Abstract: A motor pump aggregate M has a housing 1 defining an oil reservoir with first and second chambers R1, R2. An electromotor 2 is driving via its motor shaft W at least one radial piston pump arrangement P1 provided within said first chamber R2. Both chambers R1, R2 are separated by a separation wall 7. A filling and pressure biasing system V is provided for said first chamber R1 in order to adjust within said first chamber R1 a predetermined oil filling level and a pre-selected oil pressure pre-biasing for said radial piston pump arrangement P1.

Abstract: In a stacker control of a stacker (fork lift) for high storage racks comprising a swing-shift fork (G) which is pivotable about a vertical axis (7) and horizontally movable in computer-assisted fashion by hydraulically controlled hydraulic motors (H1, H2) via a directional control valve (W1, W2) which is connected to a joint source of pressure (15, P), a three-way pressure balance (D) is provided between the source of pressure (15) and the directional control valves (W1, W2) for giving priority to one of said hydraulic motors (H1, H2). the three-way pressure balance (D) being controlled by control pressures tapped upstream and downstream of the directional control valve, at least the directional control valve of the preferential hydraulic motor having an open zero position, and the three-way pressure balance (D) forming part of a neutral circulation circuit (U) led via the control piping of the further hydraulic motor from the source of pressure to tank.

Abstract: In a hydraulic pump (P) comprising at least one piston pump element whose ston (11) is oriented towards an eccentric (E) of a drive shaft (2), and being equipped between the eccentric (E) and a bearing ring (R) rotatable on the eccentric (E) with an eccentric slide bearing (G) having a bearing bush (B) fixed in the bearing ring (R), the bearing bush (B) and the bearing ring (R) each have molded and locally meshing stop portions (A1, A2) which positively fix the bearing bush (B) in the bearing ring (R) in rotational and axial direction. (FIG. 1).

Abstract: In a magnetically operated drain valve of an electrohydraulic lifting mod comprising a closing element which in the closing direction is assigned to a main valve seat, a pilot valve which is actuable by the magnet and arranged in a control chamber of the closing element, a throttle arranged upstream of the control chamber, and a closing member of the pilot valve which is adjustable by the magnet against a spring, the closing member being actuable by the magnet against the spring acting either in the closing adjustment direction or in the opening adjustment direction, a spring with a steep characteristic curve is used as the spring, and the closing element and the main valve seat form a lift-dependent flow-quantity adjusting device.

Abstract: An electromagnetically operable valve, comprising a coil and an electromat containing an armature, the armature of which impinges an actuating member connected to or forming an active member of the valve in operating connection and a lever mechanism arranged between the armature and the valve member for the step-up or step-down transmission of the stroke.In valves of this kind known from prior art a considerable expense in construction is incurred for the accommodation of the lever mechanism which offsets the savings with respect to the costs and the constructive area in long-stroke magnets; this is avoided by a novel construction incorporating the lever mechanism into the electromagnet and between the armature and the actuating member.

Abstract: Switching valve (1') with hydraulic self-holding properties, in which a s piston (11') having a closure piston element (15) connects or locks a pressure inlet (16') and a pressure outlet (17'), in which a pressure line (18, 19) leading to the pressure inlet (16') and continued to a consuming point (A), and a duct (21) leading from the pressure line to a control chamber (10) of a control piston element (12), are provided; and in which an overflow connection and a relief duct (34), openable as a function of the stroke from the annular chamber (25), are provided between the pressure inlet (16') and the annular chamber (25). The overflow connection is formed by a continuously open duct (32'), whose passage cross-section is smaller than the passage cross-section of the relief duct (34).

Abstract: The invention relates to a hydraulic control apparatus comprising a hydraulically adjustable throttle opening between an inlet passage and an outlet passage, a three-way pilot valve connected to an external actuator and having its inlet connected to a control pressure inlet passage, its control outlet being connected to the throttle valve in such a manner that the throttle valve element thereof is adapted to be biased in opposition to the pressure in the outlet passage and to the force of a spring. Known control apparatus require the employ of a displacement sensor for sensing the position or displacement of the throttle valve element and for correspondingly acting on the actuator to thereby vary the actuating force thereof for maintaining the opening degree of the throttle opening. This construction involves considerable complications. It is also disadvantageous that the pilot valve is subjected to the full operating pressure, requiring it to be of a highly accurate and therefor expensive construction.

Abstract: The invention relates to a hydromechanical tool or workpiece clamping apptus comprising at least one spring clamping cylinder connected to a release conduit and adapted to be hydraulically operated against a spring force to a release position, a pump connected to said release conduit and operable for a release operation, and a discharge conduit extending from said release conduit to a fluid reservoir and including a discharge control element for discharging the pressurized fluid from said spring clamping cylinder to said reservoir after deenergization of said pump. A known clamping apparatus of this type has a solenoid poppet valve disposed in said discharge conduit and operable to close said discharge conduit for the release operation and to be actuated to a flow-through position and maintained therein for the clamping operation. The solenoid valve is expensive and requires separate control means.

Abstract: This invention relates to a hydraulic device comprising at least one adjuble working, control or regulating member between a pressure source (3) and the flow path of an outlet (5,R), said member establishing an unrestricted connection to a passage in one position with the pressure medium which is present flowing out via said connection by expanding. In the case of high working pressures and/or great quantities of delivery, a loud noise develops in such hydraulic devices throughout the whole flow path of the outlet when the jet flows out.

Abstract: A hydraulic pump unit, comprising an electric motor, the stator (5) of wh is disposed in a housing defining an oil reservoir and the rotor of which is mounted on a shaft which drives a hydraulic pump. Each front end of said stator is associated with an end shield for a shaft bearing. A pump element or the pump is secured to at least one end shield. Elongated connecting members which are distributed about said shaft in the circumferential direction support said end shields. The connecting members are designed as rods (17), abut against the outer circumference (7) of said stator (5) and, in the undeformed state, guide said stator in a close sliding fit. At least one tightening strap (19) encompasses said rods (17) and the outer stator circumference (7) for deforming said rods (17) until said stator is fixed in position and for pressing said rods against the stator circumference. A means for preventing rotation can be provided between said stator and said rods or said tightening strap.

Abstract: The invention relates to a two-position switching valve having hydraulic f-holding properties and comprising a closure piston disposed in a flow path for displacement between an open position and a closure position for controlling a pressure between a maximum value and a minimum value, and operatively coupled to a control piston mounted for displacement in a housing. In known switching valves of this type, a creeping approach of respective switching points is scarcely avoidable under certain operating conditions.

Abstract: The invention relates to a hydraulic control valve comprising a housing w a housing bore (2) formed therein, a control piston (3) being guided in said housing bore for sliding displacement between a neutral position (n) for zero-pressure through-flow and at least one control position (I, II), and further comprising a pressure inlet (6) opening in said housing bore (2), a through-passage (8) in said control piston (3), and a discharge outlet (7) communicating with said pressure inlet via said through-passage in the zero-pressure through-flow position. In a control valve of this type, particularly if employed in a high pressure hydraulic system, displacement of the control piston from a control position to the neutral position is hampered by unsatisfactory pressure compensation.

Abstract: The present invention relates to a flow divider for carrying out a load-ipendent division of a stream of hydraulic fluid, comprising a basic body including an internal bore, a central main connection and two outer consumer connections leading to said internal bore, and further comprising two approximately coaxial control pistons which are displaceably guided in said internal bore and which are each provided with a flow orifice and with at least one radial control opening, said control pistons being adapted to be moved towards each other and away from each other to a limited extent via a coupling device connecting said pistons. In the case of known flow dividers the coupling device consists of interengaging hooks which are rigidly formed on the control pistons, said hooks producing, however, eccentric forces for the control pistons in said internal bore, and said forces impair the control characteristics and the operating behaviour of the flow divider.

Abstract: Control valve in which the supply channel and the consumer channel lie in e common plane, while the outlet channel cooperating with the consumer channel lies in a second plane, standing approximately perpendicular to the first plane.

Abstract: A control valve for a high pressure hydraulic system with a piston slide ch can be moved from a neutral position into a first and, if desired, into a second control position, which makes it possible to effect a connection between a pump connection opening and at least one consumer device connection opening staggered relative thereto in a longitudinal direction with flow pockets on the circumference and throughflow channels between the flow pockets.