ENCAPSULATED STEPPER MOTOR

• Main Authors: KUWERT, OSWALD, HEINE, GUNTHER KARL, KLEIN, ENRIQUE JORGE, SEEGER, BERNHARD MICHAEL
• Format: Patent
• Language: English; Korean
• Published: 23.04.1998
• Edition: 6
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; GENERATION; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

없음 A single-housing stepper motor is disclosed comprising a rotor (14) and stator (16) both mounted in a single housing (10) (which may be a part of the base casting) the bearings (40, 42) supporting the rotor for rotation within the housing both being located on the rotor shaft on the same side of the rotor adjacent one another, the opposite end of the single housing being covered with a sealed plastic cover (44). The lamination stack (18) that forms the stator is piloted by machined surfaces (30, 32) into a high tolerence fit within the housing (10), and clamped in place with a simple wave washer/snap ring combination (66, 68). The stator laminations are designed with a decagonally interrupted periphery which can be used without changing the area of the poles (20), and allow space for the wires to the poles to be lead out past the lamination stack. A sealing plastic cover (44) is provided with a special pressure finger (60) to hold the wires (36) running to the stator coils away from the sharp edges of the stack wave spring and snap ring; the cover is also specially designed to capture the wires to relieve the strain on the wires. Alternatively (Fig. 5), the bearings (104, 106) may be located on opposite sides of the rotor (14), the stator (16) is piloted into a precisely aligned position on an inner wall of the housing adjacent the front bearing (104), the other end of the stack being held in place by a bearing holder (116) interposed between the rear bearing (106) and the edge of the stator (16), the holding forces being precisely defined to accurately align the stator with the rotor of the stepper motor. The entire assembly, including the rear bearing, bearing holder and stator support, as well as the stator is held together with a star-shaped spring (15)) comprising a plurality of fingers (106A-D) that slide into and rotate within slots (158A-D) in the housing in a bayonet arrangement. These slots allow insertion of the star-shaped spring under pressure, and rotation under pressure within the groove (160) to a seated position. The same groove then accepts the (160) to a seated position. The same groove then accepts the encapsulating plastic cover (170), preferably inserted through the same openings as the bayonet arms of the spring, though being rotated in the opposite direction.