Patents Assigned to Sauer-Danfoss (Nordborg) A/S
  • Publication number: 20080184875
    Abstract: 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: Application
    Filed: February 7, 2007
    Publication date: August 7, 2008
    Applicant: Sauer-Danfoss ApS
    Inventor: Brian Nielsen
  • Publication number: 20080184876
    Abstract: 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: Application
    Filed: February 7, 2007
    Publication date: August 7, 2008
    Applicant: Sauer-Danfoss ApS
    Inventor: Brian Nielsen
  • Publication number: 20080184877
    Abstract: 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: Application
    Filed: February 7, 2007
    Publication date: August 7, 2008
    Applicant: Sauer-Danfoss ApS
    Inventors: Helge Soe Plougsgaard, Ole Ploug
  • Publication number: 20080184703
    Abstract: 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 in
    Type: Application
    Filed: January 23, 2008
    Publication date: August 7, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventors: Gunnar Gerth, Jan Bendixen
  • Patent number: 7407374
    Abstract: The invention concerns a hydraulic machine with a toothed set comprising a toothed ring with an inner toothing, whose circumferential surface extends in parallel with its axis, and a gear wheel (3) with an outer toothing, whose circumferential surface (24) extends in parallel with its axis, at least one tooth flank having an edge as an axial end of a section, which is located between the circumferential surface and a surface directed radially inwards. It is endeavored to reduce the wear. For this purpose it is ensured that in the radial direction an edge (22, 23) ends so as to be offset inwards in relation to the circumferential surface (24).
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: August 5, 2008
    Assignee: Sauer-Danfoss Aps
    Inventors: René Andersen, Kim René Hansen, Claus Johansen
  • Publication number: 20080179159
    Abstract: A hydromechanical transmission having a self actuating clutch assembly. The self-actuating clutch assembly comprises a first and second gear clutching elements and a shaft clutching element that engages a shaft. The shaft clutching element is a cone clutch that is actuated by a ball element that is biased towards the shaft clutching element by a spring element that is disposed through the shaft.
    Type: Application
    Filed: January 29, 2007
    Publication date: July 31, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventor: Frederic W. POLLMAN
  • Publication number: 20080171626
    Abstract: A hydromechanical transmission having at least first and second three element planetaries directly connected to one another. The first and second three element planetaries work in conjunction with a hydrostatic transmission and a plurality of clutches in order to provide at least first and second forward operating modes having continuous ratios.
    Type: Application
    Filed: January 16, 2007
    Publication date: July 17, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventor: Frederic W. Pollman
  • Publication number: 20080171632
    Abstract: A transmission control system for a vehicle. The control system has a control unit that receives a plurality of inputs from the vehicle and the vehicle operator. Then based upon these inputs the control unit sends a plurality of output signals to an engine, an input clutch, and a transmission in order to selectively operate each of these components to actuate the axle and wheels of a vehicle.
    Type: Application
    Filed: January 16, 2007
    Publication date: July 17, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventor: Anthony D. Van Allen
  • Patent number: 7398796
    Abstract: The invention concerns a valve arrangement (1) with a high-pressure connection (P), a low-pressure connection (T), at least one control valve (2 to 5), which is accommodated in a control valve module and has at least one working connection (A, B) for a hydraulic consumer (7 to 10), and a safety valve (6), which is accommodated in a safety valve module, and which releases or blocks a passage between the high-pressure connection (P) and the control valves (2 to 5), the control valve module (2 to 5) and the safety valve module (6) being connected to one component group. It is endeavoured to provide a valve arrangement with a high safety level. For this purpose, it is ensured that each control valve (2 to 5, 2? to 5?) has an error detection device (19), that the safety valve module (6) has a safety switch device (21) and that the component group has a connection (20) between the safety switch device (21) and the error detection device (19).
    Type: Grant
    Filed: June 10, 2005
    Date of Patent: July 15, 2008
    Assignee: Sauer-Danfoss Aps
    Inventors: Henrik Hjorth, Jens Vester
  • Publication number: 20080139363
    Abstract: A method of operating a transmission of a vehicle. The method includes determining an open loop ratio percentage from an engine RPM input signal and a brake input signal using a first algorithm. Determining a closed loop ratio percentage from the engine RPM input signal, a vehicle RPM input signal and a throttle input signal using a second algorithm. Summing the open loop percentage and closed loop ratio percentage to calculate a ratio command percentage that is used to sum with a swashplate input to actuate a swashplate positioner and operate the transmission.
    Type: Application
    Filed: December 8, 2006
    Publication date: June 12, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventor: Keith R. WILLIAMS
  • Patent number: 7380492
    Abstract: A hydrostatic variable displacement unit is provided having a swash plate which serves to adjust the stroke of displacement pistons in a cylinder block and can be pivoted in its angular position by means of a servo system, the servo system having at least one servo piston with two servo-piston end surfaces which are in each case assigned a servo cylinder and a servo-piston rear surface, and the servo cylinders, by means of the assigned servo-piston end surfaces, in each case bounding a servo-cylinder pressure space. The servo piston is acted upon by a spring arrangement having at least one spring arranged outside the servo-cylinder pressure space and clamped between two spring plates. The two spring plates are acted upon by the springs in the direction of a stop of the particular servo cylinder that is situated on its side such that in the neutral position, the spring plates bear against the servo-piston rear surfaces and against the stop of the particular servo cylinder.
    Type: Grant
    Filed: August 30, 2004
    Date of Patent: June 3, 2008
    Assignee: Sauer-Danfoss Inc.
    Inventors: Reinhardt Thoms, Carsten Fiebing
  • Patent number: 7377354
    Abstract: A hydrostatic propulsion system includes a hydrostatic circuit fluidly connecting left front and right front motors in parallel with an outlet of a pump, left rear and right rear motors in parallel with an inlet of the pump, left front motor and right rear motor in series, and the right front motor and left rear motor in series. A valve system has a first relief valve line providing flow from a right rear motor inlet side to a left rear motor inlet side, and a second relief valve line providing flow from a left rear motor inlet side to a right rear motor inlet side. A first check valve line provides flow from a right rear motor outlet side to the right rear motor inlet side, and a second check valve line provides flow from a left rear motor outlet side to the left rear motor inlet side.
    Type: Grant
    Filed: December 27, 2005
    Date of Patent: May 27, 2008
    Assignee: Sauer-Danfoss Inc.
    Inventor: Ryan D. Smalley
  • Patent number: 7377353
    Abstract: A hydrostatic propulsion system includes a hydrostatic circuit fluidly connecting left front and right front motors in parallel with an outlet of a pump, left rear and right rear motors in parallel with an inlet of the pump, left front motor and right rear motor in series, and the right front motor and left rear motor in series. A valve system has a first relief valve line providing flow from a right rear motor inlet side to a left rear motor inlet side, and a second relief valve line providing flow from a left rear motor inlet side to a right rear motor inlet side. A first check valve line provides flow from a right rear motor outlet side to the right rear motor inlet side, and a second check valve line provides flow from a left rear motor outlet side to the left rear motor inlet side.
    Type: Grant
    Filed: December 27, 2005
    Date of Patent: May 27, 2008
    Assignee: Sauer-Danfoss Inc.
    Inventor: Ryan D. Smalley
  • Publication number: 20080105485
    Abstract: The invention concerns a hydraulic steering arrangement (1) with a supply connection arrangement (P, T), a working connection arrangement (A, B) connectable to a steering motor (5), a steering unit (6) located between the supply connection arrangement (P, T) and the working connection arrangement (A, B), and a steering valve (14) whose outlet is connected to the working connection arrangement (A, B). It is endeavoured to keep the load of such a steering arrangement small. For this purpose, the steering unit (6) is made as an open-center steering unit, an inlet (20) of the steering valve (14) being connected to a pressure supply arrangement (22) that can be activated by an activation of the steering valve (14).
    Type: Application
    Filed: March 6, 2007
    Publication date: May 8, 2008
    Applicant: Sauer-Danfoss ApS
    Inventors: Svend Erik Thomsen, Niels Bjarne Hansen
  • Publication number: 20080105484
    Abstract: A steering system for a vehicle that uses primary and secondary steering actuation devices in combination with primary and secondary valve elements to provide fluid flow within a valve body. The primary and secondary valve elements are both electrically actuated by a control unit such that if the primary steering actuation device or valve element fails the secondary steering actuation device and valve element can supply pilot oil to the system.
    Type: Application
    Filed: November 3, 2006
    Publication date: May 8, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventors: Shawn A. KENNY, John T. NEIDERT, Matthew S. SCHULTZ, James D. KOCH
  • Publication number: 20080103006
    Abstract: A hydromechanical transmission that has first and second planetaries each having first, second and third elements. The first element of the first planetary is connected to a first hydrostatic unit while the second element of the first planetary is connected to a second hydrostatic unit with the third element of the first planetary connected to an input. A primary clutch is connected between first and third elements of the second planetary while at least one secondary clutch is connected to the second planetary. When the primary and secondary clutches are selectively engaged at least two operating modes having continuous ratios are provided.
    Type: Application
    Filed: April 20, 2007
    Publication date: May 1, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventors: Frederic W. Pollman, Wilhelm Gollner
  • Patent number: 7353744
    Abstract: The invention concerns a hydraulic control (1) with a supply connection arrangement (7) having a high-pressure connection (P) and a low-pressure connection (T), a working connection arrangement having two working connections (A, B) connectable with a consumer, a control valve (8) with a valve element (9) between the supply connection arrangement and the working connection arrangement and a compensation valve (11), which is located between the high-pressure connection (P) and the control valve (8) and is acted upon in the closing direction by a pressure between the compensation valve (11) and the control valve (8). It is endeavoured to ensure the most favourable energy consumption possible. For this purpose, in the opening direction the compensation valve (11) is acted upon by a pressure of a selection device (29, 30, 30?, 38), which optionally supplies the compensation valve (11) with a pressure control pressure or a flow control pressure.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: April 8, 2008
    Assignee: Sauer-Danfoss Aps
    Inventors: Carl Christian Dixen, Knud Meldgaard Jensen, Steen Slot, Svend Giversen, Svend Erik Thomsen, Smari Johannsson
  • Patent number: 7353745
    Abstract: A hydrostatic adjustment unit with a swash plate for adjusting the stroke of displacer pistons which are arranged in a rotating cylinder block is described. The displacer pistons each have a slider block which bears against a support face of the swash plate and is held in abutment by means of a slider block holder. The slider block-holder has a number of bores for receiving the slider blocks corresponding to the number of displacers. The slider block holder at the same time forms the rotor of a rotational speed signal transmitter for determining the rotational speed of the cylinder block.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: April 8, 2008
    Assignee: Sauer-Danfoss Inc.
    Inventors: Carsten Fiebing, Bernd Hames
  • Patent number: 7354368
    Abstract: A method for achieving high quality shifts with one hydraulic unit near zero displacement when using dog clutches. This method includes selecting the proper displacement and vocation (whether the hydrostatic unit works as a pump or motor) of a low displacement hydraulic unit during the shift, selecting the appropriate speed differential between the clutch elements, selecting the proper vehicle speed at which to make the shift, and sequencing the displacement changes of the hydraulic units with a controller in order to achieve the desired shift conditions.
    Type: Grant
    Filed: January 31, 2005
    Date of Patent: April 8, 2008
    Assignee: Sauer-Danfoss Inc.
    Inventor: Frederic W Pollman
  • Publication number: 20080078456
    Abstract: The invention relates to a hydrostatic variable unit with a servo system bringing about the control of the hydrostatic unit and with a valve unit controlling the servo system, the valve unit comprising two magnetically actuated proportional pressure-reducing valves which respectively act upon one of the sides of a servo system, which sides operate counter to each other, and having a safety function which, in the event of an incident, transfers the servo system into a safety position. The safety function is realized by at least one of the proportional pressure-reducing valves being designed at the same time as a pilot valve for activating and deactivating the second proportional pressure-reducing valve.
    Type: Application
    Filed: July 2, 2007
    Publication date: April 3, 2008
    Applicant: SAUER-DANFOSS INC.
    Inventor: Reinhardt THOMS