Mechanical infinitely variable transmission for outdoor power equipment
AssigneeMTD Products Inc
InventorJay Maggard
Life of this patent
Estimating the term…
Abstract
Mechanical infinitely variable transmissions (IVTs) and vehicles employing such IVTs are discussed. The IVT can comprise a planetary gearset with a sun gear driven based on an input angular velocity and an annulus gear driven based on a combination of the input angular velocity and a variable gear ratio of a pulley system, wherein the variable gear ratio of the pulley system can be electrically controlled by an actuator. A drive element can be driven based on a carrier of the planetary gearset.
Claims18
An infinitely variable transmission (IVT), comprising:
- a planetary gearset comprising a sun gear, one or more planet gears, a carrier, and an annulus gear;
- an input shaft configured to be rotated by a prime mover at an input angular velocity, wherein the input shaft is configured to drive rotation of the sun gear at a first angular velocity and an input pulley of a pulley system at the first angular velocity, wherein the first angular velocity is based on the input angular velocity;
- the pulley system comprising the input pulley and an output pulley operationally linked to one another, wherein one of the input pulley or the output pulley is a variable diameter pulley, and wherein the output pulley is configured to rotate at a second angular velocity, wherein the second angular velocity is based on the first angular velocity and a pulley gear ratio of the pulley system;
- a mixing gear configured to rotate at the second angular velocity;
- and
- an output gear configured to rotate with the carrier.
An outdoor power equipment, comprising:
- a frame;
- a prime mover;
- one or more drive elements coupled to the frame;
- operator controls configured to receive an operator input comprising a first drive input associated with a first drive element of the one or more drive elements;
- a control unit configured to determine a commanded output based on the first driver input and to output a control signal based at least in part on the commanded output;
- a first infinitely variable transmission (IVT) coupled to a first drive element of the one or more drive elements, comprising:
- a planetary gearset comprising a sun gear, one or more planet gears, a carrier, and an annulus gear;
- an input shaft configured to be rotated by the prime mover at an input angular velocity, wherein the input shaft is configured to drive rotation of the sun gear at a first angular velocity and an input pulley of a pulley system at the first angular velocity, wherein the first angular velocity is based on the input angular velocity;
- the pulley system comprising the input pulley and an output pulley operationally linked to one another, wherein one of the input pulley or the output pulley is a variable diameter pulley, and wherein the output pulley is configured to rotate at a second angular velocity, wherein the second angular velocity is based on the first angular velocity and a pulley gear ratio of the pulley system;
- a mixing gear configured to rotate at the second angular velocity;
- an output gear configured to rotate with the carrier.
An infinitely variable transmission (IVT), comprising:
- a planetary gearset comprising a sun gear having a number of teeth Ns, a set of planet gears, a carrier, and an annulus gear having a number of teeth Na;
- an input shaft configured to be rotated by a prime mover at an input angular velocity, wherein the input shaft is configured to drive rotation of the sun gear at a first angular velocity, ω1, and an input pulley of a pulley system at the first angular velocity, wherein the first angular velocity is a fixed ratio of the input angular velocity;
- the pulley system comprising the input pulley and an output pulley operationally engaged to the input pulley to be driven thereby, wherein one of the input pulley or the output pulley is a variable diameter pulley, and wherein the output pulley is configured to rotate at a second angular velocity, wherein the second angular velocity is based on the first angular velocity and a pulley gear ratio, Rp, of the pulley system;
- and
- a mixing gear configured to rotate at the second angular velocity.
Dependencies are inferred from the claim text.