Electro-hydraulic systems
(b) . Electro-hydraulic control technology with continuously adjustable valves ( high response proportional valves , servo valves ). This technology operates with continuous sensors and electronic control [...] This term covers all combinations of electrical (electronic) signal processing with hydraulic drives. These combinations can be divided into three groups: Electro-hydraulic technology in which hydraulic [...] generally undertaken using relay technology (Figure E 22 a) . Electro-hydraulic control technology with continuously adjustable valves ( proportional valves ). This technology permits continuous adjustment
Internal gear pump
lack of play at the teeth, internal gear pumps are associated with very low delivery flow pulsation and are therefore quiet during operation. With axial play compensation they can achieve average pressures [...] Pump with two gear wheels in most cases whose outer (ring gear) has teeth on the inside. The inner sprocket is smaller. The fluid is conveyed in the spaces between the gaps in the teeth of the two gear [...] pressures of up to around 160 bar, while 300 to 320 bar is possible with combined axial and radial play compensation at the sprocket and ring gear (Figure I 11) . Their geometric displacement cannot be adjusted
Types of motion of cylinders
characteristic ). Example: presses. Feed motion : with the action of the force over the entire working stroke and a very consistent, load-independent motion with widely varying velocities. Example: feed on machine [...] between four different types of motion that affect the structure of the drive: Transport motion : with the highest force required on accelerating the load. The velocity can mostly not be maintained accurately [...] machine tools. Terminal force motion : during which the force is only required at the end of the travel with very high velocity during the movement. Example: injection moulding machine.
Compact seal
becoming deformed. Compact seals are often combined with guide elements to form piston seals . Compact seals for piston rods are often installed with a supporting ring ( back ring ) in order to improve [...] Design category for seals with a block-like body and a less pronounced sealing edge. A characteristic feature is how the preload is applied not only by the sealing lips , but also by the body of the seal [...] types of seals are elastomer/energised plastic faced seals. They consist of a sealing ring (generally with bronze or carbon-filled PTFE) which is subjected to a preload by an elastically deformed O-ring The
Hose line
Hose cut to length, with the necessary connection fittings on both sides.
Feed circuit
Low-pressure circuit in a hydrostatic transmission with the task of constantly replacing the small oil volume with fresh oil in a closed circuit. For this purpose, there is a feed circuit from the Charge
Primary and secondary control
transmission based on a combination of a pump and motor with adjustable geometric displacement. This ensures the highest rotation speed range is achieved with a good level of utilisation ( Figure P 16 ). The
Flow rate measurement procedure
part of the pipeline, there are a number of procedures, such as the displacement principle with flow sensors with oval rotor assembly , measuring turbines or gear pump flow meters , which can take direct [...] fluid technology . They work indirectly and can be very small. Procedures for measuring the duration with ultrasound and lasers are still used as a priority in laboratory measurement technology.
Automatic sealing
around the seal even in the unpressurised state. With increasing pressure increasingly large parts of the seal are pressed against the mating surface with increasing force. As a result the sealing gap becomes [...] increases and therefore also the sealing action (Figure A 28). Automatic sealing is only possible with elastic materials.
Pitot tube
associated with a fluid flowing at a subsonic rate. The pitot tube consists of a tube at a 90° angle, whose arm lies parallel to the direction of the flow ( Figure P 9 ). Pressure measured with this kind [...] kind of open tube will change in line with the angle, since dynamic pressure only acts in the direction of the flow. In order to avoid , the open area for the pitot tube must therefore be perpendicular to