Non-linear feedback in a dual yoke hydromodule
View Patent ↗A variable displacement bent axis unit comprising a housing and a yoke pivotally disposed therein wherein the yoke has a cam member attached thereto. A control mechanism that changes the displacement of the unit has a control valve disposed therein that engages the cam member. The cam member itself has a non-linear feedback profile such that the feedback profile provides a linearized speed ratio.
1. A variable displacement bent axis unit comprising:
a housing;
a yoke pivotally mounted in the housing about trunnions and having a cam member attached thereto;
first and second elongated actuator rods each having generally opposite first and second ends, the second end including a servo piston thereon, the first end of each actuator rod drivingly connected to the yoke to pivot the yoke about the trunnions;
a control mechanism for changing the displacement of the unit and including a control housing having spaced apart servo bores for receiving the servo pistons on the second ends of the actuator rods and a control valve disposed therein that engages the cam member; and
wherein the cam member has a non-linear feedback profile.
2. The unit of claim 1 wherein the non-linear feedback profile provides a linearized speed ratio.
3. The unit of claim 1 wherein the non-linear feedback profile provides a non-linear cam feedback.
4. The unit of claim 1 wherein the non-linear feedback profile comprises:
a first radial section that extends away from the cam axis;
a second radial section that extends away from the cam axis; and
a third arcuate section extending between the first and second radial sections.
5. The unit of claim 4 wherein the first radial section extends further away from the cam axis than the second radial section.
6. The unit of claim 4 wherein the second radial section extends further away from the cam axis than the first radial section.