Electric motor with functional monitoring of the motor bearings

• US 9,876,410 B2
• Filed: 03/13/2014
• Issued: 01/23/2018
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Ebm-Papst Mulfingen GmbH & Company KG
• Original Assignee: Ebm-Papst Mulfingen GmbH & Company KG
• Inventors: Sauer, Dipl.-Ing. Thomas
• Primary Examiner(s): Luks, Jeremy
• Application Number:
  US14/772,993
• Publication Number:
  US 20160020677A1
• Time in Patent Office: 1,412 Days
• Field of Search: 310 51, 310 90, 310 68 B
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: H02K 11/20 for measuring, monitoring, testing, protecting or switching rectifiers H02K11/04; power electronics H02K11/33
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 5/161 radially supporting the rotary shaft at both ends of the rotor H02K5/165, H02K5/167, H02K5/173 take precedence
• CPC Class Codes: H02K 5/1675 radially supporting the rotary shaft at only one end of the rotor H02K5/1677 takes precedence
• CPC Class Codes: H02K 5/24 specially adapted for suppression or reduction of noise or vibrations

Abstract

The present invention relates to an electric motor, comprising a stator and a rotor that can rotate relative to the stator and that is mounted in bearing arrangements, and also comprising a motor housing and a vibration sensor to pick up vibrations that occur in the electric motor and that are caused by malfunctions of the bearing arrangements. The configuration provided here is that of an external-rotor motor. The stator has a bearing support tube that is connected at one end to a ring-shaped stator flange. Bearing arrangements are arranged at a distance from each other in the bearing support tube in the direction of a center longitudinal axis of the bearing support tube, in which a shaft of the rotor is supported. The vibration sensor is attached to the stator flange.

Claims

1. An electric motor, comprising a stator and a rotor that can rotate relative to the stator and that is mounted in bearing arrangements, and also comprising a motor housing and a vibration sensor to pick up vibrations that occur in the electric motor and that are caused by malfunctions of the bearing arrangements, characterized by its configuration as an external-rotor motor, whereby the stator has a bearing support tube that is connected at one end to a ring-shaped stator flange, and bearing arrangements that are arranged at a distance from each other in the bearing support tube in the direction of a center longitudinal axis of the bearing support tube, in which a shaft of the rotor is supported, and the vibration sensor is attached to the stator flange, whereby the vibration sensor is attached directly to a free surface of the stator flange that immediately adjoins the bearing support tube in the radial direction relative to the longitudinal axis, and whereby the stator flange and the bearing support tube are configured in one piece characterized in that the vibration sensor is attached on the side of the stator flange facing away from the rotor.

2. The electric motor according to claim 1, characterized in that the vibration sensor is configured as a vibration rate sensor.

3. The electric motor according to claim 2, characterized in that the vibration rate sensor is a laser-Doppler vibrometer, a MEMS (micro-electro-mechanical system) based on a semiconductor, or else a piezoelectric sensor.

4. The electric motor according to claim 1, characterized in that the bearing support tube is arranged inside the stator laminated core, which has motor windings configured as single-tooth windings.

5. The electric motor according to claim 1, characterized in that, on the stator flange, on the side facing away from the rotor, a partial housing is attached which holds the motor electronics and in which the vibration sensor is accommodated.

6. The electric motor according to claim 1, characterized in that a metal structure-borne sound-conducting element, for example, in the form of a disc, is arranged between the vibration sensor and the stator flange.

7. The electric motor according to claim 6, characterized in that the vibration sensor is connected via a signal cable to evaluation electronics that are arranged on the printed circuit board of the motor electronics.