deceleration device

Abstract

A reduction gear is provided. The reduction gear (1) of an embodiment includes a housing, a gear carrier (3) rotatably supported to the housing, a crankshaft (4) rotatably supported to the gear carrier (3) by a first crankshaft bearing (7A), and an external gear (5A) rotatably supported to the crankshaft (4). The gear carrier (3) includes a first crankshaft insertion hole (42) into which the first crankshaft bearing (7A) is fitted, a ring accommodating recess (46) formed coaxially with the first crankshaft insertion hole (42) and communicating with the first crankshaft insertion hole (42), and a through-hole (45) communicating a bottom surface (46a) of the ring accommodating recess (46) with the outside of the gear carrier (3). The reduction gear (1) includes a constant distance ring (80) accommodated in the ring accommodating recess (46), and a passage (95) formed in the constant distance ring (80) to communicate between an inner end surface (82c) and the through-hole (45).

Description

Technical Field

[0001] This invention relates to a speed reduction device. Background Technology

[0002] Previously, there were known deceleration devices, such as the eccentric oscillating type.

[0003] This speed reduction device comprises: a cylindrical housing (outer shell) having an internal gear; a gear carrier rotatably supported on the housing; multiple crankshafts rotatably supported on the gear carrier; and an external gear housed in the gear carrier and rotatably supported on the multiple crankshafts.

[0004] The gear carrier has a storage space for accommodating the external gears and a crankshaft insertion hole. Bearings are installed in the crankshaft insertion hole. Each crankshaft is inserted into the crankshaft insertion hole and is rotatably supported on the gear carrier by the bearings.

[0005] To restrict and position the crankshaft axially, an annular restricting member is provided in the crankshaft insertion hole in addition to the bearing. The restricting member abuts against the stepped surface of the crankshaft from the axial outside. Thus, the crankshaft is restricted from axial movement and is positioned axially (see, for example, Patent Document 1).

[0006] In addition, to improve the driving efficiency of the aforementioned reduction gear, lubricant is sealed in the crankshaft insertion hole and the housing space. The lubricant is sealed in, for example, by injecting lubricant into the gear carrier through the crankshaft insertion hole.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2024-93475 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] As with the conventional techniques described above, when using a limiting member to restrict and position the crankshaft in the axial direction, the limiting member is configured to abut against the stepped surface of the crankshaft. Consequently, the clearances between the gear carrier and the limiting member, and between the crankshaft and the limiting member, are almost eliminated. Therefore, the interior of the crankshaft insertion hole easily becomes a state where both axial end sides are almost completely sealed by the limiting member.

[0012] When lubricant is injected into the gear carrier through the crankshaft insertion hole under these conditions, the internal pressure of the gear carrier increases. Therefore, there is a problem that lubricant cannot be properly injected into the gear carrier.

[0013] The present invention provides a speed reduction device capable of appropriately injecting lubricant into the interior of the gear carrier.

[0014] Solution for solving the problem

[0015] A speed reduction device according to one embodiment of the present invention comprises: a cylindrical housing having an internal gear; a gear carrier disposed radially inside the housing and rotatably supported thereon; at least one crankshaft rotatably supported by the gear carrier via a bearing and subjected to an external rotational force; and an external gear housed in the gear carrier, rotatably supported on the crankshaft, and meshing with the internal gear. The gear carrier has: a crankshaft insertion hole for engagement with the bearing; an annular receiving recess formed coaxially with and communicating with the crankshaft insertion hole; and a through hole communicating the bottom surface of the annular receiving recess with the outside of the gear carrier. The speed reduction device also includes a spacer ring housed in the annular receiving recess for axial positioning of the crankshaft. A passage is formed in the spacer ring to connect the crankshaft-side end face of the spacer ring with the through hole.

[0016] This configuration allows for communication between the inside and outside of the gear carrier via the passage of the spacer ring. Therefore, even when lubricant is injected through the crankshaft insertion bore, air can be vented to the outside of the gear carrier via the passage, thus preventing the internal pressure of the gear carrier from rising. Consequently, lubricant can be appropriately injected into the interior of the gear carrier.

[0017] In the above structure, the passage may include: a first groove formed on the outer peripheral surface of the spacer ring; and a second groove formed on the concave side end face of the spacer ring near the bottom surface of the concave portion.

[0018] In the above structure, at least a portion of the corner of the first groove and at least a portion of the corner of the second groove can be chamfered in such a way that the cross-section is arc-shaped.

[0019] In the above structure, the ring receiving recess may have: a small-diameter recess formed on the bottom surface side of the recess; and a large-diameter recess formed at a position closer to the crankshaft insertion hole than the small-diameter recess. The diameter of the large-diameter recess may be larger than the diameter of the small-diameter recess. The spacer ring may have: a cylindrical portion fitted into the small-diameter recess; and a flange portion formed on the crankshaft insertion hole side of the cylindrical portion and received in the large-diameter recess. The flange portion may extend radially outward from the cylindrical portion. The passage may include: a first groove formed on the outer peripheral surface of the flange portion; and a second groove formed on the outer peripheral surface of the cylindrical portion and the recess-side end face of the cylindrical portion near the bottom surface of the recess.

[0020] In the above structure, the circumferential width between the two opposing inner surfaces of the first groove can gradually increase as it moves away from the bottom surface of the first groove, and the circumferential width between the two opposing inner surfaces of the second groove can gradually increase as it moves away from the bottom surface of the second groove.

[0021] In the above structure, at least the corner of the first groove near the crankshaft insertion hole can be recessed relative to the axial end face of the spacer ring. A chamfer can be formed at at least the corner of the second groove near the outer circumferential surface of the cylindrical portion.

[0022] In the above structure, the spacer ring can be formed as a porous structure.

[0023] The effects of the invention

[0024] According to the speed reduction device of the present invention, lubricant can be appropriately injected into the interior of the gear carrier. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the deceleration device in an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 Enlarged view of Part II.

[0027] Figure 3 This is a perspective view of the spacer ring in the embodiment of the present invention viewed from the axial outside.

[0028] Figure 4 This is a plan view of the fixed-distance ring in the embodiment of the present invention viewed from the axial outside.

[0029] Figure 5 This is a perspective view of the spacer ring in the embodiment of the present invention viewed from the axial inside.

[0030] Explanation of reference numerals in the attached figures

[0031] 1. Reduction gear; 2. Housing; 3. Gear carrier; 4. Crankshaft; 5A. First external gear; 5B. Second external gear; 7A. First crankshaft bearing; 7B. Second crankshaft bearing; 21. Internal gear; 25. Internal pin; 42. First crankshaft insertion hole; 43. Small diameter recess; 44. Large diameter recess; 45. Through hole; 46. Ring receiving recess; 46a. Bottom surface; 55. 80. Crankshaft insertion hole (crankshaft insertion hole); 81. Spacing ring; 81. Cylindrical part; 81a. Outer peripheral surface; 81b. Outer end face (recessed side end face); 82. Flange part; 82a. Outer peripheral surface; 84. Outer peripheral groove (groove 1, groove 2); 85. End face groove (groove 2); 86a. Rounded chamfer part; 87. Flange side groove (groove 1); 88a. Rounded chamfer part; 89a. First flat chamfer part; 89b. Second flat chamfer part; 91b. Rounded chamfer part; 92. Step surface; 95. Passage. Detailed Implementation

[0032] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

[0033] <Speed ​​Reduction Device>

[0034] Figure 1 This is a cross-sectional view of the speed reduction device 1. Furthermore, Figure 1 Only the lower half of the reduction gear 1 is shown, not the entire reduction gear 1. Specifically, only half of the reduction gear 1 is shown with respect to the rotation axis A1 of the gear carrier 3 that constitutes the reduction gear 1. Figure 1 (the lower half of the middle). Figure 2 yes Figure 1 Enlarged view of Part II.

[0035] like Figure 1 , Figure 2 As shown, the reduction gear 1 includes a cylindrical housing 2, a gear carrier 3 rotatably supported on the housing 2 by means of two main bearings 6, and a reduction section 10 disposed on the gear carrier 3. For example, tapered roller bearings are used as the main bearings 6.

[0036] In the following description, the direction parallel to the rotation axis A1 of the gear carrier is defined as the axial direction. The rotation direction of the gear carrier 3 is defined as the circumferential direction. The radial direction of the gear carrier 3 (the direction orthogonal to the axial and circumferential directions) is defined as the radial direction.

[0037] In the following description, "inner axial side" refers to the axial center side of housing 2, and "outer axial side" refers to the axial side of housing 2 opposite to the center.

[0038] <Shell>

[0039] The central axis of housing 2 coincides with the rotation axis A1 of the gear carrier. An internal tooth portion 21 is formed in the axial middle portion of the inner circumferential surface of housing 2. The term "axial middle portion" is not limited to the central portion between the two ends located in the axial direction in each component, but also includes the portion near the central portion.

[0040] Multiple pin grooves 21a are formed in the internal tooth portion 21. Each pin groove 21a extends axially and is formed at equal intervals in the circumferential direction. Cylindrical internal tooth pins 25 are respectively arranged in the multiple pin grooves 21a. The internal tooth pins 25 function as internal teeth constituting part of the speed reduction portion 10.

[0041] On the inner circumferential surface of the housing 2, a first outer ring retaining surface 22 is formed via a stepped surface 26, and a second outer ring retaining surface 23 is formed via a stepped surface 27. The first outer ring retaining surface 22 and the second outer ring retaining surface 23 are disposed on opposite sides of the axial direction, separated by the internal tooth portion 21.

[0042] The outer rings 61 of the corresponding main bearings 6 are respectively fitted into the outer ring retaining surfaces 22 and 23. Each outer ring 61 is axially positioned by abutting against the corresponding stepped surfaces 26 and 27.

[0043] A sealing surface 24 is formed on the inner circumferential surface of the housing 2, on the side opposite to the internal gear portion 21, separated from the first outer ring retaining surface 22 by the axial direction, via a stepped surface 28. The inner diameter of the sealing surface 24 is larger than the inner diameter of the first outer ring retaining surface 22. An oil seal 11 is fitted into the sealing surface 24. The oil seal 11 seals the space between the housing 2 and the gear carrier 3.

[0044] <Gear Carrier>

[0045] The gear carrier 3 has a base plate portion 30 and an end plate portion 50, configured to be axially separable. The base plate portion 30 is disposed on the side of the first outer ring retaining surface 22 of the housing 2. The base plate portion 30 has a circular plate-shaped base 31 and a plurality of support portions (not shown) protruding from the base 31 toward the end plate portion 50.

[0046] The outer axial side of the outer peripheral surface of the base 31 (the side opposite to the end plate portion 50) forms a sealing surface 34. An oil seal 11 is fitted into the sealing surface 34. Thus, the housing 2 and the gear carrier 3 are sealed.

[0047] A first inner ring retaining surface 33 is formed on the base 31 at a position axially inward of the sealing surface 34 via a stepped surface 35. The outer diameter of the first inner ring retaining surface 33 is smaller than the outer diameter of the sealing surface 34. The inner ring 62 of the main bearing 6 is fitted into the first inner ring retaining surface 33. Thus, the base plate portion 30 is supported to rotate freely relative to the housing 2. The inner ring 62 is axially positioned by abutting against the stepped surface 35.

[0048] A plurality of (three in this embodiment) first mounting holes 41 are formed on the base 31 at a position radially inward of the first inner ring retaining surface 33. Each first mounting hole 41 is formed to extend through the base 31 axially. The plurality of first mounting holes 41 are arranged at equal intervals in the circumferential direction. A crankshaft 4 constituting the reduction section 10, described later, is inserted into the first mounting holes 41.

[0049] In the first mounting hole 41, a first crankshaft insertion hole 42, an annular receiving recess 46, and a through hole 45 are formed sequentially from the axial inner side to the axial outer side. These first crankshaft insertion holes 42, annular receiving recesses 46, and through holes 45 are circular in shape when viewed from the axial direction. The first crankshaft insertion holes 42, annular receiving recesses 46, and through holes 45 are formed on the same axis and are connected to each other.

[0050] The annular receiving recess 46 is formed such that the bottom surface 46a is located on the side opposite to the first crankshaft insertion hole 42 in the axial direction. The annular receiving recess 46 has a small-diameter recess 43 formed on the bottom surface 46a side and a large-diameter recess 44 formed on the side of the first crankshaft insertion hole 42 that is closer to the small-diameter recess 43 than the small-diameter recess 43.

[0051] The inner diameter of the small-diameter recess 43 is smaller than the inner diameter of the first crankshaft insertion hole 42. The inner diameter of the large-diameter recess 44 is larger than the inner diameter of the first crankshaft insertion hole 42. Therefore, the bottom surface 44a of the large-diameter recess 44 becomes a stepped surface 47 formed at the junction between the small-diameter recess 43 and the large-diameter recess 44.

[0052] The through hole 45 connects the bottom surface 46a of the annular receiving recess 46 with the outer end surface 30a of the axially outer side of the base plate portion 30. The inner diameter of the through hole 45 is smaller than the inner diameter of the small diameter recess 43.

[0053] A first crankshaft bearing 7A for supporting the crankshaft 4 in a freely rotatable manner is fitted into the first crankshaft insertion hole 42 in the first mounting hole 41. A spacer ring 80 for restricting the axial movement of the crankshaft 4 is housed in the ring receiving recess 46. A sealing cap 12 is installed from the axially outer side in the through hole 45. The details of the first crankshaft bearing 7A and the spacer ring 80 will be described later.

[0054] Multiple support sections (not shown) are arranged between adjacent first mounting holes 41 in the circumferential direction. The end plate section 50 abuts axially against the top surface of the support section located on the side of the end plate section 50.

[0055] The end plate portion 50 is disposed on the second outer ring retaining surface 23 side of the housing 2. The end plate portion 50 is fixed to the support portion (not shown) in an axial position abutting against the top surface of the support portion (not shown) of the base plate portion 30. Therefore, the base plate portion 30 and the end plate portion 50 are integrated. Furthermore, the end plate portion 50 is disposed at a distance from the base plate portion 30 by an axial height amount.

[0056] The end plate portion 50 is formed in the shape of a circular plate. A second inner ring retaining surface 52 is formed on the axially inner side (base plate portion 30 side) of the outer peripheral surface of the end plate portion 50 via a stepped surface 53. The outer diameter of the second inner ring retaining surface 52 is smaller than the outer diameter of the axially outer side portion of the end plate portion 50. The inner ring 62 of the main bearing 6 is fitted into the second inner ring retaining surface 52.

[0057] Thus, the end plate portion 50 is supported to rotate freely relative to the housing 2. The inner ring 62 is axially positioned by abutting against the stepped surface 53.

[0058] A portion of the end plate portion 50 located radially inward of the second inner ring retaining surface 52 has the same number of second mounting holes 54 as the first mounting holes 41. Each second mounting hole 54 is formed to extend axially through the end plate portion 50. Each second mounting hole 54 is coaxially arranged with the first mounting hole 41. A crankshaft 4, described later, is inserted into the second mounting hole 54.

[0059] In the second mounting hole 54, a second crankshaft insertion hole 55 and an internal thread portion 56 are formed sequentially from the axial inner side to the axial outer side. The second crankshaft insertion hole 55 is circular when viewed from the axial direction. The second crankshaft insertion hole 55 and the internal thread portion 56 are formed on the same axis and are connected to each other.

[0060] The effective diameter of the internal thread portion 56 is larger than the inner diameter of the second crankshaft insertion hole 55. A second crankshaft bearing 7B for supporting the crankshaft 4 to rotate freely is fitted into the second crankshaft insertion hole 55. The details of the second crankshaft bearing 7B will be described later.

[0061] An annular anti-loosening bolt 16 is tightened at the internal thread portion 56. The anti-loosening bolt 16 prevents the crankshaft 4, described later, from axially dislodging from the second mounting hole 54.

[0062] <Deceleration Section>

[0063] The deceleration unit 10 is a so-called eccentric oscillating type deceleration unit.

[0064] The main structure of the reduction section 10 consists of an inner toothed pin 25, multiple (three in this embodiment) crankshafts 4 that pass through each mounting hole 41, 54, and two external gears 5A, 5B (first external gear 5A and second external gear 5B) that are rotatably mounted on the crankshafts 4.

[0065] The crankshaft 4 has: a first journal 71, which is rotatably supported on the base plate portion 30 by means of a first crankshaft bearing 7A; a second journal 72, which is rotatably supported on the end plate portion 50 by means of a second crankshaft bearing 7B; two eccentric portions 73 and 74 (first eccentric portion 73 and second eccentric portion 74) formed on the axial inner side of each journal 71 and 72; and a small diameter portion 75 that protrudes axially outward from the second journal 72.

[0066] The first eccentric portion 73 of the two eccentric portions 73 and 74 is arranged axially with the first journal 71. The second eccentric portion 74 of the two eccentric portions 73 and 74 is arranged axially with the second journal 72. Each eccentric portion 73 and 74 is eccentric relative to the crankshaft rotation axis A2 of the crankshaft 4. The crankshaft rotation axis A2 is parallel to the gear carrier rotation axis A1 (axial). Each eccentric portion 73 and 74 is configured to have a phase difference of a predetermined angle (180° in this embodiment) with respect to each other.

[0067] The smaller diameter portion 75 protrudes axially outward from the end plate portion 50. A spur gear 17 is mounted, for example, on the portion of the smaller diameter portion 75 that protrudes from the end plate portion 50. The spur gear 17 meshes with an input gear 18, for example, which is fed into the rotation of an external motor (not shown).

[0068] Thus, the rotational force of the external motor (the rotational force of the input gear 18) is transmitted to the crankshaft 4 via the spur gear 17.

[0069] Two external gears 5A and 5B are formed in a circular plate shape and housed between the base portion 31 and the end plate portion 50 of the base plate portion 30. The two external gears 5A and 5B are arranged axially between the base portion 31 and the end plate portion 50. The first external gear 5A is disposed on the base portion 31 side. The second external gear 5B is disposed on the end plate portion 50 side.

[0070] External teeth 77 are formed on the outer periphery of the two external gears 5A and 5B, respectively, to mesh with internal toothed pins 25 disposed in the housing 2. The number of teeth of each external tooth 77 is, for example, one less than the number of internal toothed pins 25.

[0071] Multiple shaft through holes 78 are formed in the two external gears 5A and 5B for each crankshaft 4 to pass through. A first eccentric part 73 is mounted in the shaft through hole 78 of the first external gear 5A by means of a first eccentric bearing 8A. A second eccentric part 74 is mounted in the shaft through hole 78 of the second external gear 5B by means of a second eccentric bearing 8B.

[0072] <Crankshaft bearings and eccentric bearings>

[0073] The crankshaft bearings 7A and 7B and the eccentric bearings 8A and 8B are so-called needle roller bearings. These bearings 7A, 7B, 8A, and 8B are locally integrated with the parts that are rotatably supported.

[0074] The first crankshaft bearing 7A includes an annular inner ring 63a integrated with the first journal 71, an annular outer ring 64a integrated with the base plate portion 30 to form the first crankshaft insertion hole 42, a plurality of rolling elements 65a disposed between the inner ring 63a and the outer ring 64a, and a retainer 66a for holding the plurality of rolling elements 65a.

[0075] The second crankshaft bearing 7B includes an annular inner ring 63b integrated with the second journal 72, an annular outer ring 64b integrated with the end plate portion 50 to form the second crankshaft insertion hole 55, a plurality of rolling elements 65b disposed between the inner ring 63b and the outer ring 64b, and a retainer 66b for holding the plurality of rolling elements 65b.

[0076] The first eccentric bearing 8A includes an annular inner ring 67a integrated with the first eccentric portion 73, an annular outer ring 68a integrated with the first external gear 5A to form a shaft through hole 78, a plurality of rolling elements 69a disposed between the inner ring 67a and the outer ring 68a, and a retainer 70a for holding the plurality of rolling elements 69a.

[0077] The second eccentric bearing 8B includes an annular inner ring 67b integrated with the second eccentric portion 74, an annular outer ring 68b integrated with the second external gear 5B to form a shaft through hole 78, a plurality of rolling elements 69b disposed between the inner ring 67b and the outer ring 68b, and a retainer 70b for holding the plurality of rolling elements 69b.

[0078] Each rolling element 65a, 65b, 69a, and 69b is a needle roller arranged parallel to the axial direction.

[0079] In the crankshaft 4 constructed in this way, the spacer ring 80 housed in the ring receiving recess 46 abuts axially against the first end face 71a on the outer side of the first journal 71. The anti-loosening bolt 16 fastened to the internal thread portion 56 of the end plate portion 50 abuts axially against the second end face 72a on the outer side of the second journal 72.

[0080] This restricts the axial movement of the crankshaft 4 relative to the gear carrier 3.

[0081] <Fixed-distance loop>

[0082] Next, based on Figures 2 to 5 The details of the fixed-distance ring 80 are explained.

[0083] Figure 3 This is a three-dimensional view of the spacer ring 80 viewed from the outer side of the axis. Figure 4 This is a plan view of the spacer ring 80 viewed from the outer side of the axis. Figure 5 This is a three-dimensional view of the spacer ring 80 viewed from the inner side of the axial direction.

[0084] The spacer ring 80 is formed in a porous shape. Here, "porous" refers to an oil-containing state, including sintered metals, oil-containing resins, etc. In other words, porous means capable of impregnating a lubricant. For example, the sintered metal can be formed using any method such as powder sintering, lamination sintering of metal mesh or etched plates, or fiber sintering. As the sintered metal material, iron, stainless steel, copper alloys, aluminum alloys, nickel, nickel alloys, titanium, molybdenum, tungsten, tantalum, zirconium boride, etc., can be used, or materials with excellent wear resistance can be selected.

[0085] like Figures 2 to 5 As shown, the spacer ring 80 has a cylindrical portion 81 and a flange portion 82 integrally formed with the cylindrical portion 81.

[0086] The cylindrical portion 81 is configured to fit into the small-diameter recess 43 in the annular receiving recess 46. The flange portion 82 is configured to extend radially outward from the axially inner end of the cylindrical portion 81.

[0087] The outer diameter of the cylindrical portion 81 is smaller than the inner diameter of the small-diameter recess 43. Four cylindrical side grooves (an example of the second groove in the claim) 83 are formed in the cylindrical portion 81. The four cylindrical side grooves 83 are arranged at equal intervals in the circumferential direction.

[0088] The cylindrical side groove 83 has an outer peripheral groove 84 and an end face groove 85. The outer peripheral groove 84 is formed axially on the outer peripheral surface 81a of the cylindrical portion 81. The end face groove 85 is formed radially on the outer end face 81b of the cylindrical portion 81 on the outer side of the axial direction. The outer peripheral groove 84 and the end face groove 85 are in communication.

[0089] The width between the two circumferentially opposite inner surfaces 84a in the outer peripheral groove 84 gradually increases with distance from the bottom surface 84b. That is, the circumferential width between the two inner surfaces 84a gradually increases with radial outward movement. Therefore, the two inner surfaces 84a are inclined relative to the bottom surface 84b in such a way that the circumferential width between the two inner surfaces 84a gradually increases with radial outward movement.

[0090] A rounded chamfer 86a is formed at the corner between the inner surface 84a and the outer peripheral surface 81a in such a way that the cross-section along the radial direction is arc-shaped. An arc surface 86b is formed at the corner between the inner surface 84a and the bottom surface 84b in such a way that the cross-section along the radial direction is arc-shaped.

[0091] The width between the two circumferentially opposite inner surfaces 85a in the end face groove 85 gradually increases with distance from the bottom surface 85b. That is, the circumferential width between the two inner surfaces 85a gradually increases with axial outward movement. Therefore, the two inner surfaces 85a are inclined relative to the bottom surface 85b in such a way that the circumferential width between the two inner surfaces 85a gradually increases with axial outward movement.

[0092] A first flat chamfer 89a is formed at the corner of the cylindrical portion 81 located between the outer peripheral surface 81a and the outer end surface 81b. Furthermore, a second flat chamfer 89b is formed at the corner of the cylindrical portion 81 located between the inner peripheral surface 81c and the outer end surface 81b. These flat chamfers 89a and 89b are formed flat.

[0093] The flange portion 82 is housed within the large-diameter recess 44 of the annular receiving recess 46. The outer diameter of the flange portion 82 is larger than the inner diameter of the small-diameter recess 43, but smaller than the inner diameter of the large-diameter recess 44. Therefore, the outer peripheral surface 82a of the flange portion 82 does not contact the inner peripheral surface of the large-diameter recess 44.

[0094] Four flange side grooves (an example of the first groove in the claim) 87 are formed on the outer peripheral surface 82a of the flange portion 82. The four flange side grooves 87 are arranged at equal intervals in the circumferential direction in a manner that is axially arranged with respect to the cylinder side grooves 83.

[0095] In this embodiment, the flange portions 82 are divided in the circumferential direction due to the formation of four flange side grooves 87, and are arranged in a circumferentially spaced manner. Thus, it is as if the four flange portions 82 are arranged in a spaced manner.

[0096] The width between the two circumferentially opposite inner surfaces 87a in the flange side groove 87 gradually increases with distance from the bottom surface 87b. That is, the circumferential width between the two inner surfaces 87a gradually increases with radial outward movement. Therefore, the two inner surfaces 87a are formed inclined relative to the bottom surface 87b in such a way that the circumferential width between the two inner surfaces 87a gradually increases with radial outward movement.

[0097] A rounded chamfer 88a is formed at the corner between the inner surface 87a and the outer peripheral surface 82a of the flange 82, with a radially arc-shaped cross-section. An arc surface 88b is formed at the corner between the inner surface 87a and the bottom surface 87b, with a radially arc-shaped cross-section. The arc surface 88b has the same shape as the arc surface 86b of the outer peripheral groove 84. The arc surface 88b and the arc surface 86b of the outer peripheral groove 84 are continuously formed in the axial direction.

[0098] At the corner between the outer end face 82b on the outer side of the flange portion 82 and the outer peripheral surface 81a of the cylindrical portion 81, an arc surface 91a is formed in an arc shape along the axial direction. A rounded chamfer portion 91b is formed at the periphery of the outer end face 82b in an arc shape along the axial direction.

[0099] A stepped surface 92 is formed on the outer periphery of the inner end face 82c on the axially inner side of the flange portion 82. The stepped surface 92 is recessed relative to the inner end face 82c and is located on the axially outer side of the inner end face 82c.

[0100] In the spacer ring 80 configured in this way, the outer end face 81b of the cylindrical portion 81 abuts axially against the bottom surface 46a of the ring receiving recess 46. Furthermore, the spacer ring 80 is configured such that the first end face 71a of the crankshaft 4 abuts axially against the inner end face 82c of the flange portion 82. Additionally, the retainer 66a of the first crankshaft bearing 7A abuts axially against the inner end face 82c of the flange portion 82.

[0101] Thus, the crankshaft 4 and the first crankshaft bearing 7A are positioned using the spacer ring 80. As a result, the first crankshaft bearing 7A is also positioned relative to the crankshaft 4.

[0102] <Regarding the sealing of lubricant>

[0103] Next, based on Figure 1 , Figure 2 The sealing of lubricant (not shown) into the speed reduction device 1 will be explained.

[0104] like Figure 1 , Figure 2 As shown, with a lubricant (not shown) sealed into the reduction gear 1, lubricant is injected into the gear carrier 3 via the second crankshaft insertion hole 55 of the end plate portion 50. The end plate portion 50 side is the side that inputs the rotational force (power) of an external motor (not shown) to the crankshaft 4. When injecting lubricant, the sealing cover 12 is in the removed state.

[0105] The injected lubricant passes between the crankshaft 4 and the gear carrier 3, and between the outer gears 5A and 5B, entering the interior of the gear carrier 3. In other words, the lubricant passes through each bearing 7A, 7B, 8A, and 8B to enter the interior of the gear carrier 3. When lubricant is injected, the volume of space within the gear carrier 3 decreases accordingly, thus increasing the internal pressure of the gear carrier 3. In this situation, the increased internal pressure becomes a resistance, making it difficult for the lubricant to enter the interior of the gear carrier 3.

[0106] In this embodiment, a spacer ring 80 is provided on the base plate portion 30 on the side opposite to the end plate portion 50 where lubricant is injected. In the spacer ring 80, the outer end face 81b of the cylindrical portion 81 abuts axially against the bottom surface 46a of the ring receiving recess 46, and the first end face 71a of the crankshaft 4 abuts axially against the inner end face 82c of the flange portion 82. Therefore, the first crankshaft insertion hole 42, which is provided with the first crankshaft bearing 7A, and the ring receiving recess 46, which communicates with the crankshaft insertion hole 42, are provided in a way that the spacer ring 80 blocks the flow of lubricant and air.

[0107] However, a cylindrical side groove 83 and a flange side groove 87 are formed in the spacer ring 80. Thus, the cylindrical side groove 83 and the flange side groove 87 form a passage 95 that connects the inner end face 82c of the spacer ring 80 with the through hole 45 (see reference). Figure 2 Therefore, lubricant and air flow to the outside of the substrate portion 30 via passage 95 (see reference). Figure 2 (See arrow Y in the diagram). Therefore, it is possible to prevent the internal pressure of the gear carrier 3 from rising and to properly inject lubricant into the interior of the gear carrier 3. Furthermore, the passage 95 is a passage that at least allows the movement of air while suppressing the rise of the internal pressure of the gear carrier 3. That is, the passage 95 is a passage that, with the injection of lubricant into the interior of the gear carrier 3, at least allows air to move from the interior of the gear carrier 3 to the exterior.

[0108] Furthermore, the inner surfaces 84a and 85a of the cylindrical side groove 83 are inclined such that their circumferential width gradually increases with distance from the bottom surfaces 84b and 85b. Similarly, the two inner surfaces 87a of the flange side groove 87 are inclined such that their circumferential width gradually increases with distance from the bottom surface 87b. Therefore, the cross-sectional area of ​​the passage 95 can be maximized. This improves the flow of air and lubricant, allowing for smoother injection of lubricant into the gear carrier 3.

[0109] Furthermore, since the spacer ring 80 is formed in a porous shape, it is possible to fully impregnate the spacer ring 80 with lubricant.

[0110] After sealing the deceleration device 1 with a lubricant (not shown), a sealing cap 12 is installed in the through hole 45. Thus, the lubricant sealing operation is completed.

[0111] <Operation of the speed reduction device>

[0112] Next, the operation of the deceleration device 1 will be explained.

[0113] When driving an external motor (not shown), by means of Figure 1The input gear 18 and spur gear 17 shown cause the three crankshafts 4 to rotate simultaneously. As a result, the first eccentric portion 73 rotates eccentrically, and the first external gear 5A, in conjunction with the eccentric rotation of the first eccentric portion 73, partially meshes with the internal gear pin 25 while oscillating and rotating about the crankshaft rotation axis A2. Furthermore, the second eccentric portion 74 rotates eccentrically, and the second external gear 5B, in conjunction with the eccentric rotation of the second eccentric portion 74, partially meshes with the internal gear pin 25 while oscillating and rotating about the crankshaft rotation axis A2.

[0114] The number of teeth on each external gear 77 is, for example, one less than the number of internal gear pins 25. Therefore, each external gear 5A, 5B rotates in such a way that the meshing parts of each external gear 77 and the internal gear pin 25 (housing 2) are staggered in the circumferential direction. This rotation is decelerated relative to the rotation of the crankshaft 4.

[0115] As the external gears 5A and 5B rotate, each crankshaft 4 also rotates on its own axis about the crankshaft rotation axis A2 and revolves around the gear carrier rotation axis A1. Each crankshaft 4 is rotatably supported on the gear carrier 3 (base plate portion 30 and end plate portion 50). Therefore, the gear carrier 3 rotates along with the revolution of each crankshaft 4.

[0116] At this time, for example, if the housing 2 is fixed to an external device (not shown), the gear carrier 3, relative to the housing 2, reduces the rotation of the external motor (not shown) and outputs the speed. If the gear carrier 3 is fixed, the housing 2, relative to the gear carrier 3, reduces the rotation of the external motor (not shown) and outputs the speed.

[0117] Since the crankshaft 4 rotates in conjunction with the oscillating rotation of the external gears 5A and 5B, a biasing force F is generated toward the base plate portion 30 (see reference). Figure 2 Therefore, the force exerted by the first end face 71a of the crankshaft 4 pressing against the inner end face 82c of the spacer ring 80 acts on the crankshaft 4. No grooves or the like are formed on the inner end face 82c of the spacer ring 80. Therefore, it is possible to prevent the surface pressure of the crankshaft 4 pressing against the spacer ring 80 and the first crankshaft bearing 7A from rising.

[0118] The spacer ring 80, pressed by the crankshaft 4, may rotate in conjunction with the crankshaft 4. In this case, the spacer ring 80 simply fits its cylindrical portion 81 into the small-diameter recess 43 in the ring receiving recess 46. Therefore, compared to the case where the entire outer circumferential surface of the spacer ring 80 fits into the entire inner circumferential surface of the ring receiving recess 46, the sliding resistance of the spacer ring 80 relative to the base plate portion 30 can be reduced.

[0119] Furthermore, the spacer ring 80 has rounded chamfered portions 86a, 88a, and 91b, and flat chamfered portions 89a and 89b. The inner surfaces 84a and 85a of the cylindrical side groove 83 are inclined such that their circumferential width gradually increases as they move away from the bottom surface 84b and 85b. Therefore, when the spacer ring 80 rotates in conjunction, it will not snag on the ring receiving recess 46.

[0120] A stepped surface 92 is formed on the outer periphery of the inner end face 82c of the spacer ring 80. Therefore, it is possible to prevent the retainer 66a of the first crankshaft bearing 7A from coming into strong contact with the spacer ring 80.

[0121] Thus, in the speed reduction device 1 of this embodiment, a cylindrical side groove 83 and a flange side groove 87 are formed in the spacer ring 80. Therefore, a passage 95 can be formed that connects the inner end face 82c of the spacer ring 80 with the through hole 45. Therefore, it is possible to prevent the internal pressure of the gear carrier 3 from rising and to properly inject lubricant into the interior of the gear carrier 3.

[0122] The ring receiving recess 46 has a small-diameter recess 43 formed on the bottom surface 46a side and a large-diameter recess 44 formed on the side of the first crankshaft insertion hole 42, which is closer to the small-diameter recess 43. The spacer ring 80 is integrally formed with a cylindrical portion 81 that fits into the small-diameter recess 43 and a flange portion 82 that is received in the large-diameter recess 44.

[0123] Therefore, the spacer ring 80 can be miniaturized as much as possible. Accordingly, the wall thickness of the gear carrier 3 can be easily ensured at the location where the spacer ring 80 is provided. For example, the wall thickness of the portion of the base plate 30 corresponding to the flange portion 82 in the spacer ring 80 can be easily ensured. As a result, the miniaturization of the speed reduction device 1 can also be achieved.

[0124] Furthermore, as a limitation on the radial movement of the spacer ring 80, it is sufficient, for example, to simply fit the small-diameter recess 43 into the cylindrical portion 81. Therefore, a gap can also be provided between the large-diameter recess 44 and the flange portion 82. In this case, the sliding resistance of the spacer ring 80 relative to the gear carrier 3 can be reduced. Therefore, for example, the driving efficiency of the crankshaft 4 in contact with the spacer ring 80 can be improved.

[0125] In the spacer ring 80, in order to connect the first end face 71a of the crankshaft 4 with the through hole 45, an outer peripheral groove 84 is formed on the outer peripheral surface 81a of the cylindrical portion 81, and an end face groove 85 is formed on the outer end face 81b. A flange side groove 87 is formed on the outer peripheral surface 82a of the flange portion 82.

[0126] Therefore, compared to the case where a groove is formed on the inner end face 82c of the spacer ring 80, it is possible to prevent the surface pressure of the retainer 66a of the first crankshaft bearing 7A and the surface pressure of the first end face 71a of the crankshaft 4 from increasing. As a result, damage to the first crankshaft bearing 7A and the crankshaft 4 can be prevented.

[0127] Furthermore, by forming grooves 84, 85, and 87 on the outer peripheral surfaces 81a, 82a, and the outer end surface 81b, respectively, the gear carrier 3 can be connected internally and externally by means of the spacer ring 80. Therefore, the spacer ring 80 can be easily manufactured.

[0128] The inner surfaces 84a and 85a of the cylindrical side groove 83 are inclined such that their circumferential width gradually increases with distance from the bottom surfaces 84b and 85b. The two inner surfaces 87a of the flange side groove 87 are also inclined such that their circumferential width gradually increases with distance from the bottom surface 87b. Therefore, the cross-sectional area of ​​the passage 95 can be maximized. This improves the flow of air and lubricant, allowing for smoother injection of lubricant into the gear carrier 3.

[0129] A stepped surface 92 is formed on the outer periphery of the inner end face 82c of the spacer ring 80. In other words, a stepped surface 92 is formed at the corner of the flange side groove 87 on the side of the first crankshaft insertion hole 42. A rounded chamfer 86a is formed at the corner of the cylinder side groove 83 located between the inner surface 84a and the outer peripheral surface 81a.

[0130] In addition, edges are usually formed by forming flange side grooves 87 and cylinder side grooves 83. If the formed edges are left as they are, the retainer 66a and the ring receiving recess 46 may be damaged because the edges get caught on the retainer 66a and the ring receiving recess 46.

[0131] However, in this embodiment, the edges are eliminated by forming a stepped surface 92 and a rounded chamfer 86a. This helps to suppress damage to the retainer 66a and the annular receiving recess 46.

[0132] The spacer ring 80 is formed in a porous shape. 81b Therefore, lubricant can be sufficiently impregnated in the spacer ring 80. As a result, the sliding resistance between the spacer ring 80 and the crankshaft 4, the sliding resistance between the spacer ring 80 and the first crankshaft bearing 7A, and the sliding resistance between the spacer ring 80 and the base plate portion 30 can be reduced.

[0133] This invention is not limited to the embodiments described above, but includes embodiments obtained by making various modifications to the embodiments described above without departing from the spirit of this invention.

[0134] For example, in the above embodiment, the case where the reduction device 1, as an eccentric oscillating type reduction device, has three crankshafts 4 and two external gears 5A and 5B has been described. The case where the two external gears 5A and 5B are oscillating and rotating using the three crankshafts 4 has been described.

[0135] However, this is not the only requirement; at least one crankshaft 4 is sufficient. Similarly, at least one external gear 5A or 5B is also sufficient.

[0136] In the above embodiment, the case where the spacer ring 80 is integrally formed with a cylindrical portion 81 and a flange portion 82 has been described. However, it is not limited to this, and the spacer ring 80 can take various shapes. For example, the spacer ring 80 can also be formed as a simple ring or a circular plate. In this case, grooves can be formed on the outer peripheral surface of the spacer ring 80 and on the end face near the bottom surface 46a of the ring receiving recess 46, thereby forming a passage 95 that connects the inner end face 82c of the spacer ring 80 with the through hole 45.

[0137] Furthermore, when forming the passage 95, it is not necessary to form grooves on the outer peripheral surface of the spacer ring 80 and on the end face near the bottom surface 46a of the ring receiving recess 46. It is sufficient to ensure that the inner end face 82c of the spacer ring 80 is connected to the through hole 45. For example, a hole through the spacer ring 80 may be formed, and a groove may be formed on the inner end face 82c over the entire radial range.

[0138] In the above embodiments, the case where rounded chamfered portions 86a, 88a, 91b and flat chamfered portions 89a, 89b are formed in the spacer ring 80 has been described. The case where the inner surfaces 84a, 85a of the cylindrical side groove 83 are inclined such that their circumferential width gradually increases with distance from the bottom surface 84b, 85b has been described. The case where the width of the inner surface 87a of the flange side groove 87 is inclined such that its circumferential width gradually increases with distance from the bottom surface 87b has been described. However, this is not a limitation; the rounded chamfered portions 86a, 88a, 91b and flat chamfered portions 89a, 89b may not be formed in the spacer ring 80. The inner surfaces 84a, 85a of the cylindrical side groove 83 and the inner surface 87a of the flange side groove 87 may also not be inclined.

[0139] Ideally, a stepped surface 92 should be formed at least on the inner end face 82c of the spacer ring 80. Furthermore, it is desirable that a rounded chamfer 86a be formed at the corner of the cylindrical side groove 83 located between the inner surface 84a and the outer peripheral surface 81a. This configuration helps to suppress damage to the retainer 66a and the ring receiving recess 46.

[0140] Alternatively, a chamfered portion can be formed on the inner end face 82c of the spacer ring 80 to replace the stepped surface 92. That is, it is sufficient that the outer periphery of the inner end face 82c is concave relative to the inner end face 82c.

[0141] The case where four cylindrical side grooves 83 and four flange side grooves 87 are formed in the spacer ring 80 has been described. However, it is not limited to this, and it is sufficient to form at least one of each groove 83 and 87.

[0142] In the above embodiment, the case where rounded chamfered portions 86a, 88a, and 91b, and flat chamfered portions 89a and 89b are formed in the spacer ring 80 has been described. However, this is not a limitation, and various chamfer shapes can be used. As long as the spacer ring 80 does not get caught on the ring receiving recess 46 by forming the chamfered portions, it is acceptable. For example, rounded chamfered portions can be used instead of flat chamfered portions 89a and 89b.

[0143] For example, the cases where the rounded chamfer portions 86a, 88a, and 91b are formed with a circular arc cross-section have been described. However, this is not a limitation; flat chamfer portions may also be formed instead of rounded chamfer portions 86a, 88a, and 91b. The cross-section of the rounded chamfer portions 86a, 88a, and 91b may also be formed as an arc rather than a circular arc.

[0144] In the embodiments disclosed in this specification, for a structure composed of multiple objects, the multiple objects can be integrated into one, or conversely, a structure composed of a single object can be divided into multiple objects. Whether or not they are integrated, as long as the configuration achieves the purpose of the invention, it is acceptable.

Claims

1. A speed reduction device, wherein, The speed reduction device has the following features: A cylindrical shell with internal gears; A gear carrier is disposed radially inside the housing and is rotatably supported on the housing; At least one crankshaft, rotatably supported by bearings on the gear carrier, is subjected to an external rotational force; and An external gear, housed in the gear carrier and rotatably supported on the crankshaft, meshes with the internal gear. The gear carrier has: A crankshaft insertion hole for the bearing to fit into; A ring-shaped receiving recess is formed coaxially with and communicates with the crankshaft insertion hole; and A through hole connects the bottom surface of the recessed portion of the ring receiving recess to the outside of the gear carrier. The speed reduction device includes a spacer ring housed in a recessed area for axial positioning of the crankshaft. The spacer ring has a passageway that connects the crankshaft-side end face of the spacer ring with the through hole.

2. The speed reduction device according to claim 1, wherein, The pathway includes: The first groove is formed on the outer peripheral surface of the spacer ring; and The second groove is formed on the concave side end face of the fixed-distance ring near the bottom surface of the concave portion.

3. The speed reduction device according to claim 2, wherein, At least a portion of the corner of the first groove and at least a portion of the corner of the second groove are chamfered in such a way that the cross-section is arc-shaped.

4. The speed reduction device according to claim 1, wherein, The annular receiving recess has: A small-diameter recess, formed on the bottom side of the recess; and The larger diameter recess is formed at a position closer to the crankshaft insertion hole than the smaller diameter recess. The diameter of the large-diameter recessed portion is larger than the diameter of the small-diameter recessed portion, The fixed-distance ring has: The cylindrical portion, which fits into the small-diameter recess; and A flange portion, formed on the crankshaft insertion hole side of the cylindrical portion, is housed in the large-diameter recess. The flange portion extends radially outward from the cylindrical portion. The pathway includes: The first groove is formed on the outer peripheral surface of the flange portion; and The second groove is formed on the outer peripheral surface of the cylindrical portion and the concave side end face of the cylindrical portion near the bottom surface of the concave portion.

5. The speed reduction device according to claim 4, wherein, The circumferential width between the two opposing inner surfaces of the first groove gradually increases as it moves away from the bottom surface of the first groove, and the circumferential width between the two opposing inner surfaces of the second groove gradually increases as it moves away from the bottom surface of the second groove.

6. The speed reduction device according to claim 5, wherein, At least the corner of the first groove on the crankshaft insertion hole side is formed to be recessed relative to the shaft-side end face of the spacer ring. A chamfer is formed at least at the corner of the second groove on the outer peripheral surface side of the cylindrical portion.

7. The speed reduction device according to any one of claims 1 to 6, wherein, The fixed-distance ring becomes porous.

Images