United States
The jack module is the component of a hydraulic elevator that lifts the elevator cab. Jack modules are mounted in the hoistway pit and operate through pump units supplying the jack module with hydraulic fluid. The cab is lifted as pressure increases, and as it decreases, the cab lowers.
The jack module consists of three main components:
Piston: The part within the cylinder that is displaced by the hydraulic fluid and drives the elevator upwards.
Cylinder: The stationary component of the elevator jack module that receives the pressurized fluid.
Jack Head: The top of the cylinder where the piston exits. It is pliable and expands and contracts with the changing temperatures of hydraulic fluid. This also allows it to withstand system pressure.
Other components of an elevator jack module include:
Jack Guide
A jack guide is an assembly secured to the upper end of a cylinder that maintains the alignment of the plunger so that it remains centered during operation.
Jack Seal
Typically a pressure balanced “U” shape, the seal of a jack is a device which is mounted on the jack guide to minimize oil escaping around the plunger.
Jack Drip Ring
A jack drip ring is used to keep pit floors clean and dry by collecting the small leakage of oil from the cylinder head and drains it into the collector or scavenger pump units.
Jack Babbit
Jack babbit is a soft metal used in the guide to lower the amount of scratching that takes place on the surface of the jack plunger.
