What is Hydromotor? How Does Hydromotor Work? What are the Types of Hydromotors?
What is Hydromotor? How Does Hydromotor Work? What are the Types of Hydromotors?
What is Hydromotor?
Hydraulic motor is a circuit element that produces circular motion with hydraulic energy. They are hydraulic elements that take the hydraulic energy transferred by the hydraulic pump and convert it to work. Ultimately, the desired TORK (torque) is. TORK is the load lifting capacity of a hydromotor. The torque depends on the difference between the pressure at the inlet and the outlet of the engine. While the displacement of the motor decreases towards the minimum in variable displacement hydromotors, the rotation speed of the motor increases and its torque decreases. As the displacement of the motor increases, the rotational speed of the motor slows down, however, its torque increases.
Hydromotors These are machines that convert hydraulic energy into mechanical energy - return motion.
What are the Types of Hydromotors?
1) Gear Motors
2) Piston Motors
What are the Advantages of Hydromotor?
Speed can be adjusted without stopping the engine.
The speed adjustment range is unlimited between certain values.
Great forces are transmitted.
Since hydraulic fluids cannot be compressed, uniform velocities can be obtained.
While the motion continues, the direction of rotation can be changed.
Can be stopped in case of overload by using the safety valve
What are the Disadvantages of Hydromotor?
Since the friction resistance of hydraulic fluids is high, their rotation speed is low. Prices can be expensive. They may be large in size. It is not recommended for use at high temperatures.
It is very sensitive to pollution.
Formulas Related to Hydromotors
n = qv x 1000 / Vg
n ------- revolution (rpm) qv ------ pump flow (lt / min) Vg ------ displacement volume of the hydromotor (cm3)
T = 1.59 x Vg x Dp / 100
T --------- Torque - torque (Nm)
Dp ------- pressure difference between hydromotor inlet and outlet ports (bar)
P = qv x Dp / 600
P --------- aft output power (kW)
Variable Flow Hydromotor Displacement Control Types
HA control ----------- Automatic control based on high pressure
EP control ----------- Displacement control with externally stimulated electric proportional valve
EZ control ----------- Externally stimulated displacement control (min-max) with On-Off valve
HD control ---------- External displacement control with hydraulic pilot actuation
HZ control ----------- External displacement control with hydraulic pilot actuation (min-max)
High Pressure Dependent Automatic Control - "HA" Control
Hydromotor starts its first movement at minimum displacement (maximum speed). (by spring) As the resistance encountered by the hydromotor increases, the pressure at the inlet port increases. When the pressure value at the inlet port of the hydromotor reaches the value set with the "HA" valve adjustment bolt, the motor min. displacement (from max. speed), max. switches to displacement (min. speed). Hydromotor loses speed, gains from TORK (load lifting capacity).
Displacement Control with Proportional Valve - "EP" Control
The hydromotor starts its first movement at maximum displacement (minimum speed) (by means of the spring) The displacement of the hydromotor is adjusted by changing the current sent from the control card (from the driver card) to the coil of the proportional valve. By increasing the current, the hydromotor moves from the maximun to the minimum displacement. In proportion to the given current value, the hydromotor remains at any intermediate displacement value. The necessary control oil controlled by the proportional valve is supplied from the high pressure port of the hydromotor.
Displacement Control with On - Off Valve - "EZ" Control (min --max)
The hydromotor starts its first movement at maximum displacement (minimum speed) (by means of the spring) The displacement of the hydromotor goes from maximum to minimum with the energization of the on-off valve. Hydromotor does not work at intermediate displacement values. When the valve is not energized, it is at maximum displacement, when it is energized, it goes to minimum. The necessary control oil controlled by the on-off valve is supplied from the high pressure port of the hydromotor.
Displacement Control with External Pilot Pressure Warning - "HD" Control
The hydromotor starts its first movement at maximum displacement (minimum speed) (by means of the spring). The "Pst" pilot pressure of the hydromotor from the outside changes the displacement with the pressure applied to the inlet port. The displacement of the hydromotor decreases with the increase of the "Pst" pilot pressure, the displacement of the motor increases with the decrease of the pilot pressure (in some types it is the opposite) The pressure value at which the pilot pressure starts to change the displacement; "Start of control"; It is adjusted with the adjustment bolt on the hydromotor. Range of applied "Pst" pilot pressure, Dp; It is determined when choosing the hydromotor and is fixed by the spring force.
Displacement Control with External Pilot Pressure Warning - "HZ" Control (min-max)
The hydromotor starts its first movement at maximum displacement (minimum speed) (by means of the spring). The "Pst" pilot pressure of the hydromotor from the outside changes the displacement with the pressure applied to the inlet port. Pump displacement does not change until the "Pst" pilot pressure reaches 10 bar. When the pilot pressure reaches 10 bar, the pump goes to the minimum displacement. The displacement of the hydromotor is at a minimum of oil or at its maximum. It does not stop at intermediate levels.