accommodating the plurality of second rolling elements, the second pockets opening axially toward the first row of rolling elements. A spacer is provided between the first rolling element row and the second rolling element row.
2. The flexural meshing gear device according to claim 1, wherein, The vibrating bearing has an outer ring shared by the first and second rolling element rows.
3. The flexural meshing gear device according to claim 1, wherein, The vibrating bearing has an inner ring shared by the first and second rolling element rows.
4. The flexural meshing gear device according to claim 1, wherein, The spacer is configured to move radially between the outer periphery of the inner ring and the inner periphery of the outer ring.
5. The flexural meshing gear device according to claim 1, wherein, The spacer component does not contact either the first retainer or the second retainer.
6. The flexural meshing gear device according to claim 1, wherein, A grease with a consistency number of 1 or higher is disposed between the first rolling element row and the second rolling element row.
Citation Information
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