| 摘要 |
<p>420,122. Winches ; cooling motors. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Allgemeine Elektricitõts-Ges.; 2, Friedrich Karl-Ufer, Berlin) Dec. 19. 1933, No. 35744. Convention date, Dec. 20, 1932. [Class 78 (v)] [See also Group XXXV] In towing winches, &c., controlled by an electric motor in order that the motor may be prevented from being held for a long time under current in one position, whereby the commutator will be unevenly and unduly heated, an auxiliary motor is provided which constantly produces a slow movement between the pole casing and the armature of the main motor. In one arrangement the rotatable casing 3 of the main motor is coupled through the gearing 4 to an auxiliary motor 5. The voltage of the Leonard generator 6, Fig. 2, which supplies the motor 3, is controlled by a field regulator 9 which is operated by a travelling nut 10 running on a spindle 11 driven by the winch through a disconnectable coupling 12. The auxiliary motor is switched out in the end position of the regulator, or on rotation over a range which, under working conditions, can only be set up for a short period with a temporary overload or underload. The same result is attained by the provision of a current limiter which switches on and off in direct dependence on the load of the motor 5, or by placing a voltage cut-out across the armature of the motor 3. The motor 3 is cooled by a current of air supplied by a fan 13 driven by the motor 5. In a modification the main motor is coupled directly to one of the free shaft ends of a differential gear, and the auxiliary motor slowly drives the second free shaft end. A self-checking transmission may be placed between the auxiliary motor and the differential. When a Leonard set is interposed, the casing of the main motor, or the third shaft of the differential may be coupled to the set, and the separate auxiliary motor dispensed with.</p> |
