US 4,768,997 AGranted

Belt drive system for dual input transmissions/transaxles

AssigneeTecumseh Products Company

InventorsRocky H. Page, Edward J. Koscho, deceased

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Abstract

A two belt drive system is disclosed for lawn and garden tractors and other vehicles especially of the type including a variable speed transmission/transaxle having a constant speed rotational input, a variable speed rotational input, and an output speed dependent on the rotational speed of the variable input. A first drive belt is mounted for rotation in one direction on an engine drive pulley, a first pulley on one of the transmission/transaxle inputs, and one pulley of a variable diameter pulley assembly. A second drive belt is mounted for rotation in the same direction as the first belt on a second pulley on the other transmission/transaxle input and the other pulley of the variable pulley assembly. Shifting the position of the variable pulley assembly with a hand control changes the belt receiving diameters of the variator pulleys such that the rotational speed of the second drive belt, second pulley, transmission/transaxle output, and resulting ground speed of the tractor are all adjustable with the hand control while the engine drives the first drive belt at a constant rotational speed.

Claims43

Dependent claims

A belt drive system for use with a variable speed vehicular transmission/transaxle assembly of the type having one input shaft adapted to be driven, at a fixed rotational speed and a second input shaft adapted to be driven at. a rotational speed which may be varied to change the output speed of said transmission/transaxle, said system comprising:

a driving belt pulley adapted to be mounted on an engine drive shaft;
a first driven belt pulley adapted to be mounted on the first input shaft for rotation in a predetermined rotational direction;
a second driven belt pulley adapted to be mounted on the second input shaft ror rotation in said predetermined rotational direction;
a variator pulley assembly including a pair of rotatably mounted belt pulleys and means for changing the belt receiving diameter of one of said variator pulleys in response to a change in the belt receiving diameter of the other of said variator pulleys;
a first drive belt mounted on said driving pulley, said first driven pulley and one of pulleys in said variator pulley assembly for rotation of said first driven pulley in said predetermined direction;
a second drive belt mounted on said second driven pulley and said other pulley of said variator pulley assembly also for rotation in said predetermined direction;
and
positioning means for changing the position of said variator pulley assembly whereby when said first driven pulley is driven in said predetermined rotational direction at a predetermined rotational speed with said first drive belt and driving pulley, said second driven pulley will be rotated in said predetermined rotational direction at a rotational speed which is adjustable with said positioning means.

5 more elements

A belt drive system for vehicular transmissions/transaxles comprising:

a driving pulley adapted to be mounted on an engine drive shaft for rotation in a predetermined rotational direction;
a first driven pulley adapted to be mounted for rotation in said predetermined rotational direction on a first input shaft on the transmissmion/transaxle;
a second driven pulley adapted to be mounted for rotation in said predetermined rotational direction on a second input shaft on the transmission/transaxle;
a first drive belt mounted on said drivng pulley and said first driven pulley for rotating said first driven pulley in said predetermined rotational direction;
a second drive belt mounted on said second driven pulley;
variable diameter pulley means engagingsaid first and second drive belts for changing the rotationa speed of said second drive belt and second driven pulley in response to a change in the diameter at which said first drive belt contacts said variable pulley means whereby when said first drive belt and first driven pulley are driven at a constant rotational speed, the rotational speed of said second drive belt and second driven pulley may be varied to change the output speed of the transmission/transaxle by changing the diameter of said variable pulley means.

3 more elements

In a vehicle having a support frame, an engine having a drive shaft, a variable speed transmission/transaxle assembly having at least one axle, one input shaft adapted to be driven at a fixed rotational speed and a second input shaft adapted to be driven at a rotational speed which may be varied to change the output speed of said axle, and rotational vehicle support means secured to said axle for movably supporting said vehicle, an improved belt drive system comprising:

a driving belt pulley mounted on said engine drive shaft;
a first driven belt pulley mounted on said first input shaft for rotation in a predetermined rotational direction;
a second driven belt pulley mounted on said second input shaft for rotation in said predetermined rotational direction;
a variator pulley assembly including a pair of rotatably mounted belt pulleys and means for changing the belt receiving diameter of one of said variator pulleys in response to a change in the belt receiving diameter of the other of said variator pulleys;
a first drive belt mounted on said driving pulley, said first driven pulley and one of pulleys in said variator pulley assembly for rotating said first driven pulley in said predetermined direction;
a second drive belt mounted on said second driven pulley and said other pulley of said variator pulley assembly for rotating said second driven pulley in said predetermined direction;
and
positioning means for changing the position of said variator pulley assembly whereby when said first driven pulley is driven in said predetermined rotational direction at a predetermined rotational speed with said first drive belt and driving pulley, said second driven pulley will be rotated in said predetermined rotational direction at a rotational speed which is adjustable with said positioning means.

5 more elements

Dependencies are inferred from the claim text.