What is fluid coupling PDF?

A fluid coupling or hydraulic coupling is a device used for transmitting power from one shaft to another shaft by means of acceleration and deceleration of a hydraulic fluid. Fluid coupling is based on hydro-kinetic principles and requires that the output speed be less than the input.

How do you align a fluid drive coupling?

Alignment

  1. The driving machine must be mounted in its final position. The foundation bolts must be firmly tightened.
  2. Fit the flexible element in the connecting coupling.
  3. Push the motor up to the driven machine. To allow the motor to be correctly aligned, the feet should be adjusted by means of shims or foil plates.

How does a variable speed fluid coupling work?

Voith variable speed couplings are fluid couplings. They link the drive machine – generally an electric motor – with the corresponding driven machine. The power is transferred through the fluid energy of the working fluid.

Which oil is used in fluid coupling?

hydraulic oil
The Oil to be used in the coupling shall be hydraulic oil, mineral type, conforming to Grade-3 of IPSS: 1-09-002, “Specification for hydraulic Oil, Mineral Oil type”. The supplier shall emboss on the body of the fluid coupling the recommended filling angel and quantity of Oil required for a particular rating.

What is the maximum misalignment on a coupling?

Each coupling is designed to transmit a given limiting torque. Generally, flexible couplings are able to tolerate up to ±3 degrees of angular misalignment and up to 0.75 mm parallel misalignment depending on their design. If more misalignment is required, a universal joint can be used (see Figs.

Why do we need fluid coupling?

Fluid couplings provide a controlled soft start up, helping to prevent shock loads and protect surrounding equipment. These couplings allow variable speeds and provide easy torque control.

Which fluid is used in fluid coupling?

Hydraulic fluid
Hydraulic fluid As a fluid coupling operates kinetically, low-viscosity fluids are preferred. Generally speaking, multi-grade motor oils or automatic transmission fluids are used. Increasing density of the fluid increases the amount of torque that can be transmitted at a given input speed.

How much oil goes in a fluid coupling?

The maximum allowable oil fill amounts to approximately 80% of the total capacity of the Fluid Coupling. This level should never be exceeded since overfilling may cause over pressure inside the coupling and damage to the seals.

How many types of fluid couplings are there?

two types
In practice there are two types of fluid couplings; Constant Filling, where the oil filling is fixed and variable filling also known as variable speed where the quantity of oil in the working circuit can be varied whilst running to give control over the amount of slip between the impeller and runner and so give speed …