Detection of the amount of wear on a motor drive system

• US 20070138899A1
• Filed: 12/08/2006
• Published: 06/21/2007
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Fellmeth, Reiner, Reeb, Wolfgang, Bollwerk, Andre
• Granted Patent: US 7,629,723 B2
• Time in Patent Office: Days
• US Class Current: 310/240
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: H01R 39/58 Means structurally associated with the current collector for indicating condition thereof, e.g. for indicating brush wear

Abstract

A method and a device, respectively, for detecting the amount of wear on the carbon brush drive system of an electrically commutated d.c. motor which is used, for example, in the form of a pump motor in a motor vehicle. The d.c. motor is driven by at least two carbon brushes and includes means for detecting the generative follow-up voltage. The amount of wear on at least one carbon brush is derived from the time behavior of the generative motor voltage and displayed to the driver.

Claims

1. A method for detecting an amount of wear on a carbon brush drive system of an electrically commutated d.c. motor, the drive system having a plurality of carbon brushes, the method comprising:

detecting an amount of wear on at least one of the carbon brushes as a function of a time behavior of a generative motor voltage.

2. The method according to claim 1, wherein the motor is a pump motor in a motor vehicle.

3. The method according to claim 1, wherein the amount of wear is detected during a motor startup.

4. The method according to claim 1, wherein a single carbon brush is shorter than at least one other carbon brush for detecting the amount of wear on the carbon brushes.

5. The method according to claim 1, wherein one of the carbon brushes used for drive purposes is prevented from continuing operation at a preset amount of wear.

6. A device for detecting an amount of wear on a drive system of an electrically commutated d.c. motor, the d.c. motor being driven with the aid of a plurality of carbon brushes, the device comprising:

means for detecting a generative motor voltage; and

an arrangement for detecting an amount of wear on at least one of the carbon brushes as a function of a time behavior of the generative motor voltage.

7. The device according to claim 6, wherein the motor is a pump motor in a motor vehicle.

8. The device according to claim 6, wherein the amount of wear is detected during a motor startup.

9. The device according to claim 6, wherein a single carbon brush is shorter than at least one other carbon brush for detecting the amount of wear on the carbon brushes.

10. The device according to claim 6, further comprising a holder for the carbon brushes, wherein the holder of a single carbon brush is designed in such a way that an operation of the carbon brush is hindered at a preset amount of wear on the carbon brush.

11. The device according to claim 10, wherein the carbon brush has a contour which presses the carbon brush against a limit stop of the holder at the preset amount of wear.

12. The device according to claim 10, wherein a stranded conductor which produces an electrical contact to the carbon brush presses against a limit stop of the holder at the preset amount of wear.