| 摘要 |
<p>A thermal protection mechanism for electric motors is disclosed. A brush is urged into electrical contact with a commutator by a primary brush spring. A thermally deformable fastener releasably secures the primary brush spring to a brush housing. A secondary brush spring urges the brush away from the commutator with a force less than that of the primary spring. A thermal overload condition within the motor causes the thermally deformable fastener to substantially deform so that the force exerted on the brush by the primary spring is substantially reduced. The force exerted by the secondary spring overcomes the primary spring so that the brush is forcefully disengaged from electrical contact with the commutator, thereby terminating operation of the motor.</p> |
