JP4896103B2 - Oil pump drive structure - Google Patents

Description

  The present invention relates to an oil pump drive structure in an automatic transmission.

In an automatic transmission, hydraulic pressure is supplied to a fastening element by an oil pump driven by an engine.
For this reason, in the case of a vehicle equipped with an idling stop device, if the engine is stopped due to idling stop, the oil pump also stops.Therefore, a power-driven auxiliary pump is separately provided. To supply.

  However, before and after stopping the engine due to idling stop, it is necessary to controlly switch between the hydraulic pressure supplied from the oil pump and the hydraulic pressure supplied from the auxiliary pump, and it is necessary to provide an oil path for the auxiliary pump separately. There was a problem that there was.

In view of this, a motor that drives an oil pump instead of the auxiliary pump is provided, and the oil pump is driven by the motor when the engine is stopped (for example, Patent Document 1).
JP 2002-357266 A

  However, in the case of the apparatus disclosed in Patent Document 1, since the oil pump and the motor are arranged along the input shaft, the axial length becomes long in order to secure a space for providing the motor. End up.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automatic transmission including an oil pump driven by an engine so that the oil pump is driven even when the engine is stopped while suppressing the axial length.

  In an oil pump of an automatic transmission driven by an engine, an inner gear of the oil pump is rotatably supported by a fixed shaft, and a motor is constituted by a magnet provided on the inner gear and a coil provided on the fixed shaft. The rotation input member to which the rotation from is input is an oil pump drive structure in which the rotation input member is connected to the inner gear via a one-way clutch on the outer side in the radial direction than the fixed shaft.

  Since the inner gear can be rotationally driven by a motor composed of a magnet provided on the inner gear and a coil provided on the fixed shaft, it is necessary to provide a motor for driving the oil pump separately from the oil pump when the engine is stopped. Absent. Therefore, since it is not necessary to secure a space for providing the motor in the axial direction of the automatic transmission, the axial length of the automatic transmission can be suppressed.

Hereinafter, embodiments of an oil pump drive structure according to the present invention will be described.
FIG. 1 is a partially enlarged view of a range from a torque converter to an oil pump of an automatic transmission. FIG. 2 is an enlarged view of the vicinity of the oil pump in FIG.

  The torque converter housing 1 accommodates a torque converter 10 that transmits rotation input from an engine (not shown) to the transmission mechanism. The torque converter 10 is rotated by receiving a flow of oil from the outer shell 12, a converter cover 11 directly connected to the engine, an outer shell 12 welded to the converter cover 11 and provided with a pump impeller on an inner peripheral surface thereof. A turbine runner 13 and a lockup clutch 14 that connects the turbine runner 13 and the converter cover 11 are provided.

  A sleeve 18 connected to the inner gear 30 of the oil pump 20 is connected to the outer shell 12. The turbine runner 13 is provided with a turbine hub 15 that is splined to the input shaft 2. One end of a stator shaft 19 is connected to the stator 16 via a one-way clutch 17, and the other end of the stator shaft 19 is fitted to the inner peripheral surface of the oil pump cover 22.

  As shown in FIG. 2A, the oil pump 20 is a gear pump configured by housing an inner gear 30 and an outer gear 40 between an oil pump housing 21 and an oil pump cover 22. Hydraulic pressure is generated by meshing the gear 30 and the outer gear 40 in an eccentric state.

  The oil pump housing 21 is provided with an oil seal 23 that is fluid-tight with the sleeve 18, and the sleeve 18 is rotatably supported by the oil pump housing 21 via a bush 24.

A stator shaft 19 is positioned radially inward of the sleeve 18, and an inner gear 30 is rotatably supported on the stator shaft 19 via bushes 50 and 51.
As shown in FIG. 2B, the bushes 50 and 51 have the same axial length D, and are provided at predetermined intervals in the axial direction within the range of the width W in the axial direction of the inner gear 30. It has been.

A groove 30b is provided in the inner peripheral surface 30a of the inner gear 30 between the bushes 50 and 51, and a magnet 53 is provided in the groove 30b.
The magnet 53 is provided in the space S formed by the bushes 50, 51 between the groove 30 b of the inner gear 30 and the outer periphery 19 a of the stator shaft 19 while avoiding interference with the bushes 50, 51 and the stator shaft 19. Yes.

  Therefore, the radial thickness of the bushes 50, 51 is set to an appropriate thickness according to the thickness of the groove 30 b of the inner gear 30 and the magnet 53. The axial length D is set to a length that allows a space S having an appropriate width according to the axial width of the magnet 53 at the center in the axial direction of the inner peripheral surface 30 a of the inner gear 30.

  In the stator shaft 19, a coil 52 is provided at a position facing the magnet 53 across the space S, and the surface of the coil 52 is formed on the surface of the outer periphery 19 a of the stator shaft 19.

  Here, the magnet 53 and the coil 52 constitute a motor 54 whose operation is controlled by a motor control unit (not shown). The inner gear 30 is rotated around the axis (rotation center) O of the input shaft 2 by the motor 54. Are driven to rotate.

In the inner gear 30, a ring-shaped groove 31 centering on the axis O of the input shaft 2 is provided at a position spaced apart from the inner peripheral surface 30 a in the radial direction by a predetermined distance. (See FIG. 1).
In the inner gear 30, the radially inner side from the groove portion 31 is a support portion 32 that rotatably supports the inner gear 30 on the stator shaft 19, and the radially outer side is a gear forming portion 33 in which a gear is formed. Yes.

A thin portion 18 a on the distal end side of the sleeve 18 is inserted into the groove portion 31, and the outer peripheral surface of the thin portion 18 a is connected to the inner peripheral surface of the gear forming portion 33 via the one-way clutch 60.
Here, the depth L of the groove 31 is set to be longer than ½ of the width W of the inner gear 30, and the sprag 60 a of the one-way clutch 60 disposed in the groove 31 is connected to the inner gear 30. Arranged on a line segment X passing through the center in the width direction, the coil 52, the magnet 53, and the one-way clutch 60 (sprag 60a) are arranged in the radial direction at the same position in the axial direction of the input shaft 2. To be. This is because rotation input to the sleeve 18 from the engine side is input to the inner gear 30 at the center in the width direction of the inner gear 30.

The one-way clutch 60 includes an inner race 60b fixed to the outer peripheral surface of the thin wall portion 18a, an outer race 60c fixed to the inner peripheral surface of the gear forming portion 33, and a sprag 60a provided therebetween. .
When the one-way clutch 60 rotates the inner gear 30 by rotation input from the engine side, the sleeve 18 (thin wall portion 18a) and the inner gear 30 (gear forming portion 33) are connected, and the motor 54 causes the inner gear 30 to move. When rotating, it operates to break the connection.

In the automatic transmission having such a configuration, when the engine is started, the sleeve 18 and the inner gear 30 are connected by the one-way clutch 60, and the rotation input to the sleeve 18 is transmitted to the inner gear 30. When the engine is stopped by idling stop driven by rotation from the side, when the rotation by the motor 54 becomes larger than the rotation input to the sleeve 18, the connection between the sleeve 18 and the inner gear is cut off. Therefore, the oil pump 20 is rotationally driven by the motor 54.
When the engine is restarted and the rotation input to the sleeve 18 becomes larger than the rotation by the motor 54, the sleeve 18 and the inner gear 30 are connected, and the oil pump 20 is rotated by rotation from the engine side. Driven.
Here, by interposing the one-way clutch 60, the drive source (engine, motor) of the oil pump 20 can be switched smoothly. Further, when the rotation input to the sleeve 18 becomes larger than the rotation by the motor 54, the sleeve 18 and the inner gear 30 are connected by the one-way clutch 60, and the motor circuit is cut off, so that the coil 52 is overloaded. It prevents current from being generated.

  Here, the sleeve 18 in the embodiment corresponds to the rotation input member in the invention, and the stator shaft 19 corresponds to the fixed shaft in the invention.

As described above, in the present embodiment, the inner gear 30 is rotatably supported by the stator shaft 19, and the motor 54 is configured by the magnet 53 provided on the inner gear 30 and the coil 52 provided on the stator shaft 19. When the sleeve 18 to which the rotation is input is connected to the inner gear 30 via the one-way clutch 60 on the radially outer side than the stator shaft 19, and the motor 54 rotates the inner gear 30, the one-way clutch 60 is 18 and the inner gear 30 are disconnected from each other.
Accordingly, the inner gear 30 can be rotationally driven by the motor 54 constituted by the magnet 53 provided on the inner gear 30 and the coil 52 provided on the stator shaft 19, so that the oil pump 20 is driven when the engine is stopped. Therefore, it is not necessary to provide a motor for the oil pump 20 separately. Therefore, since it is not necessary to secure a space for providing the motor in the axial direction of the automatic transmission, the axial length of the automatic transmission can be suppressed.
In addition, in the case of the conventional example in which the motor is provided separately from the oil pump, it is necessary to provide a member for transmitting the rotation of the motor to the oil pump, but since the configuration of the motor is provided in the oil pump, Such a member is not required. In addition, there is no need to separately provide an auxiliary pump, a switching valve, and an oil path for the auxiliary pump as in the conventional example. Therefore, the number of parts can be reduced and the hydraulic circuit can be simplified, which can contribute to the reduction of manufacturing costs.
Further, when the inner gear 30 and the sleeve 18 are connected via the one-way clutch 60 and the oil pump 20 is driven by the motor 54, the connection with the sleeve 18 that is a member on the engine side is cut off. When the engine is stopped, the oil pump 20 can be driven by rotating the inner gear 30 with the motor 54.

The inner gear 30 is supported via bushes 50 and 51 provided at predetermined intervals in the axial direction on the stator shaft 19, and the magnet 53 and the coil 52 are connected to the inner peripheral surface 30 a of the inner gear 30. A space S formed by the bushes 50 and 51 and the groove 30b is provided between the outer periphery 19a of the stator shaft 19 so as to face each other.
Accordingly, the minimum configuration that functions as the motor 54 can be provided in the oil pump 20 only by securing the space S between the inner gear 30 and the stator shaft 19.
Therefore, when idling is stopped, the transmission mechanism of the automatic transmission can be lubricated and the hydraulic pressure in the oil passage can be filled, and a hydraulic pressure for obtaining the minimum required clutch holding pressure can be secured.
Here, the groove 30 b of the inner gear 30 may be omitted, and the magnet 53 may be fixed to the inner peripheral surface 30 a of the inner gear 30. In such a case, since it is not necessary to form a groove for providing the magnet 53 in the inner gear 30, the configuration of the motor 54 can be easily provided in the oil pump 20.

In the inner gear 30, a ring-shaped groove 31 centering on the axis (rotation center) O of the inner gear 30 is provided at a position spaced apart from the inner peripheral surface 30 a in the radial direction by a predetermined distance. Is configured to be provided in the groove 31.
Thereby, the magnet 53, the coil 52, and the one-way clutch 60 are arranged side by side in the radial direction in the oil pump 20, and the position where the rotation from the engine is input to the inner gear 30 and the position of the motor 54 are Since it can match in the axial direction, the axial thickness of the oil pump 20 can be reliably suppressed.

  In the embodiment, the magnet 53 is fixed to the groove 30b of the inner gear 30. The fixing method in this case is not particularly limited, and may be fixed by sticking, for example, as long as the fixing method is such that the magnet 53 does not fall off from the inner gear 30. Moreover, you may fix in the state hold | maintained in the recessed part formed in the internal peripheral surface 30a.

The magnet 53 may be completely embedded in the inner gear 30. In this case, it is not necessary to secure the space S between the inner gear 30 and the stator shaft 19, so that only one bush interposed between the inner gear 30 and the stator shaft 19 can be provided, and the oil pump 20 The number of parts can be reduced.
Furthermore, in this case, in the support portion 32 of the inner gear 30, the magnet 53 can be provided over the entire range facing the stator shaft 19. The driving force of the motor 54 can be improved.

In the embodiment, the coil 52, the magnet 53, and the one-way clutch 60 are arranged side by side on the line segment X (see FIG. 2B) in the radial direction of the input shaft 2. However, the connecting position of the one-way clutch 60 and the inner gear 30 can be changed within a range in which the inner gear 30 can be rotated by the sleeve 18.
For example, you may make it connect in the position of the left side (torque converter 10 side) in the figure rather than line segment X. FIG. In this case, since the depth L of the groove portion 31 can be reduced, the strength and durability of the inner gear 30 are improved.
Further, the inner peripheral surface of the thin portion 18 a of the sleeve 18 and the outer peripheral surface of the support portion 32 of the inner gear 30 may be connected by the one-way clutch 60.

It is the elements on larger scale of the automatic transmission which employ | adopted the oil pump drive structure which concerns on embodiment. It is an enlarged view of the oil pump vicinity in FIG.

Explanation of symbols

1 Torque converter housing 2 Input shaft 18 Sleeve (Rotating input member)
19 Stator shaft (fixed shaft)
20 Oil pump 21 Oil pump housing 22 Oil pump cover 30 Inner gear 31 Groove portion 32 Support portion 33 Gear forming portion 40 Outer gear 50, 51 Bushing 52 Coil 53 Magnet 54 Motor 60 One-way clutch S Space

Claims (4)

In an oil pump of an automatic transmission driven by an engine,
The inner gear of the oil pump is supported rotatably by a fixed shaft,
A motor is constituted by a magnet provided on the inner gear and a coil provided on the fixed shaft,
An oil pump drive structure characterized in that a rotation input member to which rotation from an engine is input is connected to the inner gear via a one-way clutch outside in the radial direction from the fixed shaft. The inner gear is supported on the fixed shaft via a bush,
The magnet and the coil are provided to face each other in a space formed by the bush between the inner periphery of the inner gear and the outer periphery of the fixed shaft. Oil pump drive structure. The oil pump drive structure according to claim 1, wherein the magnet is provided in a range facing the fixed shaft in the inner gear.   In the inner gear, a ring-shaped groove having a concentric circle about the rotation center of the inner gear is provided at a position spaced a predetermined distance radially outward from the inner peripheral surface, and the one-way clutch is provided in the groove. The oil pump drive structure according to any one of claims 1 to 3, wherein the oil pump drive structure is provided.

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