CN113007284A

CN113007284A - Series of eccentric oscillating type reduction gears, reduction gear manufacturing method and reduction gear designing method

Info

Publication number: CN113007284A
Application number: CN202011489626.5A
Authority: CN
Inventors: 志津庆刚
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 2019-12-18
Filing date: 2020-12-16
Publication date: 2021-06-22
Also published as: JP2021095964A; DE102020133956A1; JP7469873B2

Abstract

The invention provides a series of eccentric swinging type speed reducing devices which can reduce the trouble of part management by using parts in common. The series of the eccentric oscillating type reduction gears of the present invention includes a 1 st reduction gear and a 2 nd reduction gear, wherein the 1 st reduction gear includes: a 1 st outer gear; a 1 st crankshaft having a 1 st eccentric body that oscillates the 1 st external gear; and a 1 st eccentric body bearing disposed between the 1 st external gear and the 1 st eccentric body, the 2 nd speed reduction device including: a 2 nd outer gear; a 2 nd crankshaft having a 2 nd eccentric body that oscillates the 2 nd external gear; and a 2 nd eccentric body bearing disposed between the 2 nd external gear and the 2 nd eccentric body. The pitch circle diameter of the rolling body of the 1 st eccentric body bearing is smaller than that of the rolling body of the 2 nd eccentric body bearing, the shape of the rolling body of the 1 st eccentric body bearing is the same as that of the rolling body of the 2 nd eccentric body bearing, and the shape of the retainer of the 1 st eccentric body bearing is different from that of the retainer of the 2 nd eccentric body bearing.

Description

Series of eccentric oscillating type reduction gears, reduction gear manufacturing method and reduction gear designing method

The present application claims priority based on japanese patent application No. 2019-228044, applied 12/18/2019. The entire contents of this Japanese application are incorporated by reference into this specification.

Technical Field

The present invention relates to a series of eccentric oscillating type reduction gears, a method of manufacturing the reduction gears, and a method of designing the reduction gears.

Background

A speed reducer group including a 1 st speed reducer and a 2 nd speed reducer having different structures is known. For example, patent document 1 describes a speed reducer group including: a 1 st speed reducer having a 1 st crank assembly; and a 2 nd speed reducer having a 2 nd crank assembly. In the speed reducer set, the 1 st crank assembly performs a rotational motion about a 1 st transmission shaft separated from the 1 st main shaft by a 1 st distance, and the 2 nd crank assembly performs a rotational motion about a 2 nd transmission shaft separated from the 2 nd main shaft by a 2 nd distance (different from the 1 st distance). The 1 st crank assembly includes a 1 st gear support bearing disposed between the 1 st eccentric portion and the 1 st oscillating gear, the 2 nd crank assembly includes a 2 nd gear support bearing disposed between the 2 nd eccentric portion and the 2 nd oscillating gear, and the shape of the 1 st gear support bearing is the same as the shape of the 2 nd shaft support bearing.

Patent document 1: japanese patent laid-open publication No. 2016-

In the reduction gear set described in patent document 1, the 1 st gear support bearing is used in common with the 2 nd shaft support bearing to reduce the types of bearings, but the use of the bearings is limited to the case where the supported bodies supported by the bearings have the same diameter.

Disclosure of Invention

The invention aims to provide a series of eccentric swinging type speed reducing devices which can reduce the trouble of part management by using parts in common.

In order to solve the above problem, a series of eccentric oscillating type reduction gears according to an embodiment of the present invention includes a 1 st reduction gear and a 2 nd reduction gear, wherein the 1 st reduction gear includes: a 1 st outer gear; a 1 st crankshaft having a 1 st eccentric body that oscillates the 1 st external gear; and a 1 st eccentric body bearing disposed between the 1 st external gear and the 1 st eccentric body. The 2 nd speed reduction device includes: a 2 nd outer gear; a 2 nd crankshaft having a 2 nd eccentric body that oscillates the 2 nd external gear; and a 2 nd eccentric body bearing disposed between the 2 nd external gear and the 2 nd eccentric body. The pitch circle diameter of the rolling body of the 1 st eccentric body bearing is smaller than that of the rolling body of the 2 nd eccentric body bearing, and the shape of the rolling body of the 1 st eccentric body bearing is the same as that of the rolling body of the 2 nd eccentric body bearing.

In addition, any combination of the above-described constituent elements or a mode in which the constituent elements or expressions of the present invention are interchanged with each other between methods, systems, and the like is also effective as an embodiment of the present invention.

According to the present invention, it is possible to provide a series of eccentric oscillating type reduction gears in which the number of parts can be reduced by commonly using the parts.

Drawings

Fig. 1 is a sectional view of a 1 st reduction gear unit of a series of eccentric oscillating type reduction gears according to the 1 st embodiment.

Fig. 2 is a sectional view of a 2 nd reduction gear unit of the series of the eccentric oscillating type reduction gear unit according to embodiment 1.

Fig. 3 is a layout diagram showing the arrangement of rolling elements in the 1 st reduction gear of fig. 1.

Fig. 4 is a layout diagram showing the arrangement of rolling elements in the 2 nd reduction gear unit of fig. 2.

Fig. 5 is a sectional view of the 1 st reduction gear unit of the series of the eccentric oscillating type reduction gear unit according to the 1 st modification.

Fig. 6 is a sectional view of the 2 nd reduction gear unit of the series of the eccentric oscillating type reduction gear unit according to the 1 st modification.

In the figure: 1-series of eccentric oscillating type reduction gears, 10-1 st reduction gear, 50-2 nd reduction gear, 12-crankshaft, 12 a-eccentric body, 14-external gear, 16-internal gear, 18, 20-wheel carrier, 24, 26-main bearing, 30-eccentric body bearing, 30 b-rolling body, 30 c-retainer, 30 h-movement limiting part, 33-crankshaft bearing, 33 b-rolling body, 33 c-retainer, 100-series of eccentric oscillating type reduction gears.

Detailed Description

Preferred embodiments of the present invention will be described below with reference to the drawings. In the embodiment, the comparative example, and the modification, the same or equivalent constituent elements and components are denoted by the same reference numerals, and overlapping description is appropriately omitted. In the drawings, the dimensions of components are shown as being enlarged or reduced as appropriate for ease of understanding. In the drawings, parts that are not essential to the description of the embodiments are omitted.

Further, the terms including the

numbers

1, 2, and the like are used to describe various constituent elements, but the terms are only used for the purpose of distinguishing one constituent element from other constituent elements, and the terms are not used to limit the constituent elements.

[ embodiment 1 ]

Hereinafter, the structure of the series 1 of the eccentric rocking type reduction gear transmission according to embodiment 1 will be described with reference to the drawings. The series 1 of the eccentric oscillating type reduction gears includes the 1 st reduction gear 10 and the 2 nd reduction gear 50 which are different in structure from each other. Fig. 1 is a side sectional view of a 1 st reduction gear transmission 10 of a series 1 of an eccentric oscillating type reduction gear transmission according to the 1 st embodiment. Fig. 2 is a side sectional view of the 2 nd reduction gear unit 50 of the series 1 of the eccentric oscillating type reduction gear unit. The 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 according to the present embodiment are eccentric oscillating type reduction gears that oscillate an external gear meshing with an internal gear to rotate one of the internal gear and the external gear and output a generated motion component from an output member to a driven device.

Hereinafter, the same names and symbols are used for the components common to the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50. Further, the "1 st" may be added to the beginning of the name of the component constituting the 1 st reduction gear transmission 10, or the "-1" may be added to the end of the symbol. Further, the "2 nd" may be added to the head of the name of the component constituting the 2 nd reduction gear unit 50, or the "-2" may be added to the end of the symbol.

First, a general structure of the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 will be described. The 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 mainly include a crankshaft 12, an external gear 14, an internal gear 16, a carrier 18, a carrier 20, a housing 22, a main bearing 24, a main bearing 26, an eccentric body bearing 30, a crankshaft bearing 33, and a crankshaft bearing 34. Hereinafter, a direction along the central axis La of the internal gear 16 is referred to as an "axial direction", and a circumferential direction and a radial direction of a circle centered on the central axis La are referred to as a "circumferential direction" and a "radial direction", respectively. For convenience, hereinafter, one side (right side in the drawing) in the axial direction is referred to as an input side, and the other side (left side in the drawing) is referred to as an opposite-to-input side.

The crankshaft 12 is rotated about a rotation center line by rotational power input from a driving device (not shown). The 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50 according to the present embodiment are center crank type reduction gears in which the rotation center line of the crankshaft 12 and the center axis line La of the internal gear 16 are disposed on the same axis. The driving device is, for example, a motor, a gear motor, an engine, or the like.

The crankshaft 12 of the present embodiment is an eccentric body shaft having a plurality of eccentric bodies 12a for oscillating the external gear 14. The crankshaft 12 may be a solid shaft, but in the present embodiment is a hollow shaft having a predetermined hollow portion 12 d. The axis of the eccentric body 12a is eccentric with respect to the rotation center line of the crankshaft 12. In the present embodiment, two eccentric bodies 12a are provided, and the eccentric phases of the adjacent eccentric bodies 12a are shifted by 180 ° from each other.

Two external gears 14 are assembled to the outer periphery of the eccentric body 12a via an eccentric body bearing 30. In the present embodiment, a roller (cylindrical body) is illustrated as the rolling element 30b of the eccentric body bearing 30. In addition, known rolling elements such as a ball and a cone may be used as the rolling elements 30b of the eccentric body bearing 30. Each external gear 14 internally meshes with the internal gear 16. The external gears 14 are assembled in two rows to increase the load carrying capacity and reduce vibration and noise due to the shift of the eccentric phase. The structures of the outer gears of the respective rows are the same except for the difference in eccentric phase.

The external gears 14 are provided corresponding to the plurality of eccentric bodies 12a, respectively. The external gear 14 is rotatably supported by the corresponding eccentric member 12a via an eccentric member bearing 30. The external gear 14 is provided with an inner pin hole 13 through which the inner pin 32 passes and a center hole 15 which abuts against the eccentric body bearing 30.

The inner pin hole 13 is provided at a position offset from the center of the outer gear 14. A plurality of inner pin holes 13 are provided corresponding to inner pins 32 described later. In this example, three inner pin holes 13 are provided at 120 ° intervals in the circumferential direction. The center hole 15 is provided at the center of the external gear 14, and is a hole through which the eccentric body 12a is inserted.

As shown in fig. 1, the casing 22 is cylindrical as a whole, and the internal gear 16 is provided on the inner peripheral portion thereof. The internal gear 16 meshes with the external gear 14. The internal gear 16 of the present embodiment includes an internal gear main body integrated with the housing 22, and outer pins 16a (pin members) rotatably supported by the internal gear main body and constituting internal teeth of the internal gear 16. The number of internal teeth of the internal gear 16 (the number of the outer pins 16 a) is slightly larger than the number of external teeth of the external gear 14 (in this example, only 1 more).

The

carriers

18, 20 are disposed on the axial side portions of the external gear 14. The wheel frames 18, 20 include: an input-side carrier 18 disposed on the side of the input side of the external gear 14; and an anti-input-side carrier 20 disposed on the side portion of the external gear 14 opposite to the input side. The

carriers

18, 20 are disc-shaped, and are rotatably supported by the crankshaft 12 via

crankshaft bearings

33, 34.

The input-side carrier 18 and the input-side carrier 20 are coupled together via an inner pin 32. The inner pin 32 penetrates the plurality of external gears 14 in the axial direction at a position radially offset from the axial center of the external gear 14. The inner pin 32 of the present embodiment is formed integrally with the input-side carrier 20. The inner pin 32 may be provided separately from the wheel frames 18, 20. The inner pins 32 are provided in plural at predetermined intervals around the central axis La of the internal gear 16. In the present embodiment, three inner pins 32 are provided at intervals of 120 ° in the circumferential direction.

The inner pin 32 has a tip end portion fitted into a bottomed recess 18c formed in the input-side carrier 18, and couples the input-side carrier 18 and the non-input-side carrier 20 together with a bolt 36 inserted from the input side of the input-side carrier 18.

The inner pin 32 penetrates the inner pin hole 13 formed in the outer gear 14. A roller 35 is rotatably fitted around the outer periphery of the inner pin 32 as a sliding promoting member. The axial movement of the roller 35 is restricted by the input side of the input-side carrier 18 and the input side of the input-side carrier 20. A play (i.e., a clearance) for absorbing the oscillation component of the external gear 14 is provided between the roller 35 and the inner pin hole 13. The roller 35 is partially in contact with the inner wall surface of the inner pin hole 13.

Here, a member that outputs rotational power to a driven device (not shown) is referred to as an output member, and a member that is fixed to an external member that supports the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 is referred to as a fixed member. The output member of the present embodiment is the input-side opposite wheel carrier 20, and the fixed member is the housing 22. The output member is rotatably supported by the fixed member via

main bearings

24 and 26.

The

main bearings

24, 26 include: an input-side main bearing 24 disposed between the input-side carrier 18 and the casing 22; and an anti-input-side main bearing 26 disposed between the anti-input-side carrier 20 and the casing 22. In the present embodiment, the

main bearings

24 and 26 are arranged in a so-called back-to-back combination state. The outer peripheries of the

wheel carriers

18, 20 constitute the inner races of the

main bearings

24, 26, respectively. In the present embodiment, an angular ball bearing having spherical rolling elements 42 is exemplified as the

main bearings

24 and 26. The

main bearings

24 and 26 may be rolling bearings such as tapered roller bearings and angular contact roller bearings.

The

crankshaft bearings

33, 34 include: an input-side crankshaft bearing 33 disposed between the input-side carrier 18 and the crankshaft 12; and an input-side opposite crankshaft bearing 34 disposed between the input-side opposite carrier 20 and the crankshaft 12. As the

crankshaft bearings

33 and 34 of the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50, various known bearings can be used. In the present embodiment, ball bearings are used as the crank

bearings

33 and 34 of the 1 st reduction gear transmission 10. In the 2 nd reduction gear unit 50 according to the present embodiment, a ball bearing is used as the input-side crankshaft bearing 34, and a roller bearing having rollers (cylindrical bodies) as the rolling elements 30b is used as the input-side crankshaft bearing 33.

Next, the operation of the 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50 configured as described above will be described. When the rotational power is transmitted from the driving device to the crankshaft 12, the eccentric body 12a of the crankshaft 12 rotates about a rotation center line passing through the crankshaft 12. When the eccentric body 12a performs eccentric motion, it swings the external gear 14 via the eccentric body bearing 30 disposed around the eccentric body 12 a. At this time, the external gear 14 oscillates such that its axis rotates around the rotation center line of the crankshaft 12. When the external gear 14 oscillates, the meshing positions of the external gear 14 and the internal gear 16 are sequentially shifted. As a result, one of the external gear 14 and the internal gear 16 is self-transmitted by an amount corresponding to the difference in the number of teeth between the external gear 14 and the internal gear 16 per rotation of the crankshaft 12. In the present embodiment, the external gear 14 rotates and outputs the decelerated rotation from the input-side carrier 20 via the inner pin 32.

Next, a characteristic structure of the series 1 of the eccentric rocking type reduction gear of the present embodiment will be described.

Refer to fig. 1 to 4. Fig. 3 is a layout diagram showing the arrangement of rolling elements 30b of the 1 st eccentric body bearing 30-1 in the 1 st reduction gear transmission 10. Fig. 4 is a layout diagram showing the arrangement of rolling elements 30b of 2 nd eccentric body bearing 30-2 in 2 nd reduction gear unit 50. These figures show the arrangement of the rolling elements 30b as viewed from the axial direction. The eccentric body bearing 30 may have an inner ring and/or an outer ring, but in the present embodiment, the inner ring and the outer ring are not provided. The 1 st eccentric body bearing 30-1 includes a rolling element 30b and a 1 st retainer 30 c-1. The 1 st cage 30C-1 rotatably holds 30 rolling elements 30b at predetermined positions on the pitch circle C1. The 2 nd eccentric bearing 30-2 has a rolling element 30b and a 2 nd cage 30 c-2. The 2 nd cage 30C-2 rotatably holds 37 rolling elements 30b at predetermined positions on the pitch circle C2.

The rolling body 30b of the 1 st eccentric body bearing 30-1 has a pitch circle diameter D1 (e.g., 71mm) smaller than a pitch circle diameter D2 (e.g., 102mm) of the rolling body 30b of the 2 nd eccentric body bearing 30-2. In the present specification, the pitch circle diameter of the rolling element of the bearing including the other bearing means: the diameter of a circle (pitch circle) passing through the center of the rolling elements when assembled into a reduction gear. For example, the pitch circle diameters D1 and D2 of the rolling elements 30b of the eccentric body bearing 30 mean: the diameter of the circle (pitch circles C1, C2) passing through the center of the rolling element 30b in the fitted state of the eccentric body 12 a. The pitch diameter is also sometimes referred to as pcd (pitch Circle diameter).

The rolling element 30b of the 1 st eccentric body bearing 30-1 and the rolling element 30b of the 2 nd eccentric body bearing 30-2 have the same shape. In this case, the rolling elements can be used in common even when the supported bodies supported by the bearings have different diameters or different bearing loads. As a result, the number of parts in the series 1 of the eccentric oscillating type reduction gear transmission can be reduced. In addition, in the present specification, the components of the same shape refer to components manufactured according to the same design, which include components having a deviation or error in manufacturing and do not include components made of different materials.

As shown in fig. 3 and 4, the rolling elements 30b are arranged at equal intervals along pitch circles C1 and C2. In this case, by changing the number or assembly rate of the rolling elements, a desired load bearing capacity can be flexibly achieved in a bearing using the same shaped rolling elements. In the present specification, the assembly ratio of the rolling elements means: the proportion of the rolling bodies on the pitch circle.

As described above, the number of the rolling bodies 30b of the 2 nd eccentric body bearing 30-2 is greater than that of the rolling bodies 30b of the 1 st eccentric body bearing 30-1, and the assembly rate of the rolling bodies 30b of the 2 nd eccentric body bearing 30-2 is lower than that of the rolling bodies 30b of the 1 st eccentric body bearing 30-1. The distance B2 between two rolling bodies 30B of the 2 nd eccentric body bearing 30-2 adjacent to each other is greater than the distance B1 between two rolling bodies 30B of the 1 st eccentric body bearing 30-1 adjacent to each other. In this case, by changing the number or assembly rate of the rolling elements, a desired load bearing capacity can be flexibly achieved in a bearing using the same shaped rolling elements.

Since the number of rolling elements 30b held and the pitch circle diameters D1 and D2 are different, the shape of the 1 st cage 30c-1 is different from the shape of the 2 nd cage 30 c-2. In this case, the number of rolling elements and the size of the cage can be flexibly selected, and therefore, a structure suitable for the bearing capacity can be easily realized as compared with a case where the shape of the cage is the same. The shape of the cage differs depending on, for example, the difference in the number of roller arrangement portions, the difference in diameter, the difference in shape, and the like.

In the present embodiment, the eccentric amount of the eccentric body 12a of the 2 nd reduction gear transmission 50 is set to be larger than the eccentric amount of the eccentric body 12a of the 1 st reduction gear transmission 10.

As shown in fig. 1 and 2, the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 each include a plurality of (e.g., two) eccentric body bearings 30. In the 1 st speed reducer 10, the two 1 st retainers 30c-1 of the two 1 st eccentric body bearings 30-1 adjacent to each other overlap each other when viewed from the axial direction. Therefore, the retainers themselves can contact each other to restrict the movement, and therefore the axial position of the eccentric body bearing can be restricted.

On the other hand, in the 2 nd speed reducer 50, the eccentric amount of the 2 nd eccentric body 12a-2 is large, and therefore the eccentric amount of the 2 nd cage 30c-2 is also large, and two 2 nd cages 30c-2 adjacent to each other do not overlap at the maximum spaced position (the position spaced farthest in the eccentric direction) as viewed in the axial direction. Therefore, the 2 nd speed reduction device 50 of the present embodiment is provided with the movement restricting member 30h between the plurality of 2 nd eccentric body bearings 30-2. In this case, even if the retainer itself cannot regulate the axial position, the axial position of the eccentric body bearing can be regulated. The movement restricting member 30h of the present embodiment is a hollow disc-shaped member that is present between two 2 nd holders 30c-2 adjacent to each other, and has a shape that overlaps with these holders, respectively, when viewed in the axial direction. In addition, at a position in the direction orthogonal to the eccentric direction, these holders are not offset, and therefore these 2 nd holders 30c-2 overlap each other. That is, the retainers may partially overlap at a position other than the maximum spaced position when viewed from the axial direction.

In the present embodiment, the 1 st and 2 nd crankshafts 12-1 and 12-2 are hollow shafts, and the hollow diameter E2 (e.g., 81mm) of the 2 nd crankshaft 12-2 is larger than the hollow diameter E1 (e.g., 49mm) of the 1 st crankshaft 12-1. As a result, the wall thickness of the 2 nd crankshaft 12-2 can be reduced as compared with the case where the hollow diameter E2 and the hollow diameter E1 are the same, which is advantageous in weight reduction of the 2 nd reduction gear unit 50.

In the 2 nd reduction gear unit 50 according to the present embodiment, the 2 nd crankshaft bearing 33-2 is supported by the input side carrier 18 into which the inner pin 32 of the 2 nd reduction gear unit 50 is fitted, and supports the 2 nd crankshaft 12-2. The 2 nd crankshaft bearing 33-2 may have an inner ring and/or an outer ring, but in the present embodiment, the inner ring and the outer ring are not provided. The 2 nd crankshaft bearing 33-2 includes rolling elements 33b and a cage 33 c. The inner peripheral surface 18h of the through-hole of the input-side carrier 18 functions as the outer ring of the 2 nd crankshaft bearing 33-2. The outer peripheral surface 12h of the 2 nd crankshaft 12-2 functions as an inner ring of the 2 nd crankshaft bearing 33-2.

In the present embodiment, the pitch circle diameter D1 of the rolling element 30b of the 1 st eccentric body bearing 30-1 is smaller than the pitch circle diameter F2 of the rolling element 33b of the 2 nd crankshaft bearing 33-2. The shape of the rolling element 30b of the 1 st eccentric body bearing 30-1 of the present embodiment is the same as the shape of the rolling element 33b of the 2 nd crank bearing 33-2. In this case, the parts can be further commonly used. The shape of the 1 st retainer 30c-1 of the 1 st eccentric body bearing 30-1 of the present embodiment is different from the shape of the retainer 33c of the 2 nd crank bearing 33-2. In this case, the number of rolling elements and the size of the cage can be flexibly selected, and therefore, a structure suitable for the bearing capacity can be easily realized as compared with a case where the shape of the cage is fixed.

The above is the description of embodiment 1.

Next, embodiment 2 and embodiment 3 of the present invention will be described. In the drawings and the description of embodiment 2 and embodiment 3, the same or equivalent constituent elements and components as those of embodiment 1 are denoted by the same reference numerals. The description overlapping with embodiment 1 will be omitted as appropriate, and the description will be focused on the structure different from embodiment 1.

[ 2 nd embodiment ]

A method S100 for manufacturing the reduction gear transmission 10 according to embodiment 2 of the present invention will now be described. The manufacturing method S100 is a manufacturing method of the 1 st reduction gear transmission 10 having a structure different from that of the 2 nd reduction gear transmission 50. The description of embodiment 1 is applied to the 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50.

The manufacturing method S100 includes the following steps:

(1) manufacturing a crankshaft 12-1 having a 1 st eccentric body 12a such that a pitch circle diameter D1 of a rolling body of a 1 st eccentric body bearing 30-1 assembled to the 1 st eccentric body 12a-1 is smaller than a pitch circle diameter D2 of a rolling body of a 2 nd eccentric body bearing 30-2 assembled to a 2 nd eccentric body 12 a-2;

(2) a rolling element having a shape corresponding to that of the rolling element 30b of the 2 nd eccentric element bearing 30-2 is disposed on the 1 st eccentric element 12 a.

The above-described manufacturing method S100 is merely an example, and the order of the steps may be replaced, or some of the steps may be added, deleted, or changed.

According to the present embodiment, the same operational effects as those of embodiment 1 can be obtained, and parts can be used in common, thereby reducing the number of parts management man-hours.

[ embodiment 3 ]

A method S200 for designing the reduction gear transmission 10 according to embodiment 3 of the present invention will now be described. Design method S200 is a design method of the 1 st reduction gear transmission 10 having a structure different from that of the 2 nd reduction gear transmission 50. The description of embodiment 1 is applied to the 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50.

The design method S200 includes the following steps:

(1) the 1 st eccentric body 12a is designed such that a pitch circle diameter D1 of a rolling body of the 1 st eccentric body bearing 30-1 assembled on the 1 st eccentric body 12a-1 is smaller than a pitch circle diameter D2 of a rolling body of the 2 nd eccentric body bearing 30-2 assembled on the 2 nd eccentric body 12 a-2;

(2) the rolling elements of the 1 st eccentric body bearing 30-1 are designed to have the same shape as the rolling elements 30b of the 2 nd eccentric body bearing 30-2.

The above design method S200 is only an example, and the order of the steps may be replaced, or some of the steps may be added, deleted, or changed.

According to the present embodiment, the same operational effects as those of embodiment 1 can be obtained, and parts can be used in common, thereby reducing the number of design steps.

The above description explains an example of the embodiment of the present invention in detail. The above embodiments are merely specific examples for carrying out the present invention. The contents of the embodiments are not intended to limit the technical scope of the present invention, and many design changes such as changes, additions, deletions, and the like of the constituent elements can be made without departing from the scope of the inventive concept defined in the claims. In the above-described embodiments, the description has been given with the addition of words such as "in the embodiments" and "in the embodiments" to the contents in which such a design change is possible, but this does not mean that the design change is not permitted without the contents of such words.

Hereinafter, a modified example will be described. In the drawings and the description of the modified examples, the same or equivalent constituent elements and components as those of the embodiments are denoted by the same reference numerals. The description overlapping with the embodiment is omitted as appropriate, and the description is focused on the structure different from that of embodiment 1.

[ 1 st modification ]

In the description of embodiment 1, each reduction gear is an example of a center crank type eccentric rocking reduction gear, but the present invention is not limited to this. The reduction gear constituting the series of the eccentric oscillating type reduction gear of the present invention may be a reduction gear based on various principles including a crankshaft having an eccentric body and an eccentric body bearing.

Next, a series 1 of the eccentric rocking type reduction gear transmission according to modification 1 will be described. The series 1 of the eccentric oscillating type reduction gear transmission of the present modification includes the 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50 having different structures. Fig. 5 is a side sectional view showing the 1 st reduction gear transmission 10 according to the present modification, which corresponds to fig. 1. Fig. 6 is a side sectional view showing the 2 nd speed reducer 50 of the present modification, which corresponds to fig. 2.

The 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 mainly include an input gear 70, a crankshaft 12, an external gear 14, an internal gear 16, a carrier 18, a carrier 20, a housing 22, a main bearing 24, a main bearing 26, an eccentric body bearing 30, a crankshaft bearing 33, and a crankshaft bearing 34. The 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 according to the present modification include a plurality of input gears 70 and crankshafts 12. The 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 are different from the 1 st embodiment in that a plurality of crankshafts 12 are provided at positions offset from the central axis La of the internal gear 16, so-called distributed eccentric rocking type reduction gears.

The plurality of input gears 70 are arranged around the central axis La of the internal gear 16. Only one input gear 70 is shown in fig. 5. The input gear 70 is supported by the crankshaft 12 inserted in the central portion thereof, and is provided so as to be rotatable integrally with the crankshaft 12. The input gear 70 meshes with an external tooth portion of a rotary shaft (not shown) provided on the center axis La. The rotational power is transmitted to the rotary shaft from a driving device not shown, and the input gear 70 rotates integrally with the crankshaft 12 by the rotation of the rotary shaft.

The crankshaft 12 of the present modification is arranged in a plurality of (for example, three) crank shafts at intervals in the circumferential direction at positions offset from the central axis La of the ring gear 16. Only one crankshaft 12 is shown in fig. 5. Each crankshaft 12 is provided with two eccentric bodies 12a having eccentric phases shifted by 180 ° from each other in an axial direction.

Two external gears 14 are assembled to the outer periphery of the eccentric body 12a via an eccentric body bearing 30. Each external gear 14 internally meshes with the internal gear 16. The structures of the external gears 14 are the same except for the eccentric phases.

In the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 of the present modification, the movement restricting member 30h is provided between the plurality of eccentric body bearings 30. The movement restricting member 30h is present between two of the holders 30c adjacent to each other, and has a shape that overlaps each of the holders 30c when viewed in the axial direction.

In the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 according to the present modification, roller bearings having rollers (cylindrical bodies) as rolling elements are used as the crank

bearings

33 and 34. The

crankshaft bearings

33 and 34 have rolling

elements

33b and 34b and

cages

33c and 34c, and do not have inner rings and outer rings.

Next, the operation of the 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50 according to the present modification configured as described above will be described. When the rotational power is transmitted from the driving device to the rotating shaft, the rotational power is distributed from the rotating shaft to the plurality of input gears 70, and the input gears 70 rotate in the same phase. When each input gear 70 rotates, the eccentric body 12a of the crankshaft 12 rotates about the rotation center line passing through the crankshaft 12, and the eccentric body 12a oscillates the external gear 14. When the external gear 14 oscillates, the meshing positions of the external gear 14 and the internal gear 16 are sequentially shifted, and one of the external gear 14 and the internal gear 16 rotates, as in embodiment 1. The rotation of the crankshaft 12 is reduced in speed at a reduction gear ratio corresponding to the difference in the number of teeth between the external gear 14 and the internal gear 16, and then output from the output member to the driven device.

Next, a characteristic structure of the series 1 of the eccentric rocking type reduction gear unit of the present modification will be described.

The rolling body 30b of the 1 st eccentric body bearing 30-1 has a pitch circle diameter D1 smaller than a pitch circle diameter D2 of the rolling body 30b of the 2 nd eccentric body bearing 30-2. The shape of the 1 st retainer 30c-1 is different from the shape of the 2 nd retainer 30 c-2. The shape of the rolling body 30b of the 1 st eccentric body bearing 30-1 is the same as the shape of the rolling body 30b of the 2 nd eccentric body bearing 30-2. The number of the rolling bodies 30b of the 2 nd eccentric body bearing 30-2 is greater than that of the rolling bodies 30b of the 1 st eccentric body bearing 30-1, and the assembly rate of the rolling bodies 30b of the 2 nd eccentric body bearing 30-2 is lower than that of the rolling bodies 30b of the 1 st eccentric body bearing 30-1.

The shape of the rolling element 30b of the 1 st eccentric body bearing 30-1 of this modification is the same as the shape of the rolling

elements

33b, 34b of the 2 nd crank bearings 33-2, 34-2. The shape of the rolling element 30b of the 2 nd eccentric bearing 30-2 of the present modification is the same as the shape of the rolling

elements

33b and 34b of the 1 st crank bearings 33-1 and 34-1.

The shape of the rolling

elements

33b and 34b of the 1 st crank bearings 33-1 and 34-1 of the 1 st reduction gear unit 10 may be the same as the shape of the rolling element 30b of the 2 nd eccentric body bearing 30-2 of the 2 nd reduction gear unit 50. The shape of the rolling

elements

33b and 34b of the 1 st crank bearings 33-1 and 34-1 may be the same as the shape of the rolling

elements

33b and 34b of the 2 nd crank bearings 33-2 and 34-2. In this case, the parts can be further commonly used. These are not limited to the same shape between the 1 st eccentric body bearing 30-1 and the 2 nd eccentric body bearing 30-2, and the shapes of the other portions may be the same.

This modification example achieves the same operational effects as those of embodiment 1.

[ other modifications ]

In the description of embodiment 1, the example in which the 1 st reduction gear transmission 10 and the 2 nd reduction gear transmission 50 are both center crank type eccentric rocking type reduction gears is shown, but the present invention is not limited to this. One of the 1 st reduction gear unit and the 2 nd reduction gear unit may be a center crank type eccentric oscillating type reduction gear unit, and the other reduction gear unit may be a distributed type eccentric oscillating type reduction gear unit. As in modification 1, both the 1 st reduction gear unit 10 and the 2 nd reduction gear unit 50 may be distributed eccentric oscillating type reduction gears.

In the description of embodiment 1, an example having two external gears 14 is shown, but three or more external gears 14 may be provided according to desired characteristics.

In the description of embodiment 1, the case where

main bearings

24, 26 do not have an inner ring is exemplified, but the present invention is not limited thereto. One or both of the

main bearings

24, 26 may also be bearings having an inner race.

In the embodiment, an example in which the output member is the

wheel carriers

18, 20 and the casing 22 is fixed to the external member is described. In addition, the outer casing 22 may be an output member and the

wheel carriers

18 and 20 may be fixed to an external member.

In the description of embodiment 1, the example in which the maximum spaced positions of the two 2 nd holders 30c-2 of the 2 nd speed reduction device 50 that are farthest apart in the eccentric direction do not overlap when viewed from the axial direction is described, but the two 2 nd holders 30c-2 may overlap each other at the maximum spaced position that is farthest apart in the eccentric direction and the closest position that is closest to each other when viewed from the axial direction.

In the description of embodiment 1, the example in which the maximum spaced positions of the two 2 nd holders 30c-2 of the 2 nd speed reduction device 50, which are spaced the farthest in the eccentric direction, do not overlap each other when viewed from the axial direction is described, but the two 2 nd holders 30c-2 may overlap each other at the maximum spaced position and other positions, which are spaced the farthest in the eccentric direction, when viewed from the axial direction.

In embodiment 1, the shape of the rolling

elements

33b and 34b of the 2 nd crank bearings 33-2 and 34-2.

In the description of embodiment 1 and modification 1, an example in which the eccentric body bearing and the crankshaft bearing have the retainer is described, but a part or all of these bearings may be bearings without the retainer, for example, full complement roller bearings.

The above modifications provide the same operational effects as those of embodiment 1.

Any combination of the above embodiments and modifications is also effective as an embodiment of the present invention. The new embodiment which is produced by the combination has the effects of the combined embodiments and the modifications.

Claims

1. A series of eccentric oscillating reduction gears comprising a 1 st reduction gear and a 2 nd reduction gear, the series of eccentric oscillating reduction gears being characterized in that,

the 1 st speed reduction device includes: a 1 st outer gear; a 1 st crankshaft having a 1 st eccentric body that oscillates the 1 st external gear; and a 1 st eccentric body bearing disposed between the 1 st external gear and the 1 st eccentric body,

the 2 nd speed reduction device includes: a 2 nd outer gear; a 2 nd crankshaft having a 2 nd eccentric body that oscillates the 2 nd external gear; and a 2 nd eccentric body bearing disposed between the 2 nd external gear and the 2 nd eccentric body,

the pitch circle diameter of the rolling body of the 1 st eccentric body bearing is smaller than that of the rolling body of the 2 nd eccentric body bearing,

the shape of the rolling body of the 1 st eccentric body bearing is the same as that of the rolling body of the 2 nd eccentric body bearing.

2. The series of eccentrically swinging reduction gears according to claim 1,

the shape of the retainer of the 1 st eccentric body bearing is different from the shape of the retainer of the 2 nd eccentric body bearing.

3. The series of eccentrically swinging reduction gears according to claim 1 or 2,

the shape of the rolling element of the 1 st eccentric body bearing is the same as the shape of the rolling element of the 2 nd crankshaft bearing supporting the 2 nd crankshaft.

4. The series of eccentrically swinging reduction gears according to claim 3,

the shape of the rolling element of the 1 st eccentric body bearing is the same as the shape of the rolling element of the 2 nd crankshaft bearing supported by the carrier into which the inner pin of the 2 nd speed reducer is fitted and supporting the 2 nd crankshaft.

5. The series of eccentric oscillating reduction gears according to any one of claims 1 to 4,

the number of the rolling bodies of the 2 nd eccentric body bearing is more than that of the 1 st eccentric body bearing,

the assembly rate of the rolling bodies of the 2 nd eccentric body bearing is lower than that of the 1 st eccentric body bearing.

6. The series of eccentric oscillating reduction gears according to any one of claims 1 to 5,

the 1 st crankshaft and the 2 nd crankshaft are hollow shafts,

the hollow diameter of the 2 nd crankshaft is larger than that of the 1 st crankshaft.

7. The series of eccentric oscillating reduction gears according to any one of claims 1 to 6,

the 2 nd speed reduction device is provided with a plurality of the 2 nd eccentric body bearings,

a movement restricting part is provided between the plurality of 2 nd eccentric body bearings,

the eccentricity of the 2 nd crankshaft is larger than that of the 1 st crankshaft.

8. A series of eccentric oscillating reduction gears comprising a 1 st reduction gear and a 2 nd reduction gear, the series of eccentric oscillating reduction gears being characterized in that,

the 1 st speed reduction device includes: a 1 st outer gear; a 1 st crankshaft having a 1 st eccentric body that oscillates the 1 st external gear; a 1 st eccentric body bearing disposed between the 1 st external gear and the 1 st eccentric body; and a 1 st crankshaft bearing for supporting the 1 st crankshaft,

the 2 nd speed reduction device includes: a 2 nd outer gear; a 2 nd crankshaft having a 2 nd eccentric body that oscillates the 2 nd external gear; a 2 nd eccentric body bearing disposed between the 2 nd external gear and the 2 nd eccentric body; a 2 nd crankshaft bearing supporting the 2 nd crankshaft,

the pitch circle diameter of the rolling body of the 1 st crankshaft bearing is different from the pitch circle diameter of the rolling body of the 2 nd eccentric body bearing,

the shape of the rolling element of the 2 nd crank bearing is the same as the shape of the rolling element of the 1 st eccentric body bearing.

9. A series of eccentric oscillating reduction gears comprising a 1 st reduction gear and a 2 nd reduction gear, the series of eccentric oscillating reduction gears being characterized in that,

the 1 st speed reduction device includes: a 1 st outer gear; a 1 st crankshaft having a 1 st eccentric body that oscillates the 1 st external gear; a 1 st crankshaft bearing supporting the 1 st crankshaft; and a 1 st eccentric body bearing disposed between the 1 st external gear and the 1 st eccentric body,

the 2 nd speed reduction device includes: a 2 nd outer gear; a 2 nd crankshaft having a 2 nd eccentric body that oscillates the 2 nd external gear; a 2 nd crankshaft bearing supporting the 2 nd crankshaft; and a 2 nd eccentric body bearing disposed between the 2 nd external gear and the 2 nd eccentric body,

the pitch circle diameter of the rolling body of the 1 st crankshaft bearing is smaller than that of the rolling body of the 2 nd crankshaft bearing,

the shape of the rolling elements of the 1 st crank bearing is the same as the shape of the rolling elements of the 2 nd crank bearing.

10. A manufacturing method of a 1 st speed reduction gear having a structure different from that of a 2 nd speed reduction gear, the manufacturing method of the speed reduction gear being characterized in that,

the manufacturing method of the speed reducer comprises the following steps:

producing the crankshaft having the 1 st eccentric body in which a pitch circle diameter of a rolling element of the 1 st eccentric body bearing assembled to the 1 st eccentric body is made smaller than a pitch circle diameter of a rolling element of the 2 nd eccentric body bearing assembled to the 2 nd eccentric body; and

a rolling element having a shape corresponding to that of the rolling element of the 2 nd eccentric element bearing is disposed on the 1 st eccentric element.

11. A method of designing a 1 st reduction gear device having a structure different from that of a 2 nd reduction gear device, the method of designing the reduction gear device being characterized in that,

the design method of the speed reducer comprises the following steps:

designing the 1 st eccentric body such that a pitch circle diameter of a rolling body of the 1 st eccentric body bearing assembled to the 1 st eccentric body is smaller than a pitch circle diameter of a rolling body of the 2 nd eccentric body bearing assembled to the 2 nd eccentric body; and

the rolling elements of the 1 st eccentric body bearing are designed to have the same shape as the rolling elements of the 2 nd eccentric body bearing.