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Showing posts from November, 2014

Jack (device)

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Jack (device) A  jack  is a mechanical device used as a   lifting device   to lift heavy loads or apply great forces. A  mechanical jack  employ a  screw thread  for lifting heavy equipment. The most common form is a  car jack ,  floor jack  or  garage jack  which lifts vehicles so that maintenance can be performed. Mechanical jacks are usually rated for a maximum lifting capacity (for example, 1.5  tons or 3 tons). More powerful jacks use  hydraulic power  to provide more lift over greater distances and can be rated for many tons of load. Vehicle Scissor car jacks usually use  mechanical advantage  to allow a human to lift a vehicle by manual force alone. The jack shown at the right is made for a modern vehicle and the notch fits into a  hard point  on a  unibody . Earlier versions have a platform to lift on a vehicle's frame or axle. Electrically operated car scissor jacks...

Gear pump

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👂Gear pump A  gear pump  uses the meshing of gears to pump fluid by displacement. [1]  They are one of the most common types of  pumps  for  hydraulic fluid power  applications. Gear pumps are also widely used in chemical installations to pump high viscosity fluids. There are two main variations;  external gear pumps  which use two external  spur gears , and  internal gear pumps  which use an external and an internal spur gears (internal spur gear teeth face inwards, see below). Gear pumps are  positive displacement  (or  fixed displacement ), meaning they pump a constant amount of fluid for each revolution. Some gear pumps are designed to function as either a  motor  or a pump. Theory of operation As the gears rotate they separate on the intake side of the pump, creating a void and suction which is filled by  fluid . The fluid is carried by the gears to the discharge side of the pump, w...