Electric motor having a thermal fuse

Patent metadata

Field	Value
Publication number	US-9667123-B2
Application number	US-201514739100-A
Country	US
Kind code	B2
Filing date	Jun 15, 2015
Priority date	Dec 15, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

An electric motor for driving a motor vehicle component, particularly a fan wheel for cooling coolant water, contains a rotor that is rotatably mounted opposite a stator, and an electronic system. The electronic system contains a punched grid provided with a plastic over-mold and a current path which conducts the motor current and has two current path ends spaced apart from one another forming an interruption point that is bridged by a thermal fuse. The thermal fuse has a spring-loaded contact bridge which is held so as to pivot about an axis that extends perpendicularly to the plane in which the interruption point lies.

First claim

The invention claimed is:

1. An electric motor for driving a motor vehicle component, the electric motor comprising:
a stator;
a rotor mounted rotatably relative to said stator; and
an electronics system having a plastic over-mold, a punched grid covered by said plastic over-mold and a current path conducting a motor current, said current path having a thermal fuse, two current path ends lying in a same plane and spaced apart from one another forming an interruption point being bridged by said thermal fuse, said thermal fuse having a spring-loaded contact bridge, said spring-loaded contact bridge being held pivotably about a pivot axis extending perpendicularly to a plane in which said interruption point lies, said thermal fuse having a spring element with a first spring leg and a second spring leg extending at right angles to said first spring leg, said spring-loaded contact bridge being associated with said spring element, said spring-loaded contact bridge, when said thermal fuse trips, pivots in a manner of a combined rotary and shearing movement in a plane of the interruption point, as a result of a spring return force of said spring element.

2. The electric motor according to claim 1 , wherein said spring element has a spring eyelet and said first and second spring legs transition into one another via said spring eyelet, said spring eyelet in a mounted state of said spring element coaxially surrounds the pivot axis.

3. The electric motor according to claim 2 , wherein in an assembled state of said spring element, said spring eyelet surrounds said pivot axis coaxially.

4. The electric motor according to claim 1 , wherein:
said first spring leg bears against said spring-loaded contact bridge under a spring preload; and
said plastic over-mold has a storage compartment and said second spring leg lies in said storage compartment of said plastic over-mold.

5. The electric motor according to claim 1 , wherein said spring element is a groove-spring connection.

6. The electric motor according to claim 1 , wherein said thermal fuse has a guide element, said spring element and said spring-loaded contact bridge are coupled via said guide element.

7. The electric motor according to claim 1 , wherein said first spring leg has a leg end and is bent at said leg end.

8. The electric motor according to claim 1 , wherein said pivot axis is formed from said plastic over-mold.

9. The electric motor according to claim 1 , wherein said spring-loaded contact bridge has, at both ends, contact surfaces contacted with one of said path ends, wherein said pivot axis lies in a region of one of said contact surfaces.

10. The electric motor according to claim 9 , wherein both of said contact surfaces of said spring-loaded contact bridge are soldered to said current path ends.

11. The electric motor according to claim 1 , wherein said spring-loaded contact bridge is formed as, or in a manner of a punched and bent part having a number of bends forming a middle raised bridge portion.

12. The electric motor according to claim 1 , wherein the electric motor drives a fan wheel for cooling coolant water.

Assignees

• Brose Fahrzeugteile

Inventors

• Zick Stefan
• Ehrmann Steffen

Classifications

• H02K11/25 Primary

  Devices for sensing temperature, or actuated thereby · CPC title

• H01H2037/762

  using a spring for opening the circuit when the fusible element melts · CPC title

• H02K11/0047 Primary

  Electricity · mapped topic