Continuously variable transmission

• US 9,046,158 B2
• Filed: 01/13/2014
• Issued: 06/02/2015
• Est. Priority Date: 02/28/2003
• Status: Expired due to Term

• Current Assignee: Enviolo BV
• Original Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Inventors: Miller, Donald C, Allen, David J, Smithson, Robert A
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US14/153,473
• Publication Number:
  US 20140128195A1
• Time in Patent Office: 505 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B62M 11/04 of changeable ratio
• CPC Class Codes: B62M 11/14 with planetary gears
• CPC Class Codes: B62M 9/08 involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel
• CPC Class Codes: F16H 15/28 with external friction surface
• CPC Class Codes: F16H 15/40 in which two members co-operative by means of balls, or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 15/50 Gearings providing a continuous range of gear ratios
• CPC Class Codes: F16H 15/503 in which two members co-operate by means of balls or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 15/52 in which a member of uniform effective diameter mounted on a shaft may co-operate with different parts of another member
• CPC Class Codes: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• CPC Class Codes: F16H 2037/101 Power split variators with one differential at each end of the CVT
• CPC Class Codes: F16H 37/084 at least one power path being a continuously variable transmission, i.e. CVT
• CPC Class Codes: F16H 37/0853 CVT using friction between rotary members having a first member of uniform effective diameter cooperating with different parts of a second member
• CPC Class Codes: F16H 37/086 CVT using two coaxial friction members cooperating with at least one intermediate friction member
• CPC Class Codes: F16H 61/6649 characterised by the means for controlling the torque transmitting capability of the gearing
• CPC Class Codes: F16H 63/067 mechanical actuating means
• CPC Class Codes: Y10T 29/49464 Assembling of gear into force transmitting device
• CPC Class Codes: Y10T 408/65 Means to drive tool

Abstract

A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Claims

1. A power train, comprising:

a planetary gearset mounted on a shaft having a longitudinal axis, the planetary gearset including a planet carrier coupled to the shaft;

a variator mounted coaxially with and coupled to the planetary gearset, the variator comprising

a plurality of balls, each ball having a tiltable axis about which it rotates,

a cage configured to align the tiltable axes of the plurality of balls and further configured to maintain the radial and angular position of each ball in the plurality of balls,

a first disc in contact with the plurality of balls, and

a second disc in contact with the plurality of balls and further coupled to a case to form a rotating hub shell; and

an idler in contact with the plurality of balls.

2. The power train of claim 1, further comprising an axial force generator configured to generate an axial force that increases the traction between the first disc, the plurality of balls, the idler, and the second disc.

3. The power train of claim 2, wherein the axial force generator comprises a linkage assembly.

4. The power train of claim 3, wherein the linkage assembly in an extended state corresponds to a low transmission ratio and wherein the linkage assembly in a contracted state corresponds to a high transmission ratio.

5. The power train of claim 1, further comprising two legs for controlling the tilt of each ball, a first leg positioned on a first side of the ball and a second leg positioned on an opposite side of the ball relative to the tiltable axis, wherein each leg is coupled to an axle passing through the ball, and wherein each axle has two rollers, a first roller positioned relative to the first leg and a second roller positioned relative to the second leg.

6. The power train of claim 5, wherein each roller is positioned radially inward of the corresponding first leg or second leg.

7. The power train of claim 1, wherein power is input via the rotating hub shell and power is output via the shaft.

8. The power train of claim 1, wherein power is input via the shaft and power is output via the rotating hub shell.