WO2007068227A1

WO2007068227A1 - Cone pulley pair for a cone pulley belt transmission

Info

Publication number: WO2007068227A1
Application number: PCT/DE2006/002026
Authority: WO
Inventors: Hartmut Faust
Original assignee: Luk Lamellen Und Kupplungsbau Beteiligungs Kg
Priority date: 2005-12-14
Filing date: 2006-11-20
Publication date: 2007-06-21
Also published as: DE112006002811A5; DE112006002811B4; JP2009519408A; JP4982683B2; EP1963716A1

Abstract

A cone pulley pair comprises an input shaft, fixed to a fixed pulley, a moveable pulley, arranged on the shaft so as to be axially displaceable and rotationally fixed, a torque sensor device with a shaped surface which is fixed to the shaft and an additional shaped surface which is fixed to a sensor piston that encircles the shaft, can be axially displaced and rotated in relation to the shaft. Said shaped surfaces are configured in such a manner that the axial position of the sensor piston changes by rollers arranged between the shaped surfaces rolling off on the shaped surfaces once the torque effective between the sensor piston and the moveable pulley changes. The sensor piston has arms, spaced apart from each other in the peripheral direction and axially directed, on its end facing away from the moveable pulley. Said arms are provided with axial toothed sections that engage with an axial peripheral toothed section of a rotationally drivable input wheel that is received so as to be rotatable on the shaft and that cannot be substantially displaced. A support ring rests on the arms on the side radially opposite the toothed sections of the arms and forces the toothed sections of the arms to engage with the peripheral toothed section of the input wheel.

Description

Conical pulley pair for a Keqelscheibenumschlinαungsgetriebe

The invention relates to a cone pulley pair for a conical-pulley belt transmission.

Cone pulley, as used for example in motor vehicles, generally contain two conical disk pairs, which are wrapped by a belt, for example a special chain. By opposing change in the distance between the conical disks of each conical disk pair, the transmission ratio can be changed continuously.

Advantageously, a pair of conical disks, preferably the drive side, includes an integrated torque sensor with which the torque acting on a drive motor is detected and a contact pressure between the conical disks of the associated disk pair is changed in accordance with the torque. For a compact design of the torque sensor, it is advantageous if the torque sensor is arranged directly in the space between a support plate of the cone pulley pair supporting, rigidly connected to the shaft of the cone pulley pair support ring wall and the washer. In order to make this possible, a sensing piston belonging to the torque sensor has axial arms which project through the support ring wall and are in meshing engagement outside the support ring wall with an input gear driven, for example, by a drive motor.

Due to the meshing, over which the full power or the full moment of the drive motor is transmitted to the trained with the teeth arms of the sensing piston high mechanical demands that require a precise manufacturing of high quality material and problems with durability over long Operating periods can lead.

The invention has for its object to solve the above problems, i. to provide a way to form the cone pulley pair such that the arms of the sensing piston with high durability are produced in a cost effective manner.

This object is achieved with a cone pulley pair according to claim 1. The cone pulley pair according to the invention is further developed with the features of the subclaims in an advantageous manner.

According to the invention, a pair of conical disks for a conical-pulley belt drive comprises an input shaft which is rigidly connected to a fixed disk, a travel disk axially displaceable on the shaft and non-rotatably mounted, a torque-sensing device with a sensing piston rigidly encompassing a shaft and axially displaceable and rotatable relative to the shaft is connected, which form surfaces are formed such that the axial position of the sensing piston changes by rolling arranged between the mold surfaces rolling elements on the forming surfaces in a change of effective between the sensing piston and the travel disc torque, which sensing piston on its side facing away from the shim side axially spaced arms, spaced apart in the circumferential direction, which are provided with axial toothings, which are provided with an axial peripheral toothing of a rotatably mounted on the shaft and essentially axially non-displaceable, dr ehantreibbaren input gear is engaged, and a support ring which is on the teeth of the arms radially opposite side in contact with the arms and urges the teeth of the arms in engagement with the peripheral toothing of the input gear.

By virtue of the support ring provided according to the invention, radial forces acting on the arms can be supported directly. Also acting in the circumferential direction forces are absorbed by the support ring.

The peripheral teeth of the axial extension of the sensing piston may be formed, for example, on the radial outer side, when the input gear is formed with an internal toothing.

The support ring is located advantageously on the free end portions of the arms.

Next is advantageous for power transmission when the support ring does not overlap the teeth of the arms.

It is particularly advantageous to attach the support ring to the arms by means of a snap connection.

For mounting safety, the support ring is preferably symmetrical with respect to a rotation through 180 ° about an axis containing a diameter of the support ring. Further, it is advantageous for the assembly, when the support ring is formed at its end faces with a Vorzentrierungsstufe which can be pushed onto the free ends of the arms of the sensing piston with play.

The invention is explained below with reference to schematic drawings, for example, and with further details.

In the figures represent:

Figure 1 shows a longitudinal section through a conical disk pair;

Figure 2 is a view similar to Figure 1 with axially displaced sensing piston;

Figure 3 is a detail sectional view of the support ring at the beginning of pushing on the

Poor; and FIG. 4 shows a detail sectional view similar to FIG. 3 with the sleeves pushed onto the arms

Support ring.

According to FIG. 1, a pair of conical disks of a conical-pulley belt transmission has an input shaft 10, which is formed integrally with a fixed disk 12. On the shaft 10 axiai is displaceable, but non-rotatably connected to the shaft, a spacer plate 14 is arranged. An unillustrated looping means runs between the conical surfaces of the discs 12 and 14 and the conical surfaces of a further, not shown cone pulley pair.

At the rear of the travel plate 14, a cylindrical ring 16 is rigidly fixed in the radially outer region with two radially spaced walls in which a piston 18 operates, so that according to Figure 1 the right side of the piston 18, a first pressure chamber 20 is formed by the in the spacer 14 formed radial bores 22, an annular space 24 between the washer 14 and the shaft 10 and formed in the shaft 10 radial bore 26 and axial bore 28 can be acted upon by hydraulic pressure, which is variable for a translation adjustment.

The overall annular piston 18 is rigidly connected to a generally cup-shaped support ring wall 30, which in turn is rigidly connected to the shaft 10. On the inside, a ring-shaped component 34, which is formed with molding surfaces 32, is rigidly fastened to the support ring wall 30. - A -

Further, within the support ring wall 30, a generally annular sensing piston 36 is axially slidable sealing against the peripheral surface of the shaft 10 and an inner peripheral surface of the annular member 34. The sensing piston 36 is formed with a projection directed toward the travel plate 14, on the rear side of which molding surfaces 38 are formed, which form counter surfaces to the shaping surfaces 32. Between the forming surfaces 32 and 38 are rolling elements, in the example shown balls 40, respectively.

Between the sensing piston 36 and the travel plate 14, a second pressure chamber 42 is formed, which is acted upon via a leading through the shaft 44 supply line with hydraulic pressure, wherein the hydraulic fluid via a likewise formed in the shaft 10 discharge line 46 is derivable.

The effective cross section of the leading into the second pressure chamber inlet opening 48 is determined by the axial position of the spacer plate 14. The free cross section of the outgoing from the second pressure chamber discharge opening 50 is determined by the position of the sensing piston 36. The sensing piston 36 projects with circumferentially preferably equally spaced axial arms 52 through recesses of the support ring wall 30 therethrough. The radially outer surfaces of the arms 52 are provided with axially and radially directed teeth, which are in engagement with an internal toothing of an input gear 54, which is mounted on an outer shell 56 of a bearing generally designated 58 axially substantially immovable.

The structure and function of the previously described cone pulley pair are known per se and are therefore explained only briefly:

In torque acting on the sensing piston 36 from the rotationally driven input gear 54, this torque is transmitted via the forming surfaces 38, the balls 40 and the forming surfaces 32 to the support ring wall 30 and thus the shaft 10. The mold surface are designed such that the sensing piston 36 moves to the right with increasing torque according to FIG. 1, so that the discharge opening 50, which is not completely covered by the sensing piston in the basic or initial position of the cone pulley pair shown in FIG is closed. Figure 2 shows the arrangement of Figure 1 at very high torque, in which the sensor piston is moved as far as possible to the right and the discharge opening 50 completely covered. With decreasing effective size of the discharge opening 50, the pressure in the second pressure chamber 42 increases, so that acts on the travel plate 14 a dependent on the input torque contact pressure. According to the invention, a support ring 60 is provided for supporting the free ends of the arms 52 of the sensing piston, which abuts against the radial inner sides of the end portions of the arms 52 and urges them outwardly so that the outer teeth of the arms are forced into secure engagement with the internal teeth of the input gear 54 become.

The arms 52 are, as shown, advantageously formed on a welded to the sensing piston ring part, from which they protrude axially. In this way, the welding of the arms and the ring member is relieved of directly acting on the arms in the circumferential direction bending forces.

Figures 3 and 4 show a section of the circled in Figures 1 and 2 area with the support ring 60 and the free end portions 62 of the arms 52, wherein in each case only one arm of advantageously at least three arms is shown.

In Figures 3 and 4, the external teeth 64 of the arms 52 is visible, which is in engagement with the non-referenced internal teeth of the input gear 54 in engagement. As can be seen from FIGS. 1 and 2, the external toothing 64 can shift axially relative to the internal toothing, so that the axial displaceability of the sensing piston is ensured.

According to FIG. 3, the inside of the end region 62 of each finger 52 is provided with a recess 66 which ends in a nose surface 68 at the end. The support ring 60 has a radially outwardly facing outer surface 70, which is the recess 66 correspondingly, but formed with oversize, and merges via a Vorzentrierungsstufe 72 in the end face of the support ring.

The cross section of the support ring 60 is advantageously designed such that the support ring merges with a rotation of 180 ° about a diameter in itself, that can be inserted from both sides into the circumferentially spaced fingers 52. The radial diameter of the Vorzentrierungsstufe 72 of the support ring 60 is slightly smaller, for example, by about 0.05 mm smaller than the smallest diameter of the nose surface 68, so that the support ring 60 centered when pushed onto the front ends of the arms 52 itself. Upon further sliding of the support ring 60 on the arms 52 whose end portions 62 are expanded until the support ring 60 is inserted into the recess 66 and the end portions 62 spring back, so that the nose surfaces 68 engage behind the outer surface 70 of the support ring 60 and snap. The excess of the largest diameter of the Sense surface 70 of the support ring 60 with respect to the largest inner diameter of the recess 66 is for example of the order of 0.15 mm.

As can be seen, the support ring 60 is in the inserted state in the fingers 52, preferably axially slightly outside the outer teeth 64, in the region of the fingers 52 are formed radially larger in thickness than in their end portions 62nd

For a stabilization of the fingers 52 not only in the radial direction but also in the circumferential direction, the outer surface 70 and the inner surface of the recess 66 can be knurled in the axial direction.

With the support ring according to the invention, it is possible to press back delays of the arms 52 in previous processing steps to a correct degree, so that a secure engagement of the teeth of the arms is ensured with the input wheel.

When toothing the arms a tight tolerance relative to the later joining surface with the support ring (recess 66) can be maintained. Regardless of subsequent delays of the arms, the toothed arms are pressed by the support ring used in its correct position.

In the example described, the support ring does not require additional space since it is located within the thinned end portions of the arms within an annulus formed between the bearing 58, the arms 52, and a seal carrier.

The attachment of the support ring on the described snap connection has against mechanically rigid connections, such. Welding, the advantage that no welding or soldering between the support ring and the arms is possible on nearly finished pair of discs and due to forced movements between the support ring and the arms in a cohesive connection extremely high forces occur.

The snap connection can be formed in a variety of ways, for example, a narrow snap-on nose can be formed on the support ring, wherein a radial support is given left and right of the nose. Alternatively, a wide snap-on nose can be formed on the ring, wherein the radial support takes place directly on the nose, as shown in Figures 3 and 4, and the snap takes place on both sides of the nose. To avoid chip formation, all edges will advantageously be rounded.

When mounting the support ring, it is advantageous to monitor during assembly a force-displacement curve when inserting the ring in the fingers, so that a perfect snap connection is ensured.

To optimize the snap geometry, it may be advantageous to deviate from the symmetrical design of the support ring, in which an assembly from both sides is possible.

The arms rigidly connected to the sensing piston are advantageously case hardened or carbonitrided. The support ring is advantageously made of steel, a tempering steel, for example ETG100 with Rm «1000 MPa without further heat treatment, case hardened steel, hardened or carbonitrided.

It is advantageous to use the support ring already for measuring the soft machined formed with the toothed arms component.

Furthermore, it is advantageous to use the support ring already during the heat treatment process to reduce distortion.

In the described embodiment, the arms 52 are externally toothed, so that the support ring 60 is disposed within the arms. Alternatively, the arms can be internally toothed and interact with an external toothing of the input wheel. The support ring is then disposed radially outward of the arms and urges them in meshing engagement with the input gear.

LIST OF REFERENCES

input shaft

hard disk

movable disk

cylinder ring

Piston first pressure chamber

drilling

annulus

Radiaibohrung

axial bore

Support ring wall

Form surface annular member

sensing piston

form surface

Ball second pressure chamber

supply

derivation

supply port

discharge port

poor

input gear

outer shell

camp

support ring

end

external teeth

recess

nose area

outer surface

Vorzentrierungsstufe

Claims

claims

1. Conical pulley pair for a conical pulley, soft conical pulley pair includes: an input shaft (10) which is rigidly connected to a fixed disc (12), an axially displaceable on the shaft and non-rotatably mounted washer (14), a torque sensing device with a rigid with the shaft connected forming surface (32) and a further molding surface (38) which is rigidly connected to a shaft, which is axially displaceable relative to the shaft and rotatable sensing piston (36), which forming surfaces are formed such that in a change of between the sensing piston and the effective torque disc removes the axial position of the sensing piston by rolling rolling elements (40) disposed between the forming surfaces on the forming surfaces, which sensing piston (36) is circumferentially spaced apart axially directed arms (36) on its side remote from the displacement plate (14). 52) provided with axial toothings (64 ) which is in engagement with an axial circumferential toothing of a rotatably drivable input wheel (54) mounted rotatably and substantially axially non-displaceably on the shaft (10), and a support ring (60) which projects radially on the toothings of the arms opposite side in abutment with the arms and urges the teeth of the arms in engagement with the peripheral teeth of the input gear.

2. conical disk pair according to claim 1, wherein the toothings (64) of the arms (52) of the sensing piston (36) is formed on the radially outer side.

3. conical disk pair according to claim 1 or 2, wherein the support ring (60) at the free end portions (62) of the arms (52) rests.

4. cone pulley pair according to one of claims 1 to 3, wherein the support ring (60) does not overlap the teeth (64) of the arms (52).

5. cone pulley pair according to one of claims 1 to 4, wherein the support ring (60) is attached to the arms (52) by means of a snap connection.

6. cone pulley pair according to one of claims 1 to 5, wherein the support ring (60) is symmetrical with respect to a rotation through 180 ° about an axis containing a diameter of the support ring.

7. cone pulley pair according to one of claims 1 to 6, wherein the support ring (60) is formed at its end faces with a Vorzentrierungsstufe which is pushed onto the free ends of the arms (52) of the sensing piston (36) with play.