Integrated retarder and accessory device

A method for retarding the motion of a vehicle that has an engine, a battery, a main drive shaft, and a housing structure rotatably supporting the main drive shaft, to minimize energy drain from the battery, comprising the steps of:

• selecting an electromagnetic retarder that has two relatively rotatable elements, one of which is a field winding that requires energization by an electric current;
• placing both retarder elements in surrounding relation to the main drive shaft with one element being secured to the housing structure and the other to the main drive shaft;
• selecting a gear train operatively connected on one end to the main drive shaft and on the other end to a cooperating shaft to rotate therewith;
• selecting a permanent magnet generator having two relatively rotatable elements, one carrying permanent magnets, the other having a winding to provide an alternating output voltage;
• placing both permanent magnet generator elements in surrounding relation to the cooperating shaft;
• selecting an exciter generator having a rotor with an excitation winding, and a stator, and securing the rotor to the main drive shaft and the stator to the housing structure;
• applying the alternating output voltage of the permanent magnet generator to a control unit whereby the control unit is used to regulate the level of rectified current to the excitation winding of the exciter generator;
• and,
• then rectifying the output from the rotor of the exciter generator and applying the thus rectified output to the field winding of the retarder to produce a torque that slows the main drive shaft rotation.

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 ring secured to the housing structure;
• the space between said housing structure and said main drive shaft defining a cavity;
• a permanent magnet generator having a permanent magnet rotor secured to the main drive shaft, and an output winding secured to the housing structure to provide an alternating output voltage responsive to shaft rotation;
• an exciter generator having a rotor secured to the main drive shaft to produce 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.

In a vehicle having an engine, a battery, a drive shaft, and a hydraulic-electromagnetic retarder having an induction ring and a field winding carried on the drive shaft, the space between the induction ring and rotor defining an annular region, the improvement comprising:

• a permanent magnet motor/generator cooperatively associated with the drive shaft;
• first electronic circuit means, selectively operable when it is desired to start the engine, for transmitting energy from the battery to the permanent magnet motor/generator so as to apply driving torque to the drive shaft for starting the engine;
• second electronic circuit means, selectively operable when the engine is running and electrical energy is then being generated by the permanent magnet motor/generator in response to the drive shaft rotation, for applying electrical energy that is then developed by the permanent magnet motor/generator to the hydraulic-electromagnetic retarder to apply torque to the drive shaft for slowing the shaft rotation;
• and,
• a third electronic circuit means, for controlling the flow of hydraulic fluid into the annular region between the rotor and induction ring.

In a vehicle having an engine, a battery, and a drive shaft, apparatus for controlling the driving torque applied to the drive shaft in spite of input energy pulsations inherent in the engine operation, the apparatus comprising:

• a hydraulic-electromagnetic retarder comprising an induction drum and a rotor where the space between the induction drum and rotor defines an annular region, the retarder drivingly coupled to the drive shaft;
• a permanent magnet motor/generator drivingly coupled to the drive shaft;
• a first electronic circuit means, selectively operable when the engine is running and electrical energy is then being generated by the motor/generator in response to the drive shaft rotation, for applying electrical energy that is then developed by the motor/generator to the electromagnetic retarder to apply torque to the drive shaft for slowing the shaft rotation;
• first sensing means coupled to the drive shaft for continuously sensing the rotational position of the shaft;
• second sensing means coupled to the drive shaft for continuously sensing the torque load carried by the drive shaft;
• a second electronic circuit means, for controlling the flow of hydraulic fluid into the annular region between the rotor and induction drum;
• and
• means responsive to both of the sensing means for continuously modifying the torque applied to the drive shaft by the electromagnetic retarder.

A drive system for a vehicle which produces a positive torque along a rotatable drive shaft where the improvement comprises the addition of an hydraulic-electromagnetic retarder having an induction drum and a field winding where the space between the induction drum and field winding define an annular region, an exciter generator having a rotor and a permanent magnet generator having a rotor, where said field winding, said rotor of the exciter generator and said rotor of the permanent magnet generator are coupled about and to said rotatable drive shaft, a first means for rectifying the alternating current produced by the permanent magnet generator and applying the thus rectified output to the exciter generator, a controller for selectively controlling the first means for rectifying so as to selectively energize the exciter generator in response to an external signal received, a second means 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 a first torque that slows the rotatable drive shaft rotation and a third means for controlling the flow of hydraulic fluid into the annular region where the hydraulic fluid present within said annular region provides a second torque which cooperates with said first torque for slowing the rotatable drive shaft rotation;

• and where said retarder need not be electrically connected to either a battery or alternator.