Abstract: A brake appliance for gerotor motors has a disc assembly brake comprising interacting discs that are subjected to opposing forces from pressurized fluid in one direction to disengage the discs, and from primary and secondary spring forces in the other direction to engage the discs.

Abstract: A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.

Abstract: A controller for an expansion valve of a refrigeration system for cooling a medium is configured to include, in the generation of a control signal, a measure of the evaporation temperature (T0) of the refrigerant in an evaporator and a measure of a property of the cooled medium, preferably without influence from a measure of the superheat temperature (SH) of the refrigerant. The controller comprises a PI-element for integrating and for producing a control signal for the expansion valve for controlling the flow of refrigerant into the evaporator, the PI-element being arranged in an inner control loop, a reference for which is produced by an outer control loop. The controller allows for fast response to disturbances and/or fast response of the medium temperature when the operating conditions of the refrigeration system are changed and/or fast response during start-up of the refrigeration system and maintains stable operation conditions with low, but positive superheating and a stable evaporation pressure.

Abstract: The invention concerns a cylinder head arrangement for a piston compressor, particularly a hermetically enclosed refrigerant compressor, with a suction muffler and a valve package having a valve plate, at least one suction valve and at least one discharge valve. It is endeavoured to simplify the assembly. For this purpose, the suction muffler has a housing, in which the valve package is adopted, the housing having positioning means, which determine the position of the valve package in the housing.

Abstract: In a valve used in connection with a scroll compressor, a central profiled body is designed to protrude in an opening for outlet of gas from a compression stage, a outer axisymmetric surface of which is concave, of generally toroidal shape, and is terminated by a tip, the outlet opening of the compression stage being delimited by a curved surface forming, in the downstream direction, a widening providing, with the central profiled body, a cross section for the passage of the gas which is substantially constant, closing means being provided in order to seal this passage in the closed position of the valve.

Abstract: A valve member includes an axially movable spool valve rotatably mounted in the valve member to cause the way that fluid is communicated between the inlet and outlet ports of the device and the volume chambers thereof. An outer surface of the spool has a configuration to react to fluid pressure to effect the timing between the gear set and the valving of valve member and that the timing therebetween will be adjusted when the spool valve is moved axially. A valve actuator comprising a spring loaded plunger controlled by fluid pressure at the inlet and outlet ports is in physical contact with one end of the valve spool.

Abstract: The invention concerns an electric motor with a stator, in whose bore a rotor is arranged, and with a control arrangement having at least one coil with a core passed by the motor current. The coil shall be arranged in a space saving manner without interfering too much with the magnetic field of the motor. To solve this problem the core of the coil is arranged on the stator whose iron is used for a magnetic circuit.

Abstract: A method for the operation of a centrifugal pump (2) driven by an electric motor (5) with variable frequency, wherein too small a flow through the pump (2) is ascertained by monitoring electrical quantities, and a pump arrangement (1) having a centrifugal pump (2), an electric motor (5) which drives the centrifugal pump (2), a controlled frequency converter (6) which feeds the electric motor (5), a sensor device (12, 13) and an evaluating device (15-19) are described. It is desired to detect, by simple means, when no through-flow is present. For that purpose, the electrical power is ascertained and compared to a control quantity formed as a function of the frequency of the motor (5). The sensor device ascertains values for determination of the electrical power, and the evaluating device has a dynamic limit value former (18), which forms a control quantity as a function of the frequency of the motor (5).

Abstract: A variable displacement hydraulic power unit has a housing and a rotating piston block with a rotatable axis and a servo piston bore having a reciprocal piston therein with the bore extending in a direction parallel to the rotatable axis of the rotating piston block. The housing and servo piston each have adjacent open ends. A single integral cover is attached to the housing to cover close and close the open ends of both the housing and the piston bore.

Abstract: The invention relates to a suction muffler for a hermetically enclosed compressor, with a housing having a first part with an outlet channel and a second part with an inlet channel, flow conducting means being arranged between the outlet channel and the inlet channel, said means forming, together with the inlet channel and the outlet channel, a flow path, and a filter being arranged in the outlet channel. Further improvements of the noise damping are endeavored. For this purpose, the filter has a sieve-like embodiment and that the flow path comprises at least one second filter with a sieve-like embodiment.

Abstract: In a compressor at least one bypass valve is arranged in a low-pressure zone inside a casing of the compressor. The bypass valve defines a chamber connected by a first duct to at least one compression pocket situated in the peripheral zone of the compression stage and by a second duct to the low-pressure zone, the two ducts opening near one another so that they can be shut off by a shutter which can move in the chamber, being guided by the walls that delimit this chamber, a third duct intended for conveying a shutter-control fluid opening into the lower wall of the chamber of the valve. The shutter is opened by gravity when no control fluid is applied.

Abstract: A rotary fluid pressure device has a first oil passage with relatively high pressure fluid therein surrounding the gear set; a plurality of second oil passageways connecting the first oil passageway to the expanding and contracting oil chambers; and fluid non-return valves in each of the second oil passageways to permit the flow of oil therethrough only in a direction from the first oil passageway to the oil chambers.

Abstract: The invention concerns a hydraulic dual circuit steering system with first circuit having a first control unit and a first steering motor connected with the control unit via working connections, a second circuit having a second control unit and a second steering motor connected with the control unit via working connections, a changeover valve, which in a first position activates the first circuit and deactivates the second circuit and in a second position activates the second circuit and deactivates the first circuit. To improve the steering behaviour, in the first position of the changeover valve the working connections of the second circuit and in the second position of the changeover valve the working connections of the first circuit are connected with a pressure source.

Abstract: The invention concerns a valve, particularly a solenoid valve, with an inlet connection and an outlet connection, having between them a shut-off device with a valve seat and a closure member. In such a valve, it is endeavoured to obtain a small output with a simple design. For this purpose, the closure member has a closing element and a tappet separate from the closing element, the closing element being held in a guiding arrangement.

Abstract: A refrigeration control apparatus comprises a master unit with a mother board. The mother board comprises a bus configured to carry signals between boards coupled to the mother board. A processor board interfaced to the mother board is provided. The processor board comprises a processor, and a program memory where instructions for the processor are stored on the program memory. An interface circuit coupled to the mother board is provided. A load control module interfaced to the mother board is provided, wherein the load control module comprises an interface circuit coupled to the mother board, and a circuit breaker coupled to a power input. A load relay comprising a first interlocked relay and a second interlocked relay coupled to the circuit breaker is provided. The load relay is configured to switch power. An override switch and the processor coupled to the load relay to control the load relay is provided.

Abstract: An extended male slipper servo pad provides an improved connection between the swashplate and a positioning mechanism in a variable displacement hydraulic unit. The swashplate assembly includes a swashplate having a socket formed therein and a male slipper servo pad pivotally attached to the swashplate at the socket. The male slipper servo pad has a ball end secured in the socket and a pad end having a substantially flat planar surface thereon directed away from the ball end.

Abstract: A method for testing a heating system with at least one basic unit, which controls activating elements of individual heating circuits, with the basic unit being connected with setting units. To simplify the testing of such heating systems, the elements available in the heating system are arranged hierarchically in steps, with the steps being tested in a predetermined order, one after the other.

Abstract: The invention relates to a piston compressor, particularly a hermetically enclosed refrigerant compressor, with a crankshaft, which is axially supported in an axial bearing in relation to a bearing housing, and with an oil pump arrangement. In a piston compressor of this kind, it is endeavored to improve the lubricating properties. For this purpose, an oil distribution channel extending in the circumferential direction is arranged in the axial bearing between the crankshaft and the bearing housing, a control arrangement being arranged between the oil pump arrangement and the oil distribution channel, which control arrangement connects the oil pump arrangement with the oil distribution channel for a predetermined, short period, at least once during each rotation of the crankshaft.

Abstract: A method of securing a cap on a piston body includes forming a first annular V-shaped surface at an open end of a cylindrical piston body; forming a second annular V-shaped surface on an annular surface of an oil conduit in the interior center of the piston body; forming a cap to close the open end of the piston body and forming a pair of annular surfaces therein which are flat in shape and in contact with first and second annular V-shaped surfaces on the piston body; placing the cap over the open end of the piston body and thereby placing the annular surface on the cap and the body in close intimate contacting relation; and welding the respective annular surface of the cap and the piston body together by subjecting the cap and body to an extreme high current density to fuse respective contacting annular surfaces together.

Abstract: A pump housing assembly includes a housing, a hub portion, and a flange. The housing has an end cowling defining a transition from a central portion of the housing to a transverse end portion. The hub portion extends longitudinally outwardly from the transverse end portion of housing. The flange extends radially outwardly from the outward end of the hub and is in spaced longitudinal relation to the end of the cowling to create a space to receive a head of a mounting bolt. The flange has an outer periphery with a pair of tangentially extending slots having an open end. The space for receiving a head of a mounting bolt is less than the length of a shank of a mounting bolt, to minimize the length of the housing. The slots have a width sufficient to receive the movement of a shank into and out of the open ends of the slots.