Pre-start rotor positioner for an electric vehicle
First Claim
1. An improved drivetrain of the type adapted for use with an electric vehicle having at least one tractive wheel and a motor including a stator and rotor for imparting torque to said wheel upon the energization thereof, said improvement comprising:
- means operable for rotation with said rotor and defining an engagement surface; and
actuator means comprising,(i) pawl means displaceable between a retracted position spaced from said engagement surface and an extended position wherein said pawl means contacts said engagement surface to substantially prohibit rotation of said rotor,(ii) means biasing said pawl means toward said extended position,(iii) means operable to urge said pawl means into said retracted position independently of rotor position in response to an actuation signal, and(iv) latch means including a member displaceable between a release position and a lock position to lock said pawl means in said extended position in the absence of said actuation signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A drivetrain (48) for an electric passenger vehicle (10) includes a battery (40) for energizing a single-phase A.C. traction motor (18) which drives a ground engaging wheel (12) through a multi-speed transaxle (20). The motor is characterized by an external ferrite permanent magnet rotor (26) drivingly engaging an input shaft (32) of the transaxle. The motor is controlled by an inverter circuit (44) and a control circuit (46) which generates switch command signals to reciprocally actuate power transistors (56 and 62) within the inverter circuit as a function of operator demand, rotor position and rotor speed. The control circuit includes a motor positioning circuit (442) which toggles the motor current when the rotor speed falls below a predetermined level to dither the rotor about a park position for a predetermined period. A pre-start rotor positioner (224) is provided to mechanically lock the rotor in its park position to ensure the availability of a high electrical starting torque. Finally, a minimum starting speed circuit (599) provides for motor startup from other than the normal rotor park position.
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Citations
21 Claims
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1. An improved drivetrain of the type adapted for use with an electric vehicle having at least one tractive wheel and a motor including a stator and rotor for imparting torque to said wheel upon the energization thereof, said improvement comprising:
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means operable for rotation with said rotor and defining an engagement surface; and actuator means comprising, (i) pawl means displaceable between a retracted position spaced from said engagement surface and an extended position wherein said pawl means contacts said engagement surface to substantially prohibit rotation of said rotor, (ii) means biasing said pawl means toward said extended position, (iii) means operable to urge said pawl means into said retracted position independently of rotor position in response to an actuation signal, and (iv) latch means including a member displaceable between a release position and a lock position to lock said pawl means in said extended position in the absence of said actuation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A drivetrain adapted for use with an electric vehicle having at least one tractive wheel, said drivetrain, comprising:
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a power source; a motor for imparting torque to said wheel, said motor including, (i) a stator adapted for mechanical grounding to a relatively stationary portion of said vehicle, and (ii) a rotor disposed for rotation in close proximity to said stator for magnetic interaction therewith and adapted for operably engaging said wheel; circuit means connected to said power source for selectively energizing said motor; means operable for rotation with said rotor and defining an engagement surface characterized by a plurality of spaced detents; and actuator means including means selectively displaceable between a retracted position in which said displaceable means is spaced from said engagement surface and an extended position in which said displaceable means engages at least one of said detents to substantially prohibit rotation of said rotor, said actuator means being substantially fixed with respect to said stator and in rotational alignment with said means operable for rotation with said rotor, said displaceable means comprising a pawl member, said actuator means further comprising; (i) means biasing said pawl member toward said extended position, (ii) a solenoid operable to urge said pawl member into said retracted position in response to an actuation signal, and (iii) latch means operative to lock said pawl in said extended position in the absence of said actuation signal, said latch means comprising a latch solenoid operatively engaging a latch member for displacement between a lock position and a release position. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification