Dual-motor drive circuit with high current switching
AssigneeTowmotor Corporation
InventorGrant C. Melocik
Life of this patent
Estimating the term…
Abstract
An electrically operated dual motor drive system of the type having differentially variable left and right traction motor circuits (10,12) including left and right variable duty cycle power switches (20,22) connecting the motors (14,16) independently to a power source (18), left and right auxiliary switches (28,36) in series with the traction motor circuits for complemental operation of same and a selectively operated shunt switch (64) which connects the power transistors (20,22) in parallel for high torque, low speed operating conditions.
Claims13
An electrically-operated dual-motor drive system of the type having differentially-variable first and second traction motor circuits (10,12) including respective first and second variable duty cycle power switches (20,22) connecting said motor circuits independently to a power source (18) for controlling the operating speeds of the motors in said circuits,
- the improvement comprising:
- a shunt switch (64) interconnecting the power switches (20,22) to establish a parallel connection of said switches when closed;
- and
- control means (42,44,66,68) for closing the shunt switch in response to a high-current condition in at least one of the traction motors.
In an electrically operated dual-motor drive system of the type having differentially variable first and second traction motor circuits (10,12) including respective first and second variable duty cycle power switches (20,22) connecting the traction motor circuits to a power source (18) to independently control the operating speeds of the motors (14,16) in said circuits, the improvements comprising:
- first and second current control switches (28,36) connected in series with said first and second traction motor circuits (10,12), respectively, and
- control means (42,72,74) for alternately operating the first and second current control switches and alternating making power from said source (18) available to the first and second motor circuits.
In an electrically-operated vehicle 134 having first and second traction motors (4,16) connected to non-dirigible wheels (136,138) and at least one dirigible wheel 140 for direction control, a drive control system comprising:
- a battery (18),
- first and second power switches (20,22) connecting the first and second traction motors (14,16) in series with the source,
- means (42) alternately rendering said power switches (20,22) conductive during a first mode of vehicle operation;
- means (42,44) simultaneously rendering said power switches (20,22) conductive during a second mode of vehicle operation;
- and
- switch means (64,65) connecting the power switches in parallel during employment of said second mode of operation.
Dependencies are inferred from the claim text.