WO2009065716A1

WO2009065716A1 - Polyamide-polyethylene material mixture for tensioning systems

Info

Publication number: WO2009065716A1
Application number: PCT/EP2008/064770
Authority: WO
Inventors: Bernd Hartmann; Thomas Rasche
Original assignee: Schaeffler Kg
Priority date: 2007-11-21
Filing date: 2008-10-31
Publication date: 2009-05-28
Also published as: EP2222982A1; DE102007055664A1

Abstract

The invention relates to a traction mechanism drive (1) of an internal combustion engine, said drive being configured particularly as a belt drive, comprising a drive wheel and at least one driven wheel, which are connected by a traction mechanism, in particular a belt. A tensioning system (8a) having an integrated damping mechanism is provided for achieving sufficient initial tension of the traction mechanism. A stationary friction cone (12), which is made from a polyamide-polyethylene material mixture and on which a pivot arm (13) pressurized by a torsion spring (16) can be pivoted over a hub (14), acts as a damping mechanism, wherein a receptacle (15) of the hub corresponds to the jacket contour of the friction cone (12).

Description

Name of the invention

Material mixture of polyamide-polyethylene for clamping systems

description

Field of the invention

The invention is directed to a traction mechanism drive, in particular designed as a belt drive, which is intended for an internal combustion engine and has a driven wheel and at least one drive wheel. The traction mechanism further includes a tensioning system and at least one deflection or guide element, wherein the output gear and the drive wheel and all connected to the clamping system or the deflection or guide element pulleys are connected via a traction means, preferably a belt.

Background of the invention

Traction drives of the aforementioned embodiment are used in internal combustion engines to drive auxiliary equipment, such as generator, water pump, air compressor or servo pump. Another traction mechanism drive of the internal combustion engine, also referred to as a control drive, is provided for driving the camshaft via which gas exchange valves of the internal combustion engine are actuated. Both traction mechanisms include traction means, in particular belts, which are guided over all pulleys or sprockets associated with the traction mechanism drive. The traction mechanism drives of the internal combustion engine are further associated with tensioning devices and deflection or guide elements, which are designed in particular as deflection rollers or guide rails, which ensure a pretensioning of the traction means and thus a largely slip-free drive. Furthermore, the traction mechanism drives include damping measures in order to dampen the uneven drive caused by the rotational irregularity of the internal combustion engine. fen. For this purpose, the Zugmitteltheben hydraulically or mechanically acting clamping systems are associated with integrated damping device on the example, an adjusting movement of the associated with the tensioning system roller is effectively damped, which is advantageous in terms of noise and wear of the traction drive.

From DE 696 10 811 T2, a traction mechanism layout is known in which the traction means, a belt, the crankshaft pulleys, a water pump and other ancillary components including a deflection roller encloses. The document also shows the construction of a clamping system for the traction drive with integrated damping device. This device is provided with a cylindrical frictional element which dampens spring-loaded actuating movements of the swivel arm, which is the end via a roller with the traction means in combination. The swivel arm is rotatably limited by a plastic bearing slide bearing relative to the stationary component.

For traction drives that are exposed to the atmosphere and at the same time non-lubricated, PTFE is added to the plastics used for dry sliding bearings and friction linings. This lubricant is in the form of smallest lamellae, platelets or particles in the base material, in particular polyamide. In the production of these components, a spray skin is produced during the plastic splicing process. This spray skin forms a closed surface of the finished part, enclosing the solid lubricant, PTFE, under the skin. As a result, the effect of the dry lubricant (PTFE) only comes into effect when the sprayed skin has worn out. Consequently, a disadvantageous noise development in the break-in phase of these clamping systems occurs. Object of the invention

The invention has for its object to represent for a traction drive basic materials whose stored dry lubricants are effective from the beginning in the operating state.

Inventive solution

The aforementioned problem is inventively achieved by the features of claim 1.

The invention provides that at least individual rotatable, pivotable or displaceable components of the clamping system made of polyamide Polyethylenmatehalien or a polyamide-polyethylene material mixture. This provided for a sliding, friction, deflection or guide element material or material mixture in which the solid lubricant is chemically bonded, causing the dry lubricant in the finished component also attaches to the surface of the component. As a result, a disadvantageous inlet effect is reduced or eliminated, as a result of which a noise-optimized clamping system is set in the operating state from the beginning. In addition to a constant over the entire life level noise level, the material mixture according to the invention does not adversely affect the damping or vibration behavior of the clamping system.

In addition to the sliding or friction element of a clamping system, the invention further includes, also other components of the traction mechanism, for example, a tension roller or pulley and guide or deflecting rails made of a polyamide-polyethylene material mixture. Thus, all with a storage, damping or leadership related components of the traction drive from the material mixture according to the invention can be produced, whereby even in the start-up phase a friction-optimized traction mechanism, connected to a low noise level can be realized. The advantageous properties of the material mixture according to the invention are the solid lubricant which is bound chemically in the material, as an alternative to previously used tribological materials, in which the solid lubricant (PE) is uncrosslinked and very coarsely distributed in the matrix.

The polyamide-polyethylene materials are described in DE 10 2005 946 571 A1. The document is limited to the chemical composition of this material mixture as well as to a method for producing these materials. On this basis, the present invention relates to the use of polyamide-polyethylene materials for components of traction drives.

Further advantageous embodiments of the invention are the subject of the dependent claims 2-12.

As preferred polyamide-polyethylene component for the materials according to the invention is preferably PA-66, PA-46, PA-6T, PA-6 / 6T and / or PPA, which is added in pure form or as a mixture. + Text from 044 (Leibniz)

A preferred material mixture provides a ratio of polyamide to polyethylene of> 80:20. A preferred material mixture for components of traction drives contains additives and / or reinforcing products such as reinforcing fibers or aramid fibers.

In order to ensure a sufficient dry lubricant content, the polyamide-polyethylene mixture according to the invention includes a proportion of 5-30% PTFE.

Advantageously, the material according to the invention enables a complete substitution of previous materials such as PA46 PTFE. A material change therefore requires no structural or geometric adaptation in a clamping system or other components of the traction drive. The invention further relates to components of the clamping system with a sanding transferable transferable. The polyamide-polyethylene material mixture according to the invention is combined with a base material or carrier material. As a permanent bond of these different materials is preferably a cohesive connection, such as gluing or ultrasonic welding.

For a mechanical clamping system, it is preferable to manufacture a disk-like designed damping and / or friction element made of a polyamide-polyethylene material. In addition to the sliding bearing of the pivot lever is made of the material mixture according to the invention via which the pivot lever relative to the stationary base part is rotatable.

Advantageously, the material mixture according to the invention offers the possibility also of producing a disc shape deviating designed damping and / or friction elements, such as a conically shaped socket or a wedge ring, which is intended for cone clamping systems. The use of polyamide-polyethylene is further without exception suitable for the production of different components of the traction mechanism, which exert a relative movement with sliding partners and / or arranged rotatable or pivotable. These include, for example, the running jacket of a deflection roller or a tensioning system in connection with a tensioning roller, and guide rails or slide rails on which the traction means is guided or deflected. The material mixture is also suitable for elastic bearing eyes in the region of articulation points, via which a clamping system or a guide rail is fastened to the internal combustion engine.

Brief description of the drawings

The invention will be explained in more detail below with reference to drawings of several embodiments. It shows:

Figure 1 shows schematically the layout of a traction mechanism drive; Figure 2 is a partially sectioned perspective view of a mechanically damped clamping system with integrated Reibkonus;

Figure 3 is an exploded view of a pivot lever tensioning system incorporating balanced mechanical damping;

Figure 4 shows the structure of a pivot-damped clamping system;

Figure 5 is an exploded view of a hydraulically damped clamping system.

Detailed description of the drawings

1 shows a traction mechanism drive 1 of an internal combustion engine, in which a traction means 2, in particular a belt connects a plurality of pulleys, which are inter alia with a crankshaft, individual units or tensioning or deflection in combination. The drive of the traction mechanism drive 1 via a connected to the crankshaft 3 in connection, rotating in a clockwise pulley. The traction mechanism drive 1, also referred to as a unit drive, further includes a water pump 4, an air conditioning compressor 5 and a generator 6 whose associated pulleys are at least partially enclosed by the traction means 2. The arrangement or position of the individual units results in a guide of the Zugmit- means 2, whereby the individual output gears of the units are arranged in the Zugtrum 7. To ensure a sufficient bias of the traction means 2 is a clamping system 8, which is associated with a slack side 9 of the traction mechanism drive 1. Furthermore, the traction mechanism drive 1 includes a deflection roller 10 whose position directly influences the degree of wrap of the traction means 2 on the pulleys of the generator 6 and of the tensioning system 8. The further FIGS. 2 to 5 show different variants of tensioning systems with which the pretensioning of the traction means 2 in a traction mechanism drive 1 can be directly influenced. The description and the function of these known clamping systems is limited as far as possible to the components produced from the polyamide-polyethylene material mixture according to the invention.

FIG. 2 shows a partial section of the construction of a mechanically damped clamping system 8a. The clamping system comprises a stationary housing 11, which encloses a friction cone 12, on which a pivot arm 13 is rotatably limited. For this purpose, the swivel arm 13 in the region of a hub 14 has a receptacle 15 corresponding to an outer contour of the friction cone 12. A torsion spring 16 inserted between the housing 11 and the hub 14 causes a rotation of the pivot arm 13 in a direction of rotation biasing the traction means 2. In synchronism, an axial force of the torsion spring 16 causes a displacement of the hub 14 and thus of the pivot arm 13 in a directed to the Reibkonus 12 position, whereby at the same time sets a damping of actuating movements of the pivot arm 13. The one made of polyamide polyethylene materials Reibkonus 12 containing damping device ensures effective low-noise damping from the beginning. The arranged between an end-side disc 17 and the housing 11 Reibkonus 12 serves to receive the hub 14 of the pivot arm 13. By means of a not shown in Figure 2 mounting screw inserted into the central opening 18 of the disc 17 and guided through the housing 11 and, for example screwed into the crankcase of an internal combustion engine, the clamping system 8a is attached. At the free end of the pivot arm 13 is provided with a rotatably mounted tension roller 19, which cooperates with the traction means 2 in the installed state. Depending on demand, it is also suitable for the tensioning roller 19 to produce these from a polyamide-polyethylene material mixture.

The tensioning system 8b shown in FIG. 3 shows a balanced, mechanically damped tensioning system in which the torsion spring 20 is held in a pot-like manner. taltet housing 21 is fixed with a first spring end. The further spring end of the torsion spring 20 is fastened to a cylindrical or tubular friction element 22, which abuts the outside in the installed state on an inner wall of the housing 21 and is further fixed to the pivot lever 23. The structure of the clamping system 8b further provides a plain bearing bush 24, which is inserted in the installed state in a hub 25 of the pivot lever 23 and supported on the pivot lever 23 via an end-side board frontally. To achieve optimal friction conditions, the friction element 22 and the plain bearing bush 24 are preferably made of a polyamide-polyethylene material mixture. In addition, it is advisable to produce the tension roller 26 from this aforementioned material mixture.

A pivot point-damped clamping system 8c shows the figure 4. For targeted damping of actuating movements of the pivot lever 27 has a wedge ring 29 at the pivot point 28, the cone contour cooperating with a corresponding contact surface within the pivot lever 27. In the installed state of the clamping system 8c, in which all axially offset components shown are assembled and fixed by a central, not shown in Figure 4 fixing screw, a wave spring 30 exerts via an intermediate ring 31 an axially and radially acting force on the wedge ring 29th out, which dampens immediately adjusting movements of the pivot lever 27. A receptacle 32 in conjunction with a bore 33 of the pivot lever 27 is intended for a tension roller not shown in Figure 4. At the free end of the pivot lever 27 forms a mounting bracket 34 to which a spring element is fixed in the operating state of the clamping system 8c. In order to optimize the friction of the clamping system 8c, this has two friction bearings 35a, 35b in the region of the pivot point 28 and a friction disk 36 on the side of the pivot lever 27 facing away from the wedge ring 29. According to the invention, the components, the wedge ring 29, the sliding bearings 35a, 35b and the friction disk 36 are made of polyamide-polyethylene materials. FIG. 5 shows a hydraulically damped tensioning system 8d with the following construction. An over two axially spaced slide bearings 37a, 37b pivotable toggle 38 is provided at a first end for receiving the tension roller 39. At the other end of the toggle lever 38, a hydraulic tensioning element is articulated in a known construction. For this purpose, the clamping element 40 is provided in the region of the articulation points with bearing eyes 41 a, 41 b. Both the bearing lugs 41 a, 41 b and the slide bearings 37 a, 37 b are made of a polyamide-polyethylene polyethylene material.

LIST OF REFERENCE NUMBERS

1 traction drive

2 traction means

3 crankshaft

4 water pump

5 air conditioning compressor

6 generator

7 train turn

8 clamping system

8a clamping system

8b clamping system

8c clamping system

8d clamping system

9 empty run

10 pulley

11 housing

12 friction cone

13 swivel arm

14 hub

15 recording

16 torsion spring

17 disc

18 opening

19 tension roller

20 torsion spring

21 housing

22 friction element

23 pivot lever

24 plain bearing bush

25 hub

26 tension roller

27 pivot lever 28 pivot point

29 wedged ring

30 wave spring

31 intermediate ring

32 recording

33 hole

34 mounting angles

35a slide bearing

35b sliding bearing

36 friction disc

37a slide bearing

37b sliding bearing

38 toggle lever

39 tensioning roller

40 clamping element

41 a bearing eye

41 b bearing eye

Claims

claims

1. Traction drive, in particular belt drive, used in an internal combustion engine, comprising a drive wheel and at least one driven wheel, and at least one tensioning system (8, 8a-8d) with integrated damping device and at least one guide element, which is connected via a traction means (2). , are preferably connected to a belt, characterized in that at least individual rotatable, pivotable or displaceable components of the clamping system (8, 8a-8d) and / or the guide element, in particular sliding elements or friction elements made of polyamide-polyethylene materials or a polyamide-polyethylene Material mixture are made.

2. traction drive according to claim 1, characterized in which as the polyamide component PA-66, PA-46, PA-6T, PA-6 / 6T and / or PPA are present in pure form or as a mixture.

3. Traction drive according to claim 1, characterized in that the polyamide polyethylene materials as a compatibilizer includes further reactive additives.

4. traction drive according to claim 1, characterized in that the material mixture includes reinforcing fibers in additional amounts of 1 to 30 in the Ma.-%, based on the polyamide-polyethylene material.

5. Traction drive according to claim 1, characterized in that the polyamide-polyethylene material mixture contains a proportion of 5-30 PTFE.

6. Traction drive according to claim 1, characterized in that the polyamide-polyethylene material mixture allows a complete substitution of previously used materials.

7. Traction drive according to claim 1, characterized in that the polyamide-polyethylene material mixture is applied as a sandwich construction on a carrier material.

8. traction mechanism according to claim 1, characterized in that a mechanical clamping system (8, 8a-8d) includes a made of a polyamide polyethylene material damping and / or friction element includes.

9. traction mechanism according to claim 8, characterized in that a friction disc (36) or a friction element (22) is provided as a damping and / or friction element.

10. traction mechanism according to claim 8, characterized in that a wedge ring (29) or a conically shaped socket as a damping or

Frictional element is provided.

11. traction mechanism according to claim 1, characterized in that as a sliding bearing (35 a, 35 b) for a clamping system (8 c) provided socket at least partially made of a polyamide-polyethylene

Material mixture is made.

12. traction drive according to claim 1, characterized in that a designed as a hinge point bearing eye (41 a, 41 b) of the clamping system (8 d) is made of a polyamide-polyethylene material mixture.