US3585473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamic braking system for electric drive
Assignee: Caterpillar Inc
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Filing: 1969-07-14
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Granted: 1971-06-15
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Expires: 1989-07-14
Abstract
Abstract A system for dynamically braking an electrically driven vehicle wherein a retarding means is directly coupled to the engine/generator drive and employed to absorb the major portion of the energy produced during power regeneration. Running at near rated engine speed, the retarding means generates substantially constant braking torque during vehicle deceleration and associated control systems automatically operate the retarding means in response to command signals and employ circuits to maintain the excitation of generator below that of the wheel motors during retarding whereby better power transfer is effected.
Inventors
- 👤 James T Huxtable
- 👤 Jay J Murphy
- 👤 Darrell E Stafford
- 👤 Joachim Horsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:51
CPC Classifications
H; H02; H02P; H02P29/00; H02P29/0016; H02P29/0022
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
155 words
In combination with an electric vehicle drive having a prime mover, an electric generator, a mechanical drive connecting the prime mover with the electric generator, electric motors directly connected to drive ground engaging members of the vehicle and leads coupling the electrical output of the generator to the motors, a dynamic control system comprising a mechanical retarder connected to the mechanical drive connecting the engine to the electric generator, a retarder control connected to said mechanical retarder, said retarder control having a transducer connected to said drive to monitor its speed which provides an output signal to said retarder control proportional thereto, and control circuit means coupled to said electric generator and said electric motors operable to cause said motors to convert to generators and said electric generator to convert to a motor when power regeneration occurs whereby energy motorizing said generator will be absorbed by said mechanical retarder means when said mechanical drive overspeeds.
Claim 2
Dependent Claim
155 words
In combination with an electric vehicle drive having a prime mover, an electric generator, a mechanical drive connecting the prime mover with the electric generator, electric motors directly connected to drive ground engaging members of the vehicle and leads coupling the electrical output of the generator to the motors, a dynamic control system comprising a mechanical retarder connected to the mechanical drive connecting the engine to the electric generator, a retarder control connected to said mechanical retarder, said retarder control having a transducer connected to said drive to monitor its speed which provides an output signal to said retarder control proportional thereto, and control circuit means coupled to said electric generator and said electric motors operable to cause said motors to convert to generators and said electric generator to convert to a motor when power regeneration occurs whereby energy motorizing said generator will be absorbed by said mechanical retarder means when said mechanical drive overspeeds.
Claim 3
Dependent Claim
18 words
The combination as defined in claim 1 wherein the prime mover drive is a constant speed drive design.
Claim 4
Dependent Claim
56 words
The combination defined in claim 2 wherein the retarder control means is provided with a control having at least two separate modes of operation, one mode being responsive to the output signal provided by the transducer, and the second mode being disposed to control the actuation of said retarder control means independent of said output signal.
Claim 5
Dependent Claim
57 words
The combination defined in claim 2 wherein the retarder control has at least two separate control outputs, one of said control outputs being coupled to place said retarding means in a partial operating state the other of said control outputs being coupled to said retarding control means to place said retarding means in a full operating state.
Claim 6
Dependent Claim
40 words
The combination defined in claim 4 wherein the two separate control outputs are responsive to a signal in the control circuit means when power regeneration occurs and said other control output is responsive to the output signal of the transducer.
Claim 7
Dependent Claim
44 words
The combination defined in claim 4 wherein said retarder is a hydraulic retarder and one control output from the retarder control initially charges said hydraulic retarder with fluid for partial operation and said other control output supplies fluid to said retarder for full operation.
Claim 8
Dependent Claim
81 words
The combination defined in claim 6 wherein the control circuit means includes a generator control means and a moTor control means, said generator control being operably coupled to said generator to cause said generator to operate as a generator to supply power and as a motor when power regeneration occurs, said motor control being operably coupled to said motors to cause said motors to operate as motors when said vehicle is being driven and as a generator when power regeneration occurs.
Claim 9
Dependent Claim
27 words
The combination defined in claim 7 wherein said generator and motor controls are disposed to control the excitation level of fields of said generator and motors respectively.
Claim 10
Dependent Claim
109 words
The combination defined in claim 8 wherein the control circuits include a power pedal control, coupled to the generator control, said power pedal control having two positions, one position being a run position, the other a braking position which provides a signal to the retarder control means to place the retarding means in a partial operating state, said power pedal also including a switch means for switching said generator control from a first mode where it controls the generator as a generator to a second mode where it controls said generator as a motor by controlling its field excitation level relative to the field excitation level of the motors.
Claim 11
Dependent Claim
29 words
The combination defined in claim 9 wherein an override means responsive to a maximum mechanical drive speed disables the retarder, circuit means and excitation of the generator and motors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |