DE102005062260A1 - Hybrid belt for continuously variable transmission has elasticity in range 5,000 to 10,000 N/mm(2 - Google Patents

Abstract

A continuously variable transmission has a hybrid belt drive with two belts incorporating numerous homogenous ribs (10). The belt is made of an elastomer and incorporates longitudinal tensile core reinforcements (12). The rib (10) elasticity at 20C is in the range 5,000 to 10,000 N/mm(2. The ribs are fabricated of e.g. polyamide or polyphenylsulfide, strengthened with glass fiber, aramide fiber or carbon fiber.

Description

The The invention relates to a hybrid V-belt - a so-called hybrid ring - and at least two V-belt pulleys existing drive assembly according to the preamble of claim 1.

The power transmission in continuously variable transmissions (CVT) with Hybrid rings made of tension members and block-like support elements exist, is determined by the quality the frictional force transmission between the support elements of the hybrid ring and the associated V - belt pulleys (conical disks, variator disks), which are in the Usually made of aluminum alloys or steel, determined.

Around the tribological stress on the at the frictional power transmission involved contact surfaces by pressing and sliding speed especially on the hybrid ring preferably evenly distributed, is a good shot of the hybrid ring and elements involved Conical disks on each other in terms of wedge angle desirable. This requires on the one hand a precise production as a prerequisite, on the other hand, there are games and elastic deformations in the transmission inevitable. While the games, z. B. in the guides of each movable disc, over the operating time are still nearly constant, the elastic occur Deformations in the gearbox on the shafts and especially on the variator discs dependent on from the operating point, d. H. dependent on from the ruling powers, on, as well as aluminum alloys and steel a certain, though have low elastic compliance.

To tune the wedge angle of a wrap on the wedge angle on the metal cone pulleys z. In JP 07 083315 A (Aichi Mach Ind Co Ltd) suggested slightly different wedge angles in the unloaded state. A disadvantage of this concept, however, is that such a presetting of the corresponding wedge angle to each other depending on the disc stiffness and the forces to be transmitted is well possible only for one operating point; in all other combinations only a moderate compromise will be possible.

The lined up on the at least one tension member support elements are typically made in the application of resinous plastics and are each provided with at least one metallic reinforcing body.

By the metallic reinforcing insert becomes the rigidity of the support elements elevated. This increased Stiffness at the same time represents a certain deformity dar. Due to this deformation unwillingness of the support elements arise increased claims to the accuracy and rigidity of the associated conical disks on which the hybrid V-belt should run.

Around the support elements and the associated pulleys with respect to the shape shaping especially regarding the compliance of their flanks to better match In the context of the above problem, the question of whether instead of metal-reinforced support elements massive support elements are more suitable.

Massive embodiments of plastic support elements are previously known (see, for example, US Pat. EP 0 135 710 B1 and EP 0 257 646 B1 ). The support elements are constructed in such a way that the inclination of their flanks corresponds to the flank inclination of the associated pulleys. This is obviously only in the design position, ie in the unloaded state, the case. When using larger tensile forces a certain yielding and thus a deformation of the relatively rigid pulleys can not be avoided. This yielding of the disk flanks leads to an increase of the flank (opening) angle. Since the flank angle of the support elements changed only minimally under load, the change of the disk flanks under load means an increasing mismatch between belt and pulley. Optimal intervention does not seem to be guaranteed.

Task of invention

The The object of the invention is the support elements generic hybrid belt and their associated pulleys at different load conditions to coordinate better.

Solution and advantages

The Material properties of the plastic support elements are according to claim 1 selected that is due to the rigidity of the plastic, which is far below that of the metallic disc materials lies, the hybrid ring almost automatically the metallic, deformed under load conical discs and adapts on rising forces reacts with increasing elastic deformation, and so the deformations compensates for the metal discs. This is an optimal contact surface between Hybrid ring and cone pulley ensured, allowing a uniform loading by surface pressure and sliding speed over the contact surface of the blocks given by special choice of materials.

With the invention predetermined Material property of the plastic mass, namely the higher compliance, can the permissible Deformation of the conical disks are significantly increased. Besides, they are the manufacturing costs by eliminating the metallic reinforcing element and its handling significantly lower.

The In claim 1 and 2 required material properties are preferably with polyamide (6, 66, 46, partially aromatic) or polyphenylene sulfide realized.

Without to diminish the basic object of the invention, the homogeneous base material the plastic support element reinforced with glass, aramid or carbon fibers.

According to one Training is also proposed successive supporting elements alternately made of different materials. In this way, the a support elements be optimized for a low load on the belt / disc assembly while the other support elements especially to a stronger one Strain of the belt / disc arrangement are matched.

are the successively different support elements in their alternating Difference - eg. B. optically - sensible, then this sensibility for slip measurement and speed control be used.

drawings

One embodiment the inventive hybrid V-belt / disc arrangement will follow described. The attached Drawings show:

1 a longitudinal section through a belt / disc arrangement and

2 an axial section through a laid on a V-belt pulley hybrid V-belt.

description

In the 1 in longitudinal section shown hybrid V-belt / disc arrangement 2 consists of a hybrid V-belt 4 and two V-belt pulleys (conical disks, variator disks) 6 , The hybrid V-belt 4 has at least one endless tension member 8th and a plurality of supporting elements (blocks) arranged thereon 10 on. - Further details emerge 2 ,

The 2 shows an axial section through a on a V-belt pulley 6 launched hybrid V-belt 4 , In the embodiment shown here, the hybrid V-belt 4 two endless tension members 8th on. The tension members made of elastomeric material 8th are with drawstrings (cords) 12 strengthened. The tension members 8th are each in lateral slots of the support elements 10 inserted. As the 2 further shows, the support element is based 10 with its side flanks 10a . 10b on each one of the force transmission edges 6a . 6b the disc 6 , whereby both frictionally engaged with each other.

The support elements 10 are solid, ie they have no reinforcing inserts, z. As of metal, on. The support elements 10 are made of plastic. In order to achieve the deformation according to the invention, there are the support elements 10 preferably of polyamide or polyphenylene sulfide.

To the frictional engagement for different sized power transmissions between belts 4 and disc 6 To further improve is the deformation willingness of successive support elements 10 different sized. Is the difference between successive support elements 10 Sensitive, so the sensibility can be used to determine the belt slip, for controlling the belt tension and for speed control.

LIST OF REFERENCE NUMBERS

2

Hybrid V-belt / pulley arrangement, Belt / disc arrangement, drive arrangement

4

Hybrid V-belts, V-belts, hybrid belts, belts

6

V-belt pulley (s), Conical disc (s), variator disc (s), disc (s)

6a, 6b

Force transmitting flank (n) the pulley

8th

tension members

10

Supporting member (s), Block (blocks)

10a, 10b

Side edge (s) of the support element (the support elements)

12

tension cord (Pull cords, Corde)

Claims (6)

From a hybrid V-belt ( 4 ) and at least two pulleys ( 6 ) existing drive arrangement ( 2 ), wherein the hybrid V-belt ( 4 ) of at least one tension member ( 8th ) and a plurality of attached, made of a Kunststoffimaterial existing, solid and homogeneous support elements ( 10 ) is constructed, and wherein the at least one tensile carrier ( 8th ) consists of elastomer and with tensile strands ( 12 ), characterized in that the rigidity of the support elements ( 10 ) determining elastic modulus of the plastic material in the uniaxial tensile test at 20 ° C - in anisotropic material in at least one component - in a range of 5,000 to 20,000 N / mm ² . Drive arrangement according to Claim 1, characterized that the breaking elongation of the plastic material is over 1%. Drive arrangement according to claim 1 or 2, characterized characterized in that the plastic material polyamide (6, 66, 46, partially aromatic) or polyphenylene sulfide. Drive arrangement according to one of claims 1 to 3, characterized in that the plastic material of a Base material and a fiber reinforcement consists. Drive arrangement according to Claim 4, characterized that the fiber reinforcement takes place by glass, aramid or carbon fibers. Drive arrangement according to claim 5, characterized in that on the at least one tension member ( 8th ) of the hybrid belt ( 4 ) applied, successive support elements ( 10 ) alternately have different material properties.