Hydraulics And Pneumatic Circuit o2y2e

UNIT-V HYDRAULIC AND PNUMATIC CIRCUITS

Hydraulic Circuit • A hydraulic circuit may be defined as the graphical representation of the hydraulic components in a hydraulically operated machine. 1).Hydraulic power pack: It consist of pump drive motor, mechanical couplings, oil reservoir, strainers, filters, coolers, etc. 2)Hydraulic control elements: They include various types of directional control valves, pressure control valves, flow control valves, electrical control valves.

Continue… 3)

Power drive units or actuators:

They are hydraulic cylinders and hydraulic motors. 4) System accessories: They include pipes and other fluid conductors, accumulators, boosters, pressure and temperature gauges, filters, etc.

Control of single acting hydraulic cylinder

Control of double acting hydraulic cylinder

Regenerative circuit

Machine tool Applications

Sequencing of two double acting Cylinder

Automatic Cylinder Reciprocating System

Pump Unloading Circuit

Speed Control Circuits  Flow control valves are used to control the speed of hydraulic cylinders  Location of FCV with respect to other components in a circuit will have effect on the characteristics of the circuit performance  Types 1. Meter-in circuit 2. Meter-out circuit 3. Bleed-off circuit

Meter-in speed control of Hydraulic Cylinder

Meter-out speed control of Hydraulic Cylinder

Bleed off circuit

Control of Hydraulic Motor

Meter in –Pneumatic Circuit

Meter –out pneumatic circuit

Control of Pneumatic motor

Synchronization -Cylinder in Parallel

Synchronizing circuits-two or more cylinder requires perfect synchronization

Tie Cylinders –Rack and pinion

Fail safe –Two handed Safety circuits

Hydropneumatic circuits

Other circuits Synchronizing circuit • Matching pump • Flow control valve • Flow dividing motors. Fail safe circuit Fail safe using emergency cut off valve.