Tecumseh Products Company

Other

Unipat Ag

Roland L Von Kaler

Dale I Havens

Rocky H Page

Norman E Jolliff

Christian Helmut Thoma

George Duncan Arnold

Michael P Weirich

William A Gremminger

An automatic brake adjustment for small transmissions, such as used with riding lawn mowers and the like. A brake disc rotated by the transmission is selectively engaged by friction producing pucks brought into engagement with the brake disc by a rotatable lever having a cam operating a puck. The axial position of the brake lever on its supporting shaft is determined by a threaded nut and automatic rotational nut adjustment is produced by a wheel having evenly spaced shoulders in the form of ratchet teeth defined upon its periphery selectively and sequentially engaged by a detent mounted upon the brake lever. When puck wear of sufficient extent occurs, the detent will sequentially engage the following shoulder of that previously engaged to rotate the brake lever adjustment nut during the next brake actuation thereby translating the brake lever and puck toward the brake disc to compensate for puck wear.

Automatic brake adjustment

An apparatus for balancing and supporting various loads exerted on the pump cylinder block and associated bevel gear in a radial piston type hydraulic transmission for assuring concentric rotation about the pintle during operation. A hydraulic pressure pad, acting as a hydraulic piston, is located on the outer surface of the pintle at least partially underneath the pump cylinder block hub portion for counteracting the loads exerted against the pump cylinder block and associated bevel gear. A groove circumferentially disposed in the outer surface of the pintle supplies oil to the pressure pad from a bore disposed in the groove and in communication with the high pressure passage of the pintle. The pressure pad is preferably disposed 90.degree. from the input shaft and associated input bevel gear. Additional grooving on the outside circumferential surface of the pintle provides lubrication between the rotating cylinder blocks of the pump and motor, and the pintle.

Bevel gear load balance in a hydrostatic transmission

The present invention is a front shift arrangement for transaxles of small tractors and riding lawn mowers. In one embodiment, the shifter is a cylindrical rod having arms engaging the shift collar of an in-line transmission. One end of the shifter extends out the front of the transaxle housing and has a square head with a bore for attaching to a lever and linkage. By moving the lever and thereby pivoting the shifter, the shift collar is axially moved to selectively engage gears gear ratios of the transmission, with the shifter being releasably secured in selected positions by a detent biasing mechanism. The shifter is positioned below the central plane of the transaxle in the lower housing by a cover plate. The lever attached to the shifter moves on a vertical arc to pivot the shifter. In a second embodiment, the shifter is a flat piece which is bent to form an arm and a lever portion. The arm portion extends out an opening in the lower housing and is bent to form the lever portion which may be attached to and moved by linkage to an operator lever. A bushing pivotally supports the shifter in the opening and includes a detent biasing mechanism for releasably securing the shifter at positions which correspond to the gear ratios. A wall of the housing is positioned in front of the recesses to retain the bushing within the housing.

Shift lever arrangement for transaxle

The present invention is a transaxle with an offset shaft thereby having a reduced profile. The transaxle includes an upper housing and a lower housing defining a split line. A vertical input shaft and an axle shaft are rotatably disposed in the housing. A shift shaft is rotatably disposed within the housing and operably connected to the input shaft. Gears on the shift shaft mesh with gears on a counter shaft to transmit rotational motion from the one input shaft to the axle shaft. The axle shaft is disposed in a first generally horizontal plane and the shift shaft is disposed in a second generally horizontal plane below the first generally horizontal plane to reduce the profile of the transaxle.

Offset shaft arrangement for in-line shift transaxle housing

The present invention is a transmission having a two part shift shaft. The spur gear supporting portion of the shift shaft is received by bearings of the housing at its two ends and is made of a relatively strong material for supporting the load of the spur gears. One of the bearings is formed in an internal wall of the housing to support the proximal end of the shift shaft. The shift collar supporting portion of the shift shaft supports the shift collar and is axially aligned with the gear supporting portion. A projection of the shift collar supporting portion engages a recess in the gear supporting portion to axially align and properly position the shift collar for operation of the shifting mechanism. The shift collar supporting portion is made of a less expensive material than the gear supporting portion, thus reducing the overall cost of the transmission.

Two part shifter shaft

The present invention is a brake lever arrangement for a small transmission. The brake mechanism is actuated by the rotational movement of the brake lever which causes friction pucks to move into the brake disc. A spring coupled to the brake lever biases the brake lever in a non-braking position and aligns the brake lever with its plane of rotation to prevent dragging of the friction pucks on the brake disc. Also, a bracket may be provided which has an elongated slot for receiving the upper portion of the brake lever. The bracket aligns the brake lever and guides the movement of the brake lever along one direction.

Brake lever arrangement

A hydrostatic transaxle has a hydrostatic transmission, including a pump in fluid communication with a motor, the pump including a track ring for eccentrically varying radially displaceable pistons. A control mechanism for the pump is disposed adjacent to the axle assembly on the inboard side of the transmission. The pump track ring pivots about a pin disposed through one end of the pump track ring so as to be eccentrically adjustable about the pintle. The pin is located on the outboard side of the transmission or remote from the axle assembly, and is clampingly held between the portions of the transmission housing having casing bolts extending on either end therethrough.

Control mechanism for a hydrostatic transaxle

A hydrostatic transaxle includes a hydrostatic transmission with a pump and motor, the pump and motor each including a track ring radially surrounding a cylinder in which are disposed a plurality of pistons rotatable on a fixed conduit. The motor track ring includes radially extending lugs disposed 180.degree. from each other that are captured between the upper and lower transaxle casing halves thereby preventing axial or radial movement of the motor track ring.

Hydrostatic transaxle

The present invention is a small transmission for riding lawn mowers and the like. The transmission includes a detent arrangement which aids the operator while shifting the transmission gears. The detent arrangement includes detent recesses which are formed in the casting of the housing, and a biased detent mechanism mounted on the shift fork of the transmission. The biased detent mechanism includes a projection on the shift fork which receives a spring and nose cone. The spring urges the nose into the detent recesses so that the shifting mechanism holds the transmission in the selected gear, and provides a positive feel of the changing gears. Alternatively, a spring biased ball may be mounted on the shift fork to engage the detent recesses.

Shifting mechanism detent arrangement

A transaxle driving apparatus for a small-sized vehicle such as a grass-mowing lawn tractor, formed from a two-piece housing to encapsulate a hydrostatic transmission with associated reduction gearing and mechanical differential member. One housing element is provided with a vertical input shaft which is drivingly engaged to the hydraulic pump of the hydrostatic transmission by means of bevel gearing. A hydraulic motor of the hydrostatic transmission is provided with a motor shaft, a speed reduction shaft, and a differential gear unit attached to the axle shafts, all shafts other than the input shaft being disposed horizontally along the plane containing the longitudinal axis of the transaxle for economy and compactness.

Variable speed transaxle

In a hydrostatic transmission, an oil expansion reservoir is formed as an integral part of the hydrostatic transmission housing, providing an extension to the housing chamber which encloses motion transmitting components of the transmission. The reservoir is defined by a yieldably compressible hollow body mounted within the chamber of the transmission housing. The hollow body is sealably attached at its open end to the outer wall of the transmission housing. The body includes a continuous cylindrical sidewall connected to a closed end wall and formed of alternating reversed annular folds which cause compression and expansion of the body sidewall to occur in a bellows-like fashion rectilinearly along a central longitudinal axis of the body.

Internal reservoir-defining body for permitting oil expansion within a

A transaxle having five forward speeds and reverse includes a shift shaft on which are journalled for free rotation four forward speed change gears and an input bevel gears which is integrally conjoined with a first speed change gear. A reverse gear is also journalled for free rotation on the shift shaft and a neutral spacer is disposed between reverse gear and the four forward gears. A counter shaft carries five companion spur gears in constant running mesh with the forward speed change gears. One of the companion gears is also in constant running mesh with a reverse intermediate gear which is in constant running mesh with the reverse gear. The reverse intermediate gear is supported by a half-bearing in the transaxle housing. A pair of axially slidable and radially outward biased shift keys on the shift shaft selectively couple the forward speed change gears, the input bevel gear, and the reverse gear to the shift shaft. High gear is provided by coupling the bevel gear directly to the shift shaft and bypassing the counter shaft. A differential driven by a spur gear on the shift shaft drives the output drive shafts of the transaxle. A disc brake is provided on the shift shaft.

Transaxle

An improved transaxle having an intermediate shaft on which is freely journalled a plurality of forward gears and a reverse gear in close proximity thereto, and a positive-neutral-position collar disposed between the spur gears and the reverse gear. A shifting key is axially slidably disposed on the intermediate shaft and has an end portion thereof which is yieldably biased radially outwardly from the outer surface of the intermediate shaft for selectively engaging separately each of the gears freely journalled thereon. The positive-neutral-position collar has a recess radially outwardly disposed in its bore and which recess is formed to receive the yieldably biased end portion of the shifting key therein when the shift key is moved between the forward gears and reverse gears, thereby providing the user a positive indication of neutral gear position.

A transmission/transaxle assembly for vehicles such as lawn and garden tractors which includes a housing, a dual input, a constant mesh planetary gear assembly, differential gear, axle, and output gear which transfer the planetary gear output to the differential gear and axle. The assembly reduces the rotational speed of two power inputs to a single, lower speed output and allows clutchless, infinitely variable forward, neutral and reverse output speeds by varying the rotational speed of at least one of the inputs with respect to the other. The assembly is compact and provides efficient lubrication through emersion of portions of the planetary gear assembly which continuously rotate in an oil compartment. The axes of the input shafts are arranged transverse to the axis of the output axles such that the assembly will easily accommodate vertical drive shaft engines in tractors or mowers. Output gearing transfers the reduced output of the planetary gear assembly first transverse to and then parallel to the input axes. Various differential gearing may be used while variation of the speed of one of the inputs may be made with a variable pulley assembly or other variable drive assembly.

Variable speed transaxle assembly

A ring gear assembly is also provided with the a transaxle, and includes a ring gear carrying a bevel gear assembly in its interior, both of which are contained in a cavity in the housing for the transaxle. A pair of bearing shoes are directly disposed between the teeth of the ring gear and the housing cavity and between the opposite sides of the ring gear and the housing cavity. The bearing shoes have an arcuately-shaped inner surface against which the ring gear teeth are rotatably placed. During rotation of the ring gear, bearing surface therefor is provided by the teeth of the ring gear and the inner surfaces of the bearing shoes.

Growing community of inventors

Tecumseh, MI, United States of America

Roland L Von Kaler