Clutch accumulator

What is a hydraulic accumulator?

An accumulator is a vessel that stores, maintains, and recovers pressure in a hydraulic system. You might be familiar with most hydraulic components, such as pumps, valves, motors, and actuators, but the accumulator is another very important component. Figure 1. A hydraulic accumulator located within a fluid system.

How do accumulators work?

Accumulators and their circuits have been used for years as the primary method for controlling shift feel. These components are designed to modify a shift by essentially acting as a shock absorber for the fluid pressure that is applying a clutch, brake or band.

How does a forward clutch accumulator work?

At low pressure/idle, this fluid is forced through the orifice, where it will gradually stroke the forward clutch accumulator piston against opposing spring force, thus absorbing the D4 pressure that is also routed to apply the forward clutch.

What does an accumulator store in a hydraulic device?

In a hydraulic device, an accumulator stores hydraulic energy. It does this by storing hydraulic fluid under pressure, much like a car battery stores electrical energy. Accumulators come in various sizes and designs, with an initial gas pressure known as the 'precharge pressure'.

How do hydraulic accumulators reduce pump capacity requirements?

Hydraulic accumulators store hydraulic fluid under pressure to supplement pump flow and reduce pump capacity requirements, maintain pressure and minimize pressure fluctuations in closed systems absorb shocks, and provide auxiliary hydraulic power in an emergency.

What is an accumulator circuit?

In older 3- and 4-speed, fully hydraulic transmissions, accumulator circuits were typically large pistons and springs, with numerous additional valves helping to control pressures and flow.