Service Manual

56 ZT-2100
AxialPiston: Type of design for hydraulic motors and pumps in which the pistons are arranged
parallel with the spindle (input or output shaft).
BantamDuty: A descriptive term relating to the product capacity (meaning: light duty).
BypassValve:A valve whose primary function is to open a path for the uid to bypass the motor
or pump. Also referred to occasionally as the freewheel valve or dump valve.
CaseDrainLine(ReturnLine): A line returning uid from the component housing to the reser-
voir.
Cavitation:A concentrated gaseous condition within the uid causing the rapid implosion of a
gaseous bubble.
CenterSection: A device which acts as the valve body and manifold of the transmission.
Charge Pump: A device which supplies replenishing uid to the uid power system (closed
loop).
ChargePressure: The pressure at which replenishing uid is forced into a uid power system.
ChargeReliefValve: A pressure control valve whose primary function is to limit pressure in the
charge circuit.
CheckValve: A valve whose primary function is to restrict ow in one direction.
ClosedLoop: A sealed and uninterrupted circulating path for uid ow from the pump to the
motor and back.
DecayRate: The ratio of pressure decay over time.
EndCap: See “Center Section”
EntrainedAir: A mechanically generated mixture of air bubbles having a tendency to separate
from the liquid phase.
Gerotor: A positive displacement pump frequently used as a charge pump.
HydraulicMotor: A device which converts hydraulic uid power into mechanical force and mo-
tion by transfer of ow under pressure.
HydraulicPump: A device which converts mechanical force and motion into hydraulic uid power
by producing ow.
HydrostaticPump: See “Hydraulic Pump”
HydrostaticTransaxle: A multicomponent assembly including a gear case and a hydrostatic
transmission.
GLOSSARY OF TERMS