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# Rotational Hydro-Mechanical Converter

Ideal hydro-mechanical transducer as building block for rotary actuators

## Library

Hydraulic Elements

## Description

The Rotational Hydro-Mechanical Converter block models an ideal transducer that converts hydraulic energy into mechanical energy, in the form of rotational motion of the converter shaft, and vice versa. Physically, the converter represents the main component of a single-acting rotary vane actuator. Using this block as a basic element, you can build a large variety of rotary actuators by adding application-specific effects, such as fluid compressibility, leakage, friction, hard stops, and so on.

The converter is simulated according to the following equations:

where

 q Flow rate to the converter chamber D Converter displacement, or fluid volume needed to rotate the shaft per angle unit ωS Converter shaft angular velocity ωC Converter case angular velocity F Torque on the shaft p Gauge pressure of fluid in the converter chamber or Converter orientation with respect to the globally assigned positive direction. If pressure applied at port A generates torque in positive direction, or equals 1. If pressure applied at port A generates torque in negative direction, or equals –1.

Port A is a hydraulic conserving port associated with the converter inlet. Ports S and C are mechanical rotational conserving ports associated with the shaft and the case of the converter, respectively. Pressure at port A generates torque in the direction specified by the Converter orientation parameter.

## Basic Assumptions and Limitations

The block simulates an ideal converter, with only the transduction property considered. No inertia, friction, leakage, or other effects are taken into account.

## Dialog Box and Parameters

Displacement

Effective converter displacement. The default value is 1.2e-4 m^3/rad.

Converter orientation

Specifies converter orientation with respect to the globally assigned positive direction. The converter can be installed in two different ways, depending upon whether it generates torque in the positive or in the negative direction when pressure is applied at its inlet. If pressure applied at port A generates torque in negative direction, set the parameter to Acts in negative direction. The default value is Acts in positive direction.

## Ports

The block has the following ports:

A

Hydraulic conserving port associated with the converter inlet.

S

Mechanical rotational conserving port associated with the shaft of the converter.

C

Mechanical rotational conserving port associated with the case of the converter.

Translational Hydro-Mechanical Converter