Infinitely variable traction roller transmission

• US 5,020,384 A
• Filed: 07/25/1990
• Issued: 06/04/1991
• Est. Priority Date: 10/17/1988
• Status: Expired due to Term

• Current Assignee: Excelermatic Inc.
• Original Assignee: Excelermatic Inc.
• Inventors: Kraus, Charles E.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Anchell, Scott
• Application Number:
  US07/557,464
• Time in Patent Office: 314 Days
• Field of Search: 74/190, 74/190.5, 74/199, 74/200, 475/214, 475/215, 475/216, 475/217
• US Class Current: 475/187
• 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 2015/383 with two or more sets of toroid gearings arranged in parallel

Abstract

In an infinitely variable transmission wherein two toric traction discs are rotatably supported in a housing opposite one another so as to define therebetween a toric cavity in which at least two motion transmitting traction rollers are disposed in engagement with the toric discs and supported by pivot trunnions, each pivot trunnion is provided with a single support roller disposed on a track section and has an axial control end which is supported so as to be slightly movable in a plane normal to the axis of the toric discs and means are provided for controllably moving the trunnion control ends in unison for initiation of a transmission ratio change.

Claims

1. An infinitely variable traction roller transmission comprising:

a housing;

coaxial input and output shafts rotatably supported in said housing;

a main transmission shaft rotatably supported in said housing in parallel spaced relationship with said input and output shafts, said main transmission shaft being operatively connected to said input shaft for rotation therewith;

two toric traction roller transmission structures including outer and inner toric discs disposed on said main shaft and having their axially outer toric discs mounted for rotation with said main transmission shaft and their inner toric discs mounted for rotation with a first hollow transmission shaft surrounding said main transmission shaft between said toric traction roller transmission structures, each of said toric traction roller transmission structures including a plurality of motion transmitting traction rollers in engagement with the toric discs of said each toric traction roller transmission structure, each said traction roller being supported on respective pivot trunnions so as to be rotatable about an axis normal to the respective pivot trunnion axis and disposed on opposite sides of a plane defined by the axes of said input and output and said main transmission shafts and including means associated with said trunnions for causing pivoting of said trunnions in order to change the ratio of motion transmission between said outer and inner toric discs;

an intermediate shaft rotatably supported between said input and output shafts and having at its one end a disc-shaped clutch structure associated therewith for coupling said intermediate shaft selectively with said input shaft and a brake structure for preventing rotation of said intermediate shaft, said intermediate shaft having at its other end a planetary transmission associated therewith including a ring structure mounted for rotation with said output shaft;

a planet carrier mounted for rotation with said intermediate shaft and a sun structure disposed in engagement with the planets of said planetary transmission and being associated with a second hollow transmission shaft rotatably supported on said intermediate shaft and provided with means in engagement with corresponding means on said first hollow transmission shaft for rotation therewith;

said disc-shaped clutch structure and said planetary type transmission having a given width and diameter and being arranged such that portions thereof fit between the toric discs of the toric traction roller transmission structures on said main transmission shaft.

2. An infinitely variable traction roller transmission according to claim 1, wherein a partial circular track structure is disposed adjacent each pivot trunnion and each pivot trunnion has a support roller guided in said track structure, and each pivot trunnion further has a control end projecting therefrom along the pivot trunnion'"'"'s pivot axis and being pivotally supported in said housing such that said control end is additionally movable slightly in a control plane normal to the axis of the toric discs for tilting said trunnion in said control plane and means are provided for tilting all trunnions in unison in said control plane so as to provide appropriate precess motion of said traction rollers for initiation of a transmission ratio change.

3. A traction roller transmission according to claim 2, wherein said housing has inwardly projecting wall portions provided with guide slots through which said trunnion ends project and in which they are slidably supported.

4. A traction roller transmission according to claim 3, wherein said means for tilting said trunnions include arms mounted on said trunnion ends so as to project in directions essentially normal to a plane receiving the pivot axis of said trunnions and the axis of the traction roller supported on the respective trunnion and means connected to said arms for tilting said trunnions.

5. A traction roller transmission according to claim 4, wherein said trunnion ends are projecting in the same direction and said arms project from said trunnion ends in parallel fashion in opposite directions and wherein said means connected to said arms are links connected to a common operating member, said operating member having an operating mechanism associated therewith for setting the transmission ratio.

6. A traction roller transmission according to claim 2, wherein said track structure adjacent each pivot trunnion is supported on a wedge and a hydraulic cylinder and piston arrangement is provided adjacent each wedge for forcing said wedges into wedge spaces adjacent said pivot trunnions for forcing the traction rollers on said pivot trunnions into firm engagement with the associated toric discs.

7. A traction roller transmission according to claim 1, wherein said planetary type transmission is a planetary type traction roller transmission with said sun structure being formed by one axial end of said second hollow transmission shaft.