JP2020122519A - Transaxle - Google Patents

Abstract

To provide a transaxle which can favorably supply oil even to a side opposite to a side at which the oil is scattered by oblique teeth of a ring gear.SOLUTION: An oil capturing part 51 and an oil receiving part 52 are formed at the other side of a ring gear 34 in a rotation axial line direction, that is, at a left side. At the rotation of the ring gear 34, a centrifugal force acts on oil which adheres to end faces at one side and the other side of the ring gear 34 in the rotation axial line direction, and the oil is aggregated to an external peripheral part of the ring gear 34. The oil capturing part 51 has an L-shaped face 54 which is formed so as to progress along an external peripheral face 37 of a rim 36 of the ring gear 34, and an end face 53 at the left side being the other side in the rotation axial line direction. Therefore, at the rotation of the ring gear 34, the oil aggregated to the external peripheral part of the reduction gear 34 contacts with the oil capturing part 51, the oil is captured by the oil capturing part 52, and the captured oil is dripped from the oil capturing part 52.SELECTED DRAWING: Figure 1

Description

The present invention relates to a transaxle that integrally includes a transmission (transmission) and a differential gear (differential device).

In vehicles such as automobiles, power from a drive source is transmitted to a differential gear (differential device) via a transmission (transmission), and the power is converted by the differential gear into rotations of the left and right drive shafts. The rotation of the shaft is transmitted to the drive wheels.

FIG. 5 is a perspective view showing a part of a conventional transaxle.

The differential gear 91 includes a differential case 92 that accommodates a pinion gear and a side gear, and a ring gear 93 that is supported by the differential case 92 and projects outside the differential case 92. The differential gear 91 is housed in the unit case 95 together with the transmission 94. The differential case 92 is rotatably supported by the unit case 95 via a bearing (not shown). The ring gear 93 has oblique teeth on the outer peripheral surface thereof, and the output gear 96 of the transmission 94 meshes with the ring gear 93.

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. When the power is transmitted to the ring gear 93, the differential case 92 rotates integrally with the ring gear 93, and the oil accumulated in the unit case 95 is scraped up by the gear teeth of the ring gear 93 to become droplets, and the oil splashes to the differential case 92. It is supplied to the drive shaft that is inserted. Further, the oil supplied to the drive shaft is supplied to the inside of the differential case 92 along the drive shaft, and the side gears and the like in the differential case 92 are lubricated by the oil.

JP, 2014-119084, A

However, since the gear teeth of the ring gear 93 are beveled teeth, most of the oil that is scraped up by the gear teeth is splashed from the ring gear 93 to one side in the rotation axis direction, and is hardly scattered to the opposite side. .. Therefore, on the side where the oil is hardly scattered, the oil may not be sufficiently supplied to the drive shaft and the like, and seizure may occur due to insufficient lubrication of the drive shaft and the like.

Even if the oil is scattered from the ring gear 93 to both sides in the rotation axis direction, the oil scattering direction changes depending on the rotation speed (peripheral speed) of the ring gear 93, so that the lubrication state of the drive shaft is stable. Hard to do. Therefore, it is not possible to eliminate the concern that seizure may occur due to insufficient lubrication of the drive shaft or the like.

An object of the present invention is to provide a transaxle that can favorably supply oil to the side opposite to the side where oil is scattered by the oblique teeth of the ring gear.

To achieve the above object, a transaxle according to the present invention is a transaxle having a configuration in which a differential gear is housed in a unit case in which oil is sealed together with a transmission, and the differential gear is provided in the unit case. A differential case, which is rotatably supported, and through which a drive shaft is inserted along its rotation axis, and an outer side of the differential case in a radial direction of rotation with respect to the differential case, which is supported by the differential case over the entire circumference in the rotational direction of the differential case. And a ring gear that partially immerses in the oil accumulated in the unit case, the ring gear has an outer peripheral surface with one end in the rotation axis direction at the time of rotation of the ring gear being the other end. It has oblique teeth that are inclined with respect to the rotation axis direction so as to move later, and is formed along the outer peripheral surface and the other end surface of the ring gear in the unit case. An oil trap having a raised surface is provided.

According to this configuration, the oil sealed in the unit case is collected at the bottom of the unit case, and a part of the ring gear is immersed in the collected oil. When the rotation of the output shaft of the transmission is transmitted to the ring gear of the differential gear via the output gear and the ring gear rotates, the oil is scraped up by the beveled teeth of the ring gear.

The oblique teeth of the ring gear are inclined with respect to the rotation axis direction so that one end on the rotation axis direction moves later than the other end when rotating. Therefore, during rotation of the ring gear, the oil held between the teeth of the ring gear's oblique teeth is pushed out from between the teeth by the oblique teeth into one side in the direction of the rotation axis and scattered. As a result, oil can be supplied to the drive shaft on one side in the rotation axis direction. As a result, the oil supplied to the drive shaft is guided along the drive shaft into the differential case, so that the oil can be supplied into the differential case.

When the ring gear rotates, a centrifugal force acts on the oil attached to each end surface on one side and the other side of the ring gear in the rotation axis direction, and the oil collects on the outer peripheral portion of the ring gear. An oil trap is provided in the unit case. The oil capturing portion has a surface formed along the outer peripheral surface of the ring gear and the end surface on the other side in the rotation axis direction. Therefore, when the ring gear rotates, the oil collected on the outer peripheral portion of the ring gear comes into contact with the oil capturing portion, the oil is captured by the oil capturing portion, and the captured oil drops from the oil capturing portion. As a result, the oil can be satisfactorily supplied to the other side in the rotation axis direction. As a result, the oil can be satisfactorily supplied to the drive shaft on the other side in the rotation axis direction, and the oil can also be supplied from the drive shaft into the differential case.

Therefore, it is possible to suppress the occurrence of seizure due to insufficient lubrication of the drive shafts on both sides in the rotation axis direction and the side gears accommodated in the differential case.

The amount of oil that collects on the outer peripheral part along the end surface of the ring gear is not easily affected by the number of rotations (peripheral speed) of the ring gear, so if the oil collecting part captures the oil that collects on the outer peripheral part of the ring gear, Even if the number, that is, the vehicle speed of the vehicle equipped with the transaxle changes, the change in the amount of oil captured by the oil capturing portion is small. Therefore, the oil can be stably supplied to the other side in the rotation axis direction, and the lubrication state of the drive shaft on the other side can be stabilized.

The transmission has an output shaft that extends parallel to the rotation axis of the ring gear, an output gear that is supported by the output shaft so that it cannot rotate relative to it, and a gear that meshes with the ring gear, and a parking gear that is supported by the output shaft so that they cannot rotate relative to each other. It is preferable that the parking gear is disposed on one side of the output gear in the rotation axis direction and faces the meshing portion of the ring gear and the output gear in the rotation axis direction.

With this configuration, the oil pushed out from between the gear teeth of the ring gear can be scraped off by the parking gear. As a result, oil can be satisfactorily supplied to the drive shaft on one side in the rotation axis direction. As a result, the oil can be more favorably supplied into the differential case, and the occurrence of seizure due to insufficient lubrication of the side gears accommodated in the differential case can be further suppressed.

Moreover, since the parking gear is a component that has been provided in the transmission for a long time, a good supply of oil to the drive shaft and the differential case on one side in the rotation axis direction can be achieved without adding a new component. be able to.

According to the present invention, it is possible to satisfactorily supply the oil to the side opposite to the side where the oil is scattered by the beveled teeth of the ring gear, and suppress the occurrence of seizure due to insufficient lubrication of the drive shaft or the like arranged on the opposite side. can do.

1 is a partial cross-sectional view of a transaxle according to an embodiment of the present invention. It is a side view which shows a part of internal structure (structure in a unit case) of a transaxle. It is a perspective view which shows a part of internal structure of a transaxle. It is a perspective view showing a part of internal structure of a transaxle, and illustration of a ring gear etc. is omitted. It is a perspective view which shows a part of conventional transaxle.

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

<Structure of transaxle>
FIG. 1 is a partial sectional view of a transaxle 1 according to an embodiment of the present invention. FIG. 2 is a side view showing a part of the internal structure of the transaxle 1 (the structure inside the unit case 2). FIG. 3 is a perspective view showing a part of the internal configuration of the transaxle 1.

The transaxle 1 is a transmission unit that is mounted on a vehicle and that transmits a torque generated by an engine (not shown) to drive wheels (not shown). As shown in FIGS. 2 and 3, a transmission (transmission) 3 and a differential gear 4 are housed in a unit case 2 that forms the outer shell of the transaxle 1.

The transmission 3 includes an output shaft 11 extending parallel to the rotation axis of the crankshaft of the engine. An output gear 12 is formed integrally with the output shaft 11. The output gear 12 has a large number of output gear oblique teeth 13 arranged in the circumferential direction, as schematically shown in FIG. The output shaft 11 has one side in the direction in which the rotation axis of the output shaft 11 extends with respect to the output gear 12 (hereinafter, referred to as “rotation axis direction”), that is, on the right side in FIG. The parking gear 14 is supported on the “right side” so as to be relatively non-rotatable. As shown in FIGS. 2 and 3, a large number of teeth 15 are formed at regular intervals on the outer peripheral surface of the parking gear 14, so that the teeth 15 and the tooth spaces 16 are alternately arranged.

The differential gear 4 includes a differential case 21 as shown in FIGS. 1 and 2. The differential case 21, as shown in FIG. 1, provides a gear accommodating space 22 therein. Although not shown, the differential case 21 holds a pinion shaft penetrating the gear accommodating space 22. Two pinion gears are rotatably held on the pinion shaft with a gap between them. Further, in the gear accommodating space 22, two side gears 23 and 24 are separately arranged on both sides of the pinion shaft. The side gears 23 and 24 and the pinion gear are both bevel gears, and each side gear 23 and 24 meshes with both of the two pinion gears.

Further, cylindrical shaft insertion portions 25 and 26 are formed in the differential case 21 at positions facing each other in the facing direction of the two side gears 23 and 24. The drive shafts 27 and 28 are inserted into the shaft insertion portions 25 and 26, respectively. The tip ends of the drive shafts 27 and 28 are connected to the side gears 23 and 24, respectively, in the gear housing space 22 such that they cannot rotate relative to each other.

Inner races (inner rings) of bearings 31 and 32 are fitted onto the shaft insertion portions 25 and 26, respectively. The outer races (outer rings) of the bearings 31 and 32 are non-rotatably held in the unit case 2. As a result, the differential case 21 is rotatably supported by the unit case 2 via the bearings 31 and 32 about the same rotation axis as the drive shafts 27 and 28.

The differential case 21 is further formed with a flange portion 33 protruding radially from the outer peripheral surface thereof. A ring gear 34 is fixed to the flange portion 33. The ring gear 34 integrally includes a substantially annular plate-shaped web 35 that surrounds the differential case 21, and a substantially cylindrical rim 36 that surrounds the outer periphery of the web 35. The rims 36 project from the web 35 on both sides of the differential case 21 in the rotation axis direction. As shown in FIG. 3, a large number of ring gear bevel teeth 38 are formed on the outer peripheral surface 37 of the rim 36. The ring gear bevel teeth 38 mesh with the output gear bevel teeth 13 of the output gear 12 of the transmission 3. doing.

The rotation of the output shaft 11 of the transmission 3 is transmitted to the ring gear 34 of the differential gear 4 via the output gear 12. As a result, the differential case 21 rotates integrally with the ring gear 34. The rotation of the differential case 21 is converted into the rotation of each of the side gears 23 and 24 via the pinion gear. As a result, the drive shafts 27, 28 rotate integrally with the side gears 23, 24, and the rotation of the drive shafts 27, 28 is transmitted to the drive wheels of the vehicle.

Further, as shown in FIG. 1, in the unit case 2, oil separators 41 and 42 serving as partition walls are provided on both sides of the ring gear 34 in the rotation axis direction. The oil separators 41 and 42 are fixed to the unit case 2. Due to the oil separators 41 and 42, the gear housing space 22 in the unit case 2 has a first space 43 in which the ring gear 34 is arranged and second spaces 44 and 45 on both sides in the rotation axis direction with respect to the first space 43. It is divided into and. The unit case 2 is filled with oil, and the oil separators 41, 42 prevent the oil between the first space 43 and the second spaces 44, 45 at least at the bottom of the unit case 2 where the oil is accumulated. Block distribution. A part of the ring gear 34 is immersed in the oil accumulated in the first space 43.

As shown in FIG. 3, the output gear spiral tooth 13 of the output gear 12 and the ring gear spiral tooth 38 of the ring gear 34 have one end on the rotation axis line direction, that is, the right end, more than the opposite end when rotating. It is inclined with respect to the rotation axis direction so as to move with a delay. The parking gear 14 is opposed to the meshing portion of the output gear oblique tooth 13 of the output gear 12 and the ring gear oblique tooth 38 of the ring gear 34 in the rotation axis direction from the right side.

FIG. 4 is a perspective view showing a part of the internal structure of the transaxle 1. In FIG. 4, illustration of the ring gear 34 and the like is omitted so that the configuration on the left side (the back side in FIG. 2) of the ring gear 34 appears.

Further, in the unit case 2, as shown in FIGS. 1, 2 and 4, an oil catching portion 51 and an oil receiving portion 52 are provided on the other side of the ring gear 34 in the rotational axis direction, that is, on the left side. It is provided. The oil catching portion 51 and the oil receiving portion 52 are formed integrally with the unit case 2.

The oil catching portion 51 extends from the inner surface of the unit case 2 toward the uppermost portion of the rim 36 of the ring gear 34 in the rotation axis direction. The oil catching portion 51 has a substantially L-shaped L-shaped surface 54 formed at the tip thereof along the outer peripheral surface 37 of the rim 36 and the left end surface 53. In other words, an L-shaped surface 54 is formed at the tip of the oil capturing portion 51, and the L-shaped surface 54 and the outer peripheral surface 37 of the rim 36 are spaced apart from each other by a first facing surface 55 and a rim. The left end surface 53 of the rim 36 includes a second facing surface 56 that faces the left end surface 53 at a distance, and has a substantially L shape along the outer peripheral surface 37 of the rim 36 and the left end surface 53. The second facing surface 56 is located at a substantially intermediate position between the oil separator 41 and the outer peripheral surface 37 of the rim 36 in the rotation axis direction.

The oil receiving portion 52 has a plate shape, and is formed below the oil capturing portion 51, between the inner surface of the unit case 2 and the oil separator 41 so as to straddle them. The oil receiving portion 52 is inclined so that it is located on the other side of the differential case 21 in the rotation axis direction, that is, as it is located farther to the left from the uppermost portion of the left shaft insertion portion 25. Further, the oil receiving portion 52 is positioned so as to be positioned higher from the uppermost portion of the left shaft insertion portion 25 on one side in a direction orthogonal to both the rotation axis direction and the vertical direction, that is, the farther to the left side in FIGS. 2 and 4. Is inclined to. A groove 57 extending in the rotation axis direction is formed in the oil receiving portion 52 immediately above the uppermost portion of the shaft insertion portion 25.

<Effect>
The oil sealed in the unit case 2 collects at the bottom of the unit case 2, and part of the ring gear 34 is immersed in the collected oil. When the rotation of the output shaft 11 of the transmission 3 is transmitted to the ring gear 34 of the differential gear 4 via the output gear 12 and the ring gear 34 rotates, the oil is scraped up by the ring gear 34.

The output gear spiral tooth 13 formed on the output gear 12 and the ring gear spiral tooth 38 formed on the ring gear 34 have a right end, which is one side in the rotation axis direction when the output gear 12 and the ring gear 34 rotate, on the opposite side. It is inclined with respect to the rotation axis direction so as to move later than the left end. Therefore, when the ring gear 34 rotates, the oil held between the teeth of the ring gear spiral tooth 38 is generated by the output gear spiral tooth 13 that enters between the teeth of the ring gear spiral tooth 38 and the output gear spiral tooth 13 at the meshing portion. It is pushed to the right from between the teeth.

A parking gear 14 is provided on the right side of the output gear 12 in the rotation axis direction, and the parking gear 14 faces the meshing portion of the ring gear 34 and the output gear 12 in the rotation axis direction. Therefore, the oil pushed out from between the gear teeth of the ring gear 38 is scraped off by the parking gear 14, passes through the gap between the inner surface of the unit case 2 and the bearing 32, and is inserted through the shaft on the one side in the rotation axis direction, that is, on the right side. It is supplied between the portion 26 and the drive shaft 28 inserted through the portion 26. As a result, the oil can be satisfactorily supplied to the drive shaft 28.

Further, the oil supplied to the drive shaft 28 is supplied into the differential case 21 through the groove 61 (see FIG. 1) formed in the inner peripheral surface of the shaft insertion portion 26. As a result, the oil can be satisfactorily supplied into the differential case 21, and the occurrence of seizure due to insufficient lubrication of the side gears 23, 24 and the like housed in the differential case 21 can be suppressed.

Moreover, since the parking gear 14 is a component that has been provided in the transmission 3 for a long time, it is possible to achieve good supply of oil into the differential case 21 without adding new components.

On the other hand, an oil catching portion 51 and an oil receiving portion 52 are provided on the other side of the ring gear 34 in the rotation axis direction, that is, on the left side. When the ring gear 34 rotates, a centrifugal force acts on the oil attached to each end surface on one side and the other side of the ring gear 34 in the rotation axis direction, and the oil collects on the outer peripheral portion of the ring gear 34. The oil catching portion 51 has an L-shaped surface 54 formed along the outer peripheral surface 37 of the rim 36 of the ring gear 34 and the left end surface 53 which is the other side in the direction of the rotation axis. Therefore, when the ring gear 34 rotates, the oil collected on the outer peripheral portion of the ring gear 34 comes into contact with the oil capturing portion 51, the oil is captured by the oil capturing portion 51, and the captured oil drops from the oil capturing portion 51. .. The oil receiving portion 52 is arranged below the oil capturing portion 51, and the oil dropped from the oil capturing portion 51 is received by the oil receiving portion 52. Then, the oil received by the oil receiving portion 52 flows on the oil receiving portion 52 toward the groove 57 formed in the oil receiving portion 52, and from the groove 57 to the shaft insertion portion 25 on the other side in the rotation axis direction. Toward the bottom, and flows down through between the oil receiving portion 52 and the oil separator 41. As a result, oil can be satisfactorily supplied to the drive shaft 27 that is inserted through the shaft insertion portion 25.

Further, the oil supplied to the drive shaft 27 is supplied into the differential case 21 through the groove 62 (see FIG. 1) formed in the inner peripheral surface of the shaft insertion portion 25. As a result, the oil can be satisfactorily supplied into the differential case 21, and the occurrence of seizure due to insufficient lubrication of the side gears 23, 24 and the like housed in the differential case 21 can be suppressed.

Since the amount of oil that collects on the outer peripheral portion along the end surface of the ring gear 34 is not easily affected by the rotation speed (peripheral speed) of the ring gear 34, the oil collecting portion 51 captures the oil that collects on the outer peripheral portion of the ring gear 34. Even if the rotation speed of the ring gear 34, that is, the vehicle speed of the vehicle on which the transaxle 1 is mounted changes, the change in the amount of oil captured by the oil capturing portion 51 is small. Therefore, oil can be stably supplied to the other side of the ring gear 34 in the rotation axis direction, that is, the left side, and the lubrication state of the drive shaft 27 and the like on the other side can be stabilized.

Of course, since oil is also supplied to the bearings 31 and 32 that are fitted onto the shaft insertion portions 25 and 26, the lubrication of the bearings 31 and 32 can be ensured. Therefore, it is possible to suppress the occurrence of seizure due to insufficient lubrication of the bearings 31 and 32 without using shield bearings for the bearings 31 and 32. As a result, the cost can be reduced.

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

For example, the transaxle 1 to which the present invention is applicable is not limited by the type of transmission, and the present invention is applicable to a belt type continuously variable transmission (CVT) or a non-belt type continuously variable transmission. It is widely applicable to a transaxle including a stepped automatic transmission (AT).

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 2: Unit case 3: Transmission 4: Differential gear 21: Differential case 27, 28: Drive shaft 34: Ring gear 36: Rim (outer peripheral part)
37: Outer Surface 38: Ring Gear Beveled Teeth (Beveled Teeth)
51: Oil capturing part 54: L-shaped surface (surface)

Claims (1)

A transaxle having a configuration in which a differential gear is housed in a unit case in which oil is sealed together with a transmission,
The differential gear is
A differential case that is rotatably supported by the unit case and has a drive shaft inserted along its rotation axis;
A ring gear that is supported by the differential case, extends over the entire circumference in the rotational direction of the differential case to the outside in the radial direction of rotation of the differential case with respect to the differential case, and partially immerses in the oil accumulated in the unit case. ,
The ring gear has, on its outer peripheral surface, oblique teeth that are inclined with respect to the rotation axis direction so that one end of the rotation direction of the ring gear moves later than the other end of the rotation direction when the ring gear rotates. And
A transaxle, wherein an oil catcher having a surface formed along the outer peripheral surface of the ring gear and the end surface on the other side is provided in the unit case.

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