Speed reduction device

Abstract

Provided is a speed reduction device (S1) comprising a housing (CA), such that the device is lightweight and strength and durability are improved. The housing (CA) accommodates: an input shaft member (X11) that rotates about an input shaft (AX1); and an output shaft member X (20) that is disposed parallel to the input shaft member (X11) and that rotates about an output shaft (AX2) that rotates in the same direction as the input shaft member (X11). In the housing (CA), a connection unit (M) that can be connected to a vehicle body is disposed at a position between the input shaft AX1 and the output shaft AX2.

Description

reduction gear

[0001] The present invention relates to a reduction gear device for a saddle-ride type vehicle.

[0002] A known example of a saddle-ride type vehicle is the vehicle described in Patent Document 1. In the vehicle described in Patent Document 1, power output from a prime mover and a transmission mounted in the center of the vehicle body is transmitted via a propeller shaft to a final drive unit mounted in the rear of the vehicle body. Another known example of a saddle-ride type vehicle is the vehicle described in Patent Document 2. In the vehicle described in Patent Document 2, power output from a prime mover and a transmission mounted in the center of the vehicle body is transmitted to a rear wheel via a belt. A housing that houses this belt is connected to the vehicle body by a mount seat that protrudes forward of the input shaft and by a mount seat that protrudes rearward of the output shaft. Meanwhile, assuming that a reduction gear such as that described in Patent Document 3, which includes an intermediate shaft connected to spaced-apart input and output shafts and in which bevel gears mesh with each other at their connecting portions, is applied to a saddle-ride type vehicle, the configuration would be as follows. In a reduction gear device using a gear mechanism, power output from a transmission is transmitted via a chain or the like to a first shaft (input shaft) extending in the vehicle width direction, meshes with a bevel gear formed on the first shaft, and is then transmitted to a bevel gear formed on one end of a second shaft (intermediate shaft) perpendicular to the first shaft. The power transmitted to the second shaft then meshes with a bevel gear formed on a third shaft (output shaft) oriented in the vehicle width direction via a bevel gear formed on the other end of the second shaft, and is then transmitted to the left and right rear wheels of the vehicle via a differential device formed on the third shaft.

[0003] JP 2001-328410 A JP 2016-145609 A JP 8-42670 A

[0004] In the above-described reduction gear transmission, the bevel gear engagement reaction force acts on the bearings supporting the spaced-apart first and third shafts. Furthermore, tension from the chain meshing with the sprocket attached to the end of the first shaft acts on the first shaft, exerting a bending load on the first shaft member. This bending load acts to bend the housing up and down (in the pitching direction). Furthermore, when a reduction gear transmission with such a configuration is mounted on a vehicle body as described in Patent Document 2, the meshing reaction force and bending load act on the central portion of the cylindrical housing that contains the second shaft, resulting in a bending load acting up and down. If the housing has low rigidity and elastic deformation, not only does the housing strength decrease, but the gears may not mesh accurately, reducing their strength and increasing meshing noise. Increasing the size of the housing to address these issues increases the housing's mass, affecting vehicle performance. Increasing the size of the housing also affects the layout of surrounding components.

[0005] The present invention has been devised to solve the above problems, and its object is to provide a reduction gear transmission that includes a housing that is lightweight yet has increased strength and durability.

[0006] In order to achieve the above-mentioned object, the reduction gear transmission of the present invention has a housing that houses an input shaft member that rotates around an input shaft, and an output shaft member that is arranged parallel to the input shaft member and rotates around an output shaft that rotates in the same direction as the input shaft member, and a connection portion that can be connected to a vehicle body is arranged at a position between the input shaft and the output shaft.

[0007] According to the present invention, it is possible to provide a reduction gear transmission that includes a housing that is lightweight yet has increased strength and durability.

[0008] 12 is a perspective view showing a reduction gear according to a first embodiment of the present invention. FIG. 13 is a left side view showing a reduction gear according to a first embodiment of the present invention. FIG. 14 is a right side view showing a reduction gear according to a first embodiment of the present invention. FIG. 15 is a bottom view showing a reduction gear according to a first embodiment of the present invention. FIG. 16 is a cross-sectional view taken along line VV of FIG. 3. FIG. 17 is a cross-sectional view taken along line VI-VI of FIG. 3. FIG. 18 is a cross-sectional view taken along line VII-VII of FIG. 3. FIG. 19 is a right side view showing reduction gears according to a second and third embodiment of the present invention. FIG. 19 is a cross-sectional view taken along line IX-IX of FIG. 8 showing a reduction gear according to a second embodiment of the present invention. FIG. 19 is a cross-sectional view taken along line IX-IX of FIG. 8 showing a reduction gear according to a third embodiment of the present invention. FIG. 19 is a right side view showing a reduction gear according to a fourth embodiment of the present invention. FIG. 19 is a right side view showing a reduction gear according to a fifth embodiment of the present invention. FIG. 19 is a cross-sectional view taken along line XIII-XIII of FIG. 12.

[0009] <First Embodiment> A reduction gear transmission S1 according to a first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7. In the description, identical elements are designated by the same reference numerals, and redundant description will be omitted. The reduction gear transmission S1 according to this embodiment is mounted on a four-wheeled saddle-ride vehicle (not shown), commonly known as a buggy. The reduction gear transmission S1 reduces the rotational speed of a motor (not shown) outputted through a transmission (not shown), increasing the rotational torque, and transmits the torque to an axle (not shown) of a rear wheel (not shown). The reduction gear transmission S1 includes a housing CA, an input shaft member X11, a differential mechanism X20 (output shaft member), and a bevel gear mechanism TM1 (transmission means TM) (see FIG. 5).

[0010] The housing CA has a hollow shell shape with an input-side housing chamber CR1, an output-side housing chamber CR2, and a transmission unit housing chamber CR3 formed therein. The input-side housing chamber CR1 is located in the front of the housing CA, and the output-side housing chamber CR2 is located in the rear of the housing CA. The transmission unit housing chamber CR3 is formed to connect the input-side housing chamber CR1 and the output-side housing chamber CR2.

[0011] The housing CA is divided into three members: a housing front portion C1, a housing rear portion C2, and a housing center portion C3 (see FIGS. 1 and 2). The housing front portion C1 and the housing center portion C3 are divided by a plane (input-side dividing surface CF1) along the vertical direction including the input axis AX1 set along the vehicle width direction. The housing center portion C3 and the housing rear portion C2 are divided by a plane (output-side dividing surface CF2) along the vertical direction including the output axis AX2 set parallel to the input axis AX1.

[0012] That is, the housing CA is divided into three sections by an input-side dividing surface CF1 including the input shaft AX1 and an output-side dividing surface CF2 including the output shaft AX2. The housing front section C1 and the housing center section C3, and the housing center section C3 and the housing rear section C2 are fastened together by fastening bolts FB threaded into fastening portions F. Furthermore, the housing CA is provided with mounts M (connecting portions) and is attached to the vehicle body frame VF by mount bolts MB (connecting bolts) (see FIGS. 3 and 4 ). The vehicle body frame VF has a ladder shape extending in the fore-and-aft direction of the vehicle. Connection points with the mounts M are set at locations where a pair of vertical members and multiple horizontal members constituting the ladder shape intersect.

[0013] The fastening section F is composed of an input-side upper fastening section FFU, an input-side lower fastening section FFB, an output-side upper fastening section FRU, and an output-side lower fastening section FRB (see FIGS. 1 to 4). The input-side upper fastening section FFU has a through-hole formed in the upper part of the housing front section C1 and a female thread formed in the upper part of the housing center section C3, with the input-side split surface CF1 in between. A fastening bolt FB is inserted through the through-hole and screwed into the female thread. The input-side lower fastening section FFB has a through-hole formed in the lower part of the housing front section C1 and a female thread formed in the lower part of the housing center section C3, with the input-side split surface CF1 in between. The fastening bolt FB is inserted through the through-hole and screwed into the female thread.

[0014] The output-side upper fastening part FRU has a through-hole formed in the upper part of the housing rear part C2 and a female screw portion formed in the upper part of the housing center part C3, with the output-side split face CF2 in between, and the fastening bolt FB is inserted through the through-hole and screwed into the female screw portion. The output-side lower fastening part FRB has a through-hole formed in the lower part of the housing rear part C2 and a female screw portion formed in the lower part of the housing center part C3, with the output-side split face CF2 in between, and the fastening bolt FB is inserted through the through-hole and screwed into the female screw portion.

[0015] The mounts M (connection portions) are composed of an input-side left mount MFL, an input-side right mount MFR, an output-side left mount MRL, and an output-side right mount MRR (see FIGS. 3 and 4). Each mount M is composed of a seat on the bottom surface of the housing CA, with a female threaded hole that opens vertically downward. Each mount M is disposed between the input axis AX1 and the output axis AX2. In other words, each mount M is formed vertically below the output axis AX2. In other words, each mount M is formed vertically below the imaginary line L that connects the input axis AX1 and the output axis AX2.

[0016] The input-side left mount MFL is disposed vertically below the meshing location between an input gear T11 (input bevel gear) described later and an input-side transmission gear T13 (input bevel gear) described later. The input-side left mount MFL is also disposed between the left input boss B1L and the left output boss B2L. The input-side right mount MFR is disposed vertically below the meshing location between the input gear T11 and the input-side transmission gear T13. The input-side right mount MFR is also disposed between the right input boss B1R and the right output boss B2R.

[0017] The output-side left mount MRL is disposed vertically below the meshing location between an output gear T12 (output bevel gear) (described later) and an output-side transmission gear T14 (output bevel gear) (described later). The output-side left mount MRL is disposed between the left input boss B1L and the left output boss B2L. The output-side right mount MRR is disposed vertically below the meshing location between the output gear T12 and the output-side transmission gear T14. The output-side right mount MRR is disposed between the right input boss B1R and the right output boss B2R.

[0018] The input-side housing chamber CR1 houses the input shaft member X11, and the output-side housing chamber CR2 houses the differential mechanism X20 (output shaft member) (see FIG. 5). The transmission portion housing chamber CR3 houses the transmission means TM, linking the input shaft member X11 and the differential mechanism X20. The housing CA is also provided with reinforcing ribs R on the outer surfaces of the left side wall CSL and right side wall CSR facing in the vehicle width direction. In other words, the housing CA has a plurality of reinforcing ribs R standing on its outer circumferential surface.

[0019] The input shaft member X11 is rotatably supported around an input shaft AX1 set along the vehicle width direction. The left end of the input shaft member X11 penetrates the left side wall CSL of the housing CA and is exposed, and is supported by the housing CA via a pair of input bearings X12. The input bearings X12 are made up of a right input bearing X12R and a left input bearing X12L.

[0020] The right input bearing X12R is fitted into a right input boss B1R (input boss B1) formed on the inner surface of the right side wall CSR of the input side housing chamber CR1, and supports the right end of the input shaft member X11. The left input bearing X12L is fitted into a left input boss B1L (input boss B1) formed on the inner surface of the left side wall CSL of the input side housing chamber CR1, and supports the left end of the input shaft member X11. A sprocket X13 (input point) is disposed on the left end of the input shaft member X11, which is exposed to the outside of the housing CA, and power output from the transmission is input via a chain (not shown) stretched around it.

[0021] The differential mechanism X20 (output shaft member) distributes and transmits driving force to the inner and outer axles while generating a rotational difference corresponding to the inner wheel difference that occurs between the inner and outer axles when the vehicle turns. The differential mechanism X20 is composed of a differential case X21, a pair of pinion gears X23, and left and right side gears X24, which are spline-connected to left and right axles (not shown). The rotational force input to the differential case X21 is transmitted to the left and right axles via the pinion gears X23 and the side gears X24.

[0022] The differential case X21 is supported on the housing CA via a pair of output bearings X22, with the output shaft AX2 extending in the vehicle width direction and parallel to the input shaft AX1 as its rotation center. The output bearings X22 are made up of a right output bearing X22R and a left output bearing X22L.

[0023] The right output bearing X22R is fitted into a right output boss B2R (output boss B2) formed on the inner surface of the right side wall CSR of the output side housing chamber CR2, and supports the right end of the differential case X21. The left output bearing X22L is fitted into a left output boss B2L (output boss B2) formed on the inner surface of the left side wall CSL of the output side housing chamber CR2, and supports the left end of the differential case X21.

[0024] The side gear X24 is rotatably supported in the differential case X21 around the output shaft AX2. The left and right axles (not shown) rotate around the output shaft AX2. In other words, the differential mechanism X20 is set so that the axles of the rear wheels and the rotation axis of the differential case X21 coincide with the output shaft AX2.

[0025] The transmission means TM is composed of a bevel gear mechanism TM1 using bevel gears, and transmits rotational force input to an input shaft member X11 to an output gear T12 constituting a differential mechanism X20 (output shaft member) via a first transmission shaft member T10 (transmission shaft member). The bevel gear mechanism TM1 is linked so that, when transmitting rotational force, the differential mechanism X20 rotates in the same direction as the rotational direction of the input shaft member X11. The bevel gear mechanism TM1 includes the first transmission shaft member T10, an input gear T11 (input bevel gear), an input side transmission gear T13 (input side transmission bevel gear), an output side transmission gear T14 (output side transmission bevel gear), and an output gear T12 (output bevel gear).

[0026] The first transmission shaft member T10 is disposed between the input shaft AX1 and the output shaft AX2, and is rotatably supported around a transmission shaft AX3 (first transmission shaft). The transmission shaft AX3 is set to be perpendicular to the input shaft AX1. The input gear T11 is a gear formed on the right end side of the input shaft member T11. The input side transmission gear T13 is a gear formed on the front end side of the first transmission shaft member T10. The input gear T11 and the input side transmission gear T13 are configured as bevel gears that can mesh with each other.

[0027] The output side transmission gear T14 is a gear formed on the rear end side of the first transmission shaft member T10. The output gear T12 is a ring gear formed on the outer periphery of the differential case X21. The output side transmission gear T14 and the output gear T12 are configured as meshable hypoid gears. The front end side of the first transmission shaft member T10 is journaled on the front end part of the transmission part accommodation chamber CR3 via an input side transmission bearing T15.

[0028] The rear end of the first transmission shaft member T10 is journaled on the rear end of the transmission portion accommodation chamber CR3 via an output side transmission bearing T16. The input side transmission bearing T15 journals the front end of the first transmission shaft member T10 while being fitted into an input side transmission boss B3 formed on the inner surface of the front end of the transmission portion accommodation chamber CR3. The output side transmission bearing T16 journals the rear end of the first transmission shaft member T10 while being fitted into an output side transmission boss B4 formed on the inner surface of the rear end of the transmission portion accommodation chamber CR3.

[0029] The reinforcing rib R is composed of a left reinforcing rib RL and a right reinforcing rib RR (see Figures 1 to 3). The left reinforcing rib RL is erected along the input axis AX1 on the outer peripheral surface of the left side wall CSL of the housing CA (see Figures 1 and 2). The left reinforcing rib RL is composed of an upper left convex upper rib RL1, an upper left convex middle rib RL2, an upper left convex lower rib RL3, a lower left convex rib RL4, a left front rising rib RL5, and a left front falling rib RL6. The right reinforcing rib RR is erected along the input axis AX1 on the outer peripheral surface of the right side wall CSR of the housing CA. The right reinforcing rib RR is composed of an upper right convex rib RR1, a lower right convex rib RR2, a right front rising rib RR3, and a right front falling rib RR4.

[0030] Next, the effects of the reduction gear transmission S1 of this embodiment will be described. The reduction gear transmission S1 of this embodiment is provided with mounts M (connecting portions), which include an input-side left mount MFL, an input-side right mount MFR, an output-side left mount MRL, and an output-side right mount MRR. These mounts M are set in positions on the housing CA close to the sprocket X13 (input point), the input shaft AX1, and the output shaft AX2, and are connected and fixed to the vehicle frame VF. When the reduction gear transmission S1 transmits input rotational force from the input shaft member X11 to the differential case X21 (output shaft member), a bending load in the up-down direction (pitching direction) and a torsional load in the left-right direction (rolling direction) act on the housing center portion C3.

[0031] In response to such bending loads, by providing the mount M (connection portion) between the input shaft AX1 and the output shaft AX2 as in this embodiment, the input point and the connection portion can be brought closer together, thereby suppressing vertical bending and lateral twisting. This prevents the housing CA of the reduction gear S1 from becoming larger, and allows for increased strength and durability while remaining lightweight. Furthermore, by preventing the entire device from becoming larger, it is possible to increase the degree of freedom in the layout of peripheral components when the reduction gear S1 is installed in a vehicle.

[0032] Furthermore, by suppressing bending deformation of the housing CA, it is possible to maintain the proper engagement of the gears that make up the transmission means TM, thereby ensuring the strength and durability of the transmission means TM and preventing the generation of abnormal noise due to poor meshing.

[0033] Furthermore, the mount M is disposed vertically below the transmission shaft AX3 of the casing CA, and the reduction gear S1 is mounted on the body frame VF. In other words, the mount M is formed vertically below the imaginary line L connecting the input shaft AX1 and the output shaft AX2. This configuration allows the body frame VF to be made smaller. Furthermore, this configuration positions the body frame VF at the lowest position in the vehicle body, preventing the casing CA from coming into contact with a step when the vehicle climbs over it. In addition, since the center of gravity of the reduction gear S1 is located vertically below the casing CA, maintaining the reduction gear S1 near the center of gravity makes it possible to prevent excessive loads from being applied to the casing CA.

[0034] Furthermore, since the mount M is configured with a seating surface having a female threaded hole that opens vertically downward, the workability of mounting and fastening the reduction gear S1 to the vehicle body is improved. In particular, the bolt assembly and tightening torque can be checked from one direction. In this embodiment, the input-side dividing surface CF1 that divides the housing front portion C1 and the housing center portion C3 is a flat surface that extends vertically and includes the input shaft AX1. In this embodiment, the output-side dividing surface CF2 that divides the housing center portion C3 and the housing rear portion C2 is a flat surface that extends vertically and includes the input shaft AX1. This configuration improves the assembly workability of the input shaft member X11 and the differential mechanism X20 (output shaft member), and also enables the reduction gear S1 to be made more compact.

[0035] That is, the assembly of the reduction gear S1 is improved, and the incorporation and adjustment of gears, bearings, etc. is also improved. In addition, the protrusion of the housing CA is kept small, which reduces the size of the housing CA and improves the design freedom of peripheral components. Furthermore, in this embodiment, the reduction gear S1 is configured so that the input shaft AX1 extends in the vehicle width direction. With this configuration, the above-mentioned effects can be obtained in the reduction gear S1 of a four-wheel saddle-ride vehicle in which the input shaft AX1 and output shaft AX2 are arranged parallel to each other.

[0036] Second Embodiment Next, a reduction gear transmission S2 according to a second embodiment of the present invention will be described with reference to Figures 8 and 9. In the description, the same elements as those in the first embodiment described above are designated by the same reference numerals, and duplicated descriptions will be omitted. In the reduction gear transmission S2 of this embodiment, the configuration of the transmission means is different from the transmission means TM of the first embodiment.

[0037] The reduction gear S2 of this embodiment employs a chain drive TM2 as a transmission means. The chain drive TM2 is composed of an input sprocket T21, an output sprocket T22, and a chain T23. The input sprocket T21 is provided on the input shaft member X11 and rotates together with the input shaft member X11 around the input shaft AX1. The output sprocket T22 is provided on the differential case X21 (output shaft member) and rotates together with the differential case X21 around the output shaft AX2. The chain T23 is stretched between the input sprocket T21 and the output sprocket T22 and transmits the rotational force of the input sprocket T21 to the output sprocket T22.

[0038] Even when a chain drive TM2 is used as the transmission means as in this embodiment, the mount M is disposed between the input shaft AX1 and the output shaft AX2, and the same effects as those of the first embodiment can be obtained with the configuration of this embodiment.

[0039] Although the reduction gear S2 of this embodiment employs a chain drive TM2 as the transmission means TM, this is not limiting. For example, a belt drive using a toothed belt (not shown) can be employed, and the same effects as those of this embodiment can be obtained.

[0040] Third Embodiment Next, a reduction gear transmission S3 according to a third embodiment of the present invention will be described with reference to Figures 8 and 10. In the description, the same elements as those in the first embodiment described above are designated by the same reference numerals, and duplicated descriptions will be omitted. In the reduction gear transmission S3 of this embodiment, the configuration of the transmission means is different from the transmission means TM of the first embodiment.

[0041] In the reduction gear transmission S3 of this embodiment, a spur gear mechanism TM3 using spur gears is employed as the transmission means TM. The spur gear mechanism TM3 includes a transmission shaft member T31 (second transmission shaft member), an input gear T32, an input-side transmission gear T34, an output-side transmission gear T35, and an output gear T33. The transmission shaft member T31 is disposed between the input shaft AX1 and the output shaft AX2, and is rotatably supported via a transmission bearing T36 around the transmission shaft AX4 (second transmission shaft).

[0042] The transmission shaft AX4 is set to be parallel to the input shaft AX1. The input gear T32 is a spur gear formed on the input shaft member X11. The input side transmission gear T34 is formed on the transmission shaft member T31, is capable of meshing with the input gear T11, and is composed of a spur gear with a larger number of teeth than the input gear T11. The output side transmission gear T35 is a spur gear formed on the transmission shaft member T31. The output gear T12 is formed on the outer periphery of the differential case X21, is capable of meshing with the output side transmission gear T35, and is composed of a spur gear with a smaller number of teeth than the input side transmission gear T34.

[0043] Even when the spur gear mechanism TM3 is used as the transmission means as in this embodiment, the mount M is disposed between the input shaft AX1 and the output shaft AX2, and the same effects as those of the first embodiment can be obtained with the configuration of this embodiment.

[0044] <Fourth embodiment> Next, a reduction gear transmission S4 according to a fourth embodiment of the present invention will be described with reference to Fig. 11. In the description, the same elements as those in the first embodiment described above are designated by the same reference numerals, and duplicated descriptions will be omitted. In the reduction gear transmission S4 of this embodiment, the configuration of the housing CA is different from that of the first embodiment. Except for the housing CA, the other configurations are the same as those of the first embodiment.

[0045] In the reduction gear S4 of this embodiment, the configuration of the input-side dividing surface CF1 that divides the housing front portion C1 and the housing center portion C3 is different from that of the first embodiment. The input-side dividing surface CF1 of this embodiment is configured as a surface that slopes downward toward the front and includes the input shaft AX1. With this configuration, when installing the reduction gear S4 on the vehicle body, even if there is an obstruction above the front portion of the reduction gear S4, it can be positioned to avoid this obstruction. This increases the degree of freedom in vehicle body layout.

[0046] Fifth Embodiment Next, a reduction gear transmission S5 according to a fifth embodiment of the present invention will be described with reference to Figures 12 and 13. In the description, the same elements as those in the first embodiment described above are designated by the same reference numerals, and duplicated description will be omitted. In the reduction gear transmission S5 of this embodiment, the configuration of the mount M (connection portion) is different from that of the first embodiment. Except for the mount M, the other configuration is the same as that of the first embodiment.

[0047] In this embodiment, the mount M is configured with a bearing surface having a through hole that opens laterally along the axial direction of the input shaft AX1, and the reduction gear S5 is fixed to the body frame VF via a pair of mount bolts MB (connection bolts). That is, one mount bolt MB passes through the input side left mount MFL, the input side right mount MFR, and the body frame VF and is threadedly engaged with a nut MN (connection nut). Furthermore, the other mount bolt MB passes through the output side left mount MRL, the output side right mount MRR, and the body frame VF and is threadedly engaged with the nut MN.

[0048] This configuration allows the reduction gear unit to be mounted lower on the vehicle body, further lowering the center of gravity and improving vehicle drivability. Also, this configuration allows the height of the reduction gear unit S5, including the vehicle body frame VF, to be reduced, increasing the degree of freedom in vehicle body layout.

[0049] In the reduction gear transmission S5 of this embodiment, the mount M is configured with a seating surface having a through-hole that opens laterally, but the configuration is not limited to this. For example, each mount M could be configured with a seating surface that has a female thread that opens laterally along the axial direction of the input shaft AX1. Then, a mount bolt is individually screwed into each mount M to fix the reduction gear transmission S5 to the body frame VF. Even with this configuration, the same effects as those of the fifth embodiment described above can be obtained.

[0050] Furthermore, the mount M may be disposed vertically above the imaginary line connecting the input shaft AX1 and the output shaft AX2. This configuration not only improves the design freedom of the frame VF, but also improves the design freedom for the placement of the oil fill plug and oil drain plug of the reduction gear device S1.

[0051] S1-S5...Reduction gear AX1...Input shaft AX2...Output shaft AX3...Transmission shaft B1...Input boss B2...Output boss CA...Housing CF1...Input side split surface CF2...Output side split surface L...Imaginary straight line M...Connection T10...Transmission shaft member T11...Input bevel gear T12...Output bevel gear T13...Input side transmission bevel gear T14...Output side transmission bevel gear X11...Input shaft member X12...Input bearing X20...Output shaft member X22...Output bearing

Claims

1. A speed reduction device comprising: an input shaft member that rotates about an input shaft; and an output shaft member that is disposed parallel to the input shaft member and rotates about an output shaft that rotates in the same direction as the input shaft member, and a housing that accommodates the input shaft member and the output shaft member and has a connection portion disposed at a position between the input shaft and the output shaft and connectable to a vehicle body.

2. The speed reduction device according to claim 1, wherein the housing accommodates a transmission shaft member that rotates about a transmission shaft, and the transmission shaft member has an input side transmission bevel gear that meshes with an input bevel gear that rotates integrally with the input shaft member at one end, and an output side transmission bevel gear that meshes with an output bevel gear that rotates integrally with the output shaft member at the other end.

3. The speed reduction device according to claim 2, wherein the connection portion is formed below the transmission shaft in the vertical direction.

4. The speed reduction device according to claim 1 or 2, wherein the connection portion is formed below the virtual straight line connecting the input shaft and the output shaft in the vertical direction.

5. The speed reduction device according to claim 1 or 2, wherein the connection portion is a seating surface that opens downward in the vertical direction.

6. The speed reduction device according to claim 1 or 2, wherein the connection portion is a seating surface in which a female screw hole or a through hole opens in the axial direction of the input shaft.

7. The speed reduction device according to claim 1 or 2, wherein the housing is divided at least in one of an input side cut surface including the input shaft and an output side cut surface including the output shaft.

8. The speed reduction device according to claim 1 or 2, wherein the input shaft extends in the vehicle width direction.

9. The speed reduction device according to claim 2, wherein the connection portion is disposed at least in one of a lower portion in the vertical direction of the meshing portion between the input bevel gear and the input side transmission bevel gear and a lower portion in the vertical direction of the meshing portion between the output bevel gear and the output side transmission bevel gear.

10. The speed reduction device according to claim 2, wherein the housing includes an input boss that internally fits an input bearing that pivotally supports the input shaft member, and an output boss that internally fits an output bearing that pivotally supports the output shaft member, and the connection portion is disposed between the input boss and the output boss in the vehicle front-rear direction.

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