Patents Assigned to Tecumseh Products Company
  • Patent number: 5971881
    Abstract: A variable speed, reversible transmission that utilizes two gerotor pumps for variable controlling the speed of the output shaft or axle. A rotatable input member connectable to a drive source drives first and second epicyclic gear trains, which drive the two pumps. As the fluid flow through each pump is variably restricted, the epicyclic gears associated therewith revolve about the input member, causing a worm gear intermediate the input member and the output member to variably rotate in a forward or reverse direction. The worm gear transmits rotational power from the input member to the output member in response to the fluid flow restriction through each pump. The present invention also provides for the two pumps comprising a modular pump unit and a system of transmissions employing a common modular pump assembly.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: October 26, 1999
    Assignee: Tecumseh Products Company
    Inventor: Norman E. Jolliff
  • Patent number: 5951270
    Abstract: A scroll compressor having a thrust bearing interface between a fixed and orbiting scroll member. The scroll members are axially biased together by an axial compliance mechanism and the thrust bearing interface transfers axial forces between the two scroll members. The thrust bearing interface is disposed radially exterior to the wrap elements of the two scroll members and includes non-contiguous thrust bearing elements separated by void spaces located therebetween. Alternative embodiments of the thrust bearing elements include arcuate thrust bearing pads and roller bearings. The thrust bearing pads may include a channel disposed radially exterior to the pads which interconnects the void spaces. The roller bearings are separated by voids and disposed in recesses in outer perimeter portions of the fixed and orbiting scrolls. The voids, channel and recesses promote the distribution of lubricating oil to bearing surfaces of the thrust bearing interface.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: September 14, 1999
    Assignee: Tecumseh Products Company
    Inventors: Terrence R. DuMoulin, Brian J. Gram
  • Patent number: 5951261
    Abstract: A reciprocating piston compressor including at least one cylinder, a reciprocable piston disposed therein, a crankshaft rotatable in forward and reverse directions and having an eccentric crankpin, and a cam disposed about the crankpin, the piston operatively connected to the cam. The cam is rotatable about the crankpin between a first angular position corresponding to a first piston stroke length during forward crankshaft rotation and a second angular position corresponding to a second piston stroke length during reverse crankshaft rotation. In one of its first and second angular positions, the cam is rotatably locked to the crankpin.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: September 14, 1999
    Assignee: Tecumseh Products Company
    Inventor: Andrew W. Paczuski
  • Patent number: 5951271
    Abstract: An axial compliance mechanism for a scroll-type compressor including a fixed scroll member, an orbiting scroll member and a bearing pad spatially fixed in relationship to the fixed scroll member. The axial compliance mechanism biases the orbiting scroll towards the fixed scroll by applying a fluid at high pressure to a radially inner portion of the back surface of the orbiting scroll member and a relatively lower pressure to a radially outer portion of the back surface. An annular stabilization ring is placed between a main bearing pad and the rear surface of the orbiting scroll lifting the orbiting scroll into engagement with the fixed scroll and inhibiting the tilting and wobbling of the orbiting scroll. The annular stabilization ring also maintains a clearance between the rear surface of the orbiting scroll and the main bearing pad thereby improving the performance of a sealing member disposed between the main bearing pad and the rear surface of the orbiting scroll member during start up of the compressor.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: September 14, 1999
    Assignee: Tecumseh Products Company
    Inventors: Terrence R. DuMoulin, Brian J. Gram
  • Patent number: 5947070
    Abstract: An overhead camshaft internal combustion engine having a plastic camshaft which extends through an opening on the cylinder head, the plastic camshaft having a seal ring disposed around the outer surface of the molded plastic camshaft to provide an interface surface for contacting a seal assembly disposed between the engine casing and the molded plastic camshaft. The seal assembly and the seal ring provide a fluid tight seal to prevent leakage of fluid through the cylinder head opening. The seal ring provides a smooth contact surface for the molded plastic camshaft to prevent wear and damage to the seal assembly from the abrasive surface of the molded plastic camshaft. The seal ring also provides a heat sink for dissipating the frictional heat generated by the rotation of the camshaft. In another form, the plastic camshaft includes a powder metal surface formed thereon. The powder metal surface provides the same benefits as the seal ring, namely protection from wear and dissipation of heat.
    Type: Grant
    Filed: July 10, 1997
    Date of Patent: September 7, 1999
    Assignee: Tecumseh Products Company
    Inventors: Thomas A. Immel, Erik J. Christiansen
  • Patent number: 5884593
    Abstract: An overhead cam internal combustion engine having a slanted head design which permits the camshaft assembly comprising a camshaft, rocker arms and valve assemblies to be pre-assembled to the head and valve lash to be set off of the main engine assembly line. The slanted head design allows the chain sprocket and timing chain for driving the camshaft to be installed thereon after the head has been assembled to the engine block, accommodating the easy installation of the timing chain. L-shaped rocker arms, mounted on a single shaft, follow a single lobe overhead camshaft. Each rocker arm actuates a valve located on the side of the camshaft opposite that which it follows.
    Type: Grant
    Filed: April 23, 1997
    Date of Patent: March 23, 1999
    Assignee: Tecumseh Products Company
    Inventors: Thomas A. Immel, Erik J. Christiansen
  • Patent number: 5860884
    Abstract: A variable speed transmission or transaxle that utilizes a pump for variable braking of the output shaft or axle. A rotatable input shaft connectable to a drive source extends into a transmission housing and is operatively connected to a gear train that transmits rotational power to a transmission output shaft. A gerotor pump mounted within the housing utilizes a ring gear of an epicyclic gear of the gear train as an inner gerotor gear that meshes with an outer gerotor gear to pump fluid along a fluid conduit. By adjustably varying the resistance of the pump, the revolution rate of the epicyclic ring gear is adjusted which in turn results in a controlling of the speed of rotation of the transmission output shaft. In an alternate embodiment, a reversible transmission is provided by employing two gerotor pumps and two gear trains which allow forward and reverse speeds of rotation of the output shaft to be variably controlled.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: January 19, 1999
    Assignee: Tecumseh Products Company
    Inventor: Norman E. Jolliff
  • Patent number: 5850743
    Abstract: A suction accumulator for a refrigerant compressor which is mounted to the compressor in such a way as to reduce the metal fatigue at the joint between the inlet tube and the suction accumulator, and reduce the potential for rust or oxidation of the metal of the suction accumulator. The suction accumulator includes a cylindrical housing with two domed ends, wherein an inlet tube extends into the inlet of the suction accumulator and is provided with a flared end. The flared end is attached to the inlet of the suction accumulator and the flared end matches the contour of the inlet such that when the two parts are joined they are congruent with each other to thereby reduce the vibration therebetween. The suction accumulator is also provided with an outlet which communicates refrigerant from the suction accumulator back to the compressor. The suction accumulator is secured to the outside wall of the compressor using a mounting bracket.
    Type: Grant
    Filed: November 13, 1996
    Date of Patent: December 22, 1998
    Assignee: Tecumseh Products Company
    Inventors: Nelik I. Dreiman, Rick L. Bunch, Tara C. Kandpal, deceased
  • Patent number: 5829960
    Abstract: A suction inlet passage in a cylinder block of a rotary compressor includes a generally symmetrical diverging port which has generally conic cross-sections that divergingly open into a cylinder bore. The diverging port provides a buffer cavity which reduces pulsations and associated noise. The suction inlet passage is further provided with an entrance passage and a narrower passage, which is disposed between the entrance passage and the diverging port and which has a smaller cross-section than either the entrance passage or the diverging port. The suction inlet passage serves as a diffuser with the narrower passage functioning as the throat of the diffuser so as to increase volumetric efficiency with respect to the suction gas entering the cylinder bore. The diverging port extends the point of suction inlet close-off, and correspondingly enlarges the close-off angle, resulting in extending the period of unclosed compression and enhancing the supercharging effect.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: November 3, 1998
    Assignee: Tecumseh Products Company
    Inventor: Nelik I. Dreiman
  • Patent number: 5808441
    Abstract: The present invention involves a control system for a motor having a main winding and an auxiliary winding disposed on a stator. A microprocessor determines the phase difference between the line voltage and the voltage between the main winding and the auxiliary winding to determine the rotational status of the rotor. In a moving rotor, a measurable phase difference exists. This phase difference can be measured by monitoring the zero crossings of the respective voltages. One method of measuring the phase difference is to check the logic state corresponding to the voltage between the main and auxiliary windings when a predetermined time period has elapsed after a zero crossing of the line voltage. Another method measures the time delay between the zero crossings of the two voltages. The control system of the present invention is particularly adapted for use with single phase AC motors having a main winding and an auxiliary winding disposed electrically out of phase on the stator.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: September 15, 1998
    Assignee: Tecumseh Products Company
    Inventor: Daniel A. Nehring
  • Patent number: 5797180
    Abstract: A method of manufacturing a plastic camshaft having a tubular metal insert using a die assembly having a pair of aligned pins. The tubular metal insert is cut to a length slightly shorter than the length of the finished camshaft and is placed on one of the pins. The second pin is then inserted into the opposite end of the tubular metal insert during the closing of the die assembly. The pins properly align the metal insert within the mold cavity of the die assembly during injection of a surrounding plastic material which forms the remainder of the camshaft. The pins also axially compress the tubular metal insert and have tapered shoulders which bear against and slightly deform or flare the end regions of the insert. The flared ends of the tubular metal insert tightly engage the pins and prevent the formation of flash within the hollow interior of the tubular metal insert.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: August 25, 1998
    Assignee: Tecumseh Products Company
    Inventor: Brian S. Buchholz
  • Patent number: 5795127
    Abstract: A self-priming, vertical-shaft centrifugal pump having an impeller design which creates an upward thrust and which is heavy enough to carry an engine having a standard weight flywheel through a compression stroke. The pump is comprised of a vertical-shaft engine mounted onto a pump housing. The pump housing includes an inlet chamber, a pumping chamber, and a separation chamber. The shaft of the engine protrudes into the pumping chamber and is mounted to an impeller which rotates within the pumping chamber. The pump draws liquid into the pumping chamber from an inlet communicating liquid entrained with gas to the pump. The impeller uses centrifugal force to pump the liquid and gas mixture out of the pumping chamber and into the separation chamber.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: August 18, 1998
    Assignee: Tecumseh Products Company
    Inventor: David M. DeClerck
  • Patent number: 5785151
    Abstract: A compressor having an oil pick-up tube which filters incoming lubricant, and increases the volumetric pumping capacity of the compressor. The oil pick-up tube is attached to the crankshaft of the compressor, and is partially disposed within an oil sump also provided in the compressor. When the motor of the compressor is energized, the crankshaft and the oil pick-up tube rotate, and oil from the oil sump is drawn into the oil pick-up tube. A passageway is provided within the motor shaft to communicate oil from the oil pick-up tube to the compressor mechanism of the compressor for lubrication purposes. A cylindrical screen is also provided within the oil pick-up tube to both filter the incoming oil and provide a surface to which the oil adheres as it migrates upward through the rotating tube and expels the oil radially outward to increase the velocity of the migrating oil. The volumetric pumping capacity of the compressor is thereby increased.
    Type: Grant
    Filed: November 15, 1996
    Date of Patent: July 28, 1998
    Assignee: Tecumseh Products Company
    Inventors: Emanuel D. Fry, Scott L. Reiniche
  • Patent number: 5784232
    Abstract: The present invention involves control and protection circuit for a compressor motor which includes an inductively activated contactor for controlling the flow of current to the compressor motor. The circuitry of the present invention includes a plurality of current detectors associated with each phase winding of the compressor motor for sensing the current in each phase winding. The sensed currents are combined in a predetermined manner and used to provide protection against an overcurrent condition, single phase operation and light loading condition. Additional detector circuits are also connected to the present control and protection circuit to provide protection against high temperature in the compressor motor windings, high temperature in various component of the compressor motor, and undervoltage in the power supply.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: July 21, 1998
    Assignee: Tecumseh Products Company
    Inventor: James B. Farr
  • Patent number: 5775885
    Abstract: A hermetically sealed reciprocating refrigeration compressor has a suction gas arrangement including a suction gas plenum formed integral with a cylinder block for supplying suction gas directly to a cylinder so as to eliminate the need for external suction gas conduits. Apertures are formed about the circumference of the cylinder for receiving suction gas directly from the suction gas plenum. Pistons are provided with multiple suction gas entrances and a semi-toroidal suction valve to provide an efficient way of introducing suction gas into a compression chamber during a suction stroke of the compressor. A spherical discharge valve assembly is provided in a valve plate adjacent the compression chamber for improved flow characteristics and increased through flow area.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: July 7, 1998
    Assignee: Tecumseh Products Company
    Inventors: Nelik I. Dreiman, Russell A. Cowen
  • Patent number: 5775894
    Abstract: In a refrigerant compressor, a discharge valve assembly which reduces reexpansion volume. The present invention provides a discharge valve assembly for reciprocating, rotary, and scroll types of compressors, and includes a spherical valve member that engages and penetrates a discharge port provided on a compressor cylinder head, valve plate or scroll plate. The discharge port is formed in the cylinder head or scroll plate and is dimensioned such that the spherical member penetrates and substantially fills the discharge port. The reexpansion volume within the discharge port is thereby reduced. To maintain engagement of the spherical member with the discharge port, an elastically deformable arm having an aperture is positioned to hold the spherical member in the discharge port. The arm is elastically deformable to allow the spherical valve member to move out of engagement with the discharge port during the compression phase of the compressor.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: July 7, 1998
    Assignee: Tecumseh Products Company
    Inventor: John Kosco, Jr.
  • Patent number: 5755194
    Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.
    Type: Grant
    Filed: July 1, 1996
    Date of Patent: May 26, 1998
    Assignee: Tecumseh Products Company
    Inventors: James W. Moorman, Erik J. Christiansen, Roberto Molina, Gar M. Adams
  • Patent number: 5701738
    Abstract: A mechanical disconnection mechanism for a hydrostatic transmission. The output shaft of the hydrostatic transmission is divided into a drive portion and a driven portion, with both the drive portion and the driven portion being provided with external splines or gears. To connect the drive portion to the driven portion, a splined sleeve is positioned to engage the splines of both the driven portion and the drive portion such that rotation of the drive portion rotates the driven portion. To disconnect the drive portion from the driven portion, the splined sleeve is positioned to engage only one of the drive portion and the driven portion. In the disconnected position, the implement may be manually pushed without reverse driving the hydraulic unit of the transmission to thereby allow for relatively easy movement. A brake is mounted about the driven portion of the output shaft to enable the vehicle to be stopped regardless of the position of the splined sleeve.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: December 30, 1997
    Assignee: Tecumseh Products Company
    Inventors: Frederick P. Eberle, Norman E. Jolliff
  • Patent number: 5701668
    Abstract: A refrigeration compressor includes a polyamide annular thrust bearing pressfit within a countersunk recess in the rotor aperture and having radially extending lubricating oil grooves on a lower surface thereof. A vertical crankshaft being concentrically disposed within and secured to the rotor at one end and being journalled for rotation within a vertical bore defined by a bearing hub formed in a frame. The bearing hub supports the rotor and crankshaft combination. The bearing hub includes an upper end face which is machine ground and polished to a smooth surface and which is in contact with the smooth lower surface of the thrust bearing thereby forming a frictional pair. A reduction in mechanical friction and power consumption is realized by use of the polyamide thrust bearing and the smooth polishing of the hub upper end face thereby increasing the overall efficiency associated with the refrigeration compressor.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: December 30, 1997
    Assignee: Tecumseh Products Company
    Inventors: Nelik I. Dreiman, Tara C. Kandpal
  • Patent number: D396045
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: July 14, 1998
    Assignee: Tecumseh Products Company
    Inventor: Brian D. Neeley