Method of operating an electric machine having an integrated coolant level sensor

• US 8,653,706 B2
• Filed: 01/17/2013
• Issued: 02/18/2014
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: Remy Technologies LLC (BorgWarner Incorporated)
• Inventors: Fulton, David A., Chamberlin, Bradley D.
• Primary Examiner(s): Lam, Thanh
• Application Number:
  US13/743,408
• Publication Number:
  US 20130127269A1
• Time in Patent Office: 397 Days
• Field of Search: 310 52- 59, 310/68.C
• US Class Current: 310/54
• CPC Class Codes: H02K 11/20 for measuring, monitoring, testing, protecting or switching rectifiers H02K11/04; power electronics H02K11/33
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
• CPC Class Codes: H02K 9/24 Protection against failure of cooling arrangements, e.g. due to loss of cooling medium or due to interruption of the circulation of cooling medium

Abstract

A method of operating an electric machine includes flowing a coolant into an interior portion of a housing of the electric machine, and sensing a level of coolant in a coolant collection area within the interior portion with a coolant level sensor arranged at the housing.

Claims

1. A method of operating an electric machine, the method comprising:

flowing a coolant into an interior portion of a housing of the electric machine; and

sensing a level of coolant in a coolant collection area within the interior portion with a coolant level sensor mounted to a wall of the housing.

2. The method of claim 1, further comprising:

sending a signal indicating a level of coolant in the coolant collection area from the coolant level sensor to a controller.

3. The method of claim 1, further comprising:

controlling the flow of coolant based on the level of coolant in the coolant collection area.

4. The method of claim 1, further comprising:

signaling an alarm if the coolant in the coolant collection area rises above a predetermined level.

5. The method of claim 4, further comprising:

initiating an electric machine shut down if the coolant in the coolant collection area rises above the predetermined level.

6. The method of claim 1, wherein sensing a level of coolant in the coolant collection area includes sensing a change in capacitance of the coolant level sensor.

7. The method of claim 1, further comprising:

signaling an alarm if the coolant in the coolant collection area falls below a predetermined level.

8. The method of claim 7, further comprising:

shutting down the electric machine if the level of coolant in the coolant collection area falls below the predetermined level.

9. The method of claim 1, wherein sensing the level of coolant in a coolant collection area includes directly sensing a level of coolant with a coolant level sensor mounted in the housing.

10. The method of claim 1, wherein sensing a level of coolant in a coolant collection area comprises sensing the level of coolant through a wall of the housing.

11. The method of claim 1, further comprising:

ceasing the flow of coolant if the level of coolant in the coolant collection area contacts moving components of the electric machine.