JPS645176B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a speed reducer, and more specifically, the present invention relates to a speed reducer, and more specifically, a hub having internal teeth on the inner periphery, external teeth meshing with the internal teeth on the outer periphery, and an inner periphery. The present invention relates to a speed reducer in which a pinion having a plurality of pin holes disposed inside thereof and capable of eccentric movement is engaged with the hub, and the plurality of pins are inserted into the pin holes of the pinion.

[Conventional technology]

The above-mentioned type of reducer is, for example,
This is known from Japanese Patent No. 25398, and is used as a reduction gear with a large reduction ratio. However, the above-mentioned special public service
For the reasons detailed below, the reducer described in Publication No. 25398 has a large external size and is heavy in weight when it is designed to output the output torque required in the current specific industry. The problem is that it does not meet the requirements.

[Problems to be solved by the present invention]

In other words, in the reducer described in the above-mentioned Japanese Patent Publication No. 39-25398, the crank pin is supported in a cantilevered manner, so the output torque is limited by the strength of the crank pin, and in order to increase the output torque, the diameter of the crank pin is increased. In this case, it is necessary to enlarge the bearing support portion of the crank pin, which results in an increase in the external size of the reduction gear.

In addition, the driven shaft is rotatably supported by the case of the reducer, and since this case surrounds the hub equipped with the internal gear from the outside, the wall thickness of the case and the gap between the case and the hub are This increases the size of the reducer.

In the reduction gear disclosed in Japanese Utility Model Application Publication No. 51-19176, both ends of the crank pin are apparently supported. However, the support block described in this publication does not have a substantially integral structure, and therefore has low rigidity and is ineffective in supporting the crank pin at both ends, and therefore cannot transmit large output. Further, the reducer described in Utility Model Application No. 51-19176 does not pay any special consideration to the shape of the support block, and from this point of view, it cannot support a large load.

[Means for solving problems]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a reduction gear that is small in external size, lightweight, and capable of producing a large output.

The present invention has achieved such an object by having a hub provided with internal teeth on the inner periphery, external teeth on the outer periphery that mesh with the internal teeth, and a plurality of pin holes arranged inside in the inner circumferential direction to engage with the hub. A speed reducer comprising a pinion capable of eccentric movement, a plurality of pins inserted into pin holes of the pinion to take out rotational motion of the pinion, and a through hole bored between the pin holes of the pinion, A disc-shaped part and an end disc are disposed on both sides of the pinion, and the disc-shaped part and the end disc are integrally connected by a columnar part loosely fitted into the through hole to form a support block. Both ends of the pin are rotatably supported by a disk-shaped portion and an end disk of the support block, and the plurality of columnar portions of the support block are rotated in the circumferential direction on which torsional loads act. This is achieved by a reduction gear having a wide width, and the columnar portion is arranged such that its outermost periphery is located radially outward from the center of rotation of the pin.

[Effect]

In the present invention, the columnar part of the support block is loosely fitted into the through hole drilled in the pinion, and the disc part and the end disc are integrally connected by the columnar part of the support block. A support block is formed that is highly rigid against loads.

In the present invention, this highly rigid support block supports a pin such as a crank pin for extracting rotational motion of a pinion at both ends.
Therefore, the strain on the pin can be minimized, and when the same limit strain is allowed, the output torque can be increased several times compared to the case of cantilever support. The stable support of the pin and the reduction of strain through support at both ends allows the use of smaller bearings, making it possible to downsize the reducer. Furthermore, when bearings of the same size are used, the life of the bearings can be extended compared to conventional cantilever support. Further, by stabilizing the pin and reducing strain, the meshing efficiency between the external teeth of the pinion that is revolved by the pin and the internal teeth of the bub is improved, and the transmission of a larger output torque is promoted.

Furthermore, in the present invention, since the plurality of columnar parts of the support block are made wide in the circumferential direction on which torsional loads act, the wide parts in the circumferential direction are able to withstand the torsional loads caused when torque is generated in the reducer. effectively provides rigidity, making the support block extremely rigid against torsional loads.

Further, in the present invention, the outermost periphery of the columnar portion of the support block is located radially outward from the rotation center of the pin that takes out the rotational motion of the pinion, so that the columnar portion of the present invention described above is The torsional load-carrying function of the circumferentially wide portion can be significantly enhanced, and the external size of the speed reducer can therefore be further reduced.

Therefore, the reduction gear of the present invention can output a large output despite its small size and light weight.

Furthermore, as shown in the embodiments of the present invention, by connecting the radial portion to the circumferentially wide portion of the columnar portion, the radial load caused by the torque generation of the reducer and the connection via the reducer can be reduced. This radially extending portion can also more effectively bear rigidity against radial loads caused by external loads.

In the embodiment of the present invention, the inner ends of the plurality of through holes formed in the pinion are connected to form a star shape extending radially from the center, and the inner ends of the plurality of through holes formed in the pinion are connected to form a star shape extending radially from the center. By connecting the ends to form a similar star shape, it is possible to further increase the rigidity of the columnar portion of the support block against radial loads.

Furthermore, in the embodiment of the present invention, the pins are fixed to the inner periphery of the hub at equal intervals to form a pin gear. This makes it possible to reduce the amount of eccentricity of the pin that takes out the rotational motion of the pinion, and the center of rotation of the pin and The distance between the pinion's revolution centers can be shortened, the external shape of the hub can be made smaller than that of conventional reducers using involute tooth profile, the meshing ratio between the internal teeth of the hub and the external teeth of the pinion can be increased, and the through hole in the pinion can be reduced. The allowable gap between the support block and the outer circumferential wall of the columnar part of the support block can be reduced.

〔Example〕

The present invention will now be described in detail with reference to the accompanying drawings, which illustrate embodiments of the invention. The first embodiment shown in FIG. 1 is applied to a reducer of a hydraulic motor with a reducer for driving a crawler vehicle, and a hydraulic motor 3 of a known type is fixed to a frame 1 of the crawler vehicle, and the reducer is 5, the rotation of the hydraulic motor 3 is decelerated and the sprocket 7 of the travel drive system is driven with a large output torque. The output shaft 11 of the hydraulic motor 3 is an input rotating shaft of the reduction gear 5 of the present invention, and is rotatably supported by a casing 13 of the hydraulic motor 3 by a pair of bearings 15 and 16. The casing 13 of the hydraulic motor 3 constitutes a support block of the reduction gear 5 of the present invention, and will be hereinafter referred to as the support block.

As shown in FIGS. 1 and 3, the main body of the support block 13 includes a disc-shaped portion 17 having a recess 17a (FIG. 1) on the back surface that fits tightly into the main body of the hydraulic motor 3 (FIG. 1); It consists of a star-shaped portion 19 protruding from the disc-shaped portion 17. The star-shaped portion 19 has three columnar portions that are a combination of a head portion 21a extending in the circumferential direction and a root portion 21b extending in the radial direction from the head portion 21a, and are equally spaced in the circumferential direction. The root portion 21b extends to the center and is connected.
A bearing mounting hole 17b having a predetermined depth and a support block 13 are provided on the surface of the disk-shaped portion 17 between adjacent columnar portions 21.
A screw hole 17c is formed for bolting the holder to the frame 1 of the crawler vehicle. Furthermore, a center hole 19a is bored in the center of the star-shaped portion 19, into which an input rotating shaft is inserted. Further, as shown in FIG. 1, pin holes 21c and 21d are provided in the columnar part 21 in order to integrally connect the end disk 25 forming a part of the support block 13 to the columnar part 21 of the support block by pins 23 and 23'. It is formed in the head part of. This pin 2
3, 23' have sufficient dimensions to withstand the shear loads exerted by the load. Although two pins 23 and 23' are used in FIGS. 1 and 3, in the present invention, the head portion extends in the circumferential direction and has a sufficient size. Therefore, the number of pins can be further increased or the pin diameter can be increased as necessary. Also, attach the end disk 25 to the support block's note part 21 with the bolts 2.
A screw hole 21e for fixing by a screw hole 21e is formed inside the pin holes 21c and 21d of the columnar portion in the radial direction.

As shown in FIG.
25b, a bolt through hole 25c corresponding to the screw hole 21e, and a bearing mounting hole 25d corresponding to the bearing mounting hole 17b formed in the disk-shaped portion 17 described above.
is formed. Roller bearings 27 and 29 are mounted in the bearing mounting holes 17b and 25d, respectively, and a crank pin 31 is rotatably supported at both ends between the bearings 27 and 29 as a pin for extracting the rotational motion of the pinion 33. The crank pin 31 has its rotation axis A
It has two crank parts 31a and 31c which are eccentrically arranged by a distance e with respect to each other, and a pinion 33 is fitted into the crank parts 31a and 31c.

As shown in FIG. 4, the pinion 33 has external teeth 33a on its outer circumferential surface with a tooth shape consisting of an equidistant curve to a pericycloid curve, and a bearing 35 is attached to the crank portion 31a or 31c of the crank pin 31 (FIG. It has a pin hole 33b that engages through the pin hole 33b. Furthermore, a star-shaped groove is formed which extends radially from the center of the pinion 33 and is slightly larger than the star-shaped part 19 formed on the support block 13.

Referring again to FIG. 1, in this embodiment, ball bearings 36a and 36b are mounted on the outer periphery of the disk-shaped portion 17 of the support block 13 and the end disk 25, and a hub 37 is rotatably supported. The hub 37 drives the drive sprocket 7 of the crawler vehicle, and small-diameter pins 39, the number of which is slightly more than the number of external teeth 33a formed on the outer periphery of the pinion 33, are evenly fixed to the inner peripheral surface of the hub 37. The internal teeth are made of pin gears. As shown in FIG. 2, the star-shaped groove 33c of the pinion 33 is loosely fitted into the star-shaped part 19 formed by the columnar part 21 of the support block 13, and the rotation of the crank pin 31 causes the crank pin 31 to rotate. As the central axes of 31a and 31c revolve around the rotational axis of the crank pin 31, the two pinions 33 are eccentrically rotated,
The external teeth 33a engage with the number of pin teeth on the hub 37. Here, the outermost periphery of the columnar part 21 of the support block 13 is
It is located radially outward with respect to the rotation center of the crank pin 31. That is, the arrangement position of the pin hole 33b (FIG. 4) of the pinion 33, in other words, the bearing mounting hole 17b (FIG. 3) of the support block 13.
When the arrangement position of the support block 13 is expressed by the radius R ₁ (Fig. 2) from the center A, and the distance between the outermost part of the annotated portion 21 of the support block 13 and the center A is expressed by R ₂ , R ₁ <R ₂
It is said that In particular, the ratio R ₁ and R ₂ of R ₁ /R ₂ is 1 pair.
The ratio is preferably 1.15 to 1:1.55. Below this range, the root portion 21b extending in the radial direction of the support block column cannot have a sufficiently large load capacity against external loads and radial loads caused by torque generation. The wall thickness between the star grooves 33c becomes too small, and the strength thereof tends to be insufficient.

Also, the star-shaped portion 19 of the support block 13 (Fig. 3)
It is preferable that the radius R ₃ (Fig _{. 2} ) of the minimum diameter part of the support block 13 is within the range of 1:0.267 to 1:0.433. The wall thickness of the root portion becomes too small and the effect of connecting the root portions is not sufficiently exhibited. On the other hand, if this range is exceeded, the wall thickness of the pin hole 33b of the pinion 33 becomes too small and its strength tends to be insufficient. Also,
Head portion 21a of columnar portion 21 of support block 13
The ratio of the length L in the circumferential direction to the shortest distance S on the inner wall of the pin holes closest to each other among the pin holes inside the pinion, S/L, may be in the range of 1:0.75 to 1:1.30. preferable. If the length is less than this range, the length of the head portion 21a is too short and the load resistance against torsional load is likely to be insufficient.On the other hand, if it exceeds this range, the strength of the pinion may be insufficient. This is because a through hole must be formed in the pinion corresponding to the length L of the head portion 21a of the support block, but if the above range is exceeded, the circumferential distance of the pinion through hole becomes extremely long. be.

Further, the ratio S/W of the minimum width W of the root portion 21b and the shortest distance S of the inner wall is set to 1:0.40 to 1:0.73.
It is preferable to set it as the range of. If the width is less than this range, the width of the root portion 21b is too small and the load resistance against radial load is likely to be insufficient. On the other hand, if it exceeds this range, the wall thickness between the pin hole 33b and the star-shaped groove 33c of the pinion is too small, resulting in its strength. may be in short supply. Note that the minimum width W of the root portion 21b is normally the same as the bearing mounting holes 1 located on both sides of the root portion 21b.
It is located on or near a line connecting the centers of 7b.

As shown in FIG. 2 of the above-mentioned embodiment, the columnar portion of the present invention is arranged so that the circular arc that is the center A of the support block 13 and the center of its radius of curvature are located at the center of the bearing mounting hole 17b of the support block 13. It is preferable to form a combination of circular arcs such that the head portion 21a can extend the longest in the circumferential direction and the cross-sectional area of the columnar portion 21 can be maximized.

The head portion of the columnar part 21 of the support block 13 of the present invention may be formed into a triangular shape 21a', a rectangular shape 21a'', or an elliptical shape 21a as shown in FIG. It is sufficient that the pinion 33 has a T-shape. In this case, the star-shaped groove 33c formed in the pinion 33 has a shape corresponding to the star-shaped part 19 formed by the columnar part 21 of the support block. It is preferable that the dimensions are within the above-mentioned range.

Referring again to FIG. 1, in this example,
A first external gear 41 is integrally fixed to the right end of the input rotating shaft 11, and a second external gear 41 having a larger number of teeth than the first external gear 41 is attached to the right end of the crank pin 31 supported at both ends. The gear 43 is fixed, and both teeth 4
1 and 43 are engaged. A lid 47 is hermetically fastened to the outside of both gears 41 and 43 by bolts 45, and a bearing 3 rotatably supports the hub 37 described above.
An oil seal 49 is provided on the outside of the reducer 5.
Prevent lubricating oil from leaking.

The output shaft of the hydraulic motor 3, that is, the input rotation shaft 11 of the reducer, rotates through the first external gear 41 fixed to the input rotation shaft 11, and the second external gear 4 meshing therewith.
3, the speed is reduced according to the ratio of the number of teeth of both gears 41 and 43, and the signal is transmitted. As the second external gear 43 rotates, the crank portion 31a of the crank pin 31 rotatably supported by the support block 13 at both ends rotates, and the pin hole 33b of the pinion 33 engages with the crank portion 31a via the bearing 35. Therefore, the crank portion 31a undergoes an eccentric revolution movement due to the revolution movement.

At this time, the plurality of crank pins 31 rotate between the orbital motion component and the rotational motion component of the pinion 33.
It functions so that only the rotational motion component is taken out to the hub 37. Therefore, the external teeth 3 formed on the outer periphery of the pinion due to the eccentric revolution movement of the pinion 33
3a engages with a pin gear formed on the inner periphery of the hub 37, causing the hub 37 to rotate at a reduced speed. However, hub 3
The running system of the crawler vehicle is driven by the sprocket 7 attached to the sprocket 7.

The reduction gear of the first embodiment shown in Figs. 1 to 4 is about 10 times as large as the reduction gear described in the aforementioned Japanese Patent Publication No. 39-25398 at the same reduction ratio and the same outer diameter. It was possible to generate an output torque of .

In the embodiment described above, in a reducer having three crank pins 31, a support block 13 having a star-shaped portion 19 having three columnar portions 21 and a pinion 33 having a star-shaped groove 33c corresponding to the support block 13 are provided. An embodiment comprising the following has been described. The present invention can be applied to reduction gears in which the number of crank pins 31 is other than three, and when the number of crank pins 31 is large, for example, one columnar part 21 is not provided between all adjacent crank pins 31. The columnar portions 21 may be provided at every other interval.

In the above embodiment, the support block 13 of the reducer also serves as the casing of the hydraulic motor 3, but the present invention can also be applied to a reducer provided separately from the motor, in which case the support block 13 serves as the casing of the hydraulic motor 3. It becomes a separate entity. Further, it is also possible to use an electric motor or a pneumatic motor in place of the hydraulic motor 3 of the above embodiment.

In the above embodiment, the output torque is transferred to the hub 37 of the reducer.
Although the reducer of the present invention is taken out from the hub 37
It is also possible to take out the output from a support block provided on the same axis as the input rotating shaft by fixing the input rotating shaft. One example is shown in FIG. 6, where the same parts as in the first embodiment shown in FIGS. 1 to 4 are given the same numbers and detailed explanations thereof will be omitted, and the differences will be explained below. Hub 3 on the casing of hydraulic motor 3
The output shaft 11 of the hydraulic motor 3 is the input rotating shaft of the reducer, as in the first embodiment, but its length is sufficiently shortened so that its end face is supported. The first external gear 41 faces the hydraulic motor 3 without passing through the block. The support block 13 is composed of a disc-shaped part 17, a star-shaped part 19 consisting of three columnar parts connected together, and an end disc 25, as in the first embodiment, but the arrangement thereof is different from that in the first embodiment. The opposite is true, and the end disk 25 is the first
It is located opposite to the external gear 41. Support block 1
The crank pin 31 to which the second external gear is fixed is supported at both ends by bearings 27 and 29 provided at the support block 13, and the shape of the columnar portion of the support block 13 is formed in the same manner as in the first embodiment. Furthermore, a threaded portion 13a is formed by protruding the right end of the support block 13 to attach an output transmission drive gear (not shown), and bearings 36a and 36b are installed between the outer circumference of the support block 13 and the inner circumference of the hub. The support block is rotatable relative to the fixed hub. Therefore, the rotation of the input rotating shaft 11 by the hydraulic motor 3 is transmitted from the first external gear 41 to the second external gear 43 at a reduced speed, causing a revolution movement of the crank portion 31a of the crank pin 31, which causes the pinion 33 to move eccentrically. The external gear 33a has a tooth profile formed by a curve equidistant to a pericycloid curve formed on the outer circumference of the external gear 33a.
meshes with a pin gear consisting of a pin 39 formed on the inner periphery of the hub 37. Because the hub 37 is fixed, the support block 13 rotates at a reduced speed, producing an output torque on the drive gear.

〔Effect of the invention〕

In the present invention, since the columnar portion of the support block is wide in the circumferential direction where torsional loads act, the wide portions in the circumferential direction effectively support rigidity against the torsional loads caused when torque is generated by the reducer. . In this manner, in the present invention, the rigidity of the entire support block is significantly increased by forming the columnar portion into a special shape.

In addition, as shown in the example, when a part extending in the circumferential direction is combined with a part extending in the radial direction from the part, the radial load due to the torque generation of the reducer and the reducer are reduced. The radially extending portion effectively carries the stiffness against radial loads due to external loads connected through the radial direction.

Furthermore, in the present invention, the columnar part of the support block is loosely fitted into the through hole formed in the pinion, and the eccentric movement member is supported by both ends formed integrally with the columnar part of the support block. By integrally forming the columnar portion and both end portions of the support block, the rigidity of the entire support block is significantly increased.

As described above, in the present invention, the rigidity of the entire support block is significantly increased by forming the columnar part into a special shape and by integrally forming the columnar part and both ends of the support block. Since the eccentric member is rotatably supported by both ends of the highly rigid support block, distortion of the eccentric member can be minimized. As a result, in the present invention, when the same limit strain is allowed, the output torque can be increased several times compared to the case of cantilever support. That is, the present invention allows the use of small bearings by stably supporting the eccentric member by supporting both ends and reducing strain, thereby making it possible to downsize the speed reducer. Furthermore, when bearings of the same size are used, the life of the bearings can be extended compared to conventional cantilever support.

Furthermore, by stabilizing the eccentric member and reducing strain, in the present invention, the meshing efficiency between the external teeth of the pinion and the internal teeth of the hub, which are revolved by the eccentric member, is improved, and a larger output torque can be transmitted. Facilitate.

In addition, in the present invention, by locating the outermost periphery of the columnar portion of the support block radially outward from the rotation center of the pin for extracting the rotational motion of the pinion, the circumference of the columnar portion of the present invention described above can be adjusted. The torsional load-carrying function of the directionally extending portion can be significantly increased, and the external dimensions of the speed reducer can therefore be made even smaller.

[Brief explanation of drawings]

Figure 1 is a sectional view of the first embodiment of the present invention, Figure 2 is a cross-sectional view of Figure 1, with sprockets and their mounting bolts omitted, and Figure 3 is a cross-sectional view of the first embodiment. FIG. 4 is a perspective view of the pinion of the first embodiment; FIG. 5 is a perspective view of the support block of the first embodiment; FIG. FIG. 6, which corresponds to FIG. 2, is a sectional view of a fifth embodiment of the present invention. 3...Hydraulic motor, 5...Reducer, 11...Input rotating shaft, 13...Support block, 17...Disk-shaped part, 19...Star-shaped part, 21...Column-shaped part, 21
a, 21a', 21a'', 21a...head part, 2
1b... Root portion, 27, 29... Bearing, 31...
...Crank pin, 33...Pinion, 33a...
Tooth profile consisting of an equidistant curve to a pericycloid curve, 33b...pin hole, 33c...star-shaped groove, 36
a, 36b... Bearing, 37... Hub, 39... Pin, 41... First external gear, 43... Second external gear.

Claims (1)

[Claims] 1. A hub having internal teeth on the inner periphery, external teeth that mesh with the internal teeth on the outer periphery, and a plurality of pin holes arranged inside in the inner circumferential direction, which engage with the hub and allow eccentric movement. A reduction gear consisting of a pinion and a plurality of pins inserted into pin holes of the pinion to take out rotational motion of the pinion, and a through hole is bored between the pin holes of the pinion, with circles on both sides of the pinion. A support block is formed by disposing a plate-shaped portion and an end disk, and integrally connecting the disk-shaped portion and the end disk by a columnar portion loosely fitted into the through hole. Both ends of the pin are rotatably supported by a disk-shaped portion and an end disk of the support block, and the plurality of columnar portions of the support block are wide in the circumferential direction on which torsional loads act, A speed reducer characterized in that the columnar portion is arranged such that its outermost periphery is located radially outward from the center of rotation of the pin.