JP2019011800A - Power transmission device - Google Patents

Abstract

To provide a power transmission device in which agitation resistance received by a scraping member scraping oil accumulated in a case from the oil.SOLUTION: Oil accumulated in a unit case 2 is scraped and scattered by a ring gear 26 when the ring gear 26 rotates. Oil separators 41, 42 are arranged at both sides of the ring gear 26 in a direction along a rotating axial line of the ring gear with respect to the ring gear 26, and a first space 71 in which the ring gear 26 is arranged and a second space 72 adjoining the first space 71 in a prescribed direction are partitioned by the oil separators 41, 42. The ring gear 26 has a substantially-annular plate-shaped web 27 surrounding a differential case 11, and a substantially-cylindrical rim 28 surrounding the web 27. The oil separators 41, 42 have external peripheral end parts 57, 67 respectively, extending obliquely upwardly so as to intrude into the inside from the outside in a direction along the rotating axial line with respect to the rim 28.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power transmission device that is mounted on a vehicle and transmits power.

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

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

  The differential gear 91 is integrally provided with 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 (rotation axis direction) of the ring gear 93. The differential gear 91 is accommodated in the unit case 95, and both cylindrical portions 94 are rotatably supported by the unit case 95 via bearings 96.

  Oil is enclosed 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 to the ring gear 93 from the transmission. 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 and becomes splashed, and the splashed oil is supplied to the bearing 96 and the like. . As a result, the bearing 96 and the like are lubricated with oil, and the occurrence of wear and seizure in 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, resulting in a decrease in torque transmission efficiency due to torque loss, and hence a deterioration in vehicle fuel efficiency.

  Therefore, it is conceivable to provide oil separators 97 and 98 as partition walls on both sides in the rotational axis direction with respect to the ring gear 93 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 is possible to expect a reduction in the amount of oil accumulated in the space between the oil separators 97 and 98, that is, the space in which the ring gear 93 is accommodated.

  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 between the oil separators 97 and 98, and the shape of the oil separators 97 and 98 is reduced. It turned out that some ideas were needed.

  The objective of this invention is providing the power transmission device which can reduce the stirring resistance which the scooping member which scoops up the oil collected in the case receives from oil.

  In order to achieve the above object, a power transmission device according to the present invention is a power transmission device for transmitting power, and is rotatable about a case in which oil is sealed and a rotation axis extending in a predetermined direction in the case. A scraping member that is rotated by power and scrapes up and disperses the oil accumulated in the case, and is disposed on at least one side in a predetermined direction with respect to the scraping member. The first space and the second space adjacent to the first space in a predetermined direction are partitioned to prevent oil from flowing between the first space and the second space in at least a portion of the case where the oil is accumulated. The scraping member has an annular plate-like portion at its outer peripheral end and a cylindrical portion protruding from the outer peripheral end of the annular plate-like portion toward the oil separator. Separe , In the upper side than the axis of rotation, it has an inclined portion extending obliquely upward so as to enter from the outside to the inside in a predetermined direction relative to the cylindrical portion.

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

  An oil separator is provided on at least one side in a predetermined direction that is the rotational axis direction of the scraping member with respect to the scraping member, and the first separator and the first space in which the scraping member is disposed by the oil separator. A second space adjacent to the space in a predetermined direction is partitioned. In the portion where the oil in the case accumulates, the oil separator prevents the oil from flowing between the first space and the second space. Therefore, it can suppress that oil flows in into the 1st space from the 2nd space in the part where oil accumulates.

  The outer peripheral end portion of the scraping member has an annular plate-like portion and a cylindrical portion that protrudes from the outer peripheral end of the annular plate-like portion toward the oil separator. The oil separator has an inclined portion that extends obliquely upward so as to enter the inside from the outside in the predetermined direction with respect to the cylindrical portion above the rotational axis. Therefore, even if the oil scattered by the scraping member bounces off the member disposed above the scraping member or drops from the member, the oil travels down the inclined portion and passes through the second space. It is possible to suppress the oil that has been guided to the position and scraped up and scattered by the scraping member from returning between the scraping member and the oil separator to the first space. As a result, the amount of oil accumulated in the first space can be reduced, and the stirring resistance that the scraping member receives 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 a predetermined direction with respect to the scraping member, the space sandwiched between the oil separators is the first space, and both outer spaces 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 that the scraping member receives from the oil can be reduced, it is possible to suppress a decrease in torque transmission efficiency due to torque loss, and thus improve the traveling 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 inside of a unit case, and was seen from the shaft insertion part side. It is sectional drawing which shows the structure of the conventional differential gear schematically.

  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 a configuration of a transaxle 1 according to an embodiment of the present invention. In FIG. 1, the hatching indicating the cross section is omitted.

  The transaxle 1 is a transmission unit that is mounted on a vehicle and that shifts torque generated by an engine (not shown) and transmits the torque to drive wheels (not shown). A torque converter 3, a belt-type continuously variable transmission 4 and a differential gear 5.

  The differential gear 5 includes a differential case 11. The differential case 11 provides a gear housing space 12 therein. A pinion shaft 13 that passes through the gear housing 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. In the gear housing space 12, two side gears 16 and 17 are arranged separately on both sides of the pinion shaft 13. Both the side gears 16 and 17 and the pinion gears 14 and 15 are bevel gears, and each side gear 16 and 17 meshes with both the pinion gears 14 and 15.

  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 are inserted through the shaft insertion portions 18 and 19, respectively. The front ends of the drive shafts 21 and 22 are coupled to the side gears 16 and 17 so as not to rotate relative to each other in the gear housing space 12.

  Bearings 23 and 24 are fitted on the shaft insertion portions 18 and 19, respectively. The outer race (outer ring) of the bearings 23 and 24 is held in the unit case 2 so as not to rotate. Accordingly, the differential case 11 is supported by the unit case 2 via the bearings 23 and 24 so as to be rotatable around the same rotational axis as the drive shafts 21 and 22.

  The differential case 11 is further formed with a flange portion 25 extending radially from the outer peripheral surface between the one shaft insertion portion 18 and the pinion shaft 13. A ring gear 26 is fixed to the flange portion 25. The ring gear 26 integrally includes a substantially annular plate-shaped web 27 that surrounds the differential case 11 and a substantially cylindrical rim 28 that surrounds the outer periphery of the web 27. The rim 28 protrudes from the web 27 on both sides in the direction along the rotational 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. Thereby, the ring gear 26 and the differential case 11 rotate integrally. The rotation of the differential case 11 is converted into the rotation 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 rotational axis of the ring gear 26. The oil separators 41 and 42 are fixed to the unit case 2.

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

  The upper portion 55 along the upper half of the circular opening 51 in the oil separator 41 is formed so that the outer diameter is 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 is bent obliquely upward so as to bend from one shaft insertion portion 18 side to the ring gear 26 side and to enter the inner side from the outside in the direction along the rotation axis with respect to the rim 28 of the ring gear 26. It extends.

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

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

  The upper portion 65 of the oil separator 42 along the upper half of the circular opening 61 has a curved portion 66 curved along the upper half portion of the differential case 11, and the ring gear 26 continues to the curved portion 66 on the ring gear 26 side. A semi-annular semi-annular portion 67 extending in the rotational radial direction is integrally formed. The inner peripheral end portion of the bending portion 66 is in contact with the unit case 2 from the one shaft insertion portion 18 side. 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 semi-annular ring portion 67 is bent from the other shaft insertion portion 19 side to the ring gear 26 side, The ring gear 26 extends obliquely upward so as to enter the inner side from the outer side in the direction along the rotation axis with respect to the rim 28.

  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 first space 71 in which the ring gear 26 is disposed, and the oil separators 41 and 42, those oil separators 41 and 42. A second space 72 outside the facing direction is partitioned.

<Effect>
Oil is sealed in the unit case 2, and oil is always accumulated at the bottom of the unit case 2. When the ring gear 26 rotates, the accumulated oil is scraped up and scattered by the ring gear 26. Thereby, oil can be supplied to each part around ring gear 26, such as bearings 23 and 24 which hold differential case 11 rotatably, and generation of wear and seizure in each part can be controlled.

  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 allow the first space 71 and the first space 71 in which the ring gear 26 is disposed. A second space 72 adjacent to the space 71 in a predetermined direction is partitioned. In the part where the oil in the unit case 2 is accumulated, the oil separators 41 and 42 prevent the oil from flowing between the first space 71 and the second space 72. Therefore, oil can be prevented from flowing into the first space 71 from the second space 72 at the portion where the oil is accumulated.

  The ring gear 26 includes a substantially annular plate-shaped web 27 that surrounds the differential case 11 and a substantially cylindrical rim 28 that surrounds the outer periphery of the web 27. The oil separators 41 and 42 have outer peripheral end portions 57 and 68 that extend obliquely upward so as to enter the inner side from the outer side in the direction along the rotational axis with respect to the rim 28. For this reason, even if the scattered oil scraped up by the ring gear 26 hits the member 73 disposed above the ring gear 26 and is rebounded or dripped from the member 73, the oil travels through the outer peripheral ends 57 and 68. Thus, the oil guided to the second space 72 and scraped up and scattered by the ring gear 26 can be prevented 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 that accumulates in the first space 71 can be reduced, and the stirring resistance that the ring gear 26 receives from the oil can be reduced.

  And since the stirring resistance which the ring gear 26 receives from oil can be reduced, the fall of the torque transmission efficiency of the transaxle 1 (differential gear 5) by torque loss can be suppressed, and the driving | running | working fuel consumption of the vehicle by which the transaxle 1 is mounted is improved by extension. Can be made.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  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 rotational axis of the ring gear 26 is taken up. It can be omitted.

  The transaxle 1 is provided with a belt-type continuously variable transmission 4, but the present invention is not limited to the transaxle 1 provided with the belt-type continuously variable transmission 4, and a system other than the belt-type continuously variable transmission 4 is used. The present invention can be widely applied to a transaxle including a continuously variable transmission or a stepped automatic transmission (AT). Furthermore, the form of the power transmission device is not limited to the transaxle, but may be the differential gear 5 alone.

  In addition, various design changes can be made to the above-described 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 (scraping member)
27: Web (ring plate part)
28: Rim (cylindrical part)
41, 42: oil separator 57, 68: outer peripheral end (inclined portion)
71: First space 72: Second space

Claims (1)

A power transmission device for transmitting power,
A case filled with oil,
A scraping member that is rotatably provided around a rotation axis extending in a predetermined direction in the case, rotates by power, and scrapes up and scatters the oil accumulated in the case;
A first space provided on at least one side in the predetermined direction with respect to the scraping member, and a second space adjacent to the first space in the predetermined direction is partitioned from the first space in which the scraping member is disposed. And an oil separator that prevents oil from flowing between the first space and the second space in at least a portion of the case where the oil is accumulated,
The scraping member has an annular plate-like portion at an outer peripheral end portion thereof, and a cylindrical portion protruding from the outer peripheral end of the annular plate-like portion toward the oil separator,
The power transmission device according to claim 1, wherein the oil separator has an inclined portion that extends obliquely upward so as to enter the inside from the outside in the predetermined direction with respect to the cylindrical portion on the upper side of the rotation axis.

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