Patents by Inventor Frank H. Walker

Frank H. Walker 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).

  • Patent number: 8176838
    Abstract: A hydraulic machine arrangement includes at least one hydraulic machine having a plurality of pistons reciprocating within corresponding cylinders. The pistons can be driven by a cam to operate the hydraulic machine as a pump, and they can drive the cam to operate the hydraulic machine as a motor. The hydraulic machine can be configured to selectively disengage a certain piston or pistons from the cam to operate at less than full displacement. Controlling the pressure in the cylinders corresponding to the disengaged pistons can be accomplished by a number of mechanisms, including selectively exhausting fluid from the cylinders, or using a jet pump to siphon off some of the fluid from a high pressure side of the hydraulic machine. Two of the hydraulic machines can be mounted together to help balance axial forces and eliminate the need for an expensive high capacity thrust bearing.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: May 15, 2012
    Inventor: Frank H. Walker
  • Patent number: 8162621
    Abstract: A hydraulic machine has a plurality of pistons reciprocating within corresponding cylinders. Embodiments may operate as a pump, a motor, or both. The hydraulic machine can be configured to selectively disengage certain pistons from the cam to operate at less than full displacement. This provides a discrete variable displacement machine. The hydraulic machine can also be configured to provide a type of continuously variable displacement by changing the high and low pressure port connections to the cylinders at different positions of the pistons' stroke—i.e., positions other than TDC and BDC. To inhibit hydraulic lock when continuously variable displacement is used, the closing and opening of the high and low pressure ports are allowed to overlap; however, a barrier is used to inhibit short circuiting the fluid between the ports. Individual cylinders can be provided with relief valves to further inhibit hydraulic lock.
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: April 24, 2012
    Inventor: Frank H. Walker
  • Patent number: 8132868
    Abstract: A hydraulic regenerative braking system and method for a vehicle include a variable displacement hydraulic machine operable as a pump or a motor (22). The hydraulic machine facilitates connections between some of its piston cylinders (50, 52) and a low pressure source (32), and some other of its piston cylinders (50, 52) and a high pressure source (28). The cylinders are alternately connected to the high and low pressure sources such that a pressure transition occurs during each piston stroke. By controlling where in a piston stroke the transitions occur, the power of the hydraulic machine can be modulated. The hydraulic machine is configured to effect the pressure transitions in only a portion of the cylinders at one time. This can be accomplished by asymmetrically configuring cam lobes (86, 88, 90) and fluid ports (74, 76, 78, 80, 82, 84). Staggering the pressure transitions helps to inhibit flow disturbances in the machine when it is operating at less than full displacement.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: March 13, 2012
    Inventor: Frank H. Walker
  • Publication number: 20100101406
    Abstract: A hydraulic machine arrangement includes at least one hydraulic machine having a plurality of pistons reciprocating within corresponding cylinders. The pistons can be driven by a cam to operate the hydraulic machine as a pump, and they can drive the cam to operate the hydraulic machine as a motor. The hydraulic machine can be configured to selectively disengage a certain piston or pistons from the cam to operate at less than full displacement. Controlling the pressure in the cylinders corresponding to the disengaged pistons can be accomplished by a number of mechanisms, including selectively exhausting fluid from the cylinders, or using a jet pump to siphon off some of the fluid from a high pressure side of the hydraulic machine. Two of the hydraulic machines can be mounted together to help balance axial forces and eliminate the need for an expensive high capacity thrust bearing.
    Type: Application
    Filed: February 12, 2008
    Publication date: April 29, 2010
    Inventor: Frank H. Walker
  • Publication number: 20090236906
    Abstract: A hydraulic regenerative braking system for a vehicle is provided. The system includes two hydraulic machines, each of which is disposed proximate a corresponding vehicle wheel. A transformer is in communication with each of the hydraulic machines, and with a pair of accumulators. Each of the hydraulic machines is operable as a pump, pumping fluid to at least one of the accumulators when the vehicle is braking. Each of the hydraulic machines is also operable as a motor, receiving pressurized fluid and transferring torque to the vehicle wheels. The transformer is operable to vary the pressure of the fluid received by the hydraulic machines.
    Type: Application
    Filed: June 4, 2009
    Publication date: September 24, 2009
    Inventor: Frank H. Walker
  • Publication number: 20090223359
    Abstract: A hydraulic machine has a plurality of pistons reciprocating within corresponding cylinders. Embodiments may operate as a pump, a motor, or both. The hydraulic machine can be configured to selectively disengage certain pistons from the cam to operate at less than full displacement. This provides a discrete variable displacement machine. The hydraulic machine can also be configured to provide a type of continuously variable displacement by changing the high and low pressure port connections to the cylinders at different positions of the pistons' stroke—i.e., positions other than TDC and BDC. To inhibit hydraulic lock when continuously variable displacement is used, the closing and opening of the high and low pressure ports are allowed to overlap; however, a barrier is used to inhibit short circuiting the fluid between the ports. Individual cylinders can be provided with relief valves to further inhibit hydraulic lock.
    Type: Application
    Filed: May 19, 2009
    Publication date: September 10, 2009
    Inventor: Frank H. Walker
  • Patent number: 7562944
    Abstract: A hydraulic regenerative braking system for a vehicle is provided. The system includes two hydraulic machines, each of which is disposed proximate a corresponding vehicle wheel. A transformer is in communication with each of the hydraulic machines, and with a pair of accumulators. Each of the hydraulic machines is operable as a pump, pumping fluid to at least one of the accumulators when the vehicle is braking. Each of the hydraulic machines is also operable as a motor, receiving pressurized fluid and transferring torque to the vehicle wheels. The transformer is operable to vary the pressure of the fluid received by the hydraulic machines.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: July 21, 2009
    Inventor: Frank H. Walker
  • Publication number: 20080210500
    Abstract: One embodiment of a hydraulic regenerative braking system for a vehicle having at least one drive wheel includes first (24) and second (32) hydraulic machines operable as pumps or motors. One of the hydraulic machines operates in conjunction with the vehicle drive wheels, while the other hydraulic machine operates in conjunction with a flywheel arrangement (28) to store and receive energy. The hydraulic machines are connected to each other such that when one is operating as a pump, it provides fluid to the other to operate that machine as a motor. A control system is provided to receive inputs related to the operation of the vehicle, and to control the fluid flow through the hydraulic machines.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 4, 2008
    Inventor: Frank H. Walker
  • Publication number: 20080185909
    Abstract: A hydraulic regenerative braking system and method for a vehicle include a variable displacement hydraulic machine operable as a pump or a motor (22). The hydraulic machine facilitates connections between some of its piston cylinders (50, 52) and a low pressure source (32), and some other of its piston cylinders (50, 52) and a high pressure source (28). The cylinders are alternately connected to the high and low pressure sources such that a pressure transition occurs during each piston stroke. By controlling where in a piston stroke the transitions occur, the power of the hydraulic machine can be modulated. The hydraulic machine is configured to effect the pressure transitions in only a portion of the cylinders at one time. This can be accomplished by asymmetrically configuring cam lobes (86, 88, 90) and fluid ports (74, 76, 78, 80, 82, 84). Staggering the pressure transitions helps to inhibit flow disturbances in the machine when it is operating at less than full displacement.
    Type: Application
    Filed: December 16, 2005
    Publication date: August 7, 2008
    Inventor: Frank H. Walker
  • Patent number: 6537047
    Abstract: A compact high efficiency vane pump is disclosed having a unique T-shaped vane and rotor slot configuration with a roller tip vane in a uniquely configured chamber. To minimize friction in chamber diameter, a pressure plate is provided which is hydraulically balanced, both in the forward and reverse pump and motor modes, having micro pressure pulses which vary multiple times per rotor rotation in order to compensate for varying hydraulic axial load on the housing.
    Type: Grant
    Filed: February 15, 2001
    Date of Patent: March 25, 2003
    Inventor: Frank H. Walker
  • Publication number: 20010036411
    Abstract: A compact high efficiency vane pump is disclosed having a unique T-shaped vane and rotor slot configuration with a roller tip vane in a uniquely configured chamber. To minimize friction in chamber diameter, a pressure plate is provided which is hydraulically balanced, both in the forward and reverse pump and motor modes, having micro pressure pulses which vary multiple times per rotor rotation in order to compensate for varying hydraulic axial load on the housing.
    Type: Application
    Filed: February 15, 2001
    Publication date: November 1, 2001
    Inventor: Frank H. Walker
  • Patent number: 6138635
    Abstract: An internal combustion engine includes three engine modules. Each engine module having an associated crankshaft segment. A first clutch is provided for connecting the first crankshaft segment to the second crankshaft segment such that the first and second crankshafts are indexed at 90.degree. with respect to one another. A second clutch is provided for connecting the second crankshaft segment to the third crankshaft segment such that the second and third crankshaft segments are indexed at 90.degree. with respect to one another. A spring connects the first crankshaft segment via the first clutch to the second crankshaft segment. The spring winds to cause the second crankshaft segment to lag behind the first crankshaft segment 30.degree. such that the first, second, and third crankshafts rotate at 60.degree. intervals with respect to one another when the first, second, and third engine modules are in operation and the first, second, and third crankshafts are connected.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: October 31, 2000
    Inventor: Frank H. Walker
  • Patent number: 5971092
    Abstract: A drive train for a vehicle having a pair of mechanically driven wheels, a pair of hydraulically driven wheels, and a mechanically driven accessory is disclosed. The drive train includes a transmission system connected to the pair of mechanically driven wheels and to the accessory. A first drive source including an internal combustion engine is connected to the transmission system. A second drive source, operating through a source of stored mechanical energy, is also connected to the transmission system. At least one of the first and second drive sources is capable of driving the pair of mechanically driven wheels by driving the transmission system. One or both of the first and second drive sources can be disengaged from the transmission system so that the vehicle's kinetic energy is transmitted through the transmission system to drive the accessory.
    Type: Grant
    Filed: August 15, 1996
    Date of Patent: October 26, 1999
    Assignee: Frank H. Walker
    Inventor: Frank H. Walker
  • Patent number: 5323688
    Abstract: A hydraulic system including hydraulic units serving as wheel motors and pumps is disclosed. The hydraulic units include a stationary member supporting cylinders with piston assemblies reciprocating therein. The piston assemblies have bodies and follower assemblies which follow lobes on a rotary cam. The piston assemblies serve both as pistons and as timing valves for controlling the flow of fluids. The piston assemblies may have either undercuts or internal passages in their bodies. The follower assemblies have compliant springs elastically positioning rollers between arms of a yoke to allow lateral movement of these rollers relative to the arm of the supporting yokes. Sealing mechanisms are provided which seal between the rotary cam and the stationary member to form an annular scavenge chamber. At least one sealing mechanism has a non-rotating annular intermediate member which pilots relative to the rotary cam. A static seal accommodates radial movement between the stationary and intermediate members.
    Type: Grant
    Filed: March 16, 1993
    Date of Patent: June 28, 1994
    Inventor: Frank H. Walker
  • Patent number: 5263401
    Abstract: A hydraulic regenerative braking and four wheel drive system for a vehicle is provided. The system includes a fluid accumulator, hydraulic units locating within vehicle wheels and comprising stationary members and cooperating rotary cams, filter assemblies, and spool valves for controlling the flow of fluid in the system. The system may be operated in a regenerative mode wherein at least some of the hydraulic units operate as pumps to provide high pressure fluid to the accumulator during vehicle deceleration or braking, and wherein at least some of the hydraulic units operate as motors, receiving high pressure fluid from the accumulator during vehicle acceleration. The system may also be operated in a four-wheel drive mode wherein a pair of hydraulic units, connected to a pair of mechanically driven wheels, act as pumps to drive a pair of hydraulic units, acting as motors, to rotate a pair of non-mechanically driven wheels.
    Type: Grant
    Filed: March 5, 1992
    Date of Patent: November 23, 1993
    Inventor: Frank H. Walker
  • Patent number: 5101925
    Abstract: A hydraulic wheel motor and pump are provided for use with a motor vehicle having a pair of mechanically driven wheels and a pair of non-mechanically driven wheels. The hydraulic pumps cooperate with the mechanically driven wheels, and the hydraulic motors are coupled to the non-mechanically driven wheels. The pumps and motors are diagonally connected to one another to create a four wheel drive vehicle. Also shown is an apparatus and method for independently controlling the tractive force of the vehicle wheels during a turning maneuver.
    Type: Grant
    Filed: March 20, 1991
    Date of Patent: April 7, 1992
    Inventor: Frank H. Walker
  • Patent number: 5000282
    Abstract: A hydraulic wheel motor and pump are provided for use with a motor vehicle having a pair of mechanically driven wheels and a pair of non-mechanically driven wheels. The hydraulic pumps cooperate with the mechanically driven wheels, and the hydraulic motors are coupled to the non-mechanically driven wheels. The pumps and motors are diagonally connected to one another to create a four wheel drive vehicle. Also shown is an apparatus and method for independently controlling the tractive force of the vehicle wheels during a turning maneuver.
    Type: Grant
    Filed: September 25, 1989
    Date of Patent: March 19, 1991
    Inventor: Frank H. Walker
  • Patent number: 4896749
    Abstract: An emergency braking device is attached to the vehicle body and is shiftable between an inoperative position and an operative position upon the occurrence of an emergency braking situation. The braking device is provided with a vacuum shroud which engages the roadway to form a substantially enclosed cavity. The shroud is shifted between the operative and inoperative position by a shifting mechanism. A pump is provided to evacuate air from the enclosed cavity to cause the vacuum shroud to be urged toward the roadway. An attachment device temporarily couples the vacuum shroud to the vehicle wheel causing the normal load of the wheel on the roadway to be increased, enabling the vehicle brake to decelerate the vehicle at an increased rate.
    Type: Grant
    Filed: January 26, 1988
    Date of Patent: January 30, 1990
    Inventor: Frank H. Walker
  • Patent number: 4883141
    Abstract: A hydraulic wheel motor and pump are provided for use with a motor vehicle having a pair of mechanically driven wheels and a pair of non-mechanically driven wheels. The hydraulic pumps cooperate with the mechanically driven wheels, and the hydraulic motors are coupled to the non-mechanically driven wheels. The pumps and motors are diagonally connected to one another to create a four wheel drive vehicle.
    Type: Grant
    Filed: April 22, 1988
    Date of Patent: November 28, 1989
    Inventor: Frank H. Walker
  • Patent number: 4441520
    Abstract: An upper sealed reservoir and a lower vented reservoir are connected by a conduit and tube extending into the lower reservoir. A shroud forms a chamber around the end of the tube within the lower reservoir and is vented at its upper end. Openings are provided in the tube and the shroud and are indexed in diametrically opposite relation, with the opening in the tube pointing in the direction of the center of the lower reservoir. The arrangement maintains proper hydraulic fluid level balance between the two reservoirs under a wide range of vehicle attitudes and accelerations. When either the vehicle attitudes or acceleration, or both, momentarily reorients the actual fluid level in the lower reservoir and the shroud, trapped fluid within the shroud chamber prevents air from entering the upper reservoir through the tube and conduit so that excess fluid cannot flow into the lower reservoir from the upper reservoir.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: April 10, 1984
    Assignee: General Motors Corporation
    Inventors: Frederick G. Bruso, Frank H. Walker, Harry H. Lyon