Transmissionless drive system
First Claim
1. A vehicle driving system comprising:
- a mechanical differential means having a first input shaft for being driven at a rotational speed of ±
ω
S1, a second input shaft for being driven at a rotational speed of ±
ω
S2, and an output shaft, said differential means for driving said output shaft at a rotational speed ω
S =1/2 (±
ω
S1 ±
ω
S2) where the algebraic sign indicates direction of rotation;
a first controllable speed drive motor connected to said first input shaft for rotation thereof;
a second controllable speed drive motor connected to said second input shaft for rotation thereof;
a first power source connected to said first drive motor, said first power source including control means for controlling the speed of said first drive motor;
a second power source connected to said second drive motor, said second power source including control means for controlling the speed of said second drive motor;
first rpm comparison means connected to said first drive motor for sensing the rpm ω
M1 thereof and having an input for receiving an rpm reference signal ω
R1, said comparison means for producing a first output error signal proportional to ω
R1 -ω
M1 at an output thereof, said output connected to said control means of said first power source whereby said first drive motor, said first power source, and said first comparison means forming a first closed loop servo system;
second rpm comparison means connected to said second drive motor for sensing the rpm ω
M2 thereof and having an input for receiving an rpm reference signal ω
R2, said second comparison means for producing a second output error signal proportional to ω
R2 -ω
M2 at an output thereof, said output connected to said control means of said second power source whereby said second drive motor, said second power source, and said comparison means forming a second closed loop servo system;
torque reference means for producing a selectable torque rpm reference signal ω
T ;
acceleration reference means for producing a selectable acceleration rpm reference signal ω
A ;
first calculation means connected to said torque reference means and said acceleration reference means for calculating said rpm reference signal ω
R1 from the algebraic sum of ω
T and ω
A, said first calculation means having an output for said sum connected to said input of said first rpm comparison means; and
second calculation means connected to said torque reference means for calculating said rpm reference signal ω
R2 from the algebraic difference of ω
T and ω
A, said second calculation means having an output for said difference connected to said input of said second rpm comparison means;
whereby said output shaft rotates at a rotational speed ω
S equal to the rpm represented by acceleration rpm reference signal ω
A.
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Accused Products
Abstract
A continuously variable transmissionless drive system providing maximum torque at low speeds. The system is usable in a hybrid vehicle having a prime mover, such as an internal combustion engine, operated at its optimum rpm for efficiency. The prime mover drives a pair of amplidynes which in turn operate a pair of dc motors to produce rotation of the output shaft for driving the wheels of the vehicle via a novel differential drive system which drives the output shafts in which the effective gear ratio may be externally controlled to vary from a very high step down ratio producing very high torque to a one-to-one ratio for driving at a constant speed. Each drive motor is connected to a separate bevel gear in the differential and control of the output shaft speed and torque is obtained by controlling the speed and direction of rotating of the bevel drive gears. When the two bevel drive gears are rotating at the same rpm but in opposite directions, no output is obtained from the output shafts of the differential unit. When there is a difference in speed between the two bevel drive gears, a spider assembly in the differential unit will rotate at an rpm equal to one-half of the difference in the speeds of the two bevel drive gears and will drive the output shafts at that rpm. The speeds of the motors are controlled by controlling two closed loop servo systems including the amplidynes using two rpm reference signals produced by a network of synchros and small dc control motors. The dc control motors are responsive to signals generated by a foot pedal control operating an acceleration control system.
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Citations
16 Claims
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1. A vehicle driving system comprising:
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a mechanical differential means having a first input shaft for being driven at a rotational speed of ±
ω
S1, a second input shaft for being driven at a rotational speed of ±
ω
S2, and an output shaft, said differential means for driving said output shaft at a rotational speed ω
S =1/2 (±
ω
S1 ±
ω
S2) where the algebraic sign indicates direction of rotation;a first controllable speed drive motor connected to said first input shaft for rotation thereof; a second controllable speed drive motor connected to said second input shaft for rotation thereof; a first power source connected to said first drive motor, said first power source including control means for controlling the speed of said first drive motor; a second power source connected to said second drive motor, said second power source including control means for controlling the speed of said second drive motor; first rpm comparison means connected to said first drive motor for sensing the rpm ω
M1 thereof and having an input for receiving an rpm reference signal ω
R1, said comparison means for producing a first output error signal proportional to ω
R1 -ω
M1 at an output thereof, said output connected to said control means of said first power source whereby said first drive motor, said first power source, and said first comparison means forming a first closed loop servo system;second rpm comparison means connected to said second drive motor for sensing the rpm ω
M2 thereof and having an input for receiving an rpm reference signal ω
R2, said second comparison means for producing a second output error signal proportional to ω
R2 -ω
M2 at an output thereof, said output connected to said control means of said second power source whereby said second drive motor, said second power source, and said comparison means forming a second closed loop servo system;torque reference means for producing a selectable torque rpm reference signal ω
T ;acceleration reference means for producing a selectable acceleration rpm reference signal ω
A ;first calculation means connected to said torque reference means and said acceleration reference means for calculating said rpm reference signal ω
R1 from the algebraic sum of ω
T and ω
A, said first calculation means having an output for said sum connected to said input of said first rpm comparison means; andsecond calculation means connected to said torque reference means for calculating said rpm reference signal ω
R2 from the algebraic difference of ω
T and ω
A, said second calculation means having an output for said difference connected to said input of said second rpm comparison means;whereby said output shaft rotates at a rotational speed ω
S equal to the rpm represented by acceleration rpm reference signal ω
A. - View Dependent Claims (2, 3, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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4. A transmissionless drive system for vehicles having a pair of vehicle drive wheels, said system comprising in combination:
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a prime mover; first and second amplidynes each having a control input, said amplidynes connected to and driven by said prime mover; a first drive motor electrically connected to the dc output of said first amplidyne; a second drive motor electrically connected to the dc output of said second amplidyne; a double differential unit having a first differential portion comprising a first bevel gear driven by said first drive motor, a second bevel gear driven by said second drive motor, a first pair of pinion gears differentially driven by said first and second bevel gears, and a spider assembly for supporting said pair of pinion gears, and a second differential portion comprising a second pair of pinion gears supported by said spider assembly, a third bevel gear connected to a first output shaft, said first output shaft connected to a first of said pair of drive wheels, a fourth bevel gear connected to a second output shaft, said second output shaft connected to a second of said pair of drive wheels, said third and fourth bevel gears driven by said second pair of pinion gears; and control means for controlling the rotational speed of said first and second drive motors to thereby provide variation in the torque and the speed rotation of said vehicle drive wheels, said control means comprising controllable speed reference signal producing means, and closed loop speed control means associated with each of said first and second amplidynes and said first and second drive motors, said speed control means connected to and responsive to said speed reference signal producing means. - View Dependent Claims (5, 6)
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16. A transmissionless drive system for vehicles comprising in combination:
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a prime mover; first and second amplidynes connected to and driven by said prime mover, each of said amplidynes having an input for a control signal for controlling the output voltage thereof; a first drive motor electrically connected to the output of said first amplidyne; a second drive motor electrically connected to the output of said second amplidyne; a double differential unit having an outer differential including a first bevel gear driven by said first drive motor, and a second bevel gear driven by said second drive motor, and an inner differential driven by said outer differential including a third bevel gear connected to a first output shaft, and a fourth bevel gear connected to a second output shaft; a spider having pinion gears for coupling said first and second bevel gears to said third and fourth bevel gears; a pair of vehicle drive wheels connected to said first and second output shafts; a variable speed torque motor driving a first synchro generator and a second synchro generator; a variable speed acceleration reference motor driving a first differential synchro generator and a second differential synchro generator, said first differential synchro generator connected to receive an output from said first synchro generator and said second differential synchro generator connected to receive an output from said second synchro generator in an opposite phase to said connection of said first differential generator and said first synchro generator; a first control synchro transformer driven from said first drive motor and connected to receive an input from the output of said first differential synchro generator, said first control synchro transformer having an error signal output operatively connected to said control signal input of said first amplidyne for thereby controlling the speed of said first drive motor to be equal to the sum of the speed of said torque motor and said acceleration motor; and a second control synchro transformer driven by said second drive motor and connected to receive an input from the output of said second differential synchro generator, said second control synchro transformer having an error signal output operatively connected to said control signal input of said second amplidyne for thereby controlling the speed of said second drive motor to be equal to the difference between the speed of said torque motor and said acceleration motor; whereby said double differential causes said first and second drive shafts to rotate at the speed of said acceleration motor and said control means cooperates with said drive motors to produce a high driving torque to said vehicle drive wheels at a low rpm thereof, to produce a continuous variation in rpm of said vehicle drive wheels from zero to a selected rpm, and to maintain such selected rpm.
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Specification