Continuously variable transmission

• US 7,727,106 B2
• Filed: 10/03/2005
• Issued: 06/01/2010
• Est. Priority Date: 10/01/2004
• Status: Expired due to Fees

• Current Assignee: Pierre Maheu
• Original Assignee: Pierre Maheu
• Inventors: Dahme, Jean-Francois, Maheu, Pierre
• Primary Examiner(s): Joyce; William C
• Application Number:
  US11/240,513
• Publication Number:
  US 20060073936A1
• Time in Patent Office: 1,702 Days
• Field of Search: 476/1, 476 40- 46, 476/5
• US Class Current: 476/1
• CPC Class Codes: F16H 15/38 with two members B having hollow toroid surfaces opposite to each other, the member or members A being adjustably mounted between the surfaces
• CPC Class Codes: F16H 63/067 mechanical actuating means

Abstract

A variable ratio transmission for mechanically coupling an input member to an output member, the variable ratio transmission allowing the conversion of an input rotational motion of the input member into an output rotational motion of the output member, the input rotational motion having an input speed and an input torque and the output rotational motion having an output speed and an output torque. The variable ratio transmission includes a variable ratio transmission assembly mechanically coupled to the input member and to the output member for rotating the output member at the output speed in response to the input member being rotated at the input speed, the variable ratio transmission assembly defining a transmission ratio between the output speed and the input speed, the transmission ratio being variable; and a ratio controller mechanically coupled to the variable ratio transmission assembly and to the input member for automatically adjusting the transmission ratio as a function of the input torque.

Claims

1. A variable ratio transmission for mechanically coupling an input member to an output member, said variable ratio transmission allowing the conversion of an input rotational motion of said input member into an output rotational motion of said output member, said input rotational motion having an input speed and an input torque and said output rotational motion having an output speed and an output torque, said variable ratio transmission comprising:

a variable ratio transmission assembly mechanically coupled to the input member and to the output member for rotating the output member at the output speed in response to the input member being rotated at the input speed, said variable ratio transmission assembly defining a transmission ratio between the output speed and the input speed, said transmission ratio being variable; and

a ratio controller mechanically coupled to said variable ratio transmission assembly and to the input member for automatically adjusting the transmission ratio as a function of the input torque, said ratio controller including;

an actuating member mechanically coupled to the input member; and

a ratio defining component including a ratio defining surface, said ratio defining component being mechanically coupled to said actuating member and to said variable ratio transmission assembly for transmitting the input torque to said variable ratio transmission assembly, said ratio defining surface being disposed such that a variation in the input torque causes a predetermined variation of said transmission ratio;

said actuating member being mechanically coupled to said variable ratio transmission assembly in a manner such that a movement of said actuating member relatively to said ratio defining surface causes said predetermined variation of said transmission ratio;

said actuating member being mechanically coupled to said ratio defining component such that said variation in the input torque causes said actuating member to move in a predetermined direction relatively to said ratio defining component;

said actuating member being movable along said ratio defining surface between a high ratio position wherein said transmission ratio is maximal and a low ratio position wherein said transmission ratio is minimal, said variable ratio transmission further comprising a biasing element for biasing said actuating member towards an equilibrium position;

said ratio defining component including a substantially cylindrical shell defining a longitudinal axis, said cylindrical shell defining a shell internal surface and a shell external surface, said cylindrical shell including an aperture extending between said shell internal surface and said shell external surface, said ratio defining surface extending at the periphery of said aperture between said shell internal surface and said shell external surface, said ratio defining surface having a pitch relatively to said longitudinal axis;

said variable ratio transmission assembly including a toroidal transmission stage, said toroidal transmission stage including;

an input disc mechanically coupled to and driven by the input member;

an output disc mechanically coupled to and driving the output member, said output disc being rotatable relative to said input disc;

a plurality of traction rollers interposed between said input disc and said output disc; and

a plurality of substantially elongated support members each supporting a respective traction rollers, said support members defining each a respective roller longitudinal axis about which said respective traction roller is rotatable,

wherein said support members are mechanically coupled to said actuating member so that said movement of said actuating member relatively to said ratio defining surface causes said predetermined variation of said transmission ratio by changing an orientation of said roller longitudinal axes relatively to said input and output discs.

2. A variable transmission as defined in claim 1, wherein said actuating member includes a pin extending substantially radially within said aperture and contacting said ratio defining surface.

3. A variable transmission as defined in claim 2, wherein said pin supports a roller extending substantially perpendicularly thereto, said roller being rollable onto said ratio defining surface.

4. A variable ratio transmission as defined in claim 1, wherein said pitch is constant between said minimal ratio position and said maximal ratio position.

5. A variable ratio transmission as defined in claim 1, wherein said pitch decreases linearly between said maximal ratio position and said minimal ratio position.

6. A variable ratio transmission as defined in claim 1, wherein said pitch decreases sinusoidally between said maximal ratio position and said minimal ratio position.

7. A variable ratio transmission for mechanically coupling an input member to an output member, said variable ratio transmission allowing the conversion of an input rotational motion of said input member into an output rotational motion of said output member, said input rotational motion having an input speed and an input torque and said output rotational motion having an output speed and an output torque, said variable ratio transmission comprising:

a variable ratio transmission assembly mechanically coupled to the input member and to the output member for rotating the output member at the output speed in response to the input member being rotated at the input speed, said variable ratio transmission assembly defining a transmission ratio between the output speed and the input speed, said transmission ratio being variable;

a ratio controller mechanically coupled to said variable ratio transmission assembly and to the input member for automatically adjusting the transmission ratio as a function of the input torque, said ratio controller including

an actuating member mechanically coupled to the input member; and

a ratio defining component including a ratio defining surface, said ratio defining component being mechanically coupled to said actuating member and to said variable ratio transmission assembly for transmitting the input torque to said variable ratio transmission assembly, said ratio defining surface being disposed such that a variation in the input torque causes a predetermined variation of said transmission ratio; and

a speed dependent ratio adjusting assembly mechanically coupled to said variable ratio transmission assembly, said speed dependent ratio adjusting assembly being configured such that a variation in the output speed causes another predetermined variation of said transmission ratio.

8. A variable ratio transmission as defined in claim 7, wherein said transmission ratio is increased when the output speed increases.

9. A variable ratio transmission for mechanically coupling an input member to an output member, said variable ratio transmission allowing the conversion of an input rotational motion of said input member into an output rotational motion of said output member said input rotational motion having an input speed and an input torque and said output rotational motion having an output speed and an output torque, said variable ratio transmission comprising:

a variable ratio transmission assembly mechanically coupled to the input member and to the output member for rotating the output member at the output speed in response to the input member being rotated at the input speed, said variable ratio transmission assembly defining a transmission ratio between the output speed and the input speed, said transmission ratio being variable; and

a ratio controller mechanically coupled to said variable ratio transmission assembly and to the input member for automatically adjusting the transmission ratio as a function of the input torque, said ratio controller including

an actuating member mechanically coupled to the input member; and

a ratio defining component including a ratio defining surface, said ratio defining component being mechanically coupled to said actuating member and to said variable ratio transmission assembly for transmitting the input torque to said variable ratio transmission assembly, said ratio defining surface being disposed such that a variation in the input torque causes a predetermined variation of said transmission ratio;

said variable ratio transmission including an input stage mechanically coupled to said input member and to said variable ratio transmission assembly, said input stage driving said variable ratio transmission assembly at a variable ratio transmission assembly input rotational speed, said input stage increasing said variable ratio transmission assembly input rotational speed by a first predetermined factor relatively to said input speed;

said variable ratio transmission including an output stage mechanically coupled to said output member and to said variable ratio transmission assembly, said output stage being driven by said variable ratio transmission assembly at a variable ratio transmission assembly output rotational speed, said output stage decreasing said variable transmission assembly output rotational speed by a second predetermined factor relatively to said output speed.

10. A variable transmission as defined in claim 9, wherein said first and second predetermined factors are substantially equal.