Electric motor drive system
AssigneeRobert Bosch GmbH
InventorGerhard Schoeffler
Life of this patent
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Abstract
An electric motor drive system with an overload protector for the electric motor (10) is proposed, wherein the electric motor drive receives a signal from an input unit (18) for predetermining a desired position of a movable component. When the overload protector responds, the desired position changes to a predeterminable resting position of the movable component, which is taken by the movable component before the electric motor (10) is switched off. Apart from preventing the thermal destruction of the electric motor (10), the electric motor drive system according to the invention prevents subsequent damage, which could occur due to the fact that the component moved by the electric motor (10) could take an undefined position when an overload of the electric motor (10) occurs.
Claims15
A drive system for an electric motor which moves a movable component, comprising:
- an input unit to determine a desired position for the movable component;
- overload detection means for detecting a motor overload from the motor temperature and for generating an overload signal in response to the overload;
- and
- control means for actuating the motor to move the movable component toward the desired position, and for replacing the desired position with a predetermined resting position if the overload signal is generated and then switching the motor off only after the resting position has been reached, even if the overload signal continues to be present during movement of the movable component to the resting position.
A drive system for an electric motor which moves a movable component, comprising:
- an input unit to determine a desired position for the movable component;
- overload detection means for detecting a motor overload, the overload detection means including
- first means for finding the power consumption of the motor or a quantity that is a function of the power consumption,
- second means for integrating the power consumption or the quantity that is a function of the power consumption to find an integration value, and
- third means for comparing the integration value to a predetermined value;
- and
- control means for actuating the motor to move the movable component toward the desired position, for turning the motor off within a limited time period if a motor overload is detected, and for causing the motor to move the movable component toward a predetermined resting position during the limited time period if a motor overload is detected, even if the motor overload continues during movement of the movable component toward the resting position.
Dependencies are inferred from the claim text.