| 主权项 |
1. A relief valve assembly for a tool having a motor, said relief valve assembly comprising:
a body having a supply channel in fluid communication with a source of fluid, a spool receiving channel in fluid communication with said supply channel, a return channel in fluid communication with said spool receiving channel, a first port for receiving fluid from said spool receiving channel for transmission to the motor, wherein when fluid flows through said first port, the motor is driven clockwise, and a second port for transmitting fluid from the motor to the spool receiving channel, wherein when fluid flows through said second port, the motor is driven counterclockwise, said first and second ports being separated from each other; a spool moveably seated in said spool receiving channel, said spool having a bore therein, said bore having a first portion and a second portion extending from said first portion, said second portion having a dimension which is smaller than said first portion to define a seat therebetween, first passageways extending from said first portion of said bore, and second passageways extending from said second portion of said bore, said spool movable within said spool receiving channel to a first position wherein said second passageways align with said first port, and said spool movable within said spool receiving channel to a second position wherein said second passageways align with said second port; a spring mounted in said bore; a pin mounted in an end of said spring; wherein when said spool is in said first position such that the motor is driven clockwise, fluid flows from said supply, to said spool receiving channel, through one of said second passageways, into said second portion of said bore, through another one of said second passageways, through said second port, through said motor, through said first port, into said spool receiving channel and through one of said first passageways, into said first portion of said bore, through another one of said first passageways, and into said return channel, wherein when the motor encounters resistance, pressure from the fluid builds in said second portion of said bore and causes said pin to unseat from said seat such that fluid flows past said pin and into said first portion of said bore, through said first passageways and to said return channel; and wherein when said spool is in said second position such that the motor is driven counterclockwise, fluid flows from said supply, to said spool receiving channel, through one of said second passageways, into said second portion of said bore, through another one of said second passageways, through said first port, through said motor, through said second port, into said spool receiving channel and into said return channel, wherein when the motor encounters resistance, pressure from the fluid builds in said second portion of said bore and causes said pin to unseat from said seat such that fluid flows past said pin and into said first portion of said bore, through said first passageways and to said return channel. |
