the force analysis of power screw,gear, bearing and design procedure?

hydraulic jack
hydraulic jack
This device continuously auto lifting and lowering of a hydraulic jack that can run automatically and continuously lifting and lowering cycles without some external force. (a) the hydraulic circuit is simplified due to the location of the control valves to achieve reliable and convenient control.

Hydraulic jack uses a liquid which is incompressible, that is forced into the cylinder with the piston pump. Oil can be used as a lubricating and stable. the fuel comes from the tank through the suction check valve in the pump Chamber, when the plug is removed. When the plunger moves forward, it pushes oil through the exhaust valve per cylinder. with each win the piston opens the ball valve in the suction Chamber. The ball valve is off-camera, and opens when the oil is pushed into the cylinder.the Chamber forced to shut down at this point and the oil pressure builds in the cylinder.

Hydraulic jack and hydraulic circuit
The device consists of a basement, oil pump, working oil cylinder, piston, oil, battery box, two-position and two-directional valve, with double pressure check, control, install other dual check check check., two-position and two-directional valve, and pressure testing shall be arranged in a straight line. pusher located between on/off and two directional valve and dual control validation

For more information and pictures, please follow this link:
http://patentstorm.us/patents/6546725/fulltext.html
http://en.wikipediawiki/Hydraulic_jack