Motor vehicle balancing

Patent metadata

Field	Value
Publication number	US-10598266-B2
Application number	US-201515557479-A
Country	US
Kind code	B2
Filing date	Mar 19, 2015
Priority date	Mar 19, 2015
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

For the operation of a gearless clutch-controlled differential unit with a first clutch and a second clutch, without abandoning the possibility of assigning different torques to the clutches, it is provided that a control variable originally generated by a control variable unit is supplied to the first clutch unchanged while the control variable is supplied to the second clutch subject to the intermediate connection of an individual control element. The first and second clutches have clutch characteristics that are distinct from one another.

First claim

The invention claimed is:

1. A system for activating a gearless differential unit of an axle of a motor vehicle, comprising:
the differential unit which includes
an input element;
a first output element couplable to the input element via a first frictionally engaged clutch to transmit a drive moment to a first drive wheel; and
a second output element, couplable to the input element via a second frictionally engaged clutch to transmit a drive moment to a second drive wheel;
wherein a control variable output by a control variable unit for adjusting drive moment transmittable by the clutches is supplied to the first clutch without intermediate connection of an individual control element, while the control variable is supplied to the second clutch via the intermediate connection of an individual control element.

2. The system of claim 1 , wherein the first clutch and the second clutch have clutch characteristics that are distinct from one another.

3. The system of claim 1 , wherein the control variable unit is activatable for changing the value of the control variable.

4. The system of claim 2 , wherein the clutch characteristics of the first clutch and the clutch characteristics of the second clutch are such that when both clutches are supplied with a control variable of the same value the second clutch is capable of transmitting a greater clutch moment than the first clutch.

5. The system of claim 2 , wherein the clutch characteristics of the first clutch and the clutch characteristics of the second clutch are such that, by influencing the control variable via the individual control element, the second clutch is configured to be assigned a transmittable clutch moment that is higher, and a transmittable clutch moment that is lower, than can be assigned to the first clutch.

6. The system of claim 1 , wherein the second clutch has a pressure point that is higher than a pressure point of the first clutch.

7. The system of claim 1 , wherein the second clutch has an effective clutch friction area that is larger than an effective clutch friction area of the first clutch.

8. The system of claim 1 , wherein the second clutch has an effective clutch diameter that is larger than an effective clutch diameter of the first clutch.

9. The system of claim 1 , wherein the control variable is hydraulic pressure, the system further comprising a rotational speed-regulated hydraulic pump as the control variable unit, wherein the control variable change influencing the clutch moment of the first clutch is effected directly via the change of the rotational speed of the hydraulic pump, while the second clutch is additionally assigned an individual control element located downstream of the hydraulic pump, via which the control variable made available by the hydraulic pump is additionally reducible in the value.

10. A method for operating a gearless differential unit of an axle of a motor vehicle that can be driven at least at times, wherein the differential unit comprises
an input element;
a first output element couplable to the input element via a first frictionally engaged clutch in order to transmit drive power to a first drive wheel; and
a second output element, couplable to the input element via a second frictionally engaged clutch to transmit drive power to a second drive wheel;
the method comprising outputting, from a control variable unit, a control variable with which the first clutch and the second clutch are supplied, wherein the control variable is supplied to the first clutch without intermediate connection of an individual control element, while the control variable made available by the control variable unit is supplied to the second clutch via the intermediate connection of an individual control element.

11. The method of claim 10 , further comprising actuating the first clutch and the second clutch with a clutch actuation mechanism on which the control variable acts in order to actuate the clutches, and adjusting the value of the control variable acting on the first clutch by influencing the control variable unit, and adjusting the value of the control variable acting on the second clutch by the individual control element additionally assigned to the second clutch.

12. The method of claim 10 , wherein the control variable unit is a hydraulic pump and the control variable is hydraulic pressure and the change of the control variable acting on the first clutch is effected by changing the rotational speed of a hydraulic pump.

13. A gearless differential unit for an axle of a motor vehicle that can be driven at least at times, wherein the differential unit comprises:
an input element;
a first output element couplable to the input element via a first frictionally engaged clutch to transmit a drive moment to a first drive wheel;
a second output element, couplable to the input element via a second frictionally engaged clutch to transmit a drive moment to a second drive wheel; and
a control variable unit that is programmed to provide a control variable output by adjusting drive moment transmittable by the clutches that is supplied to the first clutch without intermediate connection of an individual control element, while the control variable is supplied to the second clutch via the intermediate connection of the individual control element; and
wherein the first clutch and the second clutch have clutch characteristics that are distinct from one another.

14. The differential unit of claim 13 , wherein the control variable is hydraulic pressure, the system further comprising a rotational speed-regulated hydraulic pump as the control variable unit, wherein the control variable change influencing the clutch moment of the first clutch is effected directly via the change of the rotational speed of the hydraulic pump, while the second clutch is additionally assigned an individual control element located downstream of the hydraulic pump, via which the control variable made available by the hydraulic pump is additionally reducible in the value.

15. The differential unit of claim 13 , wherein the clutch characteristics of the first clutch and the clutch characteristics of the second clutch are such that when both clutches are supplied with a control variable of the same value the second clutch is capable of transmitting a greater clutch moment than the first clutch.

16. The differential unit of claim 13 , wherein the clutch characteristics of the first clutch and the clutch characteristics of the second clutch are such that, by influencing the control variable via the individual control element, the second clutch is configured to be assigned a transmittable clutch moment that is higher, and a transmittable clutch moment that is lower, than can be assigned to the first clutch.

17. The differential unit of claim 13 , wherein the second clutch has a pressure point that is higher than a pressure point of the first clutch.

18. The differential unit of claim 13 , wherein the second clutch has an effective clutch friction area that is larger than an effective clutch friction area of the first clutch.

19. The differential unit of claim 13 , wherein the second clutch has an effective clutch diameter that is larger than an effective clutch diameter of the first clutch.

Assignees

• Gkn Automotive Ltd

Inventors

• Möhlmann Reinhard

Classifications

• B60K2023/0866

  with hydraulic means only · CPC title

• B60K2023/0858

  with electric means, e.g. electro-hydraulic means · CPC title

• F16D2500/1026

  Hydraulic · CPC title

• F16D2500/1045

  Friction clutch · CPC title

• F16H48/19 Primary

  consisting of two linked clutches · CPC title