Method for operating a universal motor

Patent metadata

Field	Value
Publication number	US-10461680-B2
Application number	US-201415029438-A
Country	US
Kind code	B2
Filing date	Oct 7, 2014
Priority date	Oct 17, 2013
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A method for operating a universal motor, comprising the following steps: —establishing a synthetic variable from at least two physical operating parameters of the universal motor; and —operating the universal motor using operating parameters of this type so that the synthetic variable remains at a substantially constant level or at least does not exceed a defined permissible upper limit.

First claim

The invention claimed is:

1. A method for operating a universal motor, the method comprising:
measuring a first physical operating variable corresponding to a rotational speed of an armature in the universal motor;
measuring a second physical operating variable corresponding to one of an amperage, armature voltage, and armature field voltage, in the universal motor;
ascertaining with a control device a synthetic variable corresponding to a mathematical combination of the first physical operating variable and the second physical operating variable; and
operating the universal motor with the control device to influence a firing angle to adjust the second physical operating variable to maintain the synthetic variable at or below a predetermined level while the rotational speed of the armature in the universal motor changes during at least one of a braking and a start-up operation to reduce or eliminate sparking from a plurality of brushes in the universal motor.

2. The method as claimed in claim 1 , the operating the universal motor further comprising:
operating the universal motor with the control device to influence the firing angle of the motor to adjust the second physical operating variable to maintain the synthetic variable at a substantially constant level while the rotational speed of the universal motor changes.

3. The method as claimed in claim 1 , the operating the universal motor further comprising:
ascertaining with the control device the synthetic variable as a product of (i) the rotational speed of the armature, and (ii) an amperage in the universal motor.

4. A universal motor comprising:
a commutator;
a plurality of brushes;
an armature; and
a control device configured to control a firing angle of an electrical signal supplied to the plurality of brushes and the commutator to turn the armature, the control device being configured to:
measure a first physical operating variable corresponding to a rotational speed of an armature in the universal motor;
measure a second physical operating variable corresponding to one of an amperage, armature voltage, and armature field voltage, in the universal motor;
ascertain a synthetic variable corresponding to a mathematical combination of the first physical operating variable and the second physical operating variable; and
operate the universal motor to influence a firing angle to adjust the second physical operating variable to maintain the synthetic variable at or below a predetermined level while the rotational speed of the armature in the universal motor changes during at least one of a braking and a start-up operation to reduce or eliminate brush sparking in the universal motor.

5. The universal motor as claimed in claim 4 , the control device being further configured to:
operate the universal motor to influence the firing angle of the motor to adjust the second physical operating variable to maintain the synthetic variable at a substantially constant level while the rotational speed of the universal motor changes.

6. The universal motor as claimed in claim 4 , the control device being further configured to:
ascertain the synthetic variable as a product of (i) the rotational speed of the armature, and (ii) an amperage in the universal motor.

Assignees

• Bosch Gmbh Robert

Inventors

• Wiszniewski Jacek
• Dengler Klaus

Classifications

• H02P1/18

  for starting an individual DC motor · CPC title

• H02P25/14 Primary

  Universal motors (H02P25/12 takes precedence) · CPC title

• H02P1/16

  for starting dynamo-electric motors or dynamo-electric converters · CPC title

• H02P3/06

  for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter · CPC title