Planetary power take off device

Patent metadata

Field	Value
Publication number	US-9579976-B2
Application number	US-201414501899-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Oct 16, 2008
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A power take off device that includes a clutch that is engaged by a pressure operated actuator. The pressure operated actuator may be a two directional fluid pressure operated actuator that selectably engages the clutch. A single input signal may operate the two directional fluid pressure operated actuator in both directions. In one mode of operation of the power take off device, a substantial speed reduction and torque increase is provided between the input shaft and the output shaft to start rotating the blower and to overcome the inertial start up resistance of the blower. The power take off device may change to a second mode of operation without stopping to provide a direct one to one speed and torque ration between the input shaft and the output shaft.

First claim

What is claimed is:

1. A power take off device comprising:
a housing;
an input gear;
an output shaft;
a clutch for selectably engaging said input gear to said output shaft;
a first bore in said housing;
a second bore in said housing coaxial with said first bore and having a smaller diameter than said first bore;
a first fluid passage in said housing in fluid communication with said first bore;
a second fluid passage in said housing in fluid communication with both said first bore and said second bore; and
a two directional fluid pressure operated actuator to selectably engage said clutch, said two directional fluid pressure operated actuator including:
an annular piston;
said piston having a first cylindrical surface slidably and sealingly received in said first bore between said first passage and said second passage and a second cylindrical surface slidably and sealingly received in said second bore;
said piston having a first annular lateral cross sectional area disposed between said first and second bores and in fluid communication with said second passage and facing in one longitudinal direction; and
said piston having a second annular lateral cross sectional area disposed between said first bore and another bore and in fluid communication with said first passage and facing in a longitudinal direction opposite said one longitudinal direction; and said first area being substantially larger than said second area.

2. The power take off device set forth in claim 1 , wherein the power take off device is a single speed device.

3. The power take off device set forth in claim 1 , wherein the power take off device is a two speed device, said clutch being used to transition between a first gear ratio and a second gear ratio.

4. The power take off device set forth in claim 1 , further comprising:
said housing having an outer surface and an inner surface, said inner surface defining a central cavity, and a plurality of openings extending from said outer surface to said inner surface to provide access to said central cavity;
said input gear being disposed in one of said plurality of openings, at least a first portion of said input gear being disposed within said central cavity, and at least a second portion of said input gear being disposed outside said central cavity outwardly of said outer surface; and
said output shaft being disposed in another one of said openings, and at least a portion of said output device being disposed outside said central cavity outwardly of said outer surface.

5. The power take off device set forth in claim 1 , wherein said clutch has first and second clutch surfaces and said actuator is arranged to move said clutch surfaces between an engaged position and a disengaged position.

6. The power take off device set forth in claim 1 , wherein said clutch is a first clutch; and
wherein the power take off device further includes:
a second clutch for selectably engaging said input gear and said output shaft; and
a second actuator arranged to move said second clutch between an engaged position and a disengaged position.

7. The power take off device set forth in claim 6 , wherein each of said first clutch and said second clutch includes a longitudinal axis, said axes are coaxial, and one of said first clutch and said second clutch is disposed laterally inwardly of and is substantially laterally aligned with the other of said first clutch and said second clutch.

8. The power take off device set forth in claim 1 , further including:
a solenoid valve for controlling fluid pressure to said second fluid passage.

9. The power take off device set forth in claim 8 , wherein fluid pressure within said first fluid passage is equal to fluid pressure controlled by said solenoid valve.

10. The power take off device set forth in claim 8 , wherein said solenoid valve alone controls the engagement and disengagement of said clutch.

11. The power take off device set forth in claim 8 , further including:
a pump fluidly communicating with said first fluid passage and said solenoid valve to provide substantially the same pressure to said first fluid passage and said solenoid valve.

12. The power take off device set forth in claim 11 , wherein said pump provides substantially the same pressure to said first fluid passage and said second fluid passage when said solenoid valve allows fluid pressure from said pump to reach said first annular cross sectional area via said second fluid passage, thereby actuating said actuator in said longitudinal direction opposite said one longitudinal direction to engage said clutch.

13. The power take off device set forth in claim 11 , wherein when said clutch is engaged and said solenoid valve restricts fluid pressure from said pump from reaching said first annular cross sectional area via said second fluid passage, said pump provides greater pressure to said first fluid passage than said second fluid passage, thereby actuating said actuator in said one longitudinal direction to disengage said clutch.

14. The power take off device set forth in claim 1 , further including:
a third bore in said housing coaxial with said second bore and having a larger diameter than said second bore;
wherein said actuator further includes a stationary spacer received in said third bore and a third cylindrical surface of said piston slidably and sealingly received in an inside diameter of said spacer.

15. The power take off device set forth in claim 14 , wherein said second annular lateral cross sectional area faces said stationary spacer.

16. A system comprising:
a prime mover power source;
a primary powered device;
a transmission including at least one transmission gear and mechanically connecting said prime mover power source and said primary powered device to transmit rotational torque from said prime mover power source to said primary powered device;
an accessory device;
and a transmission mounted power take off device;
said power take off device including;
a unitary housing, said housing having a unitary outer surface and a unitary inner surface, said unitary inner surface defining a unitary central cavity, and a plurality of openings extending from said unitary outer surface to said unitary inner surface to provide access to said unitary central cavity;
an input gear, said input gear being disposed in one of said plurality of openings, at least a first portion of said input gear being disposed within said unitary central cavity, and at least a second portion of said input gear being disposed outside said unitary central cavity outwardly of said unitary outer surface and engaging said transmission gear;
an output device, said output device being disposed in another one of said plurality of openings, and at least a portion of said output device being disposed outside said unitary central cavity outwardly of said unitary outer surface and mechanically connected to said accessory device;
an intermediate gear set disposed entirely within said unitary central cavity and mechanically connecting said input gear and said output device;
a clutch connecting said input gear to said output device;
a first bore in said housing;
a second bore in said housing coaxial with said first bore and having a smaller diameter than said first bore;
a first fluid passage in said housing in fluid communication with said first bore;
a second fluid passage in said housing in fluid communication with both said first bore and said second bore; and
an actuator for selectably engaging said clutch, said actuator including:
an annular piston;
said piston having a first c

Assignees

• Parker Hannifin Corp

Inventors

• Horsfall Stephen D
• Loeffler John

Classifications

• B60Y2200/41

  Construction vehicles, e.g. graders, excavators · CPC title

• F16H3/54 Primary

  one of the central gears being internally toothed and the other externally toothed · CPC title

• B60K25/06 Primary

  from the transmission power take-off · CPC title

• B60K17/28

  characterised by arrangement, location, or type of power take-off · CPC title

• F16H2200/2005

  with one sets of orbital gears · CPC title