Electrical machine with torque limitation

• US 7,671,501 B2
• Filed: 12/18/2007
• Issued: 03/02/2010
• Est. Priority Date: 12/20/2006
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Groening, Ingolf
• Primary Examiner(s): Lam; Thanh
• Application Number:
  US11/958,679
• Publication Number:
  US 20080150381A1
• Time in Patent Office: 805 Days
• Field of Search: 310/86, 310103-104, 310/266, 310112-114, 310/261, 310/267
• US Class Current: 310/114
• CPC Class Codes: H02K 16/02 Machines with one stator and two or more rotors
• CPC Class Codes: H02K 21/16 having annular armature cores with salient poles with homopolar co-operation H02K21/20
• CPC Class Codes: H02K 7/11 with dynamo-electric clutches

Abstract

An electrical machine with torque limitation which is only slightly larger structurally than an identical machine without torque limitation and is thus as compact as possible has a stator with windings and a rotor supported movably relative to the stator, recesses distributed over the circumference and extending axially are present on the rotor surface, and a driver, located coaxially relative to the rotor and extending axially, is located in the air gap between the rotor and the stator, and exciter magnets on the upper driver face toward the stator and driver magnets on the inner driver face toward the rotor are located in such a way that upon rotation of the driver, the rotor is likewise capable of being set into rotation as a result of the rotary field generated by the windings and by the driver magnets.

Claims

1. An electrical machine, comprising a stator with windings;

a rotor supported movably relative to said stator, said rotor having a rotor surface provided with longitudinal recesses which are distributed over a circumference and extending axially;

a driver located coaxially relative to said rotor and extending axially, said driver being located in an air gap between said rotor and said stator; and

exciter magnets on an upper driver face toward said stator and driver magnets on an inner driver face toward said rotor located in such a way that upon rotation of said driver, said rotor is likewise settable into rotation as a result of a rotary field generated by said windings.

2. An electrical machine as defined in claim 1, wherein said rotor has a rotor shaft, said driver being supported on said rotor shaft.

3. An electrical machine as defined in claim 1, wherein said longitudinal recesses are distributed uniformly over the circumference of said rotor surface and said driver magnets are distributed uniformly over a circumference of said inner driver face, wherein longitudinal protrusions located between said longitudinal recesses and said driver magnets are located diametrically opposite to one another.

4. An electrical machine as defined in claim 1, wherein said driver magnets are located on said inner driver face corresponding to said longitudinal recesses on said rotor surface.

5. An electrical machine as defined in claim 3, wherein said driver magnets and said longitudinal protrusions have dimensions that are dimensioned in accordance with a torque threshold value, upon exceeding of which an rpm of said rotor decreases relative to an rpm of said driver.

6. A rotary-current synchronous motor with magnetic torque limitation, implemented by an electrical machine as defined in claim 1.

7. A generator with magnetic torque limitation implemented by an electrical machine as defined in claim 1.

8. A wind farm having a generator as defined in claim 7.