Mechanism for a two-speed engine accessory drive system in a vehicle
AssigneeFord Global Technologies, LLC
InventorsHassan FARHAT, Ravi GOPAL
Life of this patent
Estimating the term…
Abstract
A vehicle has an internal combustion engine, an accessory, and a system having first and second belts extending between a drive assembly rotatably connected to a crankshaft of the engine and a driven assembly rotatably connected to a driveshaft of the accessory. One of the drive and driven assemblies comprises a mechanism with a shaft supporting first and second pulleys, with the first and second pulleys associated with the first and second belts, respectively. The first pulley is selectively engaged with the shaft in response to an engine speed being below a threshold value, and the second pulley is selectively engaged with the shaft in response to the engine speed being above the threshold value.
Claims20
A vehicle comprising:
- an internal combustion engine;
- an accessory;
- and
- a system having first and second belts extending between a drive assembly rotatably connected to a crankshaft of the engine and a driven assembly rotatably connected to a driveshaft of the accessory;
- wherein one of the drive and driven assemblies is provided by a mechanism comprising a shaft supporting first and second pulleys, the first and second pulleys associated with the first and second belts, respectively, wherein the first pulley is selectively engaged with the shaft in response to an engine speed being below a threshold value, and wherein the second pulley is selectively engaged with the shaft in response to the engine speed being above the threshold value.
A mechanism comprising:
- a core positioned for translation within a coil and about a shaft having first and second pulleys;
- a spring supported by the coil and configured to bias the core with the coil deactivated to a first position to drivingly engage the first pulley with the shaft;
- and
- wherein the coil is configured to be activated to move the core to a second position to drivingly engage the second pulley with the shaft.
A two-speed mechanism for an engine accessory drive comprising:
- a carrier;
- a shaft supported for rotation within the carrier, the shaft supporting first and second pulleys;
- a first ball ramp assembly supported by the carrier and having a first ramp profile;
- a second ball ramp assembly supported by the carrier and having a second ramp profile oriented opposite to the first ramp profile;
- a first spring biasing the first and second ball ramp assemblies towards one another;
- a solenoid and second spring supported by the carrier and connected to the first and second ball ramp assemblies;
- wherein the solenoid is configured to be activated to rotate the first and second ramp assemblies to engage the second ramp assembly such that the second pulley is drivingly engaged with the shaft and the first pulley freewheels;
- and
- wherein the first spring is configured to engage the first ramp assembly with the solenoid deactivated such that the first pulley is drivingly engaged with the shaft and the second pulley freewheels.
Dependencies are inferred from the claim text.