Electromotive drive
AssigneeSiemens Aktiengesellschaft
InventorsKarl-Friedrich Diener, Hermann-Josef Conraths, Werner Hopf, Wolfgang Lienert, Ekkehard Pittius, Peter Seitz
Life of this patent
Estimating the term…
Abstract
The aim is to improve the cooling of a self-ventilated electric motor (1). To this end, an electromagnetic speed limiting and governing device is provided between the motor shaft (3) and the fan wheel (2), the fan wheel, which is driven via an electromagnetic slip coupling (6, 10) in accordance with the motor speed, being mounted freely rotatably on the motor casing or on the motor bearing plate (5).
Claims44
An electromotive drive, with at least one fan wheel (2) which can be driven by an electric motor (1) and is supported freely rotatably by a motor casing (5) of the electric motor (1) via a bearing (4, 4′),
- wherein an electromagnetic slip coupling dependent on the motor speed is arranged between a motor shaft (3) and the freely rotatably mounted fan wheel,
- wherein an electromagnetic speed limiting and governing device which limits the delivery of cooling air to the required quantity of cooling air is provided between the motor shaft (3) and the fan wheel (2),
- wherein the fan wheel speed decreases in relation to the motor speed, when the motor speed exceeds a predetermined level so that the slip coupling becomes increasingly ineffective to engage the fan wheel, and increases again, when the motor speed drops below the predetermined level and the slip coupling increasingly re-engages the fan wheel, and
- wherein the motor shaft (3) bears permanent magnets (6), and a hub (7) of the fan wheel (2) has an electrically conductive part or the fan wheel is provided with permanent magnets and the motor shaft is provided with an electrically conductive part.
An electromotive drive, comprising:
- an electric motor having a motor casing and a motor shaft received in the motor casing;
- at least one fan wheel driven by the electric motor and having a hub,
- a bearing unit positioned between the motor casing and the fan wheel for so supporting the fan wheel as to freely rotate with respect to the motor casing;
- an electromagnetic speed limiting and governing device for controlling a supply of cooling air, said electromagnetic speed limiting and governing device including an electromagnetic slip coupling, which is disposed between the motor shaft and the fan wheel and so configured that at a predetermined motor speed an engagement action of the slip coupling with the fan wheel decreases to almost zero as the motor speed further increases, and increases to full engagement action, as the motor speed drops again below the predetermined motor speed, and
- wherein the slip coupling includes a configuration selected from the group consisting of a first configuration in which the motor shaft supports a permanent magnet arrangement and the hub of the fan wheel has an electrically conductive part, and a second configuration in which the fan wheel is provided with a permanent magnet arrangement and the motor shaft is provided with an electrically conductive part.
Dependencies are inferred from the claim text.