JPH07110059A - Differential gear - Google Patents

Abstract

PURPOSE:To provide a small, light and unitized differential gear having no possibility that durability of a motor for performing the differential limit is damaged even in the high differential, motion. CONSTITUTION:A differential gear 1 is provided with a differential case 5 housed in a fixed case 3, a differential mechanism 13 housed in the differential case 5, a motor 15 connected to a power supply 65 through step rings 47, 49, 51, 53 so as to receive differential torque of the differential mechanism 13 in the differential case 5, and a controller 63 for controlling the supply power to the motor 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle differential device.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 1-269745 discloses an apparatus as shown in FIG. This is a transfer 201 used in a four-wheel drive vehicle, and a planetary gear type differential mechanism 2 that distributes the driving force of the engine to the front wheels and the rear wheels.
03 and a mysterious gear mechanism 205 that accelerates the differential rotation
The motor 207 is connected to the differential mechanism 203 via the.

The motor 207 limits the differential of the differential mechanism 203 via the mysterious gear mechanism 205.

[0004]

As described above, in the transfer 201, the motor 207 has the mysterious gear mechanism 205.
Since the differential mechanism 203 is coupled to the differential mechanism 203 via the speed increasing mechanism as described above, the motor 207 is driven at an extremely high speed when the differential mechanism 203 is subjected to a high differential rotation, which may reduce the durability. There is. Also, a planetary gear type differential mechanism 2
03 has a narrow axial width and is convenient for downsizing, but by incorporating the mysterious gear 205, it is large and heavy, and the motor 207 is a separate body from the differential mechanism 203, so that it is unitized as a whole. Since it has not been done, advantages such as easy attachment and detachment and high degree of freedom in layout cannot be obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a small and lightweight unitized differential device which does not impair the durability of a motor for limiting the differential even when the differential is high.

[0006]

A differential device of the present invention includes a differential case housed in a fixed case, a planetary gear type differential mechanism of a double pinion having an internal gear provided on the side of the differential case, and a differential case. It is characterized in that it is provided with a motor that is arranged and connected to an external power source through a slip ring, and that receives a differential torque of a differential mechanism, and a controller that controls electric power supplied to the motor.

[0007]

The differential case is housed in the fixed case, and the motor is connected inside the differential case so as to receive the differential torque of the differential mechanism, and is also connected to the external power source via the slip ring. The controller controls the torque of the motor to limit the differential of the differential mechanism. At that time, energy can be recovered by charging the battery with electric power generated by the motor when the motor is driven by the differential torque. Since the motor is directly connected to the differential mechanism and does not use the speed increasing mechanism unlike the conventional example, the motor is not driven at an ultrahigh speed even when the differential is high, and durability is not impaired.

The differential mechanism and the motor are arranged in a differential case, and the differential case is housed in a fixed case to be unitized, and the differential mechanism is of a planetary gear type and has a narrow axial width, thus increasing the speed increasing mechanism. It is small and lightweight because it does not use.

[0009]

EXAMPLE A first example will be described with reference to FIG. In this embodiment, the center differential 1 is installed in the transfer of a four-wheel drive vehicle.
It is used as a (differential device that distributes the driving force of an engine to front wheels and rear wheels). It should be noted that members and the like without reference numerals are not shown.

A differential case 5 is supported inside the fixed case 3 via bearings 7, 7. Differential case 5
The input gear 11 of the hollow shaft 9 connected to the gear meshes with the output gear of the transmission, and the driving force of the engine rotationally drives the differential case 5 via the transmission.

A double pinion planetary gear type differential mechanism 13 and a DC motor 15 (motor) are arranged in the differential case 5. The internal gear 17 of the differential mechanism 13 is formed on the differential case 5, and the sun gear 19 is formed on the output shaft 21 on the front wheel side. The outer and inner pinion gears 23 and 25 are rotatably supported by the pinion shafts 27 and 27. Both ends of each pinion shaft 27 are supported by a pinion carrier 29 and a housing 31 of the DC motor 15. The permanent magnet 33, which is the stator of the DC motor 15, is fixed to the housing 31. The pinion carrier 29 and the housing 31 are the bearing 3
It is supported by the differential case 5 via 5, 35.

A coil 37 which is a rotor of the DC motor 15.
Is fixed on the output shaft 21, and the output shaft 21 is supported by the pinion carrier 29 and the housing 31 via bearings 39, 39. An output shaft 41 on the rear wheel side is connected to the housing 31. Output shaft 21 is gear 4
3 is connected to the front differential (front wheel side differential device) side, and the output shaft 41 is connected to the rear differential (rear wheel side differential device) side via a gear 45.

The driving force of the engine for rotating the differential case 5 is distributed to the sun gear 19 (output shaft 21) and the housing 31 (output shaft 41) via the pinion gears 23 and 25, and further to the left and right front wheels by the front differential and the rear differential. It is distributed to the rear wheels. When a driving resistance difference occurs between the front and rear wheels, the driving force of the engine is differentially distributed to the front and rear sides due to the rotation and revolution of the pinion gears 23 and 25.

The coil 37 of the DC motor 15 is connected to the controller 63 via slip rings 47, 49, 51, 53, brushes 55, 57 and external lead wires 59, 61, and the controller 63 is provided with a battery 65 ( The power supply) and the resistor 67 are connected.

The controller 63 switches the polarity of the electric power of the battery 65 on the basis of signals from the rotation speed sensors arranged on the front wheel side and the rear wheel side, and applies a torque that opposes the differential torque of the differential mechanism 13 to the DC motor. The differential limiting force is adjusted by controlling the torque of the DC motor 15 according to the throttle opening and the like. If necessary to improve the steering characteristics, torque may be applied in the direction of promoting the differential. Battery 65
Even if the driving of the DC motor due to is stopped, the differential is limited by the drive resistance of the DC motor 15. The controller 63 can switch the electromotive force of the DC motor 15 at this time to the battery 65 and the resistor 67. Energy can be recovered by switching to the battery 65 and charging it.

In this way, the center differential 1 is constructed.

In the center differential 1, the differential mechanism 13 and DC
Unlike the conventional example, since the motor 15 is directly connected and the speed increasing mechanism is not used, even if the differential mechanism 13 is in a high differential state, the DC motor 15 is not driven to rotate at an ultrahigh speed and is durable. There is no fear of losing sexuality. Further, it is not necessary to supply the electric power of the battery 65 in order to avoid the super high speed rotation. Further, the center differential 1 has the differential mechanism 13 and the DC motor 15 as described above.
Are coaxially housed in the differential case 5, and the differential case 5 is housed in the fixed case 3 to form a unit. Therefore, the attachment / detachment to / from the vehicle body is easy, and the degree of freedom in layout is high. Further, the differential mechanism 13 is of a planetary gear type and has a small axial width, and since it does not use a speed increasing mechanism, it is small and lightweight.

Next, a second embodiment will be described with reference to FIG. This embodiment is also used as the differential center 69.
It should be noted that members having the same functions as those in FIG. 1 are designated by the same reference numerals, and members not designated by the reference numerals are not shown.

Inside the differential case 5, a differential mechanism 13 and A
A C motor 71 (motor) is arranged. The coil 73, which is the stator of the AC motor 71, is fixed to the housing 31. The permanent magnet 75, which is a rotor, is fixed on the output shaft 21. The coil 73 is connected to the controller 89 via the slittings 77, 79, 81, 83 and the external lead wires 85, 87, and the controller 89
An AC power supply 91 and a resistor 67 are connected to the.

The controller 89 switches the polarity of the AC power source 91 to generate a torque against the differential torque of the differential mechanism 13 in the AC motor 71 to limit the differential, and controls the torque of the AC motor 71. Adjust the differential limiting force.
Further, even if the driving of the AC motor 71 by the AC power source is stopped, the differential resistance is limited by the driving resistance of the AC motor 71. The electromotive force of the AC motor 71 at this time is supplied to the resistor 67. Further, the battery may be charged by the electromotive force via the AC-DC converter.

The center differential 69 thus constructed is
Similar to the center differential 1, since the speed increasing mechanism is not used, the AC motor 71 is not driven at an extremely high speed even when the differential is high and durability is not impaired, and the unit is small and lightweight.

[0022]

According to the differential device of the present invention, the planetary gear type differential mechanism and the motor that directly receives the differential torque are housed in a case to form a unit. Therefore, the differential limitation can be performed by the motor, and since the speed increasing mechanism is not used, the motor is small and lightweight, and there is no fear that the motor is driven at an ultrahigh speed and the durability is impaired.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a configuration diagram of a second embodiment.

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

1,69 Center differential (differential device) 3 Fixed case 5 Differential case 13 Differential mechanism 15 DC motor 17 Internal gear 47, 49, 51, 53, 77, 79, 81, 83 Slip ring 63, 89 Controller 65 Battery (power supply) ) 71 AC motor 91 AC power supply

Claims (1)

[Claims] 1. A differential case housed in a fixed case,
The internal gear is a double pinion planetary gear type differential mechanism provided on the side of the differential case, and is connected to an external power source via a slip ring arranged inside the differential case and receives the differential torque of the differential mechanism. A motor,
A differential device, comprising: a controller that controls electric power supplied to a motor.