Patents by Inventor Michael R. Schwab

Michael R. Schwab has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20150219126
    Abstract: There is provided a multi-function hydraulic hybrid swing circuit including a fluid source, swing circuit and swing supply circuit. The swing supply circuit includes at least one accumulator and a pump/motor operatively connected to a power source. The pump/motor is fluidly connected to the swing circuit, the accumulator, and the fluid source. The pump/motor is configured to provide both closed loop and open loop operation with the swing circuit.
    Type: Application
    Filed: February 6, 2014
    Publication date: August 6, 2015
    Applicant: Caterpillar Inc.
    Inventors: Jiao Zhang, Michael R. Schwab
  • Publication number: 20130111888
    Abstract: A hydraulic circuit including a hydraulic swing motor having a first port and a second port. A first motor conduit connected to the first port of the hydraulic swing motor, and a second motor conduit connected to the second port of the hydraulic swing motor. The hydraulic circuit further includes a pump to selectively supply a flow of pressurized hydraulic fluid to the hydraulic swing motor through the first and the second motor conduits. A controller electrically connected to the pump adjusts a torque output of the pump based on a swing speed of the hydraulic swing motor.
    Type: Application
    Filed: November 9, 2011
    Publication date: May 9, 2013
    Applicant: Caterpillar Inc.
    Inventors: Michael R. Schwab, John V. Mount
  • Patent number: 7908852
    Abstract: This disclosure relates to a hydraulic system and method that converts the kinetic energy generated by the operation of a swing motor into hydraulic potential energy and reuses the hydraulic potential energy for swing motor acceleration. An accumulator can be provided for storing exit oil from the swing motor that is pressurized by the inertia torque applied on the moving motor via movement of an upper structure of a machine. The pressurized oil in the accumulator can be reused to accelerate the swing motor by supplying pressurized oil to the swing motor.
    Type: Grant
    Filed: February 28, 2008
    Date of Patent: March 22, 2011
    Assignees: Caterpillar Inc., Caterpillar S.A.R.L.
    Inventors: Jiao Zhang, Pengfei Ma, Michael R. Schwab, Tonglin Shang, Kalpesh N. Patel
  • Publication number: 20090217653
    Abstract: This disclosure relates to a hydraulic system and method that converts the kinetic energy generated by the operation of a swing motor into hydraulic potential energy and reuses the hydraulic potential energy for swing motor acceleration. An accumulator can be provided for storing exit oil from the swing motor that is pressurized by the inertia torque applied on the moving motor via movement of an upper structure of a machine. The pressurized oil in the accumulator can be reused to accelerate the swing motor by supplying pressurized oil to the swing motor.
    Type: Application
    Filed: February 28, 2008
    Publication date: September 3, 2009
    Applicants: CATERPILLAR INC., SHIN CATERPILLAR MITSUBISHI LTD.
    Inventors: Jiao Zhang, Pengfei Ma, Michael R. Schwab, Tonglin Shang, Kalpesh N. Patel
  • Patent number: 7302797
    Abstract: A hydraulic system for a work machine is disclosed. The hydraulic system has a reservoir configured to hold a supply of fluid and a source configured to pressurize the fluid. The hydraulic system also has a fluid actuator, a first valve, and a second valve. The first valve is configured to selectively fluidly communicate the source with the fluid actuator to facilitate movement of the fluid actuator in a first direction. The second valve is configured to selectively fluidly communicate the fluid actuator with the reservoir to facilitate movement of the fluid actuator in the first direction. The hydraulic system further has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the fluid actuator and the reservoir.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: December 4, 2007
    Assignees: Caterpillar Inc., Shin Caterpillar Mitsubishi Ltd
    Inventors: Jiao Zhang, Pengfei Ma, Michael R. Schwab
  • Patent number: 6609369
    Abstract: A pressure compensator for use in a control system for an electro hydraulic-implemented work element being operated through the use of operator input control mechanisms generating operator input signals upon the application thereof, the control system including an actuator coupled thereto for controlling the operation thereof, the pressure compensator determining a pressure compensator coefficient to be applied to an operator input signal to compensate for changes of pressure drop across a valve in communication with the actuator. The pressure compensator coefficient is used to produce an input flow control signal for inputting to the valve to control the amount of hydraulic fluid that flows therethrough to the actuator so that a desired velocity of the actuator is achieved.
    Type: Grant
    Filed: November 28, 2001
    Date of Patent: August 26, 2003
    Assignee: Caterpillar Inc
    Inventors: Douglas W. Koehler, Michael R. Schwab, Jiao Zhang
  • Publication number: 20030097925
    Abstract: A pressure compensator for use in a control system for an electro hydraulic-implemented work element being operated through the use of operator input control mechanisms generating operator input signals upon the application thereof, the control system including an actuator coupled thereto for controlling the operation thereof, the pressure compensator determining a pressure compensator coefficient to be applied to an operator input signal to compensate for changes of pressure drop across a valve in communication with the actuator. The pressure compensator coefficient is used to produce an input flow control signal for inputting to the valve to control the amount of hydraulic fluid that flows therethrough to the actuator so that a desired velocity of the actuator is achieved.
    Type: Application
    Filed: November 28, 2001
    Publication date: May 29, 2003
    Inventors: Douglas W. Koehler, Michael R. Schwab, Jiao Zhang