A method for operating a device for dosed supply of a liquid, having a pump to deliver the liquid. The pump has an inlet and an outlet. An eccentric is arranged on the pump housing and a deformable diaphragm is arranged between a pump housing and the eccentric. The deformable diaphragm and the pump housing delimit a delivery path from the inlet to the outlet. The seal can be displaced along the delivery path by movement of the eccentric. A pressure sensor is connected to the outlet of the pump. A liquid is delivered by the pump. A time curve of the pressure at the outlet of the pump is monitored during delivery by the at least one pressure sensor. An angle position of the eccentric of the pump is detected using at least one characteristic feature of the time curve at the outlet.

A hydraulic actuator includes a piston housing having a head end and a base end opposite the head end and a drive piston movable between a first piston position proximate to the head end and a second piston position proximate to the base end. The hydraulic actuator further includes a control valve positionable between a first control valve position, in which the control valve directs fluid into the base end, and a second control valve position, in which the control valve directs fluid into the head end. A pressure-based position feedback system configured to facilitate transition of the control valve between the first control valve position and the second control valve position in response to predetermined head end and base end pressures.

A coiled wave spring used by a diaphragm damper device and arranged in a fuel chamber defined by a housing and a cover is provided. The coiled wave spring is configured to be arranged between a diaphragm damper of the diaphragm damper device and the cover. The coiled wave spring is configured to fix the diaphragm damper to the housing with its elastic force. The coiled wave spring includes a coil portion, a winding initiation portion, and a winding termination portion. The winding initiation portion and the winding termination portion form flat seat windings. The seat windings each have a larger outer diameter than the coil portion. One of the seat windings is configured to be fixed to the diaphragm damper.

A vehicle for line marking, having a steering mechanism (10) including: a directional wheel (5) that pivots about a steering shaft (12) coupled to a steering actuator (13); a control actuator (21) responsive to a steering wheel (22); and a universal joint coupling the control actuator (21) and the steering actuator (13) at a fixed angle between 20 to 70, preferably 30 to 60; the angle of the universal joint acting to produce a varying steering ratio as the steering wheel is moved away from its centered position. The vehicle includes a hydraulic pump circuit for a motor (101) driven line marking spray device (77) having a hydraulic supply line (105) for the motor with a check valve (107) and a high pressure accumulator (109) between the check valve and the motor and a pressure actuated ram (102) to deactivate the pump (100) when the pressure exceeds a threshold; the motor return line having a low pressure accumulator (110) and a restricted (112) bypass line (111).

A liquid supply mechanism includes a lower cover, an upper cover, a plunger, at least one resilient member and at least one damping member. The lower cover has a liquid outlet and the upper cover is connected to the lower cover. A chamber is formed between the lower cover and the upper cover. The chamber communicates with the liquid outlet and contains a cooling liquid. The upper cover has an axial hole. The plunger is movably disposed in the chamber. The plunger has an axial rod and the axial rod is inserted into the axial hole. The resilient member is disposed in the chamber. Opposite ends of the resilient member abut against the upper cover and the plunger. The damping member is disposed on the axial rod and abuts against an inner wall of the axial hole.

A high-pressure pump has an elastic member arranged in a damper chamber between a first diaphragm and a second diaphragm. The elastic member is always in contact with both diaphragms while the high-pressure pump is operated. When the diaphragms are further vibrated due to a resonance under a situation where a frequency of the pressure pulsation of low-pressure fuel is in agreement with the characteristic frequency of the diaphragms, the elastic member restricts the deformation of the diaphragms. Therefore, the resonance of the first diaphragm and the second diaphragm can be restricted.

The pressure of compressed air supplied to an object to be filled with air is controlled at a specified pressure or less without using a relief valve. Given that a cylinder volume (stroke volume) during a piston moves from the lower dead point to the top dead point is V1, a cylinder volume (compression volume) when the piston reaches the top dead point is V2, the atmospheric pressure is P.sub.0, and the specified pressure is P.sub.P, the compression volume V2 in the compressor system satisfies the following expression (1). The diameter D of the air intake hole of an air intake valve provided on the piston is 3 to 15 mm.
0.8{V1P.sub.0/(P.sub.PP.sub.0)}=<V2<1.0{V1P.sub.0/(P.sub.PP.sub.0)}(1)

A hydraulic pump includes: a valve plate including a suction port and a delivery port; a valve cover to which the valve plate is mounted; and a cylinder block that slides on the valve plate. The valve cover includes a suction passage and a delivery passage. The valve cover includes: a first chamber that communicates with the delivery passage through a communication passage and functions as a Helmholtz resonator; and a second chamber that communicates with the delivery passage, or with the first chamber, through an introduction passage including a restrictor. In the valve cover and the valve plate, a supply passage extends from the second chamber to a bottom dead center-side sealing surface of the valve plate, the bottom dead center-side sealing surface being a surface located between the suction port and the delivery port. The supply passage includes a restrictor.

A device (DV) for damping pressure fluctuations in a pressure medium (DM) comprises the following features. It has a base body (GK) in which an intake chamber (AK11) is provided, which has an intake-chamber opening (OA1) which is located at a first side (S1) of the base body. A first expansion chamber (EK11) is furthermore provided in the base body, which has a first expansion-chamber opening (OE1), which is likewise located at the first side of the base body. A partition wall (T1) separates the intake chamber from the first expansion chamber. A cover element (AD) for positioning on a contact surface (AF) of the first side of the base body is furthermore provided in order to close the intake chamber and the first expansion chamber to the outside. Finally, an overflow channel is provided, in particular in the partition wall between the intake chamber and the first expansion chamber, so that pressure fluctuations in the pressure medium are damped during the through-flow from the intake chamber through the first overflow channel into the first expansion chamber.

A hydrostatic axial piston machine includes a pot-like housing, a connection plate that closes the pot-like housing, a rotatably mounted cylinder drum, and pistons arranged in cylinder chambers of the cylinder drum. The cylinder chambers are each alternately connected via a cylinder chamber opening to a low-pressure control opening and a high-pressure control opening of a resting control part. The control part has two switching regions located between the low-pressure and high pressure control openings. A piston reverses its movement direction in a dead center within the two switching regions. In the switching region, the cylinder chambers are connected via a connecting line to a fluid volume arranged in the housing. The fluid volume extends between the connection plate and the housing such that it is sealed to an interior by the connection plate and the housing.