Patent ID: 6820728
Filing Date: 2004-11-23
Classification: B60L,B60T,B60W,F16F

Abstract:
A vehicle retarder system comprising:a main drive shaft, and a housing structure supporting the main drive shaft; a hydraulic electromagnetic retarder having a field winding secured to the main drive shaft in surrounding relation thereto, and an induction drum secured to the housing structure; the space between said housing structure and said main drive shaft defining a cavity; a secondary drive shaft drivingly coupled to said main drive shaft by a gear train; a permanent magnet generator having a permanent magnet rotor secured to said secondary drive shaft, and an output winding secured to the housing structure to provide an alternating output voltage responsive to rotation of the secondary drive shaft; a retarder electronic circuit means, selectively operable for developing an output voltage and applying electrical energy from the permanent magnet generator to the electromagnetic retarder; an exciter generator having a rotor secured to the drive shaft, and an output winding secured to the housing structure to provide an alternating output voltage, and a stator with an excitation winding secured to the housing structure; a power control unit for receiving the alternating output voltage of the permanent magnet generator in order to power the excitation winding of the exciter generator, a controller for selectively controlling the power control unit so as to selectively energize the stator of the excitation generator from the output winding of the permanent magnet generator, rectifiers carried by the main drive shaft and rotating therewith, for rectifying the alternating output from the rotor of the exciter generator and applying the thus rectified output to the field winding of the retarder so as to produce an electromagnetic torque that slows the main drive shaft rotation; and, where said hydraulic-electromagnetic retarder further comprises a fluid circuit which can be operated upon demand to pump hydraulic fluid into and fill said cavity as necessary thus providing additional torque to supplement the electromagnetic torque generated.