JP6851917B2 - Power transmission device - Google Patents

Description

The present invention relates to a power transmission device mounted on a vehicle to transmit power.

In a vehicle such as an automobile, the power from the drive source is input to the transmission (transmission), and the power shifted by the transmission is transmitted to the drive wheels via a differential gear or the like.

FIG. 3 is a cross-sectional view schematically showing the configuration of a conventional differential gear.

The differential gear 91 integrally includes a differential case 92 and a ring gear 93 projecting outward from the differential case 92. The differential case 92 is formed with cylindrical cylindrical portions 94 at both ends in the center line direction (rotational axis direction) of the ring gear 93. The differential gear 91 is housed in the unit case 95, and both cylindrical portions 94 are rotatably supported by the unit case 95 via a bearing 96.

Oil is sealed in the unit case 95, and a part of the ring gear 93 is immersed in the oil accumulated in the unit case 95. Power is transmitted from the transmission to the ring gear 93. When power is transmitted to the ring gear 93, the differential case 92 and the ring gear 93 rotate, and the oil accumulated in the unit case 95 is scraped up by the ring gear 93 to become droplets, and the oil droplets are supplied to the bearing 96 and the like. .. As a result, the bearing 96 and the like are lubricated by the oil, and wear and seizure of the bearing 96 and the like can be prevented.

Utility Model Registration No. 2584081

If the amount of oil accumulated in the unit case 95 is large, the oil becomes a resistance of the ring gear 93, which causes a decrease in torque transmission efficiency due to torque loss, which in turn causes a deterioration in running fuel efficiency of the vehicle.

Therefore, it is conceivable to provide oil separators 97 and 98 as partition walls on both sides of the ring gear 93 in the direction of the rotation axis so that the oil supplied to the bearing 96 does not return to the inside of the oil separators 97 and 98. .. With this configuration, it can be expected that the amount of oil accumulated in the space sandwiched between the oil separators 97 and 98, that is, the space in which the ring gear 93 is housed, is reduced.

However, as a result of verification by the inventor of the present application, simply providing the oil separators 97 and 98 does not significantly reduce the amount of oil accumulated in the space sandwiched between the oil separators 97 and 98, resulting in the shape of the oil separators 97 and 98. It turned out that some ingenuity was required.

An object of the present invention is to provide a power transmission device capable of reducing the stirring resistance received from the oil by the scraping member that scrapes up the oil accumulated in the case.

In order to achieve the above object, the power transmission device according to the present invention is a power transmission device that transmits power, and is rotatable about a case filled with oil and a rotation axis extending in a predetermined direction in the case. A scraping member that is provided in the above and is rotated by power to scoop up and scatter the oil accumulated in the case, and a scraping member that is provided on at least one side in a predetermined direction with respect to the scraping member and is arranged. The first space and the second space adjacent to the first space in a predetermined direction are partitioned, and the flow of oil between the first space and the second space is blocked at least in the portion of the case where oil collects. The scraping member has an annular plate-shaped portion and a cylindrical portion protruding from the outer peripheral end of the annular plate-shaped portion toward the oil separator side at the outer peripheral end portion thereof. The separator has an inclined portion extending diagonally upward above the rotation axis so as to enter from the outside to the inside in a predetermined direction with respect to the cylindrical portion.

According to this configuration, oil is accumulated in the case, and when the scraping member rotates, the accumulated oil is scraped up by the scraping member and scattered. As a result, oil can be supplied to each part around the scraping member, such as a bearing that rotatably holds the scraping member, and wear and seizure can be suppressed in each part.

An oil separator is provided on at least one side of the scraping member in a predetermined direction, which is the direction of the rotation axis of the scraping member, and the oil separator provides a first space and a first space in which the scraping member is arranged. A second space adjacent to the space in a predetermined direction is partitioned. In the portion where the oil collects in the case, the oil separator prevents the oil from flowing between the first space and the second space. Therefore, it is possible to suppress the inflow of oil from the second space to the first space at the portion where the oil collects.

The outer peripheral end portion of the scraping member has an annular plate-shaped portion and a cylindrical portion protruding from the outer peripheral end of the annular plate-shaped portion toward the oil separator side. The oil separator has an inclined portion that extends diagonally upward so as to enter from the outside to the inside in a predetermined direction with respect to the cylindrical portion on the upper side of the rotation axis. Therefore, even if the scattered oil scraped up by the scraping member hits the member arranged above the scraping member and is bounced off or dropped from the member, the oil travels along the inclined portion to the second space. It is possible to prevent the oil that is guided to and scattered by the scraping member from returning to the first space from between the scraping member and the oil separator. As a result, the amount of oil accumulated in the first space can be reduced, and the stirring resistance received by the scraping member from the oil can be reduced.

The oil separator may be provided on both one side and the other side in a predetermined direction with respect to the scraping member. In the configuration in which the oil separators are provided on both sides in the predetermined direction with respect to the scraping member, the space sandwiched between the oil separators is the first space, and the spaces on both outer sides in the predetermined direction with respect to the first space are the second spaces. It becomes.

The scraping member may be a ring gear provided in the differential gear.

According to the present invention, since the stirring resistance received by the scraping member from the oil can be reduced, it is possible to suppress a decrease in torque transmission efficiency due to torque loss, and it is possible to improve the running fuel consumption of the vehicle.

It is sectional drawing which shows the structure of the transaxle which concerns on one Embodiment of this invention. It is the figure which took out the differential gear from the unit case and looked at from the shaft insertion part side. It is sectional drawing which shows the structure of the conventional differential gear graphically.

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

<Transaxle>
FIG. 1 is a cross-sectional view showing the configuration of a transaxle 1 according to an embodiment of the present invention. Note that in FIG. 1, the addition of hatching representing a cross section is omitted.

The transaxle 1 is a transmission unit mounted on a vehicle to shift torque generated by an engine (not shown) and transmit it to drive wheels (not shown), and is contained in a unit case 2 forming an outer shell thereof. , Torque converter 3, belt-type continuously variable transmission 4, and differential gear 5.

The differential gear 5 includes a differential case 11. The differential case 11 provides a gear accommodating space 12 inside the differential case 11. A pinion shaft 13 penetrating the gear accommodating space 12 is held in the differential case 11. Two pinion gears 14 and 15 are rotatably held on the pinion shaft 13 at intervals from each other. Further, in the gear accommodating space 12, two side gears 16 and 17 are separately arranged on both sides of the pinion shaft 13. The side gears 16 and 17 and the pinion gears 14 and 15 are all bevel gears, and the side gears 16 and 17 mesh with both of the pinion gears 14 and 15.

Further, the differential case 11 is formed with cylindrical shaft insertion portions 18 and 19 penetrating in a direction in which the side gears 16 and 17 face each other, in other words, in a direction orthogonal to the pinion shaft 13. Drive shafts 21 and 22, respectively, are inserted into the shaft insertion portions 18 and 19, respectively. The tip portions of the drive shafts 21 and 22 are coupled to the side gears 16 and 17, respectively, so as not to rotate relative to each other in the gear accommodation space 12.

Bearings 23 and 24 are externally fitted to the shaft insertion portions 18 and 19, respectively. The outer races (outer rings) of the bearings 23 and 24 are non-rotatably held in the unit case 2. As a result, the differential case 11 is rotatably supported by the unit case 2 via bearings 23 and 24 around the same rotation axis as the drive shafts 21 and 22.

Further, in the differential case 11, a flange portion 25 is formed between one of the shaft insertion portions 18 and the pinion shaft 13 so as to project radially from the outer peripheral surface thereof. A ring gear 26 is fixed to the flange portion 25. The ring gear 26 integrally has a substantially annular plate-shaped web 27 surrounding the differential case 11 and a substantially cylindrical rim 28 surrounding the outer circumference of the web 27. The rim 28 projects from the web 27 on both sides in the direction along the rotation axis of the differential case 11. Gear teeth 29 are formed on the outer peripheral surface of the rim 28, and these gear teeth mesh with the output gear 31 of the continuously variable transmission 4.

The power output from the continuously variable transmission 4 is transmitted from the output gear 31 to the ring gear 26. As a result, the ring gear 26 and the differential case 11 rotate integrally. The rotation of the differential case 11 is converted into the rotation of each of the side gears 16 and 17 via the pinion gears 14 and 15. As a result, the drive shafts 21 and 22 rotate integrally with the side gears 16 and 17, and the rotation of the drive shafts 21 and 22 is transmitted to the drive wheels of the vehicle.

<Oil separator>
FIG. 2 is a view of the differential gear 5 taken out from the unit case 2 and viewed from the shaft insertion portion 19 side.

In the unit case 2, oil separators 41 and 42 serving as partition walls are provided on both sides of the ring gear 26 in the direction along the rotation axis of the ring gear 26, respectively. The oil separators 41 and 42 are fixed to the unit case 2.

The oil separator 41 provided on the one shaft insertion portion 18 side has a circular opening 51 having a diameter larger than the outer diameter of the outer race of the bearing 23.

The lower portion 52 of the oil separator 41 along the lower half of the circular opening 51 has an inner peripheral end portion 53 and an outer peripheral end portion 54 in contact with the unit case 2 from the other shaft insertion portion 19 side.

The outer diameter of the upper portion 55 of the oil separator 41 along the upper half of the circular opening 51 is formed to be smaller than the diameter of the ring gear 26. The inner peripheral end portion 56 of the upper portion 55 is in contact with the unit case 2 from the other shaft insertion portion 19 side. The outer peripheral end portion 57 of the upper portion 55 bends from the one shaft insertion portion 18 side toward the ring gear 26 side, and diagonally upward so as to enter the rim 28 of the ring gear 26 from the outside to the inside in the direction along the rotation axis. It is extending.

The oil separator 42 provided on the other side of the shaft insertion portion 19 has a circular opening 61 having a diameter larger than the outer diameter of the outer race of the bearing 24.

The lower portion 62 along the lower half of the circular opening 61 of the oil separator 42 has a curved portion 63 curved along the lower half portion of the differential case 11, and the curved portion 63 is continuously provided with the ring gear 26 on the ring gear 26 side. A semicircular ring portion 64 extending in the radial direction of rotation is integrally formed. The inner peripheral end of the curved portion 63 and the outer peripheral end of the semicircular ring portion 64 are in contact with the unit case 2 from the one shaft insertion portion 18 side.

The upper portion 65 along the upper half of the circular opening 61 of the oil separator 42 has a curved portion 66 curved along the upper half portion of the differential case 11, and the curved portion 66 is continuously provided with the ring gear 26 on the ring gear 26 side. A semicircular ring portion 67 extending in the radial direction of rotation is integrally formed. The inner peripheral end portion of the curved portion 66 is in contact with the unit case 2 from the one shaft insertion portion 18 side. Further, the upper portion 65 is formed so that the outer diameter is smaller than the diameter of the ring gear 26, and the outer peripheral end portion 68 of the semicircular ring portion 67 is bent from the other shaft insertion portion 19 side to the ring gear 26 side. It extends diagonally upward with respect to the rim 28 of the ring gear 26 so as to enter from the outside to the inside in the direction along the rotation axis.

With the oil separators 41 and 42 having such a configuration, the unit case 2 is sandwiched between the oil separators 41 and 42 from both sides and the ring gear 26 is arranged in the first space 71 and the oil separators 41 and 42. It is partitioned from the second space 72 on the outer side in the opposite direction.

<Effect>
Oil is sealed in the unit case 2, and oil is always collected in the bottom of the unit case 2. When the ring gear 26 rotates, the accumulated oil is scraped up by the ring gear 26 and scattered. As a result, oil can be supplied to each part around the ring gear 26 such as bearings 23 and 24 that rotatably hold the differential case 11, and the occurrence of wear and seizure in each part can be suppressed.

Oil separators 41 and 42 are provided on both sides of the ring gear 26 in the direction along the rotation axis of the ring gear 26, and the oil separators 41 and 42 provide the first space 71 and the first space 71 in which the ring gear 26 is arranged. A second space 72 adjacent to the space 71 in a predetermined direction is partitioned. In the portion of the unit case 2 where the oil collects, the oil separators 41 and 42 prevent the oil from flowing between the first space 71 and the second space 72. Therefore, it is possible to prevent the oil from flowing into the first space 71 from the second space 72 at the portion where the oil collects.

The ring gear 26 has a substantially annular plate-shaped web 27 surrounding the differential case 11 and a substantially cylindrical rim 28 surrounding the outer circumference of the web 27. The oil separators 41 and 42 have outer peripheral end portions 57 and 68 extending diagonally upward so as to enter the rim 28 from the outside in the direction along the rotation axis, respectively. Therefore, even if the scattered oil scooped up by the ring gear 26 hits the member 73 arranged above the ring gear 26 and is repelled or dropped from the member 73, the oil is transmitted through the outer peripheral end portions 57 and 68. It is possible to prevent the oil that is guided to the second space 72 and scooped up by the ring gear 26 and scattered from returning to the first space 71 from between the ring gear 26 and the oil separators 41 and 42. As a result, the amount of oil accumulated in the first space 71 can be reduced, and the stirring resistance that the ring gear 26 receives from the oil can be reduced.

Since the stirring resistance that the ring gear 26 receives from the oil can be reduced, it is possible to suppress a decrease in the torque transmission efficiency of the transaxle 1 (differential gear 5) due to torque loss, which in turn improves the running fuel efficiency of the vehicle on which the transaxle 1 is mounted. Can be made to.

<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, the configuration in which the oil separators 41 and 42 are provided on both sides of the ring gear 26 in the direction along the rotation axis of the ring gear 26 has been taken up, but if one of the oil separators 41 and 42 is unnecessary, one of the oil separators 41 and 42 is used. It can be omitted.

Further, although the transaxle 1 is provided with a belt-type continuously variable transmission 4, the present invention is not limited to the transaxle 1 including the belt-type continuously variable transmission 4, and a method other than the belt-type transmission is used. It can be widely applied to transaxles equipped with continuously variable transmissions and stepped automatic transmissions (ATs). Further, the form of the power transmission device is not limited to the transaxle, and the differential gear 5 may be a single unit.

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

1: Transaxle (power transmission device)
2: Unit case (case)
5: Differential gear (power transmission device)
26: Ring gear (raising member)
27: Web (annular plate-shaped part)
28: Rim (cylindrical part)
41, 42: Oil separator 57, 68: Outer peripheral end (inclined part)
71: First space 72: Second space

Claims (1)

A power transmission device that transmits power
A case filled with oil and
A scraping member that is rotatably provided in the case about a rotation axis extending in a predetermined direction and that rotates by power to scrape and scatter the oil accumulated in the case.
A first space provided on at least one side of the predetermined direction with respect to the scraping member and where the scraping member is arranged and a second space adjacent to the first space in the predetermined direction are partitioned. Includes an oil separator that blocks the flow of oil between the first space and the second space, at least in a portion of the case where oil collects.
The scraping member has an annular plate-shaped portion and a cylindrical portion protruding from the outer peripheral end of the annular plate-shaped portion toward the oil separator at the outer peripheral end portion thereof.
The oil separator is a power transmission device having an inclined portion extending diagonally upward above the rotation axis so as to enter the inside from the outside in the predetermined direction with respect to the cylindrical portion.

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