JP7278697B2 - power transmission device - Google Patents

Description

The present invention relates to power transmission devices.

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

The transfer has a front shaft for transmitting power to the front wheels and a rear shaft for transmitting power to the rear wheels. The front shaft and the rear shaft extend parallel to each other and are rotatably supported by a transfer case containing a transfer. Sprockets are supported on the front and rear shafts in the transfer case, and endless chains are wound around the sprockets.

Power output from the transmission is transmitted to, for example, the rear shaft to rotate the rear shaft. Power is transmitted from the rear axle to the rear wheels by rotating the rear axle. 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. Power is transmitted from the front shaft to the front wheels by rotating the front shaft together with the sprocket.

The transfer case contains oil for lubrication. When the chain rotates, the oil accumulated at the bottom of the transfer case is raked up by the chain, and the raked up oil scatters in the transfer case. As a result, each part in the transfer case can be lubricated with oil.

JP-A-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 supply of oil. However, in the prior art, there is no structure in which the oil that is raked up by the chain is positively supplied to specific members such as bearings that support 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 second rotating body.

To achieve the above object, the power transmission device according to the present invention provides a first rotor that rotates about a first rotation axis extending in a predetermined direction and a second rotation axis that extends parallel to the first rotation axis. a second rotating body that rotates freely, a revolving member that is wound around the first rotating body and the second rotating body and revolves with the rotation of the first rotating body and the second rotating body, and a case that houses the revolving member and a breather chamber projecting in a predetermined direction from the inner wall surface of the case at a position above between the first rotating body and the second rotating body, and allowing breathing due to the differential pressure between the inside and outside of the case; an oil guide provided between the first rotating body and the second rotating body and below the breather chamber for guiding oil flowing down from the outer wall surface of the breather chamber toward the second rotating body; .

According to this configuration, the winding member is wound around the first rotating body and the second rotating body as the first rotating body and the second rotating body rotate. A breather chamber is provided at a position above the first rotating body and the second rotating body in the case housing the encircling member. The breather chamber protrudes from the inner wall surface of the case in the direction in which the rotation axes of the first rotating body and the second rotating body extend. An oil guide is provided in the case at a position between the first rotating body and the second rotating body and below the breather chamber.

When the encircling member rotates, the oil accumulated in the bottom portion of the case is raked up by the encircling member, and the raked up oil scatters in the case. Some of the scattered oil adheres to the outer wall surface of the breather chamber and flows down the outer wall surface. The oil flowing down from the outer wall surface of the breather chamber is guided by the oil guide toward the second rotating body and supplied to the periphery of the second rotating body.

Therefore, oil can be positively supplied to the periphery of the second rotating body.

According to the present invention, oil can be positively supplied to 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 second rotating body, and the occurrence of wear and seizure of the bearings and the like can be prevented.

1 is a cross-sectional view of a transfer according to an embodiment of the present invention taken along a plane along a rotation axis; FIG. 4 is a cross-sectional view of the transfer cut along a plane perpendicular to the axis of rotation; FIG. It is a perspective view which shows the structure between a 1st rotating body and a 2nd rotating body graphically. FIG. 4 is a perspective view schematically showing the configuration between the first rotating body and the second rotating body, showing a state in which the second oil guide is omitted;

BEST MODE FOR CARRYING OUT THE INVENTION Below, 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 a transfer 1 according to an embodiment of the present invention taken along a plane along the axis of rotation.

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

The transfer 1 has a transfer case 11 . The transfer case 11 is divided into 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 cast by die casting. The first transfer case 12 and the second transfer case 13 are arranged in this order from the front side and are integrated by fastening with bolts 14 . The transfer case 11 contains oil for lubrication.

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

The first rotor 21 is rotatably supported by the first transfer case 12 and the second transfer case 13 . Specifically, the first rotating body 21 includes a substantially cylindrical body portion 31 and an annular plate-shaped first sprocket portion 32 projecting outward in the rotational radial direction from the central portion of the body portion 31 in the rotational axis direction. and are integrated. Inner rings of ball bearings 33 and 34 are press-fitted to the front and rear sides of the first sprocket portion 32 in the main body portion 31 , respectively. The outer ring of the front ball bearing 33 is fixedly held by the first transfer case 12 , and the outer ring of the rear ball bearing 34 is fixedly held by the second transfer case 13 . Thereby, the first rotor 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 .

Adjacent to the front side of the ball bearing 33, two front oil seals 35 and 36 are arranged side by side. The outer peripheral surfaces of the front oil seals 35 and 36 are fixed to the first transfer case 12, and the inner peripheral ends of the front oil seals 35 and 36 are in liquid-tight contact with the main body portion 31 with an appropriate tightening force.

On the other hand, two rear oil seals 37 and 38 are arranged adjacent to the rear side of the ball bearing 34 so as to be symmetrical with the front oil seals 35 and 36 in the longitudinal direction. The rear oil seal 37 has a shape symmetrical with the front oil seal 35 in the longitudinal direction, and the rear oil seal 38 has a shape symmetrical with the front oil seal 36 in the longitudinal direction. The rear oil seals 37, 38 have their outer peripheral surfaces fixed to the second transfer case 13, and their inner peripheral ends in liquid-tight contact with the main body portion 31 with an appropriate tightening force.

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

The second rotor 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 cylindrical body portion 41 and an annular plate-shaped second sprocket portion 42 projecting outward from the body portion 41 in the radial direction of rotation. there is Inner rings of ball bearings 43 and 44 are press-fitted to the front and rear sides of the second sprocket portion 42 in the main body portion 41 , respectively. The outer ring of the front ball bearing 43 is fixedly held by the first transfer case 12 , and the outer ring of the rear ball bearing 44 is fixedly held by the second transfer case 13 . Thereby, the second rotor 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 rotor 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 .

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

Since the output shaft 2 and the first rotating body 21 are coupled so as not to rotate relative to each other, the power of the output shaft 2 is transmitted to the first rotating body 21 to rotate the first rotating body 21 . In addition, since the rear propeller shaft 3 and the first rotating body 21 are coupled so as not to rotate relative to each other, 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. When the first rotating body 21 rotates, the rotation is transmitted to the second rotating body 22 through the chain 23, and the second rotating body 22 rotates. 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 of the transfer 1 taken along a plane perpendicular to the axis of rotation.

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

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

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

A breather chamber 61 is formed in the transfer case 11 at a position above between the first rotor 21 and the second rotor 22 so as to protrude rearward from the front inner wall surface of the transfer case 11 . there is The breather chamber 61 opens rearward, 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 due to the running state of the vehicle, etc., and the pressure in the transfer case 11 increases with the change in the temperature of the oil, the pressure rises through the breather chamber 61 and the breather 63 . can be released to the atmosphere.

3 and 4 are perspective views schematically showing the configuration between the first rotating body 21 and the second rotating body 22. FIG.

A first oil guide 71 is provided between the first rotating body 21 and the second rotating body 22 and below the breather chamber 61 . The first oil guide 71 is formed in a plate shape that slopes downward to the left, and the left end thereof extends while curving upward. The left end of the first oil guide 71 is located, for example, at a position slightly higher than the liquid surface of the oil that collects at the bottom of the transfer case 11 .

Further, the first transfer case 12 is formed with a shaft insertion portion 72 that is a cylindrical wall that surrounds the main body portion 41 of the second rotor 22 . A cutout 73 extending in the axial direction is formed in the upper right portion of the shaft insertion portion 72 , and a guide surface 74 extending from the lower end of the cutout 73 toward the first oil guide 71 is formed in the first transfer case 12 . ing. The rear edge of the guide surface 74 is located forward of the rear edge of the first oil guide 71 .

A second oil guide 75 is fixed to the first transfer case 12 with bolts 76 . The second oil guide 75 extends along the rear edge of the guide surface 74 , bends rearward along the left edge of the first oil guide 71 , and extends along the rear edge of the first oil guide 71 . Extends to the edge.

When the vehicle travels forward, the first rotating body 21 and the second rotating body 22 rotate counterclockwise when viewed from the rear side, and accordingly the chain 23 rotates counterclockwise. When the chain 23 rotates, the oil accumulated at the bottom inside the transfer case 11 is raked up by the chain 23, and the raked up oil is spread along the inner peripheral wall surface 51 of the transfer case 11 above the first rotating body 21. flow toward

The oil flowing along the inner peripheral wall surface 51 reaches the dispersion projections 53 , and part of it leaves the dispersion projections 53 at the boundary between the first arcuate surface 54 and the second arcuate surface 55 . It scatters along the curve from the center of rotation of the first rotor 21 toward the right side. As a result, the oil is positively supplied to the periphery of the first rotating body 21 .

In addition, part of the oil moves from the first arcuate surface 54 of the dispersion projection 53 to the second arcuate surface 55, leaves the dispersion projection 53 at the boundary between the second arcuate surface 55 and the third arcuate surface 56, It scatters toward the second rotating body 22 . As a result, the oil is actively supplied to the periphery of the second rotating body 22 . Also, part of the oil that scatters toward the second rotor 22 hits the outer wall surface of the breather chamber 61 , flows down the outer wall surface toward the first oil guide 71 , and is received by the first oil guide 71 . Furthermore, part of the oil that scatters toward the second rotating body 22 does not reach the position of the second rotating body 22 and is directly received by the first oil guide 71 because of its weak momentum. As a result, oil accumulates in the first oil guide 71 .

When a certain amount or more of oil accumulates in the first oil guide 71 , the oil overflows from the left end of the first oil guide 71 . At this time, since the second oil guide 75 is provided, oil is prevented from overflowing between the rear end of the guide surface 74 of the first transfer case 12 and the rear end of the first oil guide 71 . As a result, oil overflowing from the left end of the first oil guide 71 flows along the guide surface 74 toward the notch 73 of the shaft insertion portion 72 so as to bridge the guide surface 74 of the first transfer case 12 . The oil then flows into the notch 73 and is supplied to the periphery of the main body portion 41 of the second rotating body 22 .

<Effect>
Thus, oil can be positively supplied to the periphery of the second rotating body. As a result, a sufficient amount of oil can be supplied to the ball bearings 43, 44, etc., which support the second rotating body 22, and the wear and seizure thereof can be prevented.

Further, the transfer case 11 is formed with an inner wall surface portion 52 curved along the chain 23 around the first rotor 21 . Dispersion projections 53 are provided on the inner wall surface portion 52 , and the oil that is raked up from the bottom of the transfer case 11 by the rotation of the chain 23 is dispersed by the dispersion projections 53 in the directions toward the first rotor 21 and in the direction toward the first rotor 21 . 2, the direction toward the rotating body 22 and the direction toward the rotating body 22 . Therefore, the oil can be positively supplied to the periphery of the first rotating body 21 as well. As a result, a sufficient amount of oil can be supplied to the ball bearings 33, 34, etc., which support the first rotor 21, thereby preventing wear and seizure thereof.

Moreover, since the oil that is raked up from the bottom of the transfer case 11 by the circulation of the chain 23 is dispersed in the direction toward the first rotor 21 and the direction toward the second rotor 22, the first rotor 21 and the second rotor 22 are dispersed. It is possible to prevent oil from entering the breather chamber 61 located above the rotating body 22 . As a result, it is possible to suppress the oil from blowing out from the breather chamber 61 to the outside.

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

For example, in the above-described embodiment, the transfer 1 was taken up as an example of the power transmission device, but the present invention is a belt-type stepless transmission device having a configuration 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 configuration within the scope of the matters described in the claims.

1: Transfer (power transmission device)
11: Transfer case (case)
21: First rotating body 22: Second rotating body 23: Chain (surrounding member)
61: Breather chamber 71: First oil guide (oil guide)
75: Second oil guide (oil guide)

Claims (1)

a first rotating body rotating around a first rotation axis extending in a predetermined direction;
a second rotor that rotates about a second rotation axis that extends parallel to the first rotation axis;
a winding member that is wound around the first rotating body and the second rotating body and that rotates as the first rotating body and the second rotating body rotate;
a case that houses the encircling member;
A breather provided at a position above between the first rotating body and the second rotating body so as to protrude from the inner wall surface of the case in the predetermined direction, and enables breathing due to the differential pressure between the inside and outside of the case. room and
Provided between the first rotating body and the second rotating body and below the breather chamber, the oil flowing down from the outer wall surface of the breather chamber is guided toward the second rotating body. an oil guide ;
The case has a cylindrical wall surrounding the second rotating body,
The wall is formed with a notch extending in the direction of the second rotation axis in the upper part of the first rotating body side,
A power transmission device , wherein the case is formed with a guide surface extending from a lower end of the notch toward the oil guide .

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