Abstract: A method of operating a reciprocating compressor for a vapour compression system is disclosed. The reciprocating compressor comprises at least two cylinders and at least two unloaders, each unloader can be operated in an idle mode or in an active mode and therefore the reciprocating compressor can run in more than two capacity states. The capacity states alternates periodically between states in such a way that a substantially continuous range of effective capacities can be obtained while the individual cylinders are evenly loaded.

Abstract: A working machine comprises a direct voltage source (301), a first power converter (302) for transferring energy from the direct voltage source to electric machines (303a, 303b) driving actuators of the working machine, an electric connector system (304) for electrically connecting to an external power grid, a second power converter (305) for transferring energy from the external power grid to the direct voltage source, and alternating current electric machines (306a, 306b) driving auxiliary devices of the working machine. The electric connector system is suitable for connecting the alternating current electric machines to receive alternating voltage of the external power grid, and the second power converter is suitable for transferring energy from the direct voltage source to the alternating current electric machines. Thus, the electric machines driving the auxiliary devices can be energized directly by the external power grid when the working machine is connected to the external power grid.

Abstract: A method for controlling a vapour compression system having an ejector includes, in the case that a pressure difference between a pressure prevailing in the receiver and a pressure of refrigerant leaving the evaporator decreases below a first lower threshold value, the pressure of refrigerant leaving the heat rejecting heat exchanger is kept at a level which is slightly higher than the pressure level providing optimal coefficient of performance.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (5) and a tank port (T) connected to a tank flow path (6), a working port arrangement having a left working port (L) connected to a left working flow path (7) and a right working port (R) connected to a right working flow path (8), a bridge arrangement (14) of variable neutral open orifices, said bridge arrangement (14) comprising a first left orifice (A2L) connected to a main flow path (5) and to the left working flow path (7), a first right orifice (A2R) connected to a main flow path (5) and to the right working flow path (8), a second left orifice (A3L) connected to the left working flow path (7) and to the tank flow path (6), and a second right orifice (A3R) connected to the right working flow path (8) and to the tank flow path (6). Such a steering unit has a good steering behavior but can function as a closed-center solution.

Abstract: The present invention relates to an electronically controlled valve for a variable displacement pump, a hydraulic pump and a hydraulic pump system with switchable control functions. Multiple control functions of different types of hydraulic pumps can be implemented via one single electronically controlled valve combined with control elements and sensors. The hydraulic pump systems can be easily integrated into the overall application systems for intelligent control.

Abstract: The invention relates to a valve (1) comprising a main valve (2), a pilot valve (3), a housing (4), an inlet (5) and an outlet (8). Opening and closing of the main valve (2) is controlled by the pilot valve (3). A pilot valve seat (10) is arranged in a diaphragm (6). A pilot chamber (11) is arranged in the housing (4) separated from the inlet (5) and the outlet (8) by the diaphragm (6). Task of the invention is to provide a valve with a lower cost. According to the invention a support member (17) supports the diaphragm (6), wherein the support member (17) is guided in the housing, and wherein a radial gap (26) is arranged between the radially outer end of the diaphragm (6) and the housing (4) in a radial direction perpendicular to the opening direction of the pilot valve (3). Thereby, a cheaper, less resistant material for the diaphragm can be used.

Abstract: The axial bearing arrangement comprises a first axial bearing plate (12) and a second axial bearing plate (13) each having an annular ring shape, the first axial bearing plate (12) having a first surface (12.1) axially facing the second axial bearing plate (13) and a second surface (12.2) opposite to the respective first surface (12.1), the second axial bearing plate (13) having a first surface (13.1) axially facing the first axial bearing plate (12) and a second surface (13.2) opposite to the respective first surface (13.1); a spacer ring (14) clamped between the first surfaces (12.1, 13.1) of the first and second axial bearing plates (12, 13), the spacer ring (14) defining an axial distance between the first and second axial bearing plates (12, 13); and a bearing sleeve (15) abutting the second surface (13.2) of the second axial bearing plate (13) and being secured to a compressor block (16).

Abstract: The scroll compression device includes a first scroll element (11) having a first base plate (13) and a first spiral wrap (14); a second scroll element (12) having a second base plate (15) and a second spiral wrap (16), one of the first and second scroll elements (11, 12) being configured to perform an orbiting movement in relation to the other one of the first and second scroll elements, the first and second scroll elements (11, 12) intermeshing with each other and delimiting compression chambers (17); and a sealing device (28) arranged in an end face (19) of the first spiral wrap (14) and having a sealing surface configured to cooperate with the second base plate (15).

Abstract: The scroll compressor (1) includes a fixed scroll (7); an orbiting scroll (8); a drive shaft (16); a support arrangement (5) including a thrust bearing surface (9) on which is slidably mounted the orbiting scroll (8); a rotation preventing device configured to prevent rotation of the orbiting scroll (8) with respect to the fixed scroll (7), the rotation preventing device including orbital discs (28) respectively arranged in circular receiving holes (29) provided on the support arrangement (5), each orbital disc (28) being provided with an outer circumferential bearing surface (31) cooperating with an inner circumferential bearing surface (32) of the respective circular receiving hole (29); and a lubrication system configured to lubricate the inner and outer circumferential bearing surfaces (32, 31) with oil supplied from an oil sump (50), the lubrication system including lubrication passages (41) formed within the support arrangement (5), each lubrication passage (41) including an oil outlet aperture (41.

Abstract: Provided is a monitoring apparatus used to monitor lubricating oil inside a compressor. The monitoring apparatus comprises a first capacitance detector (100), a calculation unit, and a determining unit. The first capacitance detector (100) is disposed in a compressor (10) and is completely immersed in lubricating oil (20) inside the compressor (10), and is used to detect a first capacitance value (Cn). The calculation unit calculates a relative dielectric constant of the lubricating oil inside the compressor according to the first capacitance value (Cn) detected by the first capacitance detector (100). The determining unit monitors, according to the calculated relative dielectric constant, whether quality of the lubricating oil (20) inside the compressor (10) encounters an exception. Further provided are a method for monitoring quality of lubricating oil inside a compressor and an apparatus and a method for monitoring a fluid level of lubricating oil inside a compressor.

Abstract: A power converter comprises an inductor coil whose first pole is connected to an input terminal of the power converter, a controllable switch between the ground and a second pole of the inductor coil, a first unidirectionally conductive component providing a path for electric current from the inductor coil towards an output terminal of the power converter when the controllable switch is non-conductive, and an over-current protector at the output terminal. The power converter comprises a second unidirectionally conductive component for conducting electric current from the input terminal to the over-current protector in a fault situation where voltage at the output terminal is smaller than voltage at the input terminal. Thus, the second unidirectionally conductive component constitutes a low-inductance bypass route for fault current and enables the over-current protector to react fast to a fault situation.

Abstract: Embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, and a controller in communication with the motor. The controller receives input of a performance value that is determined utilizing information from operation of the motor and compares the performance value to a reference value. The controller also is configured to prime and run the pump when the performance value equals the first reference value and to continue to do so until the performance value equals a second reference value. Alternatively, the controller receives user input of an amount of time the system can take to attempt to successfully prime the pump and is configured to operate the motor at maximum speed until the amount of time elapses.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (2) and a tank port (T) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (4) and a right working port (R) connected to a right working flow path (5), a bridge arrangement (21) of variable orifices (A2L, A3L, A2R, A3R) having a first left orifice (A2L) connected to the main flow path (2) and to the left working flow path (4), a first right orifice (A3R) connected to the main flow path (2) and to the right working flow path (5), a second left orifice (A3L) connected to the left working flow path (4) and to the tank flow path (3), and a second right orifice (A3R) connected to the right working flow path (5) and to the tank flow path (3). Such a steering unit allows steering a vehicle with low energy consumption.

Abstract: A method for controlling a fan (6) of a vapour compression system (1) is disclosed, the fan (6) being arranged to provide a secondary fluid flow across a heat rejecting heat exchanger (3). A temperature difference, ?T=Tout?Tamb, between a temperature, Tout, of refrigerant leaving the heat rejecting heat exchanger (3) and a temperature, Tamb, of ambient air of the heat rejecting heat exchanger (3) is established. A setpoint value, ?Tsetp, for the temperature difference, ?T, is obtained, the setpoint value, ?Tsetp, being dependent on the fan speed of the fan (6) in such a manner that the setpoint value, ?Tsetp, increases as the fan speed increases. The fan speed of the fan (6) is controlled in order to control the temperature difference, ?T, in accordance with the obtained setpoint value, ?Tsetp.

Abstract: Some embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, a user interface associated with the pump designed to receive input instructions from a user, and a controller in communication with the motor. The controller determines a power parameter associated with the motor and compares the power parameter to a predetermined threshold value. The controller triggers a safety vacuum release system based on the comparison of the power parameter and the threshold value.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) connected to a main flow path (2) and a tank port (5) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (4) and a right working port (R) connected to a right working flow path (5), a variable first left orifice (A2L) connected to the main flow path (2) and to the left working flow path (4), a variable first right orifice (A2R) connected to the main flow path (2) and to the right working flow path (5), a variable second left orifice (A3L) connected to the left working flow path (4) and to the tank flow path (3), and a variable second right orifice (A3R) connected to the right working flow path (5) and to the tank flow path (3). Such a steering unit should allow comfortable steering. To this end a measuring motor (15) is arranged in one of the working flow parts (4, 5).

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) connected to a main flow path (6) and a tank port (T) connected to a tank flow path (7), a working port arrangement having a left working port (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (14) of variable orifices having a first left orifice (A2L) connected to the main flow path (6) and to the left working flow path (9), a first right orifice (A2R) connected to the main flow path (6) and to the right working flow path (10), a second left orifice (A3L) connected to the left working flow path (9) and to the tank flow path (7), and a second right orifice (A3R) connected to the right working flow path (10) and to the tank flow path (7). Such a hydraulic steering unit should allow comfortable steering.

Abstract: A hydraulic machine is described having a first part (2) and a second part (3) moveable relative to said first part (3), one of said first part (2) and said second part (3) having a first land (9) resting against the other one of said second part (3) and said first part (2), having a predetermined first height (H1), and being arranged between a high pressure area (7) and a low pressure area (8). Such a machine should have a long working life. To this end a second land (10) having a predetermined second height (H2) smaller than said first height (H1) is located adjacent to said first land (9).

Abstract: A pressure limiting system for a dual path machine wherein an input propel command from a propel device is scaled based upon the largest detected pressure in a hydraulic system to determine a modified propel command. Also, response time is adjusted within an electrical control system based upon the type of input propel command signal received.