Hydraulic Power Transmission Systems

System Design:

✓ Precise derivation of connected power, Power conservation with various techniques. System to facilitate No Load starting and safe Idle running.
✓ Proper derivation of Oil-Tank capacity. Consider the Oil level fluctuations and Heat dissipation.
✓ Using the correct elements to achieve desired functional parameter. Such as Breaking, Clamping, regulated pressure, sequencing operations, fine speed controls, safety functions.
✓ Incorporating Cartridge elements for high flow circuits. Electro-modulated Control Valves and Pumps where NC automation is desired. Closed circuit Hydrostatic drives for stiff rotating motion control.

✓ Main Hydraulic Elements like Pumps, Control valves, Hydraulic Motors and Pressure line Filters preferred reputed manufacturers like Bosch, Vickers, Rexroth, Yuken, Denison, Parker, Danfoss. Most components adhere to international standards such as DIN, ISO, CETOP, interchangeable.
✓ Electric Motors normally TEFC type, of a reputed manufacturer.
✓ Good quality accessories.

✓ Fixed displacement pumps normally assembled vertical with the Pump immersed in the tank, improve pump performance and reduce noise level. Large Motor-Pump units assembled horizontal by the side of the Tank on a common Base Structure, with Ball valves and sensors provided on the Suction line.
✓ Variable Delivery Pump units, assembled on top of the Tank or by the side of tank, Air-Bleed valve provided for pump safety.
✓ Motor-Pump Units to have Anti-vibration pads to reduce Vibration and Noise level. The Motor Pump coupled with good quality Flexible Coupling. Exposed rotating parts well covered.

✓ Manifolded circuit construction has distinct advantages. Enables compact construction of the System.
✓ Reduces piping and joints there by diminishing leakage points. Utilizes Gasket Mounting type of elements that is easy to maintain/replace. Improves System Stiffness and performance

✓ Life of the system mainly the pump/hydraulic motors, depends on the quality of oil. The pump manufacturer recommendations are final.
✓ Viscosity depends on the ambient temperatures. The minimum cleanliness level in most cases is to NAS1638 class 9 or 18/15 to ISO.
✓ In practice, Pump suction is provided with 125-micron filters commonly known as Strainers. Return oil filtration is over a 10-micron filter commonly known as Return-line filter. Pressure line filters provided when proportional or servo elements are in the circuit.
✓ In special cases systems are provided with continuous off-line Filtration, Magnetic Grids and Moisture absorbing filters.
✓ Generally, Tanks are sized such that the Oil temperature is maintained within limits.
✓ Some cases where oil temperature needs a tight control, or circuits that produce heat such as constant breaking circuits. Additional cooling arrangement is provided. This is achieved by incorporating Oil to water Heat exchangers, commonly known as Oil coolers.
✓ Impeller type Air-Oil Cooler fitted on the motor shaft to cool the Case Drain of variable delivery pumps.

✓ Tanks are generally made from sheet-steel, fabricated with minimum welded joints. Baffle plates inside the tank is to reduce turbulence near to the Pump Suction. Large tanks have Manhole covers to facilitate cleaning. Tank inside thoroughly de-scaled and treated to minimize contamination. Tanks carefully sealed to maintain Oil cleanliness.
✓ Tanks to have generous ground clearance and proper lifting arrangement.
✓ Standard accessories on the tank: Drain Port, Inspection cover, Oil-Level indicator, Air-breather.
✓ Optional Accessories: Oil level Switch, Temperature Indicator, Thermostat, oil coolers.
✓ Good quality piping contributes to the system performance, Preferred Cold drawn seamless tubes to DIN2391. Ermeto Bite type Ferrule Fittings as end connectors. Tubes thoroughly cleaned prior to final assembly. Piping should be well supported.
✓ Tubes correctly sized considering oil Velocity and Pressure.
✓ Usage of Hoses mainly on Pump Delivery and areas where flexibility is required.