System for electronic parking brake actuation
AssigneeGM Global Technology Operations LLC
InventorsDumitru Puiu, Luiz Lopes Lima
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Abstract
A two-stage actuation mechanism for a brake system includes a first lead screw having a first plurality of threads, a second lead screw having a second plurality of threads, a preloaded torsional spring, and an actuator assembly having an input shaft coupled with the preloaded torsional spring of the two-stage actuation mechanism. The preloaded torsional spring is configured to activate a first stage of movement of the two-stage actuation mechanism via rotation of the first lead screw. The size and pitch of each of the first and second lead screws are configured to minimize power consumption by the actuator assembly and satisfy a desired actuation time with a low current consumption and high actuator gear train ratio.
Claims20
An electronic parking brake system, comprising:
- a caliper;
- a first brake pad and a second brake pad positioned on either side of a brake rotor and enclosed within the caliper;
- an apply piston enclosed within the caliper and configured to act on the first brake pad;
- and
- a two-stage actuation mechanism coupled with the apply piston, the two-stage actuation mechanism comprising:
- a first lead screw having a first plurality of threads;
- a second lead screw having a second plurality of threads;
- a preloaded torsional spring;
- and
- an actuator assembly having an input shaft coupled with the preloaded torsional spring of the two-stage actuation mechanism;
- wherein the preloaded torsional spring is configured to activate a first stage of movement of the two-stage actuation mechanism via rotation of the first lead screw and a size and a pitch of each of the first and second lead screws are configured to minimize power consumption by the actuator assembly and satisfy a desired actuation time.
A two-stage actuation mechanism for a brake system having an apply piston configured to apply a brake pressure to a brake rotor, the two-stage actuation mechanism comprising:
- a first lead screw having a first plurality of threads;
- a second lead screw having a second plurality of threads;
- a preloaded torsional spring;
- and
- an actuator assembly having an input shaft coupled with the preloaded torsional spring of the two-stage actuation mechanism;
- wherein the preloaded torsional spring is configured to activate a first stage of movement of the two-stage actuation mechanism via rotation of the first lead screw and a size and a pitch of each of the first and second lead screws are configured to minimize power consumption by the actuator assembly and satisfy a desired actuation time.
A brake system, comprising:
- a caliper having an octagonal interior surface;
- a brake pad enclosed within the caliper;
- an apply piston configured to act on the brake pad, the apply piston enclosed within the caliper and configured to translate along a longitudinal axis;
- and
- a two-stage actuation mechanism coupled with the apply piston, the two-stage actuation mechanism comprising:
- a first lead screw having a first plurality of threads;
- a second lead screw having a second plurality of threads;
- a preloaded torsional spring;
- and
- an actuator assembly having an input shaft coupled with the preloaded torsional spring of the two-stage actuation mechanism;
- wherein the preloaded torsional spring is configured to activate a first stage of movement of the two-stage actuation mechanism via rotation of the first lead screw and a size and a pitch of each of the first and second lead screws are configured to minimize power consumption by the actuator assembly and satisfy a desired actuation time.
Dependencies are inferred from the claim text.