Adams Car Package > Adams Driveline > Working with Components > Conceptual Wet Clutches

Conceptual Wet Clutches

Creating or Modifying Wet Clutches

About Wet Clutches

A wet clutch is a torque that connects an I part and a J part.

Learn about wet clutches:

■Creating or Modifying Wet Clutches

■About Wet Clutches

Creating or Modifying Wet Clutches

To create or modify wet clutches:

1. From the Driveline Components menu, point to Conceptual Wet Clutch, and then select New/Modify.

2. Press F1 and then follow the instructions in the dialog box help for Wet Clutch.

3. Select OK.

About Wet Clutches

The clutch pressure is pre-defined as a function of time (defined in the property file). It cannot be connected to the driving machine’s clutch demand state.

The wet clutch torque is the summation of three single-component torques. The first torque is based on the inputs stored in the property file, such as number of friction surfaces, effective radius, pressure area, turning point pressure, and friction coefficient. Second is a drag torque, defined in the property file by a coefficient. The wet clutch also includes a part with a rotational degree of freedom and compliant connection to the J part.

Adams Driveline uses the following formulas to evaluate the resulting torque:

Parameters in property file:

Parameter	Description	Unit
N_OF_SURFACE	Number of friction surfaces in the clutch pack	None
EFFECTIVE_RADIUS	Effective radius of the friction surface(s)	Length
PRESSURE_AREA	Area of one friction surface	Area
TURNING_POINT_PRESSURE	Minimum pressure that must be overcome	Pressure
CLUTCH_MU	Friction coefficient	None
OPEN_CLUTCH_DRAG_GAIN_FACTOR	Drag torque gain	Torque
TIME_OFFSET	Time at which pressure spline begins	Time
CLUTCH_COMPLIANT_STIFFNESS	Stiffness of the compliant connection	Torque/angle
CLUTCH_COMPLIANT_DAMPING	Damping of the compliant connection	Torque/angular velocity

Curve in the property file:

Parameter	Description	Unit
CLUTCH_PRESSURE	Pressure vs. time	Time and pressure

States:

■clutch_pressure = AKISPL(time + time offset, 0,clutch_pressure_spline) - turning point pressure

■clutch_capacity = STEP(varval(clutch_pressure),0,0,0.1,1) * number of surfaces * effective radius * clutch mu * pressure area * clutch_pressure

■clutch_switch = STEP(WZ(I_part, compliance_part, compliance_part), -0.2, -1, 0.2, 1)

■clutch_torque = -clutch_capacity * clutch_switch

■clutch_drag = -number of surface * drag gain * WZ(I_part, compliance_part, compliance_part)

■clutch_compliance = -clutch compliance stiffness * AZ(compliance_part, J_part) -clutch compliance damping * WZ(compliance_part, J_part, J_part)

In the Standard Interface (see Interface Modes), you can vary the property file.

Request Definition

Result name: request

Component:	Component name:	Component units:	Definition:
F2	angle	angle	The angle between the I and J part.
F3	angular_velocity	angular velocity	The angular velocity of the I part with respect to the J part.
F6	clutch_pressure	pressure	The input pressure of the clutch.
F7	capacity	torque	The capacity that the clutch is able to develop.
F8	torque	torque	The torque developed in the compliant connection to the J part

Subsystem Parameters

Property file (<db_name>/clutch_forces.tbl)