Patents Assigned to Danfoss A/A
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Publication number: 20080245222Abstract: The invention concerns a hydraulic valve arrangement (1) with a supply connection arrangement comprising a high-pressure connection (P) and a low-pressure connection (T), a working connection arrangement comprising two working connections (A, B), which can be connected to a motor (4), a directional valve arrangement (5) located between the supply connection arrangement (P, T) and the working connection arrangement (A, B), and a compensation valve (15) acted upon in a first activation direction by a pressure in a first pressure chamber (33), which is connected to a load-sensing pipe (LS), and, if required, by a spring (32), and in a second activation direction opposite to the first activation direction by a pressure downstream of the directional valve arrangement (5), said pressure acting in a second pressure chamber (34), the compensation valve (15) having an inlet (14) and an outlet (19).Type: ApplicationFiled: December 14, 2007Publication date: October 9, 2008Applicant: Sauer-Danfoss ApSInventors: Thorkild Christensen, Siegfried Zenker, Svend Erik Thomsen
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Patent number: 7431052Abstract: The present invention relates to apparatus for delivering a controlled or restricted flow of liquid and limiting bubble fragmentation at the inlet. This is achieved in flow restrictor with a flow channel having over most of its length a substantially constant, minimum hydraulic diameter D=4A/W wherein A is the minimum local cross-sectional area of the channel and W is the minimum local wetting perimeter of the channel, by smoothly widening the channel at its inlet such that: at distances z from the inlet face with 0<z<z1, the channel has a hydraulic diameter Dz?k*D wherein k?1.3; at distances z from the inlet face with z1<z<z2, the channel has a hydraulic diameter Dz with k*D?Dz?D; and at distances z from the inlet face with z2<z, the channel has a hydraulic diameter Dz with Dz?1.02D, except possibly for a similar widening of the channel at the outlet.Type: GrantFiled: September 4, 2004Date of Patent: October 7, 2008Assignee: Danfoss A/SInventors: Peter Gravesen, Martin Manscher, Per Brandt Rasmussen
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Publication number: 20080236931Abstract: The invention provides a steering system e.g. for a vehicle. The system comprises a system-pump, a steering actuator, a rotary valve, a rotary meter, and a motor. The system-pump is arranged to provide a flow of a fluid to the steering actuator via the rotary valve and via the rotary meter, and the motor is arranged to provide rotation of the rotary valve and the rotary meter. To handle an emergency situation if the system-pump fails, the motor is dimensioned to operate the rotary meter as a fail-operational pump for pumping a flow of the fluid to the steering actuator if the system-pump fails.Type: ApplicationFiled: February 7, 2008Publication date: October 2, 2008Applicant: SAUER-DANFOSS APSInventors: Stephen Crow, Kjeld Buus Jensen, Preben Albrecht, John Kristensen
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Publication number: 20080236932Abstract: The invention provides a method and a system for moving an element, e.g. a rudder of a ship or a wheel of a vehicle. The element is moved by a hydraulic fluid. According to the invention, an operator indicates a desired movement, and in accordance with the desired movement, at fluid is provided from at least three fluid providers each providing a share of the fluid in parallel streams and only considering the desired movement not the shares provided by the other fluid providers. The invention allows continuation of a steering task even if one fluid provider is disabled, and the invention allows the continuation even without having to notice that one provider is disabled. Accordingly, the invention provides an improvement and simplification relative to the known hydraulic steering systems.Type: ApplicationFiled: December 14, 2007Publication date: October 2, 2008Applicant: Sauer-Danfoss ApSInventors: Preben Albrecht, John Kristensen, Steve Crow, Kjeld Buus Jensen
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Publication number: 20080240966Abstract: The invention concerns a hydraulic machine (1) with an externally toothed gear wheel (2) and an internally toothed ring (3), which is made of a sintered material or of a ceramic material. It is endeavored to provide good operation behaviour at low costs. For this purpose, the toothed ring (3) is provided with a sealing element (7) in the area of its outer circumference.Type: ApplicationFiled: March 26, 2008Publication date: October 2, 2008Applicant: Sauer-Danfoss ApSInventors: Niels E. Sevelsted, Hans Christian Petersen, Claus Jesper Johansen
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Publication number: 20080223207Abstract: 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).Type: ApplicationFiled: December 3, 2007Publication date: September 18, 2008Applicant: DANFOSS A/SInventors: Palle Olsen, Ove Thorboel Hansen, Lars Martensen
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Publication number: 20080226878Abstract: A composite for a transducer facilitates an increased actuation force as compared to similar prior art composites for transducers. The composite facilitates increased compliance of the transducer in one direction, an improved reaction time as compared to similar prior art composites for transducers, and provides an increased lifetime of the transducer in which it is applied.Type: ApplicationFiled: October 31, 2007Publication date: September 18, 2008Applicant: Danfoss A/SInventors: Mohamed Yahia Benslimane, Peter Gravesen
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Publication number: 20080225447Abstract: 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).Type: ApplicationFiled: November 6, 2007Publication date: September 18, 2008Applicant: DANFOSS COMPRESSORS GMBHInventors: Claus Schmidt, Hans Peter Kristensen
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Publication number: 20080224073Abstract: The invention concerns a hydraulic valve arrangement (1) with several valve modules (2-6), each having a supply channel arrangement with a high-pressure channel (7) and a low-pressure channel (8), a working connection arrangement with at least one working connection (A, B), a directional valve arrangement (15, 16) between the supply channel arrangement and the working connection arrangement and a compensation arrangement (19, 28). It is endeavoured to improve the control possibilities. For this purpose, it is provided that in at least one valve module (3, 5) the compensation arrangement is a pre-compensation arrangement (19) and in at least one other valve module (4, 6) the compensation arrangement is a post-compensation arrangement (28).Type: ApplicationFiled: December 14, 2007Publication date: September 18, 2008Applicant: Sauer-Danfoss ApSInventors: Thorkild Christensen, Siegfried Zenker
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Publication number: 20080225002Abstract: A joystick (1) comprising a substantially stationary part (4) and a movable part (3) adapted to be manipulated by an operator. The joystick further comprises a sensor device adapted to detect a position of the movable part (3) relatively to the substantially stationary part (4), the sensor device comprising a magnet arrangement comprising one or more magnets (9) and defining a predetermined magnetic field, and a magnetic detector being adapted to detect a magnetic flux and to generate a corresponding output. The magnet arrangement or the magnetic detector is arranged on the substantially stationary part (4), while the magnetic detector or the magnet arrangement is arranged on the movable part (3). Thereby relative movements between the parts (3, 4) result in relative movements between the magnet arrangement and the magnetic detector.Type: ApplicationFiled: March 14, 2008Publication date: September 18, 2008Applicant: SAUER-DANFOSS APSInventor: Nick Weppenaar
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Publication number: 20080223456Abstract: The invention concerns a hydraulic valve arrangement (1) with at least two valve modules (2-6), each having a supply channel arrangement with a high-pressure channel (9) and a low-pressure channel (15), a working connection arrangement with at least one working connection (A, B), one directional valve arrangement (16) between the supply channel arrangement (9, 15) and the working connection arrangement (A, B) and a compensation arrangement (19), which is acted upon by a pressure in a load-sensing arrangement. It is endeavoured to increase the number of control possibilities. For this purpose, the load-sensing arrangement of at least one valve module (2-6) has a pressure influencing arrangement (25-29) that differs from a pressure influencing arrangement (25-29) of a load sensing arrangement of another valve module (2-6).Type: ApplicationFiled: December 14, 2007Publication date: September 18, 2008Applicant: Sauer-Danfoss ApSInventors: Thorkild Christensen, Siegfried Zenker
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Publication number: 20080228336Abstract: A method of calibrating a valid operating range. The method includes loading a default calibration limit and then monitoring an input for new calibration limits provided by an input device. An algorithm then detects if the new calibration limits provide a fault and if not the algorithm rescales the output based upon the new calibration limits to increase the valid operating range.Type: ApplicationFiled: March 14, 2007Publication date: September 18, 2008Applicant: SAUER-DANFOSS INC.Inventor: Brian E. Spranger
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Patent number: 7421940Abstract: 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.Type: GrantFiled: May 29, 2003Date of Patent: September 9, 2008Assignee: Danfoss Compressors GmbHInventors: Jens Erik Nissen, Frank Holm Iversen
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Patent number: 7419587Abstract: A water purification device includes a fluid pump, a diaphragm unit having a diaphragm, which separates a primary side from a secondary side, and a consumer having a pressure requirement. The fluid pump is connected with the primary side and the consumer is connected with the secondary side. In order to supply the consumer with water under a high pressure, the fluid pump supplies the pressure (P2) for the consumer through the diaphragm. A pressure control valve is arranged upstream of the diaphragm unit to control the pressure on the primary side in dependence of the pressure on the secondary side.Type: GrantFiled: January 21, 2004Date of Patent: September 2, 2008Assignee: Danfoss A/SInventors: Anders Valbjoern, Palle Olsen
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Publication number: 20080202152Abstract: In known filter-drier cases for refrigerant circuits, the refrigerant flows through filter and drying means in a serial manner. During operation of the refrigerant circuit, this causes an undesirably large pressure drop. It is the task of the invention to provide an improved filter-drier arrangement (1, 1?) with a smaller pressure drop. For this purpose, it is proposed to design the filter-drier arrangement so that a part of the refrigerant flows in parallel through the filter (21, 43) and the drying means (17, 43).Type: ApplicationFiled: March 16, 2007Publication date: August 28, 2008Applicant: Danfoss A/SInventors: Nestor E. Cabrera Munoz, Sergio Uribe Gutierrez
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Publication number: 20080198522Abstract: 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).Type: ApplicationFiled: March 1, 2006Publication date: August 21, 2008Applicant: DANFOSS COMPRESSORS GMBHInventor: Rune Thomsen
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Publication number: 20080184876Abstract: A hydraulic actuator for a hydraulic servomotor 4 is disclosed. The hydraulic servomotor 4 has a first chamber 5 and a second chamber 6 associated therewith. The hydraulic actuator is connected to a fluid source 2 and a fluid drain 3, and it comprises a valve assembly arranged between the fluid source 2 and the fluid drain 3 to control fluid pressures in the chambers 5, 6. At least one auxiliary valve 11 is fluidly connected between the valve assembly and the fluid drain 3, said auxiliary valve(s) 11 being of a kind which is normally closed in a de-energized state. In the case of a power cut off the auxiliary valve(s) 11 will close, thereby preventing fluid flow from the valve assembly towards the fluid drain 3. This causes a servomotor piston member 12 to be hydraulically locked in its instantaneous position, thereby locking the hydraulic servomotor 4. The valve assembly may be designed without taking the locking function into consideration.Type: ApplicationFiled: February 7, 2007Publication date: August 7, 2008Applicant: Sauer-Danfoss ApSInventor: Brian Nielsen
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Publication number: 20080184875Abstract: A valve assembly (2) forming a bridge circuit and a hydraulic actuator comprising at least one valve assembly (2) are disclosed. The valve assembly (2) is fluidly connectable between a fluid source (3) and a fluid drain (4). The valve assembly (2) comprises a first valve (8) fluidly connected between the fluid source (3) and a first diagonal point (12) of the bridge circuit, a second valve (9) fluidly connected between the fluid source (3) and a second diagonal point (13) of the bridge circuit, a third valve (10) fluidly connected between the first diagonal point (12) and the fluid drain (4), and a fourth valve (11) fluidly connected between the second diagonal point (13) and the fluid drain (4). The valves (8, 9, 10, 11) are such that in the case of a power cut off, flows of fluid away from the diagonal points (12, 13) are prevented.Type: ApplicationFiled: February 7, 2007Publication date: August 7, 2008Applicant: Sauer-Danfoss ApSInventor: Brian Nielsen
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Publication number: 20080184877Abstract: A control system for a hydraulic servomotor (13) is disclosed. The control system comprises an electro hydraulic actuator (2) comprising a number of valves (9, 10, 11, 12, 18) for controlling fluid flows, a main control module (1), and one or more connectors. The control system further comprises at least one extension control module (3) comprising one or more connectors. Finally, the control system comprises means (6) for communicating signals between the main control module (1) and each of the extension control module(s) (3). Since the main control module (1) and the extension control module(s) (3) are able to communicate signals, it is possible to provide signals to/from the main control module (1) via an extension module (3), thereby in effect providing additional connectors to the main control module (1). Thereby the main control module (1) may be able to perform additional functions as compared to similar prior art control modules.Type: ApplicationFiled: February 7, 2007Publication date: August 7, 2008Applicant: Sauer-Danfoss ApSInventors: Helge Soe Plougsgaard, Ole Ploug
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Publication number: 20080184703Abstract: The invention relates to a method for regulating a hydrostatic drive system which has at least one pump which is driven by an internal combustion engine and at least one hydraulic motor which is driven by the pump, and comprises the method steps: determining the volume flow rate flowing through the hydraulic motor; determining a first adjustment nominal value for the hydraulic motor as a function of the previously determined volume flow rate rate; determining a second adjustment nominal value by modifying the first adjustment nominal value by a correction value which is determined as a function of the nominal/actual value deviation of the internal combustion engine rotational speed by means of a vehicle-specific characteristic curve which incorporates the different power profiles for traction and overrun operation, respectively, of the internal combustion engine, with the hydraulic motor being adjusted in such a way that a substantially constant pressure level is generated at the maximum power level of the inType: ApplicationFiled: January 23, 2008Publication date: August 7, 2008Applicant: SAUER-DANFOSS INC.Inventors: Gunnar Gerth, Jan Bendixen