Starter motor having labyrinth ventilation passage
AssigneeDenso Corporation
InventorsYoshikazu Yokochi, Masayuki Tomura
Life of this patent
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Abstract
An inside space of a starter motor having a motor, a magnetic switch and a reduction gear train is ventilated through a ventilation passage formed in the starter motor. The ventilation passage includes a labyrinth passage formed at a portion connecting a front housing containing the reduction gear and a center housing containing the motor and the magnetic switch. The labyrinth passage connecting a motor chamber and a switch chamber prevents brush dusts generated in the motor chamber from being scattered in the other spaces. Grease splash from the gear train does not enter into the ventilation passage separated the gear train. Thus, the ventilation passage well functions for a long time without being clogged with the grease, brush dusts or the mixture thereof.
Claims5
A starter motor for cranking an internal combustion engine, the starter motor comprising:
- a motor having an armature for generating a rotational torque, the armature being housed in a motor chamber;
- a magnetic switch for supplying electric power to the motor and for engaging the armature with the internal combustion engine to transfer the rotational torque of the armature to the internal combustion engine, the magnetic switch being housed in a switch chamber;
- a reduction gear train for reducing rotational speed of the armature, the reduction gear train being housed in a gear chamber;
- and
- a ventilation passage formed in the starter motor for ventilating the motor chamber and the switch chamber, the ventilation passage including a communicating passage connecting the motor chamber and the switch chamber, the communicating passage being formed around the gear chamber bypassing the gear chamber.
A starter motor for cranking an internal combustion engine, the starter motor comprising:
- a motor having an armature for generating a rotational torque, the armature being housed in a motor chamber;
- a magnetic switch for supplying electric power to the motor and for engaging the armature with the internal combustion engine to transfer the rotational torque of the armature to the internal combustion engine, the magnetic switch being housed in a switch chamber;
- a reduction gear train for reducing rotational speed of the armature, the reduction gear train being housed in a gear chamber;
- and
- a ventilation passage formed in the starter motor for ventilating the motor chamber and the switch chamber, the ventilation passage including a communicating passage connecting the motor chamber and the switch chamber, the communicating passage being formed around the gear chamber bypassing the gear chamber, wherein:
- the gear chamber is formed with a front housing and a center housing, both housings being connected to each other by abutting connecting surfaces of both housings;
- and
- cavities are formed on each connecting surface, the cavities formed on the connecting surface of the front housing being positioned not to completely overlap but partially overlap the cavities formed on the connecting surface of the center housing, thereby forming a labyrinth passage.
Dependencies are inferred from the claim text.