Abstract: A method of analyzing a refrigeration system (1) comprising at least one compressor (4), at least one condenser (5) and at least two refrigeration entities (2), each comprising at least one evaporator (9). Based on information relating to the gas production by the evaporators (9) it is determined whether or not two or more evaporators (9) are running in a synchronized manner, i.e. are switching between an active and an inactive state at least substantially simultaneously. In case two or more evaporators (9) are running in a synchronized manner, the refrigeration system (1) may be controlled in order to desynchronize the evaporators (9). This may, e.g., be done by changing a cut-in temperature and/or a cut-out temperature for one of the corresponding refrigeration entities (2). Synchronization causes undesired variations in the suction pressure, and preventing synchronization therefore results in a more appropriate control of the refrigeration system (1). Reduces wear on the compressors (4).

Abstract: A hydraulic machine has a gear wheel (2) with outwardly extending teeth and a gear ring (4) with inwardly extending teeth formed by rollers each of which is supported in a pocket (8) in the gear ring, and pressurized spaces are formed between the gear wheel and the inwardly extending teeth. To keep the wear of the machine small each pocket (8) has at least two different radii (R1, R2, Rn) whereby a radius (R2, Rn) at a smaller displacement from the edge (12) of the pocket is larger than a radius (R1) at a larger displacement from the same edge (12) of the pocket (8).

Abstract: The invention relates to a circuit for enabling or disabling hydraulic actuating devices, in particular for enabling the braking system of a hydraulic propel drive, having a device for checking the pressure level in working lines or control lines of hydraulic circuits, a maximum or minimum pressure level being checked in two or more working lines or control lines. An ‘OR’ logic circuit is provided for checking the pressures. In said ‘OR’ logic circuit, two or more pistons are arranged in series in a common bore. In each case one of the pressures to be checked is introduced into one of the spaces between the pistons and the space between one of the pistons and the base of the bore.

Abstract: The invention relates to a circuit for enabling or disabling a braking system of a hydraulic propel drive, having a device for checking operating parameters which are relevant to a neutral setting and having a spring device, in particular a load spring, which acts counter to the control piston of an electrohydraulic solenoid valve which is designed to enable the braking system by means of electrical operation. A device for generating a force, which is dependent on the neutral position, of the spring device is provided, wherein when a neutral setting is not present, the force action of the spring arrangement prevents the electrohydraulic solenoid valve from enabling the braking system, by acting counter to the electrical operation of the magnet of said solenoid valve.

Abstract: A cooling unit for cooling in particular power semiconductors contains a distributor for guiding liquid across a surface to be cooled. The distributor comprises an inlet manifold (8) and outlet manifold (9), whereby the inlet and outlet manifolds are connected through a flow cell, which has a main flow channel (50). The main channel is formed as a meandering sequence of channel segments (61,62,63,64). It has been found, that the transfer of heat by the liquid in the main flow channel can be improved by introducing a bypass flow channel (71,72,73) which allows the flow of liquid from the cell inlet to the cell outlet, wherein the bypass flow channel interconnects the channel segments of the main flow channel.

Abstract: A multilayer composite includes at least two composites, each composite having a film and an electronically conductive layer. Several composites are laminated to provide an increased conversion between mechanical and electrical energies not only due to the multiplication of the effect of each layer, but also due to the fact that the multilayer structure itself renders the multilayer composite more rigid. In addition, the multilayer structure facilitates application of an electrical field over thinner portions of the structure, thereby requiring much less potential difference between electrodes.

Abstract: A method for providing a multilayer composite includes the steps of providing a first composite comprising a film of a dielectric material with a front surface and an opposite rear surface, the front surface comprising a surface pattern; depositing an electrically conductive layer onto the surface pattern; providing a second composite comprising a film with a front surface and an opposite rear surface, the front surface comprising a surface pattern; depositing an electrically conductive layer covering at least a portion of the surface pattern; arranging the first composite on the second composite; and fixating the position of the first composite relative to the second composite.

Abstract: The invention provides a fluid controller, e.g. for a hydrostatic power steering. The controller comprises a cylindrical valve member cooperating with a housing to define at least one fluid path from a pressure source to a steering cylinder. The valve member is rotatable in the housing and comprises a sleeve and a spool, wherein the spool is rotatable within the sleeve. The fluid flow is metered by a flow meter, and the valve member comprises a plurality of meter ports communicating the fluid between the valve member and the flow meter. To obtain less friction between the sleeve and the housing and between the sleeve and the spool, the meter ports are grouped in two groups in which groups the ports are in mutually fluid communication.

Abstract: A pumping system includes a pump for moving water. In one aspect, this is in connection with performance of an operation. The system includes a variable speed motor operatively connected to drive the pump. A value indicative of flow rate of water is determined and the motor is controlled to adjust the flow rate indicative value toward a constant. A value indicative of flow pressure is determined and the motor is controlled to adjust the flow pressure indicative value toward a constant. A selection is made between flow rate control and flow pressure control. In another aspect, the pump is controlled to perform a first operation, and is operated to perform a second water operation. Control of operation of the pump to perform the first water operation is altered in response to operation of the pump to perform the second operation.

Abstract: The invention is directed to controlling an electric motor by means of a frequency converter. The frequency converter can be connected to one of several different mains voltages. According to the present invention, the maximum output power of the frequency converter, is limited when the actual mains voltage is lower than the maximum nominal mains voltage, for which the frequency converter is designed, and during the limitation the frequency converter controls the speed of the motor within a power range up to a limited maximum output power. This gives a genuine multi-voltage unit, which can be connected to a wide range of mains voltages.

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive, the supply to and the outflow from the hydraulic drive being separately controllable. It is endeavoured to realise separate controls of the speed and the hydraulic pressure of the hydraulic drive. For this purpose, a pump pipe is connected with a first control valve, the first control valve is connected through a pipe with a first working connection and a second working connection of the hydraulic drive, and the first working connection is connected with a second control valve and the second working connection is connected with a third control valve, the second control valve and the third control valve opening into a tank (T).

Abstract: The invention concerns a plunger piston compressor (1) for refrigerants, particularly for CO2, with a case-like housing, having a compressor block (2) with a compression section comprising a cylinder (13) as first housing element and a bottom part (3) as second housing element, the compressor block (2) and the bottom part (3) being connected with each other, and with a motor (25) with a drive shaft (23) located in the inner chamber (17). It is endeavoured to provide a high-pressure refrigerant compressor with a simple design, which is cost effective in manufacturing. For this purpose, it is ensured that the drive shaft (23) is only supported on one side of the motor (25).

Abstract: The invention relates to a cylinder head arrangement for a piston compressor, particularly for a hermetically enclosed refrigerant compressor, with a valve plate, a suction gas channel, a discharge chamber and a retainer element for a discharge valve. It is endeavoured to improve the efficiency of the piston compressor. For this purpose, it is ensured that the suction gas channel and the discharge chamber are arranged on different sides of the retainer element.

Abstract: A method for regulating a most loaded circuit of a refrigeration system is provided. Each circuit includes at least one case and an EEPR valve. At least one controller communicates with the EEPR valves for receiving signals from the circuits corresponding to operating conditions for each circuit, and for issuing command signals to the EEPR valves and compressor. The operation of each circuit is monitored and a load signal is calculated for each circuit. The load signals for each circuit are compared and the most loaded circuit is determined. The EEPR valve of the most loaded circuit is adjusted to be approximately 100 percent open and a suction pressure of the compressor is adjusted to move a circuit temperature of the most loaded circuit to a target temperature. The process of selecting and regulating the most loaded circuit is repeated after a predetermined period of time.

Abstract: A pressure transmitter includes a body part and a sensor unit which are joined hermetically. Adjacent to the hermetic joint, there is a gap between adjacent surfaces of the body and sensor unit, which gap facilitates an easier assembling procedure and which facilitates transportation of gases away from the hermetic joint zone when the body and sensor unit is assembled e.g. by welding.

Abstract: A valve arrangement in a hydraulic circuit comprises a longitudinal duct 3 and a transverse duct 2. A throttle slide 10 can be displaced in the direction of the longitudinal duct 3. Arranged in the throttle slide 10 is a valve piston 25, by means of which the flow through the hollow throttle slide 10 can be enabled or blocked. The flow of hydraulic fluid takes place through two groups of passage holes 33a, 35a, which are arranged in the throttle slide 10. The interaction of pressure and flow direction of the hydraulic fluid, and also the restoring force of a slide spring 20 and a piston spring 30, achieves a situation where hydraulic fluid can flow through the valve arrangement in both directions but that a throttling action occurs only when the hydraulic fluid flows from the transfer duct 2 to the longitudinal duct 3 under increased pressure.

Abstract: The invention concerns a valve arrangement (1) with at least two valve modules (2, 4, 5), each having a valve element, whose position can be changed by means of an actuator (13, 13a, 13b), and to which a position sensor (19, 19a, 19b) is allocated, a line arrangement (24) being connected with the valve modules (2, 4, 5), through which control signals can be transmitted to the valve modules (2, 4, 5). It is endeavoured to increase the safety of such valve modules. For this purpose, at each valve module (2 to 5) the actuator (13) is provided with a control device (22, 22a, 22b), which is connected with the position sensor (19, 19a, 19b) and evaluates control signals for the valve module (2 to 5) concerned, that at least the control device (22b) of a first valve module (5) additionally evaluates the control signals for another, second valve module (4), and that this control device (22b) receives signals from the position sensor (19a) of the second valve module (4).

Abstract: A method and a control unit for controlling a power level being drawn from a power source (26). Based on a determined rate of change of a measured voltage (1) an estimated remaining runtime is calculated. The estimated remaining runtime represents a time where specific run criteria will no longer be fulfilled if the present power level is maintained. The estimated remaining runtime is compared to a threshold value, and in case the estimated remaining runtime is shorter than the threshold value, the power drawn from the power source (26) is decreased. Thereby the runtime for the power source (26) is maximised. This is particularly useful if the power source is a limited power source, such as a battery (26), e.g. for running a compressor (27) for a movable refrigeration system (24). The invention is suitable for automotive applications.

Abstract: A method and a control unit (4) for controlling a supply of power to an electrical circuit comprising a switch (3). An output voltage of a first power source (5), which is connected to the circuit, is measured and compared to a predefined threshold voltage. If the measured voltage is smaller than the threshold value it is determined that the switch (3) is in a closed state, and if the voltage is larger than the threshold value it is determined that the switch (3) is in an open state. The supply of power is controlled in accordance with the open/closed state of the switch (3). Preferably, the electrical circuit is connected to a second power source (9) when the switch (3) is in a closed state. Power is conserved while it is ensured that sufficient power is available when needed. The invention is very suitable for supplying power to a lamp (1) positioned inside a refrigeration compartment (2), especially when the system is battery powered.