AU694631B2

AU694631B2 - Variable diameter pulley for continuously variable transmissions

Info

Publication number: AU694631B2
Application number: AU50496/96A
Authority: AU
Inventors: Boris Klaricic
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-07-10
Filing date: 1996-04-04
Publication date: 1998-07-23
Anticipated expiration: 2016-04-04
Also published as: AU5049696A

Description

AUSTRALIA

Patent Act 1990 *54* COMPLETE SPECIFICATION Invention Title: Variable Diameter Pulley For Continuously Variable Transmissions This invention is described in the following statement: -L -y VARIABLE DIAMETER PULLEY FOR CONTINUOUSLY VARIABLE TRANSMISSIONS This invention relates to variable diameter pulley for a flat or Vee belts continuously variable transmissions.

ABSTRACT

The subject invention includes a pair of pulleys mounted for rotation on spaced parallel axes, each pulley having axially spaced slots for adjustable receiving drive elements of one kind which engage the internal face of an endless flat belt or receiving drive elements of other kind which engage the inclined surfaces of Vee belts extending around the pulleys and transmitting power from one to the other; one set of guide slots on one pulley is axially movable relatively to the other to adjust drive elements toward and away from the pulley axis and vary the effective diameters of the pulleys thus changing the drive ratio of the transmission.

The relative movement of the one pulley to the other to change pulley diameters is achieved by the pressure responsive actuators and suitable control system which may be manual or automatic. The actuators and control system are not part of this invention.

SUMMARY OF THE INVENTION As mentioned, the variable diameter pulley system is constructed so that power is transmitted to and from the inner surface of the flat belt or from the inclined surfaces of the Vee belts and the pulley drive elements can be adjusted to vary the effective diameters thereof and change the drive ratio essential for continuous variable transmissions.

Primary object of the invention is to provide a novel continuously variable diameter pulley construction having one set of vertical guide slots and one set of inclined relatively adjustable guide slots and drive elements adjustably received by the I I, IIISL~A 3 guide slots, the drive elements being shaped to engage the inner surface of the endless flat belt or the inclined surfaces of the endless Vee belts and transmit power from the belt to effect rotation of the driven pulley.

A second object of the invention is to construct the guide slots and drive elements, mentioned in the preceding paragraph, in such a manner to facilitate the adjustments thereof in the operation of changing the effective sizes of the pulleys.

A th;"d object of the invention is to provide a pulley construction having a set of vertical guide slots and opposite to them a set of inclined guide 15 slots and to provide drive elements with relatively :friction free ends disposed in the guide slots, the ends having a close sliding fit in the guide slots to insure ease of adjustment during the change of effective size of the pulleys.

A fourth object of this invention is to provide a pulley construction of the type mentioned in the preceding paragraph in which inclined set of guide slots is adjustable by a pressure responsive mechanism and the guide slots of inclined set are at predetermined angle which will cause the drive elements to be forced toward or away from the axis of rotation of the pulley upon relative axial adjustment of the guide slot set.

A fifth object of the invention is to provide the guide slots mentioned in the preceding paragraphs with a semi circular grooves so that the drive elements are positively engaged with the guide slots by appropriately shaped inserts which prevent drive elements to disengage from the pulley under the influence of rotational and centrifugal forces.

A sixth object of this invention is to provide drive elements, mentioned in the preceding paragraphs so formed adjacent each vertical and horizontal end to receive appropriate set of bearings so when in contact with the bottom of the guide slots a minimum opposition will be offered to the movement of the drive elements during the adjustments of the guide slots in changing the effective diameters of the pulleys.

A seventh object of this invention is to provide drive elements, mentioned in the preceding paragraphs so formed and shaped to withstand high stress conditions generated by torque transmissions.

An eighth object of this invention is to provide drive elements mentioned in the preceding paragraphs with sliding surfaces so formed for contact with the guide slots to minimise wear rate 15 between the moving components.

And final object of this invention is to provide a common form of variable diameter pulley which can receive either the drive elements for the flat belt drive or the drive elements for Vee belts drive.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a pair of pulleys employed in transmission, the flat belt being composed around the pulleys.

Figure 2 is a sectional view taken through the 25 pulley on the plane indicated by A-A of Figure 1.

Figure 3 is a sectional partial view of the pulley taken on the plane indicated by C-C of Figure 2.

Figure 4 is sectional view taken through the pulley on the plane ind;i ted b B-B of Figure 1.

Figure 5 is a -ectional partial view taken through the pulley on the plane indicated by D-D of Figure 4.

Figure 6 is a sectinal view of the guide slot taken on the plane indicated by E-E of Figure Figure 7 is a view of drive element for flat belt drive.

Figure 8 is a scctiona! view taken on the plane indicated by F-F of T'igare 7.

Figure 9 is a view of drive element for Vee belts drive.

Figure 10 is a sectional view taken on the plane indicated by G-G of Figure 9.

DESCRIPTION

Referring first to Figure 1, there is shown the arrangement of two pulleys 1 and 2 and flat belt 3 composed around the pulleys to transmit rotary motion from one, the driving pulley to the other, the driven pulley. In this kind of continuously variable diameter pulleys, either pulley can be driving or driven pulley. Pulleys 1 and 2 are identical in construction, each having one fixed sheave to the shaft and one which is axially 15 movable relatively to the other.

In the form of invention shown in Figure 2 and Figure 3, sheave 1 rigidly fixed to the shaft 5 is designated as a perpendicular guide disc because it has a number of guide slots 12 perpendicular to the axis of rotation which extend from points spaced a ~predetermined distance from the axis of rotation to the periphery of the disc and sheave 2 adjustable on shaft 10 is designated as a conical guide disc because it has a number of guide slots 11 on a conical surface which controls the effective size of the pulley by its axial movement from and towards the perpendicular guide disc 1.

As shown in Figure 2 and Figure 4, the conical guide disc 2 is formed in the shape of the conical surface with the guide slots 11 extending from points spaced a predetermined distance from the axis of rotation to the periphery of the cone.

Cylindrical extension 16 of Figure 4 with guide slots protracted from the cone is shown in the configuration adapted for assembling of drive elements 3 with the guide slots 11 by means of grooves 15 and inserts 6. The conical surface in the form illustrated in which the said guide slots 11 are

I

formed is disposed at a predetermined angle X to the axis of rotation of the shaft The guide slots 11 and 12 of Figure 2 and Figure 4 are of the same shape and cross sections and are positioned opposite to each other.

The guide slots 11 and 12 mentioned in the preceding paragraph are parallel deep grooves in cross section incorporating a semi circular grooves 13, 14 and 15 for reception of inserts 6 and 6a which prevent drive elements from pulling away from slots during the operation. Figure 6 shows a typical cross section of the said guide slots and semi circular grooves. The slots 11 and 12 are arranged in such a manner to receive either drive 15 elements 3 of Figure 7 or drive elements 3a of Figure 9 for radial adjustment in the operation of changing the effective diameters of the pulleys.

Each drive element mentioned in the preceding paragraph is L-shaped having substantial Tee-cross section and is formed adjacent each end with holes S.:I to accept inserts 6 of Figure 8 and inserts 6a of Figure 10 for reception by the semi circular grooves mentioned in the preceding paragraph. Each drive :i element end is also so formed to receive special bearing train 7 and 8 as shown in Figure 7 and Figure 9 for reception by the guide slots. The bearing trains provide almost friction free movement, when in the operation of the drive elements in the corresponding guide slots 12 of the perpendicular guide disc 1 and the guide slots 11 of the conical disc 2.

Each drive element mentioned in the preceding paragraph is engaged with the said guide slots in such a manner to provide a solid element resistant to bending and shear forces, a requirement for the higher powered transmissions.

It will be observed that axial adjustment of the relatively movable conical disc 2 will vary the distance between the discs and cause radial

Claims

1. A variable speed belt drive pulleys comprising: 0 a pair of pulley components mounted on spaced shafts, one of said pulley components having radially spaced a number of guide slots and opposed axially spaced a number of guide slots in the other element extending outwardly from a predetermined distance from the pulley axis; 0 a number of drive elements having their vertical and horizontal ends engaged for adjustment in respective guide slots of said pulley components; 0 a flat belt for one kind of transmission composed around said pulley members with surface of said I -I belt engaging said drive elements to transmit torque from one pulley member to the other adjustment of said drive elements in said guide slots varying the effective diameters of said pulley members; 0 a Vee belts for another kind of transmission composed around said pulley members with surfaces of said belts engaging said drive elements to transmit torque from one pulley member to the other, adjustment of said drive elements in said 0io guide slots varying the effective diameters of said pulley members.

2. The variable speed belt drive of claim 1 in which all guide slots of one pulley element rigidly fixed to the one shaft are perpendicular to the axis of 15 rotation.

3. The variable speed belt drive of claim 1 in which all guide slots of one pulley element movable on the other shaft are inclined at a predetermined angle to Ioo• the axis of rotation.

4. The variable speed belt drive of claim 3 in which the predetermined angle of inclination of the guide slots can vary from substantially 300 to substantially

5. The variable speed belt drive of claim 1 in which the drive elements are L-shaped having Tee cross sections with vertical and horizontal portions formed therein to adjustably fit in the guide slots.

6. The variable speed belt drive of claim 1 in which set of guide slots on one pulley member are axially movable relatively to the other set of guide slots on the other pulley member.

7. The variable speed belt drive of claim 1 in which the transmission from one pulley to the other pulley is generated by the area of contact between the inner surface of the flat belt and the number of the drive elements engaged in the operation.

8. The variable speed belt drive of claim 1 in which the transmission from one pulley to the other pulley is generated by the area of contact between the _I I _I _CI_ inclined surfaces of the Vee belts and the number of the drive elements engaged in the operation.

9. The variable speed belt drive of claim 5 in which the guide slots have deep grooved cross sections.

10. The variable speed belt drive of claim 9 in which the deep grooved guide slots have semi circular grooves formed therein to receive inserts and engage the drive elements.

11. The variable speed belt drive of claim 5 in which the drive elements have low friction bearings inserted in the vertical and horizontal portions therein for engagement with the bottom walls of deep grooved guide slots to facilitate adjustment of the drive elements. 15

12. The variable speed belt drive of claim 5 in which the drive elements formed for flat belt drive may be interchangeable with the drive elements formed for Vee belts drive. DATED THIS EIGHTEENTH DAY OF MARCH 1996 BORIS KLARICIC THE INVENTOR 0000 par~ r~-cl ~-~clr -CR