Abstract:
The invention concerns a displacer unit (3) of a Stirling cooling arrangement (1) with a housing (20), a displacer (10) that is arranged to reciprocate in a cylinder (11) between a cold side (12) and a hot side (13) of the displacer unit (3), and a regenerator (16) arranged between the cold side (12) and the hot side (13), a gas being permitted to flow through said regenerator (16) on its way from the cold side (12) to the hot side (13) and back. It is endeavoured to permit defrosting in a simple manner. For this purpose, at least one bypass conduit (23) is arranged in parallel to the regenerator (16), an opening or closing of said bypass conduit (23) being con- trolled by a control unit (22).
Abstract:
A control system (12) for controlling a refrigeration system (17) comprising two or more compressors (13a, 13b) (e.g. a twin compressor system) . Each compressor (13a, 13b) is connected to an electronic unit (14a, 14b) , and the electronic units (14a, 14b) are adapted to communicate appropriate signals to each other when the corresponding compressor (13a, 13b) starts or stops operation. The electronics units (14a, 14b) are further adapted to control the operation of the corresponding compressor (13a, 13b) in response to a signal received from the other electronic unit (14a, 14b) . Thereby the control system (12) is adapted to control the operation of the two or more compressors (13a, 13b) in a mutually dependent manner.
Abstract:
Es wird eine Vorrichtung und ein Verfahren zur Bereitstellung einer Gleichspannung angegeben mit einer ersten Anschlußanordnung (3, 4) für eine erste Gleichspannungsquelle (8) und einer zweiten Anschlußanordnung (5, 6, 7) für eine zweite Gleichspannungsquelle (11), wobei die Vorrichtung (1 ) ein Schutzelement (18) aufweist, das an der ersten Anschlußanordnung (3, 4) angeschlossen ist und das Schutzelement (18) einen Ladungsausgleich von einer Gleichspannungsquelle (8, 11 ) zur anderen Gleichspannungsquelle (11 , 8) verhindert. Man möchte die Bereitstellung einer Gleichspannung (2) vereinfachen. Dies wird erreicht, indem das Schutzelement (18) zusätzlich an der zweiten Anschlußanordnung (5, 6, 7) angeschlossen ist, wobei das Schutzelement (18) bei einer Verpolung der ersten Gleichspannungsquelle (8) eine fehlerhafte Arbeitsweise der Vorrichtung (1) verhindert.
Abstract:
A bimetal protector (115; 125) for an electric motor comprising a pair of fixed contacts (112), which is normally closed by a bimetal element (108), such as a bimetal disc or a pair of bimetal strips, optionally comprises a first heating element (114) which is supplied with motor current. The protector comprises a second heating element (116;126) which is supplied from motor fault current when the pair of fixed contacts (112) opens, the second heating element (116; 126) providing a heating of the bimetal element (108) during locked rotor fault or motor overload and being arranged to allow an automatic resetting of the bimetal element. The second heating element may be a PTC or a high-ohmic resistor. The protector may form an integrated unit as an external protector, or it may be an internal protector, in which the second heating element is arranged outside a hermetically tight glass enclosure (122.7) containing the bimetal element.
Abstract:
Die Erfindung betrifft einen Rotor für einen Elektromotor, insbesondere einen Line-Start-Elektromotor, mit in axialer Richtung verlaufenden Aufnahmeräumen (4 bis 6) für Leiterstäbe und in axialer Richtung verlaufenden Aufnahmeräumen (10, 11) für Permanentmagnete (14, 15), die so ausgebildet und angeordnet sind, dass sie ein Permanentmagnetfeld mit einer Permanentmagnetachse (22) und einer Neutralachse (23) erzeugen. Um Drehmomentschwankungen im Betrieb des Elektromotors zu vermeiden, ist die Dicke der Permanentmagneten (14, 15), im Querschnitt durch den Rotor betrachtet, im Bereich der Permanentmagnetachse (22) am größten und nimmt ausgehend von der Permanentmagnetachse (22) zur Neutralachse (23) hin insbesondere stetig ab.
Abstract:
The invention relates to a method for controlling a rectifier circuit and to a corresponding rectifier circuit. Said rectifier circuit has a rectifier (2) in series with an inductor (4), a diode (5) and a load (6). A capacitor (7) is arranged parallel to the load (6) and a controlled switch (8) is arranged parallel to the series connection of the diode (5) and load (6). Said switch is connected to a control device (9) which produces a control signal using the voltage (U3) through the load. The aim of the invention is to improved the efficiency. The control device (9) has a phase displacement device (12) which effects a phase displacement of the alternating component of the voltage (U3) through the load in the order of magnitude of 270 degrees. This allows the direct voltage signal that is used for obtaining a control signal for the switch (8) to be superposed by an alternating voltage signal whose frequency corresponds to the frequency of the ripple at the output of the rectifier (2) and which has a phase difference in relation to the ripple that is less than a predetermined measure.
Abstract:
An oil pump is disclosed, especially for a hermetically-encapsulated refrigerant compressor (1), having a motor (2) that has a stator (3) and a rotor (4), which motor drives a hollow shaft (8), the facing end of which is immersed in an oil sump (15). Such an oil pump is designed to enable operation of the compressor even within a range of speed well below 900 rev/min. For that purpose, a stationary displacement body (13) is arranged inside the hollow shaft (8), a substantially helically-running oil transportation path (14) being arranged between the displacement body (13) and the shaft (8).
Abstract:
The invention relates to a Stirling cooling arrangement (19 with at least one pis¬ ton (5, 6) to be movable in a drive unit (2) along a piston axis (7), and a dis- placer (14) to be movable in a displacer housing (15) along a displacer axis (16), the displacer housing (15) being guided through an isolating wall (17). It is endeavoured to keep the space requirements as small as possible. For this purpose, the piston axis (7) has a different spatial direction than the displacer axis (16).
Abstract:
The invention relates to a Stirling cooling arrangement (1) with a driving unit (2) generating periodically changing gas pressures, and a displacer unit (4) connected to the driving unit (2) and having a displacer that is movable along a displacer axis (26) in a displacer housing (16) and being guided in a cylinder (21). It is endeavoured to provide such a cooling arrangement with a simple design. For this purpose, the cylinder (21) is held unilaterally in the displacer housing (16).
Abstract:
The invention concerns a Stirling cooling arrangement with a pressure wave generator (2) that is connected to a displacer unit via a connection pipe (4), the pressure wave generator (2) having two pistons (7, 8) that are located in a cylinder block. It is endeavoured to ensure a good efficiency. For this purpose, the cylinder block has two parts (11, 12) each comprising a cylinder (15, 16), in which one piston (7, 8) is arranged, the two parts (11, 12) being connected to each other at a connection face (13) that also goes through a connection channel (19) for the connection pipe (4).