Transmission of the toroidal-race, rolling-traction type having a mixer and a reducer epicyclic type gearing with clutches brakes

• US 5,401,221 A
• Filed: 02/04/1993
• Issued: 03/28/1995
• Est. Priority Date: 08/17/1990
• Status: Expired due to Term

• Current Assignee: Torotrak Limited (Torotrak Plc)
• Original Assignee: Torotrak Limited (Torotrak Plc)
• Inventors: Soar, Geoffrey B., Fellows, Thomas G.
• Primary Examiner(s): Wright, Dirk
• Assistant Examiner(s): TA, KHOI QUANG
• Application Number:
  US07/983,580
• Time in Patent Office: 782 Days
• Field of Search: 475/192, 475/214, 475/215, 475/216, 475/219, 476/40
• US Class Current: 475/214
• CPC Class Codes: F16H 2015/383 with two or more sets of toroid gearings arranged in parallel
• CPC Class Codes: F16H 2037/0886 with switching means, e.g. to change ranges
• CPC Class Codes: F16H 37/086 CVT using two coaxial friction members cooperating with at least one intermediate friction member

Abstract

A continuously variable transmission with coaxial input (from 6) and output (17), capable of operating in at least two regimes, and having a variator (2) of the toroidal-race rolling-traction type, and gearing including both a speed reducing unit (10) and an epicyclic mixing gear unit (15) in which the components of the mixing gear unit are locked up in at least one of the regimes, and in which the speed-reducing unit (10) effects its speed-reduction without reversal of the direction of rotation between its input (1) and output (from 26). The operating axis (5) of the variator (2) may either coincide with the coaxial input and output of the transmission (FIG. 2 ) or be parallel to but displaced from it (FIG. 3 ). In addition to a brake (13) and a clutch (20), operable to engage first and second regimes, a further clutch (48) operable to engage a third regime is shown.

Claims

1. A CVT (continuously-variable-ratio transmission) having a coaxial input (from 6) and output (17) and that selectively operates in at least first and second regimes, said CVT comprising in combination:

a toroidal-race rolling-traction type ratio-varying variator (2) having an operating axis (5) that is coaxial with the input and output of the CVT, and

a gearing arrangement comprising both a speed reducing gear unit (10) and a mixing epicyclic type gear unit (15),

wherein the mixing epicyclic type gear unit includes first engagement means (20) that selectively locks the mixing epicyclic type gear unit components (18, 25,

     16) so that they rotate as one in at least one of the first and second regimes, and so that a direction of rotation of an output member (26) of the speed reducing gear unit (10) and an input (1) of the speed-reducing gear unit are the same.

2. A CVT (continuously-variable-ratio transmission) having a coaxial input (from 6) and output (17) and that selectively operates in at least first, second and third regimes, said CVT comprising in combination a toroidal-race rolling-traction type ratio-varying variator, and a gearing arrangement comprising both a speed reducing gear unit (10) and a mixing epicyclic type gear unit (15),

wherein the mixing epicyclic type gear unit includes first engagement means (20) that selectively locks the mixing epicyclic type gear unit components (18, 25, 16) so that they rotate as one in at least one of the first and second regimes, and so that a direction of rotation of an output member (26) of the speed reducing gear unit (10) and an input (1) of the speed-reducing gear unit are the same;

and

second (13) engagement means are associated with the reducing gear unit, in that the second and first engagement means respectively and selectively engage the CVT in first and second regimes, and in that a third engagement means (48) selectively engages the CVT in a third regime.

3. A CVT according to claim 2 wherein the third engagement means is a clutch that selectively connects the engine output (from 6) directly to the output member (26) of the reducing gear unit (10).

4. A CVT according to claim 3 wherein the reducing gear unit is of an epicyclic type and the output member of the reducing gear unit is a planet carrier.

5. A CVT (continuously-variable-ratio transmission) having a coaxial input (from 6) and output (17) and that selectively operates in at least first and second regimes, said CVT comprising in combination:

a toroidal-race rolling-traction type ratio-varying variator (2) having an operating axis (5) that is displaced from but parallel to the common axis of the input and output of the CVT, and

a gearing arrangement comprising both a speed reducing gear unit (10) and a mixing epicyclic type gear unit (15),

wherein the mixing epicyclic type gear unit includes first engagement means (20) that selectively locks the mixing epicyclic type gear unit components (18, 25,

     16) so that they rotate as one in at least one of the first and second regimes, and so that a direction of rotation of an output member (26) of the speed reducing gear unit (10) and an input (1) of the speed-reducing gear unit are the same.