Continuously variable planetary gear set

#1. Field of the Invention

#The field of the invention relates generally to transmissions, and more particularly the invention relates to continuously variable planetary gear sets that can be used in transmissions as well as other industrial and land, air and water-borne vehicles.

#2. Description of the Related Art

#FIG. 1 is a schematic cutaway side view of an embodiment of a transmission shifted into high.

#FIG. 2 is a partial cross-sectional view of the transmission taken along line II—II of FIG. 1.

#FIG. 3 is a schematic partial cutaway side view of the idler and ramp sub-assembly of the transmission of FIG. 1.

#Embodiments of the invention will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner simply because it is being utilized in conjunction with a detailed description of certain specific embodiments of the invention. Furthermore, embodiments of the invention may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the inventions herein described.

#The transmissions and drives described herein are of the type that utilizes speed adjuster balls with axes that tilt as described in U.S. Pat. Nos. 6,241,636, 6,322,475, and 6,419,608. The embodiments described in these patents and those described herein typically have two sides generally separated by a variator portion, to be described below, an input side and an output side. The driving side of the transmission, that is the side that receives the torque or the rotational force into the transmission is termed the input side, and the driven side of the transmission or the side that transfers the torque from the transmission out of the transmission is termed the output side. As a general and abstract description of the operation of the ratio variation of many of the embodiments herein, an input disc and an output disc are in contact with the speed adjuster balls. As the balls tilt on their axes, the point of rolling contact on one disc moves toward the pole or axis of the ball, where it contacts the ball at a circle of decreasing diameter, and the point of rolling contact on the other disc moves toward the equator of the ball, thus contacting the disc at a circle of increasing diameter.

#If the axis of the ball is tilted in the opposite direction, the input and output discs respectively experience the converse relationship. In this manner, the ratio of rotational speed of the input disc to that of the output disc, or the transmission ratio, can be changed over a wide range by simply tilting the axes of the speed adjuster balls. As an arbitrary assumption for use herein, the plane connecting the centers of the balls will be considered to define the border between the input side and the output side of the transmission and similar components that are located on both the input side of the balls and the output side of the balls are generally described herein with the same reference numbers. As a convention often used in the following description similar components located on both the input and output sides of the transmission generally have the suffix “a” attached at the end of the reference number if they are located on the input side, and the components located on the output side of the transmission generally have the suffix “b” attached at the end of their respective reference numbers.