Vibration motor
US5159224A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1991 |
| Grant date | Oct 27, 1992 |
| Priority date | — |
| Expiry date | May 30, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N2/16
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A vibration motor having a disk-shaped stator containing a piezoelectric excitation system, a disk-shaped rotor aligned parallel to the stator and mounted on a driven shaft in a manner fixed against relative rotation, and a pressing element that presses the rotor and stator together axially. To assure free travel of the driven shaft when the motor is currentless, the pressing element is embodied as a force-transmitting element that changes shape as a function of temperature, for instance a compression spring of memory metal. In motor operation, the element is kept at a temperature above its temperature point for the shape change, and it is disposed such that the pressing force between the rotor and stator diminishes as a result of the shape change ensuing if the temperature drops below this temperature point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.