Brushless DC-motor
US8314580B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 2005 |
| Grant date | Nov 20, 2012 |
| Priority date | — |
| Expiry date | Nov 5, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/21
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A DC-motor (46) actuates a highly-reduced reduction gear of an actuating drive for a flap or valve in order to regulate a gas or liquid volume flow, particularly for heating/ventilation/climatization, or fire or room protection. Current flow in the stator coils (A, B, C) is commutated in a program-controlled manner without integrated position sensors. Algorithms enable counting rotations of rotor (54) of the DC-motor (46). Problems related to the principle of motor rotation speed at low rpm are prevented. The DC-motor (46) includes a stator (44) having three stator coils (A, B, C) which extend over 3n stator poles (52), and an annular-shaped permanent magnet rotor (54) having 2m permanent magnet segments with alternating polarity (N, S), a coaxial cup-shaped external rotor (110) and a coaxial drive shaft (108), whereby n and m are whole multiplication factor numbers (1, 2, 3, 4) and are different from each other. Drive shaft (112) comprises, preferably, a spring (120) for the automatic return in case of current interruption.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.