JP2022101249A - Power transmission device - Google Patents

Abstract

To provide a power transmission device which can actively supply an oil to a periphery of a first rotating body and a periphery of a second rotating body.SOLUTION: A chain 23, which revolves in conjunction with rotation of a first rotating body 21 and a second rotating body 22, is wound around the first rotating body 21 and the second rotating body 22. In a transfer case 11 which houses the chain 23, an inner wall surface part 52 which curves along the chain 23 in a periphery of the first rotating body 21 is formed. The inner wall surface part 52 is provided with a dispersion protrusion 53. The dispersion protrusion 53 disperses an oil, scraped from a bottom part in the transfer case 11 by revolving of the chain 23, in a direction toward the first rotating body 21 and a direction toward the second rotating body 22.SELECTED DRAWING: Figure 2

Description

The present invention relates to a power transmission device.

In a vehicle adopting a 4WD (four-wheel-drive) system, the power of the engine is input to the transfer via a transmission, and the input power is distributed to the front wheels and the rear wheels by the transfer.

The transfer has a front axle for transmitting power to the front wheels and a rear axle for transmitting power to the rear wheels. The front and rear shafts extend parallel to each other and are rotatably supported by a transfer case that houses the transfer. In the transfer case, sprockets are supported on the front shaft and the rear shaft, respectively, and an endless chain is wound around the sprockets.

The power output from the transmission is transmitted to, for example, the rear axle to rotate the rear axle. By rotating the rear axle, power is transmitted from the rear axle to the rear wheels. Further, when the sprocket supported by the rear shaft rotates with the rotation of the rear shaft, the rotation is transmitted to the sprocket supported by the front shaft via the chain. Then, the front shaft rotates integrally with the sprocket, so that power is transmitted from the front shaft to the front wheels.

Oil for lubrication is sealed in the transfer case. When the chain goes around, the oil collected at the bottom of the transfer case is scraped up by the chain, and the scraped oil scatters inside the transfer case. As a result, each part in the transfer case can be lubricated with oil.

Japanese Unexamined Patent Publication No. 60-234173

It is desirable that a sufficient amount of oil be supplied to the bearings that support the front shaft in order to prevent wear and seizure due to insufficient oil supply. However, in the prior art, the oil scraped up by the chain is not positively supplied to a specific member such as a bearing that supports the front shaft.

An object of the present invention is to provide a power transmission device capable of positively supplying oil to the periphery of the first rotating body and the periphery of the second rotating body.

In order to achieve the above object, the power transmission device according to the present invention is wound around a first rotating body, a second rotating body, a first rotating body and a second rotating body, and has a first rotating body and a first rotating body. A case having an orbiting member that orbits as the two rotating bodies rotate, a case that accommodates the orbiting member and has an inner wall surface portion that curves along the orbiting member around the first rotating body, and a case that is provided on the inner wall surface portion and the orbiting member. Includes a dispersion protrusion that disperses the oil scraped up from the bottom of the case by the orbit of the case in the direction toward the first rotating body and the direction toward the second rotating body.

According to this configuration, a rotating member that orbits with the rotation of the first rotating body and the second rotating body is wound around the first rotating body and the second rotating body. In the case for accommodating the circumferential member, an inner wall surface portion that curves along the circumferential member is formed around the first rotating body. Dispersion protrusions are provided on the inner wall surface portion, and the oil scraped up from the bottom of the case by the circulation of the orbiting member is directed toward the first rotating body and the second rotating body by the dispersion protrusions. Disperse to and. Therefore, oil can be positively supplied to the periphery of the first rotating body and the periphery of the second rotating body. As a result, a sufficient amount of oil can be supplied to the bearings and the like arranged around the first rotating body and the second rotating body, and wear and seizure of the bearings and the like can be prevented.

A breather chamber may be provided in the case at an upper position between the first rotating body and the second rotating body to enable breathing by differential pressure inside and outside the case.

Since the oil scraped up from the bottom of the case by the orbiting of the orbiting member is dispersed in the direction toward the first rotating body and the direction toward the second rotating body, the upper part between the first rotating body and the second rotating body. It is possible to prevent oil from entering the breather chamber located in. As a result, it is possible to suppress the oil from being blown out from the breather chamber to the outside.

According to the present invention, oil can be positively supplied to the periphery of the first rotating body and the periphery of the second rotating body. As a result, a sufficient amount of oil can be supplied to the bearings and the like arranged around the first rotating body and the second rotating body, and wear and seizure of the bearings and the like can be prevented.

It is sectional drawing when the transfer which concerns on one Embodiment of this invention is cut in the plane along the rotation axis. It is sectional drawing when the transfer is cut in the plane orthogonal to the rotation axis.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Transfer>
FIG. 1 is a cross-sectional view of the transfer 1 according to the embodiment of the present invention when the transfer 1 is cut along a plane along the rotation axis.

In a vehicle in which the engine is installed vertically, for example, a transmission for shifting the power from the engine is arranged behind the engine. The transfer 1 is a mechanism mounted on such a vehicle, coupled to the output shaft 2 of the transmission from the rear side, and distributes the power of the output shaft 2 to the front wheels and the rear wheels of the vehicle.

The transfer 1 includes a transfer case 11. The transfer case 11 is composed of two parts, a first transfer case 12 and a second transfer case 13. The first transfer case 12 and the second transfer case 13 are made of, for example, an aluminum alloy and are cast by a die casting method. The first transfer case 12 and the second transfer case 13 are arranged in this order from the front side and are integrated by being fastened with bolts 14. Oil for lubrication is sealed in the transfer case 11.

The transfer 1 includes a first rotating body 21, a second rotating body 22, and a chain 23. The first rotating body 21 and the second rotating body 22 are provided so that their respective rotation axes extend in the front-rear direction and are parallel to each other.

The first rotating body 21 is rotatably supported by the first transfer case 12 and the second transfer case 13. Specifically, the first rotating body 21 has a substantially cylindrical main body portion 31 and an annular plate-shaped first sprocket portion 32 projecting outward in the rotational radial direction from the central portion in the rotational axis direction of the main body portion 31. And have one. The inner rings of the ball bearings 33 and 34 are fitted onto the main body 31 on the front side and the rear side of the first sprocket portion 32 by press fitting, respectively. The outer ring of the ball bearing 33 on the front side is fixedly held in the first transfer case 12, and the outer ring of the ball bearing 34 on the rear side is fixedly held in the second transfer case 13. As a result, the first rotating body 21 is rotatably supported by the first transfer case 12 and the second transfer case 13 via the ball bearings 33 and 34.

A plurality of teeth are formed at equal intervals in the circumferential direction on the outer peripheral portion of the first sprocket portion 32.

Further, two front oil seals 35 and 36 are arranged side by side in front and behind adjacent to the front side of the ball bearing 33. The outer peripheral surfaces of the front oil seals 35 and 36 are fixed to the first transfer case 12, and the inner peripheral end thereof is in liquidtight contact with the main body 31 with an appropriate tension.

On the other hand, two rear oil seals 37, 38 are arranged adjacent to the rear side of the ball bearing 34 so as to be symmetrical with the front oil seals 35, 36 in the front-rear direction. The rear oil seal 37 has a shape symmetrical to the front oil seal 35 in the front-rear direction, and the rear oil seal 38 has a shape symmetrical to the front oil seal 36 in the front-rear direction. The outer peripheral surface of the rear oil seals 37 and 38 is fixed to the second transfer case 13, and the inner peripheral end thereof is in liquidtight contact with the main body 31 with an appropriate tension.

The output shaft 2 is inserted into the main body 31 of the first rotating body 21 from the front side thereof. The output shaft 2 and the first rotating body 21 are coupled to each other so as not to rotate relative to each other. Further, the rear propeller shaft 3 is inserted into the main body 31 from the rear side. The rear propeller shaft 3 and the first rotating body 21 are coupled to each other so as not to rotate relative to each other.

The second rotating body 22 is rotatably supported by the first transfer case 12 and the second transfer case 13. Specifically, the second rotating body 22 integrally has a substantially columnar main body portion 41 and an annular plate-shaped second sprocket portion 42 projecting outward from the main body portion 41 in the radial direction of rotation. There is. The inner rings of the ball bearings 43 and 44 are fitted onto the main body 41 on the front side and the rear side of the second sprocket portion 42, respectively, by press fitting. The outer ring of the ball bearing 43 on the front side is fixedly held in the first transfer case 12, and the outer ring of the ball bearing 44 on the rear side is fixedly held in the second transfer case 13. As a result, the second rotating body 22 is rotatably supported by the first transfer case 12 and the second transfer case 13 via the ball bearings 43 and 44. A front propeller shaft (not shown) is coupled to the second rotating body 22 so as to be relatively non-rotatable.

The second sprocket portion 42 is arranged at the same position as the first sprocket portion 32 of the first rotating body 21 in the front-rear direction. A plurality of teeth are formed at equal intervals in the circumferential direction on the outer peripheral portion of the second sprocket portion 42.

The chain 23 is formed in an endless shape. The chain 23 is wound around the first sprocket portion 32 of the first rotating body 21 and the second sprocket portion 42 of the second rotating body 22.

Since the output shaft 2 and the first rotating body 21 are coupled so as not to be relatively rotatable, the power of the output shaft 2 is transmitted to the first rotating body 21 to rotate the first rotating body 21. Further, since the rear propeller shaft 3 and the first rotating body 21 are coupled so as not to be relatively rotatable, the rear propeller shaft 3 rotates integrally with the first rotating body 21. As a result, power is transmitted from the rear propeller shaft 3 to the rear wheels. Further, when the first rotating body 21 rotates, the rotation is transmitted to the second rotating body 22 via the chain 23, the second rotating body 22 rotates, and the second rotating body 22 is non-rotatably coupled to the second rotating body 22. The front propeller shaft rotates. As a result, power is transmitted from the front propeller shaft to the front wheels.

FIG. 2 is a cross-sectional view when the transfer 1 is cut along a plane orthogonal to the rotation axis.

The transfer 1 is provided so as to incline upward to the right and extend in the left-right direction. The first rotating body 21 is arranged at the right end portion in the transfer case 11, and the second rotating body 22 is arranged at the left end portion in the transfer case 11.

The transfer case 11 has an inner peripheral wall surface 51 having a substantially elliptical cross section. On the inner peripheral wall surface 51, an inner wall surface portion 52 having a substantially circular cross section is formed so as to face a substantially half portion of the first rotating body 21 from the diagonally upper right side.

The inner wall surface portion 52 is formed with a dispersion protrusion 53 projecting toward the rotation center (rotation axis) of the first rotating body 21 at a position diagonally upper right with respect to the first rotating body 21. The dispersion protrusion 53 has a first arc surface 54, a second arc surface 55, and a third arc surface 56. The first arc surface 54 is continuous with the inner wall surface portion 52 without a step, and is curved in an arc shape having a central angle of about 110 °, which is convex upward. The second arc surface 55 is continuous with the first arc surface 54 and is curved in a semicircular shape that is convex downward. The third arc surface 56 is continuous with the second arc surface 55 and is curved in an arc shape having a central angle of about 50 °, which is convex diagonally upward to the right.

Further, in the transfer case 11, a breather chamber 61 is formed at an upper position between the first rotating body 21 and the second rotating body 22. The breather chamber 61 is open to the rear side, and the opening is closed with a lid 62. A breather 63 is provided in the first transfer case 12 (see FIG. 1). When the temperature of the oil in the transfer case 11 changes depending on the traveling state of the vehicle and the pressure inside the transfer case 11 increases due to the temperature change of the oil, the pressure is increased through the breather chamber 61 and the breather 63. Can be opened to the atmosphere.

An oil guide 71 is provided between the first rotating body 21 and the second rotating body 22 at a position below the breather chamber 61. The oil guide 71 is formed in a plate shape that is inclined downward to the left, and its left end portion extends while being curved upward. The left end of the oil guide 71 is located, for example, at a position slightly higher than the liquid level of the oil collected at the bottom of the transfer case 11.

When the vehicle is traveling forward, the first rotating body 21 and the second rotating body 22 rotate counterclockwise when viewed from the rear side, and the chain 23 orbits counterclockwise accordingly. When the chain 23 goes around, the oil collected at the bottom of the transfer case 11 is scraped up by the chain 23, and the scraped oil is pushed above the first rotating body 21 along the inner peripheral wall surface 51 of the transfer case 11. It flows toward.

The oil flowing along the inner peripheral wall surface 51 reaches the dispersion protrusion 53, and a part thereof separates from the dispersion protrusion 53 at the boundary between the first arc surface 54 and the second arc surface 55, and the oil flows on the first arc surface 54. It scatters along the curve from the center of rotation of the first rotating body 21 toward the right side portion. As a result, oil is positively supplied around the first rotating body 21.

Further, a part of the oil moves from the first arc surface 54 of the dispersion protrusion 53 onto the second arc surface 55, and separates from the dispersion protrusion 53 at the boundary between the second arc surface 55 and the third arc surface 56. It scatters toward the second rotating body 22. As a result, oil is positively supplied around the second rotating body 22. Further, a part of the oil scattered toward the second rotating body 22 hits the outer wall surface of the breather chamber 61, flows down the outer wall surface toward the oil guide 71, and is received by the oil guide 71. Further, a part of the oil scattered toward the second rotating body 22 does not reach the position of the second rotating body 22 due to the weak momentum, and is directly received by the oil guide 71. As a result, oil is accumulated in the oil guide 71, and the oil overflows from the left end of the oil guide 71 and is supplied to the periphery of the second rotating body 22.

<Action effect>
As described above, the chain 23 that rotates with the rotation of the first rotating body 21 and the second rotating body 22 is wound around the first rotating body 21 and the second rotating body 22. The transfer case 11 that houses the chain 23 is formed with an inner wall surface portion 52 that curves along the chain 23 around the first rotating body 21. The inner wall surface portion 52 is provided with a dispersion protrusion 53, and the oil scraped up from the bottom portion in the transfer case 11 by the circulation of the chain 23 is directed toward the first rotating body 21 by the dispersion protrusion 53. 2 Disperse in the direction toward the rotating body 22. Therefore, oil can be positively supplied to the periphery of the first rotating body 21 and the periphery of the second rotating body 22. As a result, a sufficient amount of oil can be supplied to the ball bearings 33, 34 that support the first rotating body 21, the ball bearings 43, 44 that support the second rotating body 22, and the like, and wear and seizure of them occur. Can be prevented.

Inside the transfer case 11, a breather chamber 61 is provided at an upper position between the first rotating body 21 and the second rotating body 22 to enable breathing by differential pressure inside and outside the transfer case 11. .. Since the oil scraped up from the bottom of the transfer case 11 by the circulation of the chain 23 is dispersed in the direction toward the first rotating body 21 and the direction toward the second rotating body 22, the first rotating body 21 and the second rotating body are dispersed. It is possible to prevent oil from entering the breather chamber 61 located above the space between the 22 and the breather chamber 61. As a result, it is possible to suppress the oil from being blown out from the breather chamber 61 to the outside.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, in the above-described embodiment, the transfer 1 is taken up as an example of the power transmission device, but the present invention has a belt-type stepless structure in which an endless belt is wound around a primary pulley and a secondary pulley. It can be applied to a power transmission device other than the transfer 1 such as a transmission.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

1: Transfer (power transmission device)
11: Transfer case (case)
21: 1st rotating body 22: 2nd rotating body 23: Chain (circling member)
52: Inner wall surface 53: Dispersive protrusions

Claims (1)

The first rotating body and
The second rotating body and
An orbiting member that is wound around the first rotating body and the second rotating body and orbits with the rotation of the first rotating body and the second rotating body.
A case that accommodates the circumferential member and has an inner wall surface portion that curves along the circumferential member around the first rotating body.
Dispersing protrusions provided on the inner wall surface portion and which disperse the oil scraped up from the bottom portion of the case by the circulation of the peripheral member in the direction toward the first rotating body and the direction toward the second rotating body. Including power transmission device.

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