Gm Global Technolgoy Operations, Inc.

Howard E Chana

Michael B Solt

Roderick G Tipping

Calmer M Stordahl

A fan-folded drive belt is comprised of a folded metal belt maintained in a continuous loop by a plurality of continuous metal bands maintained in tension and supported in a band slot on the folded metal belt. The folded metal belt is made from a single strip of metal which is formed by machining processes, such as stamping, and then accordion folded to produce individual drive members arranged with long and short drive leg members being adjacent. The adjacent drive members are connected at either the inner or outer extremes. The drive belt transfers drive forces between spaced pulleys or sheaves through frictional engagement therewith. During such driving, the outer portion of the belt is deflected or flexes as the belt travels around the pulleys. This causes high stress levels to be induced within the individual drive members. To reduce the stress level, the various points on the folded belt, a portion of material disposed outwardly from the continuous metal bands is removed at the fold line. This portion of the folded belt is also made transversely wider and preferably slightly longer in the outward direction.

Fan-folded belt

A synchronizer clutch assembly incorporates spline teeth on both a sleeve and a ratio gear. The sleeve is slidably disposed on a hub which is rotatably secured to a shaft member. The sleeve is moved longitudinally so that the spline teeth thereon intermesh with the spline teeth on the ratio gear to provide a drive connection therebetween. The spline teeth on the sleeve have a locking angle portion to prevent the inadvertent disengagement of the spline teeth and a flat portion to prevent fore and aft movement of the ratio gear from being transmitted via the spline teeth to the sleeve.

Synchronizer clutch assembly

A hydraulic control system including a torque sensor for producing a hydraulic signal proportional to torque transmission includes a control chamber or cavity which is supplied with fluid pressure through a plurality of restrictions or orifices from a pressure source. An accumulator is disposed between two of the restrictions such that the torque signal proportional to the pressure in the cavity is modulated or otherwise adjusted to accommodate the changing torque levels which occur as transients during the ratio interchanges in an automatic transmission.

Hydraulic control system including a torque sensor

A variable ratio pulley system has a pair of pulleys mounted on input and output shafts, respectively, and interconnected by a drive belt. The pulleys are adjustably controlled in axial width to establish the drive ratio between the shafts. Each pulley has a load cam sensitive to the torque load being imposed on the respective shaft. The load cams are interconnected by a linkage and preload spring which establishes the minimum axial force operable on the pulleys. The linkage transmits forces between the pulleys thereby imposing a tension force on the belt established by the greater of the forces generated at the load cams. A drive ratio selector is connected to one side of the input pulley to add or subtract a force so that the axial forces on the input and output pulleys are properly balanced when the desired drive ratio is established. The output shaft of the pulley system is connected through a starting mechanism to a forward-reverse gear arrangement and then to a final drive and gear differential.

Control mechanism for a variable ratio drive system

There is disclosed a multistage gear pump and control valve arrangement comprising two hydraulic gear pump sets each having a suction port connected to a common sump and a discharge port for delivering hydraulic fluid to a circuit line. Only one of the discharge ports is continuously open to the circuit line while a check valve operates to connect the other of the discharge ports to the circuit line and prevent reverse flow. A regulator valve regulates the pump discharge to the circuit line by diverting fluid therefrom in response to circuit line pressure below a predetermined setting while both the discharge ports are delivering fluid thereto and by being responsive to circuit line pressures thereabove to connect the other discharge port to the sump to thereby relieve the associated gear pump set of hydraulic work while again regulating the pump discharge to the circuit line by diverting fluid therefrom but with only the one discharge port delivering fluid thereto.

Multistage gear pump and control valve arrangement

A synchronizer for a power transmission has a split cone ring rotatable with a ratio gear and a split bearing ring rotatable with the synchronizer ring. During ratio change, the synchronizer ring transmits a normal force to the split cone ring which develops into axial and radial components. The normal component imposes a first frictional torque on the cone ring while the radial component causes contraction of the cone ring about the split bearing to create a second frictional torque acting on the cone ring. The contraction of the cone ring causes contraction of the bearing which frictionally engages a hub on the ratio gear and transmits a third frictional torque to the hub. The three torques are additive to cause the ratio gear to accelerate or decelerate so that speed synchronizing between the shift ring, synchronizer ring and ratio gear will occur.

Gear synchronizer for a power transmission

A torque converter and mechanically engaged slipping clutch wherein the impeller is driven by the input shell through a cam mechanism. The impeller has a clutch engaging mechanism which moves axially, due to the drive torque transmitted through the cam mechanism, to enforce slipping frictional engagement of the clutch disposed between the input shell and the turbine. The cam surfaces are designed such that the clutch cannot transmit all of the input torque since this would result in zero (0) torque transmission to the cam mechanism thereby releasing the clutch engagement force.

Torque converter and torque engaged slipping clutch

An automatic continuously variable transmission having a power train with a dual path hydromechanical unit and a multistep ratio mechanical gear unit connected in series for overall continuously variable ratio change. The hydromechanical unit has planetary gearing and a variable displacement hydrostatic transmission connecting the reaction and output members to provide progressive and step ratio change. The controls have an automatic gear unit control responsive to output speed and torque demand for step shifting the gear unit to higher gear ratios at higher speeds, and a hydrostatic control responsive to input speed, output speed, and throttle position having hydrostatic power transfer pressure and displacement control of hydromechanical unit speed ratio in first gear from zero at stall through the mechanical speed ratio at zero reaction member speed to the stepup speed ratio and a cycle on each gear shift to step change to a step-down ratio to provide the same overall ratio and to progressively increase the speed ratio from the step-down speed ratio through the mechanical speed ratio to the next step-up speedratio in intermediate gear ratios and, in the highest gear ratio, only up to the mechanical speed ratio. The overall speed ratio is continuusly varied from zero with all power transmitted hydraulically at stall for starting drive to maximum speed ratio with all power transmitted mechanically to meet an engine speed and vehicle speed program varying with throttle for optimum engine and vehicle performance.

Hydromechanical mechanical continuously variable transmission

A power train having a single shaft gas turbine engine having high idle speed and higher maximum torque speed and a progressively variable ratio transmission matched and controlled to provide increasing speed ratio and decreasing torque ratio relative to increasing engine torque and output speed for an accelerating drive at constant maximum tractive effort for a maximum performance vehicle starting and accelerating drive in a low output speed range up to maximum engine power and then increasing speed ratio and decreasing torque ratio for higher speed drives with reduced torque. The transmission has a hydromechanical unit having an engine driven planetary gear providing a variable speed ratio constant torque ratio drive to the input of a friction drive toric unit and a hydrostatic transmission with a constant displacement pump motor driven by the planetary gear reaction member and a variable displacement motor connected in one arrangement to drive the input and in another arrangement to drive the output which is connected by a forward reverse gear unit to drive the vehicle. The hydrostatic transmission differential pressure and motor displacement are controlled in response to engine speed and throttle position to reduce reaction member speed from the free rotary speed to zero speed to increase speed ratio from zero to a maximum and decrease torque ratio from a maximum to a minimum. The pump brake and toric unit are both controlled by speed and power requirements to provide high torque ratio at high input speed for constant maximum torque in a low output speed starting range up to maximum engine power. Then the pump brake holds the reaction member stationary to provide its highest speed ratio, and the toric unit speed ratio is increased for higher speed drives.

Progressively variable transmission

A four-speed planetary transmission providing two underdrive ratios, a direct drive ratio, an overdrive ratio and a reverse ratio is disclosed. Three selectively operable friction clutches and two friction brakes are provided to connect the transmission input to the planetary gearing arrangement and to establish the above speed ratios. One of the clutches has serially disposed therewith a one-way clutch which is operable on a 3-4 upshift or, a 4-3 downshift or, a 4-2 downshift to provide a controlled drive path so that simultaneous overlapping of other friction drive establishing devices in the transmission is avoided during these ratio changes.

Four-speed transmission

A gas turbine engine and automatic transmission power train having a modulator valve controlled by an engine compressor pressure and altitude responsive force actuator and a speed governor to provide a modulator pressure increasing with increasing engine power during normal engine operation and decreasing with increasing output speed operative to increase friction drive capacity and increase upshift speed with increasing modulator pressure. The force actuator provides a force which increases with increasing compressor discharge pressure and an altitude aneroid provides an opposing force decreasing with increasing altitude so the net actuator apply force increases with increasing compressor discharge pressure and altitude and is the same at the same engine power at all altitudes. The actuator has a compressor discharge pressure chamber having on one side a small apply diaphragm connected to a force apply member and on the other side a large release diaphragm and an apply spring acting through the diaphragms on the force apply member. When the engine is operating, minimum to maximum normal operating range compressor discharge pressure acts on the release diaphragm to disable the apply spring and on the apply diaphragm to provide with aneroid altitude correction an apply force increasing from a low value to a high value as compressor discharge pressure increases from minimum to maximum. On engine shut down or other loss of compressor discharge pressure when the engine is operating, as compressor discharge pressure decreases below the minimum operating value the release diaphragm release force is reduced and when compressor discharge pressure equals atmospheric pressure the apply spring force transmitted to the apply member provides a high modulator pressure operative in the transmission to delay upshifts to indicate this condition and to meet maximum drive torque requirements.

Turbine engine compressor discharge pressure modulated transmission

A hydrodynamic drive and slipping clutch arranged in parallel drive relation to provide a controlled slip input drive to a mechanical gear arrangement. The slip speed of the clutch, and therefore the hydrodynamic drive, is controlled by clutch engagement responsive to differential pressure on the clutch. The differential pressure is maintained by controlling fluid flow through a restriction which has a variable opening responsive to a control element which is movable in response to pressure generated by the speed difference between the hydrodynamic drive input and output to establish clutch engagement of sufficient force to maintain a predetermined slip speed in the hydrodynamic drive.

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Troy, MI, United States of America

Howard E Chana