Abstract: The invention provides a method of making a squirrel cage rotor for an electrical motor, and to a rotor for such a motor. The rotor comprises a rotor stack of a magnetically conductive material and a squirrel cage of an electrically conductive material. At least one of the short circuit rings are made by compression and sintering of a powder in which a solid element is embedded. The solid element facilitates manufacturing by increasing strength of potentially weak areas of the rotor, e.g. around openings into the shaft bore, rotor slots etc.

Abstract: Motor start circuit for an induction motor, particularly a single-phase AC induction motor, with a main winding (4) and an auxiliary winding (5), which are supplied with current, particularly alternating current, via current supply connections (24, 25), and with a start switching device (15) serving the purpose of interrupting the current flow through the auxiliary winding (5) after the start of the motor, the start switching device (15) being connected to a control device (20) via a connector (18), the control device (20) being connected between the current supply connections (24, 25), and with a winding protection switch (28), which is normally closed and which opens on the occurrence of a fault. The invention is characterised in that the control device (20) is connected to the winding protection switch (28) via at least one further connector (22, 17), preferably via at least one further connector (22, 17) and the auxiliary winding (5).

Abstract: The invention concerns a piston compressor, particularly a hermetically enclosed refrigerant compressor, with at least one cylinder a piston reciprocating in said cylinder, the piston being connected with a driving rod via a piston pin and having in its outer jacket surface a circumferential lubrication groove, the piston pin having a longitudinal bore, which is connected with a lubricant source. It is endeavoured to improve the lubrication. For this purpose, the longitudinal bore is open downward in the gravity direction and has a ventilation opening upward.

Abstract: The invention relates to a device and method for supplying direct voltage, wherein said device comprises a first connection arrangement (3, 4) for a first direct voltage source (8) and a second connection arrangement (5, 6, 7) for a second direct voltage source (11), wherein the device (1) is provided with a protective element (18) which is connected to the first connection arrangement (3, 4) and prevents a charge equalisation between one direct voltage source (8, 11) and the other direct voltage source (11, 8). The aim of said invention is to ease the direct voltage supply (2) For this purpose the protective element (18) is also connected to the second connection arrangement (5, 6, 7) in order to prevent the defective operation of the device (1) in the case of the reversed polarity of the first direct voltage source (8).

Abstract: The invention concerns a piston compressor, particularly a hermetic refrigerant compressor, with a compression chamber, which is limited by a valve plate arrangement having a valve plate with a suction gas opening and a pressure gas opening, a suction valve plate with a suction valve element, and a pressure valve plate with a pressure valve element. It is endeavoured to achieve a good efficiency combined with a simple assembly. For this purpose, it is ensured that the pressure valve plate and the suction valve plate are located on the side of the valve plate facing the compression chamber.

Abstract: The invention concerns a piston compressor, particularly a hermetic refrigerant compressor, with a compression chamber, which is limited by a valve plate arrangement having a valve plate with a suction gas opening and a pressure gas opening, a suction valve plate with a suction valve element, and a pressure valve plate with a pressure valve element. It is endeavoured to achieve a good efficiency combined with a simple assembly. For this purpose, it is ensured that the pressure valve plate and the suction valve plate are located on the side of the valve plate facing the compression chamber.

Abstract: The invention provides a rotor for an electrical motor, a tool for making a rotor core and a method of making the rotor. The rotor could be incorporated e.g. in a line-start motor and comprises a squirrel cage and magnet located in a rotor core. The magnets are, in one end of the rotor, secured by an end plate with apertures which are larger than the magnet openings, and the end plate is indexed relative to the magnet slots such that a first portion of openings into the magnet slots is in communication with the aperture and such that a remaining, second, portion of the magnet slots is covered by the end plate. In one aspect, the end plate forms an integrated part of the rotor core and comprises openings cooperating with conductor slots to form through-going passages for conductors of the squirrel cage. In that way, the end plate is held in a completely fixed position by the squirrel cage which is moulded directly onto the core and into the conductor slots.

Abstract: An electric circuit for supplying power to a DC application is disclosed. The electric circuit comprises a DC power source (1) connectable to an alternator charging circuit (2), an FET (T7), and a capacitor (8) connected across the gate terminal and the source terminal of the FET (T7). The drain terminal of the FET (T7) is connected to a negative terminal of the DC source (1). The FET (T7) protects the circuit against accidental connection of the alternator charging circuit (2) to the DC power source (1) with reversed polarity, by opening a switch (6) of the FET (T7) when this occurs. The capacitor (8) protects the FET (T7) from being pushed into avalanche in case a load-dump transient occurs. This is because the capacitor (8) in this case will charge and discharge, thereby introducing a time delay before the switch (6) is opened. Protection against load-dump transients is thereby obtained by means of a small component with low energy dissipation.

Abstract: A method for starting a battery driven motor, wherein an input voltage is measured continuously. In case the input voltage becomes smaller than a predefined minimum voltage the attempt to start the motor is stopped and the maximum permitted current level to be supplied from the battery to an electronic unit of the motor is lowered before the next attempt. This is repeated until the input voltage is larger than the minimum voltage and the motor is no longer in start-up mode. The method protects the battery from collapsing. The method is suitable for starting battery driven motors for driving compressors. The number of attempted start-up sequences may be counted and on the basis of this it may be determined that the battery is weak or that the wiring is misdimensioned. Furthermore, a control system for controlling starting of a motor.

Abstract: Motor start circuit for an induction motor, particularly a single phase AC induction motor, with a main winding (4) and an auxiliary winding (5) having two end connections (6, 7) supplied with current, mainly AC, via current supply connections (34, 35), and with a start circuit device (15) serving the purpose of stopping the current flow through the auxiliary winding (5) after the start of the motor, and being connected via a conductor (18) to a control device (20) connected between the current supply connections (34, 35), and with a preset timer device interacting with the start circuit device (15) to stop the current flow through the auxiliary winding (5), as soon as a predetermined period after the start of the current flow has lapsed.

Abstract: The invention concerns a suction muffler for a hermetic refrigerant compressor with a housing having an inlet and an outlet and limiting at least one muffling chamber, and a gas supply channel located in the muffling chamber between the inlet and the outlet. It is endeavoured to prevent too much oil from remaining in the refrigerant gas flow. For this purpose, the gas supply channel forms a throttling path and ends in the muffling chamber, and that in the area of the inlet of the gas supply channel an oil extraction opening is located, which ends in the muffling chamber.

Abstract: The invention concerns a compressor crankshaft, particularly a refrigerant compressor crankshaft (1) and a method for manufacturing such a crankshaft, with a shaft element (2), a crank pin (9) located eccentrically to the shaft element and a transition element (7) between the shaft element (2) and the crank pin (9). The purpose of the invention is to keep the manufacturing costs low. For this purpose, it is ensured that along its circumference the transition element (7) has at least one first reference point (20) and one second reference point (21a, 21b), with which the transition element (7) can be positioned in a holding fixture (25) of a working machine.

Abstract: The invention concerns a rotor arrangement for an electrical drive motor of a compressor, particularly a refrigerant compressor, with a rotor having a rotor lamination of stacked sheet plates, and a shaft, which is inserted in an axial recess of the rotor lamination and is unrotatably connected with the rotor lamination, the recess being formed by openings in adjacent sheet plates. It is endeavoured to simplify the manufacturing of such rotor arrangements. For this purpose, it is ensured that openings of different sizes are provided in the sheet plates, at least two sheet plates forming a first group, each having an opening, which is smaller than the cross-section of the shaft, the remaining sheet plates forming a second group, each having an opening, which is larger than the cross-section of the shaft.

Abstract: The invention concerns a motor starter circuit for an induction motor, particularly a single-phase AC induction motor, with a main winding (4) and an auxiliary winding (5) supplied with current, particularly AC, via current supply connections (24, 25), and with a starter switch arrangement (15), which serves the purpose of interrupting the current flow through the auxiliary winding (5) after the start of the motor, the starter switch arrangement (15) interacting with a measuring arrangement serving the purpose of measuring the voltage across the auxiliary winding (5).

Abstract: The invention concerns a valve plate for a reciprocating compressor, the valve plate being made as a sintered part, having on at least one valve plate surface at least one valve seat surface (30, 31) being worked after sintering. In order to simplify the manufacturing of the valve plate, the valve plate surface has at least one defined area portion with a relatively uneven surface and at least one defined area portion with a relatively even surface.

Abstract: A cooling medium compressor arrangement is comprised of a compressor, a control mechanism electrically connected with the compressor, and a gas sensor, and the safety of the arrangement is improved by arranging the control mechanism and the gas sensor in a common housing.

Abstract: The invention concerns a starter for a line start electric motor having at least one main winding (4) and at least one start winding (12) and which start winding is connected in series with a run capacitor (14) with which a start capacitor (17) and a PTC-thermistor (19) are connected in parallel. In order to make a simply constructed starter for a line start electric motor the start capacitor (17) and the PTC-thermistor (19) are connected in series with a switch mechanism (20). The series connected circuit made up of the start capacitor (17), the PTC-thermistor (19) and the switch mechanism (20) is connected in parallel with the run capacitor (14).

Abstract: The invention concerns a cylinder head arrangement for a piston compressor, with a cylinder block, in which a compression chamber is formed, which is delimited on one side by a valve plate that is clamped between the cylinder block and a cylinder head cover. In order to provide a cylinder head arrangement that has a high degree of tightness and can be manufactured in a cost-effective manner, the valve plate (6) has on at least one side at least one bead (40) projecting from the valve plate surface (21) concerned.

Abstract: The invention relates to a rotor for an electric motor, especially an electric line-start motor, comprising spaces (4 to 7) which receive permanent magnets (10 to 13) and extend in an axial direction, and spaces (20 to 25) that accommodate conductor rods and extend in an axial direction. In order for the rotor to run as regularly as possible, the spaces (20 to 25) accommodating the conductor rods are provided with a substantially elongate cross-section in at least one sector of the rotor while being embodied in a curved manner along the longitudinal axis thereof in said sector when viewed from a cross-sectional perspective.

Abstract: The invention concerns a piston compressor with a piston, which is connected with a crank pin of a drive shaft via a connecting rod having a longitudinal channel. It is endeavored to make the manufacturing of a piston compressor cost effective. For this purpose, it is ensured that the shaft of the connecting rod is made as a sheet metal pipe.