Rapid traverse circuits
(Figure E 3 a) , Rapid traverse by means of piston for rapid traverse , Rapid traverse due piston free fall (Figure E 3 b) . Figure E 3: Rapid traverse circuit; a) pumps for rapid traverse, b) piston free fall
Radial piston motors
using large piston diameters. The oil is distributed via control rings in the shaft extension ( Figure R 3 ). Figure R 2: Radial piston motor with internal pressurization Figure R 3: Radial piston motor with [...] Fluidlexikon Radial piston motors Design of hydraulic motors with a radial arrangement of pistons . Radial piston motors are predominantly slow speed high torque motors in which several pistons are positioned [...] formation in a cylinder block. As with radial piston pumps a distinction is made between internal and external pressurization in the designs. Radial piston motors with internal pressurization : These are
Damping of valves
Above all on pressure valves the closing element (cone or piston) has a damping piston to prevent undesirable oscillations (chattering) (Figure D 3) . It must be designed such that the damping is only effective [...] effective on the closing stroke while the opening stroke is not allowed to be hindered. Figure D 3: Damping on valves
Pump with banked pistons/in-line piston pump
or as 3-piston pumps for pressurised water operation . Pumps with banked pistons/in-line piston pump with multiple pistons are now worthless. Figure R 24: Pump with banked pistons/in-line piston pump [...] pistons/in-line piston pump Hydraulic pump with pistons arranged alongside one another and perpendicular to the drive shaft Piston ( Figure R 24 ). They are preferably made as single-piston pumps (also for
Relative delivery fluctuation δ
beneath it at certain angles. Table U 3: Kinematic relative delivery flow of different pumps a) gear pumps; b) piston pumps Figure U 16: Torque fluctuations in an axial piston pump [...] resulting from the final number of displacement units and their sinusoidal working patterns ( Table U 3 ). It is expressed in the form of flow rate pulsations (flow rate pulsations caused by the pump kinematics) [...] construction design of the pump and the number of displacement elements. In addition, in the case of piston pumps with an even number of pistons, δ is around twice as high as in the case of an uneven number
Tandem cylinder
pressurised pistons are arranged one after another, which act on a piston rod such that their forces are added together ( Figure T 3 ). Tandem cylinders are used if the space provided is not sufficient [...] sufficient for a normal cylinder. Example: Pneumatic die cushion cylinder in mechanical presses. Figure T 3: Tandem cylinder
Hydraulic cylinder
oscillation ( servo cylinder ). Hydraulic cylinder with piston : The mechanical force is generated by the action of the hydraulic fluid on a piston. With this approach, a single cylinder is able to apply [...] ranging from just a few cm to over 20 m. There are 3 basic designs available: single acting cylinders and double-acting cylinders with 1 or 2 piston rods. There are also numerous special forms. The load [...] 100 bar and above). Given the relatively low compressibility of the fluid and the low weight of a piston, hydraulic cylinders offer high dynamic performance (generally >600 Hz), which means the dynamic
Directional valve
negative or zero cut overlap). Construction design : piston or and seated valves . Task : Valves with 2, 3, 4, sometimes 5 and more lines (ports) and with 2, 3, sometimes 4 switching positions . The directional [...] switching positions (open and closed); 3/2-way directional valves : Valves with three controlled ports and two switching positions (open and closed); single action consumers; 3/3-way directional valves : As above [...] switching positions to control a dual action consumer; 4/3-way directional valves : As above, but with a centre position with several design forms; 5/3-way directional valves : As above, but with two separate
Flow divider
the control piston of the valve works like a pressure compensator , the same also applies largely for different pressures in the subflows ( Figure S 106 ). The indexing accuracy is around ±3-5 %. Alternative:
Run up time constant To
time constant To for, say, a 50 kW axial piston motor would be around 0.2 s (the run up time constant To for an electric motor with the same power would be over 3 s).