Swash Plate
An inclined disk of an axial piston pump in an isothermal fluid network.
blockType: EngeeFluids.IsothermalLiquid.Turbomachinery.Auxiliary.SwashPlate
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Description
Block Swash Plate It models a single inclined disk with a piston drive in an axial piston pump. It converts linear motion into rotational motion, which, when connected to the unit, Valve Plate Orifice (IL) periodically connects the piston to the suction and discharge nozzles of the pump. You can connect multiple blocks Swash Plate to multiple pistons.
Diagram of an inclined disk in an axial piston pump
The balance of power
The disc is in dynamic equilibrium if the useful work of the piston, drive and disc is zero.:
where
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— work performed by displacement of the piston;
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— work performed by shifting the drive;
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— the work performed due to the useful torque of the disk, directed tangentially to its movement.
The torque of the disc is:
where
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— parameter value Cylinder block pitch radius;
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— parameter value Swash plate actuator arm;
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— moving the drive;
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— piston force;
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— angular displacement of the plate.
The torque of the viscous friction forces, or the resistance to movement due to the contact of the disc with the piston, is:
where
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— parameter value Viscous friction coefficient;
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— angular velocity of the rotor.
Piston dynamics
Piston movement proportional to the movement of the drive:
where — parameter value Piston offset from the plate. The displacement will be positive if the piston is moving towards the cylinder block.
The speed of the piston is:
where — drive speed.
Assumptions and limitations
This unit takes into account the effect of viscous friction between the piston and the disc, but neglects the inertia of the disc and the fluid.
Variables
Use the parameter group Initial Targets to set the priority and initial target values for the block parameter variables before modeling. For more information, see Configuring physical blocks using target values.
Ports
Conserving
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A
—
mechanical port associated with the actuator
translational mechanics
Details
Velocity and drive force of an inclined disc.
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P
—
mechanical port associated with the piston
translational mechanics
Details
Velocity and force of the piston.
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S
—
mechanical port connected to the shaft
`rotational mechanics
Details
The angular velocity and torque of a drive shaft. Rotation is performed relative to the environment.
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Parameters
Parameters
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Swash plate actuator arm —
actuator arm length
m | um | mm | cm | km | in | ft | yd | mi | nmi
Details
Length of the fully extended actuator lever.
| Units |
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| Default value |
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| Program usage name |
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| Evaluatable |
Yes |
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Cylinder block pitch radius —
radius of the initial surface of the cylinder
m | um | mm | cm | km | in | ft | yd | mi | nmi
Details
The radius of the initial surface of a rotating cylinder.
| Units |
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| Default value |
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| Program usage name |
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| Evaluatable |
Yes |
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Piston offset from the plate —
piston displacement in neutral position
m | um | mm | cm | km | in | ft | yd | mi | nmi
Details
Piston displacement when the actuator is in the neutral position. A positive non-zero value indicates a partially retracted piston. A negative non-zero value indicates a retracted piston that remains in the cylinder block during the initial displacement of the actuator from the cylinder.
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| Default value |
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| Program usage name |
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| Evaluatable |
Yes |
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Viscous friction coefficient —
viscous friction moment coefficient
N*s/m | kgf*s/m | lbf*s/ft | lbf*s/in
Details
A coefficient used in the equation for torque due to viscous friction.
| Units |
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| Default value |
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| Program usage name |
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| Evaluatable |
Yes |