INFINITELY VARIABLE FRICTION MECHANISM

• US 3,695,120 A
• Filed: 01/14/1971
• Issued: 10/03/1972
• Est. Priority Date: 01/14/1971
• Status: Expired due to Term

• Current Assignee: Georg Titt
• Original Assignee: Georg Titt
• Inventors: Titt, Georg
• Primary Examiner(s): Husar, C. J.
• Application Number:
  US05/106,373
• Time in Patent Office: 628 Days
• Field of Search: 74/190,190.5,690
• US Class Current: 475/186
• 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

Abstract

Infinitely variable friction mechanism having axially aligned driving and driven shafts with attached friction disks that are rotated in opposite directions by barrel-shaped rollers that are articulated in a basket and in a first ring that is longitudinally shiftable relative to the basket. A second ring that is also independently longitudinally shiftable cooperates with the first ring in conjunction with the torque prevailing on the basket for providing counter pressure regulation of the frictional matings. Coupled to the output of the friction mechanism is a planetary gearing arrangement having an inside sun wheel driven by the driving shaft and an outside wheel connected to the driven friction disk but supported by a wheel which may be allowed to turn freely or to be braked in one or both rotational directions.

Claims

1. Apparatus for varying the rotational velocity of an output shaft driven by a rotating input shaft comprising an infinitely variable friction mechanism including a pair of friction disks each mounted for rotation about the axis of the input shaft, said friction disks having spaced facing surfaces with an input disk coupled to rotate with the input shaft and an output disk coupled to rotate with said output shaft, a plurality of barrel-shaped friction roller bodies that are each mounted for rotation about a shaft and have surfaces which frictionally engage the facing surfaces of said friction disks;

a basket for positioning the shafts of said barrel-shaped friction roller bodies;

means for varying the transmission ratio of said friction mechanism including means for articulating said barrel-shaped friction roller bodies including a first ring mounted for Shiftable movement only in a longitudinal direction parallel to said input shaft axis; and

means for producing a continuous counter pressure between said friction disks to maintain the requisite frictional matings with said barrel-shaped friction roller bodies.

2. Apparatus according to claim 1 wherein the shiftable mounting means for said ring includes swivel bearings (7), and characterized in that the basket for the barrel-shaped friction roller bodies consists of two stamped symmetrical cups each having a flat side with openings (8) corresponding to the locations of said roller bodies and corresponding recesses (11) for receiving the outer ends of the shafts for said roller bodies.

3. Apparatus according to claim 1 characterized in that the basket for the barrel-shaped friction roller bodies and said first ring have at their peripheries oppositely threaded members, and said articulating means comprises a second ring (15) with correspondingly threaded portions for shifting said basket and said first ring in said longitudinal direction in relation to one another;

and means including a bolt (14) for preventing a twisting of said basket and said first ring in relation to one another.

4. Apparatus according to claim 1 characterized in that the barrel-shaped friction roller bodies (2) have diameters of different sizes at the ends of their friction surface.

5. Apparatus according to claim 1, wherein said output friction disk is supported on said input shaft against longitudinal adjustment by means including an axial bearing and an adjusting nut, and said input friction disk is mounted for shiftable movement in a longitudinal direction along said input shaft by said counter pressure producing means.

6. Apparatus according to claim 1 characterized in that the torque prevailing on basket (5) for the friction bodies is used for the counter pressure regulation of the frictional matings.

7. Apparatus according to claim 6 characterized in that the counter pressure producing means consists of third and fourth rings (18) and (19) which have alternating slanting planes on the periphery of their front surfaces.

8. Apparatus according to claim 7 characterized in that said third ring (18) is connected shiftably and flexibly with said basket while said fourth ring (19) is mounted for shiftable movement in relation to a fixed point.

9. Apparatus according to claim 8 characterized in that the force produced by said counter pressure means is transferred to the input friction disk by means including said fourth ring (19), an axial bearing (25) and lever means (26), while the pivotal point of said lever means (26) lies on said input shaft.

10. Apparatus according to claim 7 wherein said counter pressure producing means comprises roller bodies (20) which are guided in a cage located between said third and fourth rings (18) and (19), said cage having a shape corresponding to slanting planes in facing surfaces of said third and fourth rings (18) and (19).

11. Apparatus according to claim 10 characterized in that the running path of the roller bodies (20) is formed by a case hardened, spring steel sheet placed onto the rings (18) and (19).

12. Apparatus according to claim 5 further having means to produce an additional driving force from the cage of the axial bearing (6) against which said output friction disk is supported.

13. Apparatus according to claim 12 further having a differential transmission (30, 31, 32) connected between said output friction disk and the output shaft wherein the torques and the r.p.m.'"'"''"'"'s of the output friction disk and the cage of the axial bearing (6) have been combined.

14. Apparatus according to claim 12 further having a planetary gear arrangement including an inside sun wheel (30) which is rigidly connected to the cage of said axial bearing.

15. Apparatus according to claim 1 further having a differential transmission including an inside sun wheel (34) mounted on the input shaft to rotate concomitantly with said input frIction disk, and an outside wheel (35) mounted to rotate concomitantly with said output friction disk, and wherein the transmission ratio is equal to the smallest transmission ratio of said friction mechanism (FIG. 7).

16. Apparatus according to claim 15 characterized in that the outside wheel (35) is supported by a free wheeling (36) counter to the power take off rotational direction.

17. Apparatus according to claim 15 further including a brake (38) for restraining the outside wheel (35) against rotation.

18. Apparatus according to claim 15 characterized in that said fourth ring (19) of the counter pressure producing means is connected for rotation with said input shaft and for shiftable movement along the axis thereof.

19. Apparatus according to claim 1 wherein said transmission ratio varying means comprises speed responsive means, including centrifugal weights (39) which are displaceable for adjusting the position of the basket and first ring in relation to one another.

20. Apparatus according to claim 19 wherein said centrifugal weights act on levers whose effective length across a swiveling range is variable.

21. Apparatus according to claim 20 wherein said centrifugal weights (39) are connected with the input shaft via return springs (41).

22. Apparatus according to claim 1 characterized in that the barrel-shaped friction roller bodies comprise hollow bodies pressed about their respective shafts.

23. Apparatus according to claim 2 characterized in that the cups of the basket have an area expanding in the shape of a cone in the receiving range of barrel-shaped friction roller bodies in the direction of the input shaft.

24. Apparatus according to claim 2 characterized in that the cups of said basket are connected with one another and located at a distance from one another by means including a friction bearing (48) arranged on said input shaft.

25. Apparatus according to claim 1 wherein the transmission ratio varying means includes a hand-manipulatable drive shaft (27, 28) pointed at an acute angle relative to the longitudinal axis of said input shaft, an indicating device, and means for setting said indicating device in response to the adjustment of the transmission and for displaying the number of revolutions of the output shaft.