Patent ID: 8754604
Filing Date: 2014-06-17
Classification: B60K,B60L,F16H,H02P,Y02T

Abstract:
1. In an electro-mechanical drive system that includes a moveable power output component and further includes a plurality of electric drive motors, apparatus comprising: a first transfer mechanism that is connectable to and disconnectable from each of said motors, for transferring power from each connected motor to cause said output component to move at a first speed relative to the motor speed, comprising a first speed ratio, and to deliver power at a specified constant level when moving at said first speed ratio; a second transfer mechanism that is connectable to and disconnectable from each of said motors, for transferring power from each connected motor to cause said output component to move at a second speed relative to the motor speed, comprising a second speed ratio, and to deliver power at said specified constant level when moving at said second speed ratio; a shift mechanism configured to selectively connect each motor to, and disconnecting each motor from, the first and second transfer mechanisms, respectively; a source for selectively supplying electric current to each of said motors; and a control device coupled to the shift mechanism and the source, wherein the control device is configured to control the shift mechanism to produce a substantially constant power output from the moveable power output component regardless of a change in movement speed of the moveable power output component.