Glossary of Terms

Glossary of Terms

A

A

Axial Piston - Type of design for hydraulic motors and pumps in which the pistons are arranged parallel with the spindle (input or output shaft).

Accelerator - An electric sensor that replaces the trunnion arm and mechanical linkage function that is found in a traditional hydrostatic drive system.

Axle - A shaft or spindle on which a wheel or pair of wheels revolves.

B

B

Bypass Valve - A valve whose primary function is to open a path for the fluid to bypass the motor or pump. Also referred to occasionally as the freewheel valve or dump valve.

C

C

CAN (Control Area Network) - A communication protocol for active components in a system.

Case Drain Line (Return Line) - A line returning fluid from the component housing to the reservoir.

Cavitation - A concentrated gaseous condition within the fluid causing the rapid implosion of a gaseous bubble.

Center Section - A device which acts as the valve body and manifold of the transmission.

Charge - To replenish a hydraulic system faster than what normal atmospheric pressure can accomplish.

Charge Pump - A device which supplies replenishing fluid to the fluid power system (closed loop).

Charge Pressure - The pressure at which replenishing fluid is forced into a fluid 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 flow in one direction.

Closed Loop - A sealed and uninterrupted circulating path for fluid flow from the pump to the motor and back.

Continuity - An uninterrupted path from point A to point B.

Contactor - An electromagnetic switch device (a relay) used for switching an electrical circuit.

D

D

Decay Rate - The ratio of pressure decay over time.

Deck Controller - The computer controller for the deck motors, reports to the Traction Controller.

Deck Motor - The electric motor that powers the cutting blades.

Digital Display - LCD dash display that communicates system status from the traction controller to the operator.

Displacement - The quantity of fluid that can pass through a pump or motor in a single revolution.

DMM (Digital Multi-meter) - combination ohm, voltage, and current meter.

Drive Motor - The electric motor that powers the gear case.

E

E

Electric Current - Is the rate of charge flow past a given point in an electric circuit measured in Amps.

Electric Short - A low resistance connection between two points in an electrical circuit. The current flows through the area of low resistance, bypassing the intended current flow in the circuit.

End Cap - See "Center Section."

Entrained Air - A mechanically generated mixture of air bubbles having a tendency to separate from the liquid phase.

F

F

Flow - To move or proceed steadily (fluid); pump creates flow (expressed in gallons per minute - GPM).

G

G

Gerotor - A formed rotor set operating about an eccentric that provides a fixed displacement for pumps or motors.

H

H

Hydraulic Motor - A device which converts hydraulic fluid power into mechanical force and mo­tion by transfer of flow under pressure.

Hydraulic Pump - A device which converts mechanical force and motion into hydraulic fluid power by producing flow.

Hydraulics - Engineering science pertaining to liquid pressure and flow.

Hydrostatic Pump - See "Hydraulic Pump."

Hydrostatic Transaxle - A multi-component assembly including a gear case and a hydrostati­c transmission.

Hydrostatic Transmission - The combination of a hydraulic pump and motor in one housing to form a device for the control and transfer of power.

Hydrostatics - Engineering science pertaining to the energy of confined fluids.

I

I

Inlet Line - A supply line to the pump.

Integrated Electric Transaxle - The electric motor and gear case assembly that transmits power to the wheels.

Integrated Zero-Turn Transaxle - The combination of a hydrostatic transmission and gear case in one housing to form a complete transaxle.

M

M

Manifold - A conductor which provides multiple connection ports.

N

N

NC - Normally closed switch.

Neutral - Typically described as a condition in which fluid flow and system pressure is below that which is required to turn the output shaft of the motor.

NO - Normally open switch.

O

O

Ohm Meter - A meter that only measures resistance, measured in ohms.

P

P

Pressure - Application of steady force by one body in contact with another; caused by resistance to flow; normally expressed in pounds per square inch (PSI).

Pressure Decay - A falling pressure.

Priming - The filling of the charge circuit and closed loop of the fluid power system during start up, frequently achieved by pressurizing the fluid in the inlet line.

Purging - The act of replacing air with fluid in a fluid power system by forcing fluid into all of the components and allowing the air a path of escape.

R

R

Rated Flow - The maximum flow that the power supply system is capable of maintaining at a specific operating pressure.

Relief Valve - A pressure operated valve which bypasses pump delivery (flow), limiting system pressure to a predetermined maximum value.

Resistance - The level of opposition to current flow in an electrical system, measured in Ohms.

S

S

Smartec ZT 45 Traction Controller - The computer controller for the drive and deck system.

Swash Plate - A mechanical device used to control the displacement of the pump pistons in a fluid power system.

System Charge Check Valve - A valve controlling the replenishing flow of fluid from a charge circuit to the closed loop in a fluid power system.

System Pressure - The pressure which overcomes the total resistance in a system, including all efficiency losses.

V

V

Valve - A device which controls fluid flow direction, pressure, or flow rate.

Variable Displacement Pump - A pump in which the displacement per revolution can be varied.

Voltage - A measurement of the electrical energy in a circuit at a given point; measured in volts.

Voltage Inverter - An electrical device that converts the system DC voltage to AC voltage.

Volumetric Displacement - The volume for one revolution.

Wiring Harness - Grouping of conductors (wires) that carry information and electricity.

Have A Question?

This website uses cookies

We use cookies to personalize content and to analyze our traffic. We also may share information about your usage to our third parties such as Google, Facebook and other social media, advertising and analytics partners. Click here if you'd like to learn more about cookies.