GB2311569A

GB2311569A - A friction lining which is simple and cost-effective to manufacture

Info

Publication number: GB2311569A
Application number: GB9705872A
Authority: GB
Inventors: Hans-Dieter Elison; Martin Kraus; Wolfgang Reik
Original assignee: LuK Lamellen und Kupplungsbau GmbH
Current assignee: LuK Lamellen und Kupplungsbau GmbH
Priority date: 1996-03-27
Filing date: 1997-03-21
Publication date: 1997-10-01
Anticipated expiration: 2017-03-21
Also published as: FR2746875A1; FR2746875B1; BR9701511A; IT1290472B1; GB2311569B; ITMI970702A1; ZA972619B; GB9705872D0; MX9702183A; DE19712203A1; DE19712203B4

Description

FRICTION LINING The invention relates to a friction lining, more particularly for clutch discs, brakes or the like, and to clutch discs, brakes or the like equipped with same.

Furthermore the invention relates to a friction lining, more particularly for clutch discs or brakes, for example for motor vehicles, which is formed substantially circular ring shaped and consists of a substantially circular ring shaped support element and of friction material.

Friction linings of this kind are known from the prior art.

Friction linings where the friction material is applied on one side on a support element have with given friction lining mixtures a different thermal expansion and/or expansion as a result of moisture absorption of the friction material and support element. This fact can lead to the friction lining bulging or rising as a result of these expansion ratios so that it loses its flat or planar shape.

The object of the invention is to provide a friction lining as well as a clutch disc with a friction lining which is simple and cost-effective to manufacture and has only slight or no distortion. Furthermore a friction lining of this kind is to meet with regard to its properties the demands placed on it regarding burst strength and rigidity as well as the friction and wear properties.

According to the invention this is achieved with a friction lining, more particularly for clutch discs or brakes, by way of example for motor vehicles, which is designed substantially circular ring shaped and consists of a substantially circular ring shaped support element and a friction material in that the friction lining consists both of the support element and also of a friction material substantially embedding this support element, the friction lining has receiving or shaping areas to fix the friction lining on a fixing element wherein the substantially circular ring shaped support element is mounted substantially in the middle of the friction lining, seen in the axial direction.

It can be advantageous with a friction lining of this kind if the support element has a substantially circular ring shaped base area which is mounted substantially in the middle of the friction lining, seen in the axial direction.

Furthermore it is advantageous if the friction material of the friction lining, viewed in the axial direction, is applied or provided both in front of and behind the substantially circular ring shaped base area of the support element. It is thereby achieved that the support element is mounted substantially between a front and rear friction lining layer.

With a friction lining according to the invention it is advantageous if the expansion, viewed in the axial direction, of the friction lining layer in front of the base area of the support element is substantially equal to the expansion, viewed in the axial direction, of the friction lining layer behind the support element.

Furthermore it can be advantageous if the expansion d1, viewed in the axial direction, of the friction lining layer in front of the base area of the support element is substantially larger than the expansion d2, viewed in the axial direction, of the friction lining layer behind the support element. It can thereby be expedient if the ratio of the expansion d1 to the expansion d2 is in the range from 4 to 1, preferably from 2 to 1. This means that the friction lining layer which serves as the friction face is four times to once time as thick as the back of the friction lining.

It can be expedient if the expansion d11 viewed in the axial direction, of the friction lining layer in front of the base area of the support element, viewed in the axial direction, is substantially smaller than the expansion d2 , viewed in the axial direction of the friction lining layer behind the support element. It can thereby be advantageous if the ratio of the expansion d1 to the expansion d2 is in the range from 1 to 0.3, preferably from 1 to 0.5.

According to the idea according to the invention it can be advantageous in the case of a friction lining, more particularly for clutch discs or brakes, by way of example for motor vehicles, which is designed substantially circular ring shaped and consists of a substantially circular ringshaped support element and a friction material substantially embedding this support element, with receiving or forming areas for fixing the friction lining on a fixing element, if the substantially circular ring-shaped support element has a circular ring shaped base area and at least one further area which has an expansion in the axial direction so that this area protrudes axially from the circular ring shaped base area of the support element.

It can likewise be expedient if the radially outer marginal area of the circular ring shaped support element protrudes axially opposite the base area of the support element.

Furthermore it can be expedient if the radially inner marginal area of the circular ring shaped support element protrudes axially opposite the base area of the support element. The radially inner or outer marginal area of the support element can protrude to the same or different extent in the axial direction.

It can furthermore be expedient if in the base area of the circular ring shaped support element at least one zone is formed, such as curved, raised or dished so that it protrudes axially opposite the base area of the support element. Such areas can be used for fixing, such as rivetting, the friction lining on a fixing element wherein it is expedient if the area has at least one opening. The base area can be formed resilient in a suitable manner.

Furthermore it can be expedient if at least two zones of the base area of the circular ring shaped support element, which protrude in the axial direction, are spread evenly, viewed over the circumference of the circular ring shaped support element. It can be advantageous if at least one zone in the base area of the circular ring shaped support element protrudes axially and is substantially circular ring shaped or oval. It can be particularly expedient if at least one zone in the base area of the circular ring shaped support element protrudes axially and is substantially angular such as square or rectangular.

According to the idea according to the invention it can be advantageous if at least one zone in the base area of the circular ring shaped support element which protrudes axially, viewed circumferentially, has a circular ringshaped contour. It is thereby expedient if the at least one circular ring-shaped zone protruding axially is mounted coaxial with the axis of the friction lining.

It can be advantageous if openings are formed, such as punched, pierced or drilled in the base area of the circular ring shaped support element. Furthermore it can be expedient if marginal areas of at least one opening are raised in the axial direction in the circular ring shaped support element.

Furthermore it can be advantageous if in the base area of the circular ring shaped support element openings, such as holes, are formed with different cross-section or with different expansion.

It can likewise be expedient if the areas or zones which protrude axially opposite the circular ring shaped base areas of the support element have openings.

According to the idea according to the invention it is expedient if the expansion of the circular ring shaped support element, viewed in the radial direction is less than the expansion of the friction lining, viewed in the radial direction. It can likewise be expedient if the expansion of the support element, viewed in the radial direction, is less than the radial expansion of the friction lining, but greater than a quarter of the radial expansion of the friction lining. Furthermore it can be expedient if the expansion of the circular ring shaped support element, viewed in the radial direction is equal to the expansion of the friction lining, viewed in the radial direction.

According to the invention it is expedient if the expansion of the circular ring shaped support element viewed in the radial direction is greater than the expansion of the friction lining, viewed in the radial direction.

According to the idea according to the invention it can be expedient if the substantially circular ring shaped support element is made of metal, such as for example steel or aluminium. It is likewise expedient if the substantially circular ring shaped support element is made of plastics, such as for example fibre-reinforced such as glass fibre reinforced, plastics.

According to a further idea according to the invention it can be expedient in the case of a clutch disc more particularly for a friction clutch which supports on its outer circumference at least one friction lining, with an input part, such as an entrainment disc, which where applicable is connected rotationally secured to a counter disc, and the entrainment and counter disc form the input part of a torsion vibration damper, wherein a circular ring shaped component part such as a flange serves as the output part of the torsion vibration damper and transfers a transferable torque on the output side directly or where applicable through a further torsion vibration damper to the hub of the clutch disc, wherein between the flange and the clutch disc hub can be provided a torsion vibration damper, for example for the idling area, if the friction linings of the clutch disc which serve as the input part consist of a support element and a friction lining layer and the support element is mounted substantially in the middle of the friction lining and the support element has areas which project radially opposite a base area of the support element.

It can likewise be advantageous with a clutch disc more particularly for motor vehicles if the friction linings of the clutch disc are formed according to one of claims 1 to 27.

The invention will now be explained with reference to the drawings in which: Figure 1 shows a sectional view through a clutch disc; Figure 2a shows a section through a friction lining; Figure 2b shows a section through a friction lining; Figure 3 is a view of a friction lining; Figure 4a shows a support element of a friction lining; Figure 4b shows a section through a support element according to Figure 4a; Figure 4c shows a section through a support element according to Figure 4a; Figure 4d shows a section through a support element according to Figure 4a; Figure 5 shows a support element of a friction lining; Figure 6 shows a support element of a friction lining; Figure 7a shows a support element of a friction lining; Figure 7b shows a section through a partial area of Figure 7a; Figure 7c shows a section through a partial area of Figure 7a; Figure 7d shows a detail of Figure 7a; and Figure 8 shows a support element of a friction lining.

Figure 9a shows a section through a friction lining; Figure 9b shows a section through a friction lining; Figure 9c shows a section through a friction lining; Figure 10a shows a plan view of a friction lining; Figure 10b shows a plan view of a friction lining; Figure 10c shows a section through two mounted friction linings and Figure 10d shows a section through two mounted friction linings.

Figure 1 shows a clutch disc 1 with substantially circular ring shaped friction linings 2 mounted radially on the outside wherein two friction linings are arranged substantially coaxial with each other wherein the friction faces 2a and 2b point away from each other in the opposite direction. The friction linings 2 are resiliently connected together by means of resilient elements such as spring segments 3 wherein a fixing of the friction linings on the entrainment disc 4 can be guaranteed through the resilient elements such as spring segments 3. The spring segments are connected to the entrainment disc in their radially inner area 3a by means of for example a rivet connection 5. The entrainment disc represents the input part of a torsion vibration damper wherein the entrainment disc 4 is connected rotationally secured to a counter disc 6. The rotationally secured connection between the entrainment disc 4 and counter disc 6 can be achieved for example by means of spacers 7 which undergo in their outer area 7a, 7b a material deformation to fix the entrainment and counter discs.

Through the biasing of the energy accumulators 8 which are arranged in the circumferential direction and are mounted in windows of the entrainment and counter discs a component part such as a circular ring shaped component 9 such as a flange is arranged so that the energy accumulators are received in windows 10 of the flange. During turning of the flange opposite the entrainment and counter discs 4, 6 the energy accumulators 8 become biased, viewed circumferentially. A further torsion vibration damper 11 can be mounted in the radially inner area of the flange 9 wherein the output part of the second torsion vibration damper 11 such as an idling damper or of the flange are in connection with the output part such as hub 12 of the clutch disc wherein torsional play can be provided between the flange 9 and hub 12 with or without biasing of the energy accumulator 13 of the torsion vibration damper 11.

The clutch disc can furthermore have friction devices such as for example friction elements such as friction rings or discs 14,15 and 16. The friction discs 14, 15 and/or 16 are biased in the axial direction by energy accumulators 17, 18 such as for example plate springs in order to achieve a friction action with relative rotation between the friction faces of the friction rings and the counter friction faces.

The friction rings thereby as a rule have a positive or force-locking connection with a supporting element wherein they are formed rotatable in the area of the friction faces.

The friction ring 15 can for example carry out a sliding or friction movement relative to the flange 9 wherein the friction ring as a rule is formed rotationally secured with the plate spring 17 which engages in the counter disc and is thus held rotationally secured.

Figure 2a shows a section through a friction lining 2 according to the invention wherein the friction lining has a friction face 2a and a face 2c opposite the friction face.

The friction face 2c passes in friction engagement with a counter friction face wherein the side face 2c of the friction lining comes into contact for example with a spring segment 3. The friction lining 2 consists substantially of friction material 100 and a support element 101. The support element 101 has a circular ring shaped area such as a base area 102 which is angled or bent or reformed in the axial direction in the marginal areas 103 and 104. The circular ring shaped elements 102 have furthermore openings 105 through which friction material extends or in which friction material is found wherein the friction material of the one side 106 is cross-linked with the friction material of the other side 107 in relation to the circular ring shaped element 102. A friction face of a flywheel or of a clutch pressure plate can serve for example as the counter friction face.

Furthermore openings or holes 104a can be formed in the angled marginal areas 103, 104 of the support element wherein these openings serve for the cross-linking or bonding of the radially outer marginal layers of the friction lining. This is advantageous because the connection or cross-linking between the friction material and support element is as a rule not so good as between the friction material areas together.

The angled radially inner and radially outer areas 103 and 104 of the support element 102 of the friction lining 2 can serve at the same time as spacers. The spacer function of the elements 103 and 104 can thereby be achieved in that the element 102 is placed in a machine or apparatus for pressing the friction linings so that the element 102 rests on the faces 103a and 104a and then the friction material of the side 106 is supplied in measured amount. This can take place if the material of side 107 has already previously been measured into the machine. It can however also be advantageous if the friction material passes through openings into the area 106, such as for example flows into same.

Furthermore an area 110 is worked or formed in the circular ring shaped element of the lining support 102 so that for example by deep drawing or by material reforming a potshaped bulge, dish or sinking of the material takes place.

This area is formed as a receiving or reforming area in order to fix the friction lining. In the area of the potshaped bulge or depression 110 is located a further opening 111 which is used in order to connect the friction lining 2 with a holding element in order to connect the friction lining rotationally secured by way of example with a clutch disc. A rivet connection can engage in the opening 111 of the deep-drawn area 110 in order to connect the friction lining 2 with a spring segment 3.

The circular ring shaped element 102 such as lining support is formed so that the circular ring shaped area 102 is arranged through the spacer action of the end areas 103 and 104 substantially in the centre area of the friction lining, viewed in the axial direction so that the thickness d1 of the friction lining layer in front of the circular ring shaped area is substantially equal to the thickness of the friction lining layer behind the circular ring-shaped element 102. The thickness D of the friction lining is thus divided into the thickness d1, the thickness d2 and the material thickness d of the element 102. The thickness d1 can in the new state be substantially equal to the thickness d2 wherein the thickness d1 can however also assume a three to four times the amount of the thickness d2. The element 102 is substantially a metal element of steel or of other metal such as for example aluminium or non-improved iron or plastics, with or without fibre reinforcement wherein the thickness d is in the range between 0.1 mm to 2.0 mm, preferably in the range between 0.2 to 1.0 mm. When using steel a thickness of 0.1 to 0.6 mm can be advantageous.

Preferably the thickness of the lining support or of the sheet metal can be from 0.2 mm or from 0.25 mm to 0.4 mm.

It is particularly advantageous for the friction lining if in the new state the thickness is substantially equal to the thickness d2. It is thereby reached that the friction lining is not or only minimally distorted or dished through a thermal expansion. With suitable friction material however thickness ratios d,/d2 of 4 to 0.33 are expedient.

The angled axially pointing areas 103 and 104 furthermore serve to increase the bending stiffness of the friction lining.

The radial expansion of the friction lining can as shown in Figure 2a be larger than the radial expansion of the circular ring shaped element 102, such as lining support.

In Figure 2b the radial expansion of the friction lining 2 is equal to the radial expansion of the lining support 1O2.

Likewise it can be advantageous if the lining support 102 projects for example in the radially inner area out of the friction lining in order to allow the friction lining in the area of these protruding areas to fix with for example an entrainment disc.

Furthermore in Figures 2a and 2b a groove 120 is shown which is worked such as formed in the friction lining in order to be able to carry the ground dust which arises through the rubbing of the friction lining away from the area of the friction faces. This groove can be formed in the pressing process in the case of mass-pressed linings. Furthermore grooves can also be formed in the radial direction.

In Figure 2b the lines 121 and 122 are shown which provide in the area of the dished area 110 and opening 111 a recess of the friction material of substantially circular ring shape in order to achieve in the area of the dish 110 a rivetting of the friction lining with a friction lining support such as spring segment. The free space 121 serves to hold the rivet head of the rivet 121a.

Figure 3 shows a friction lining in plan view wherein the friction lining 200 is formed as a circular ring shaped element which has circumferentially spaced out openings 201 and recesses 202 with central openings 203. The recesses 202 with a central opening 203 serve for fixing, such as rivetting the friction lining to a support element such as spring segment 3. The openings 201 are provided so that an opposing friction lining can be fixed such as rivetted to a support element such as for example a spring segment wherein a tool can engage through this opening 201 for rivetting.

The surface of the friction lining is divided up into segments 204 and 205 which are divided by grooves 206 and 207. The groove 206 is a substantially circular ring shaped or elliptical groove in the circumferential direction of the friction lining, such as already marked by 120 in Figures 2a and 2b. The grooves 207 run in the substantially radial direction wherein a tilt of the groove in the clockwise or anti-clockwise direction can be advantageous. The grooves serve to remove the dust arising though wear on the friction lining away from the area of the friction faces. The depth of the groove amounts only to a fraction of the thickness of the friction lining layer, such as for example 0.5 mm to 2 mm.

The groove 206 is advantageously not ideally circular but at least slightly elliptical or in the form of another slight deviation from a circular ring so that grinding dust conveyed therein does not always rub or wear out the same surface area on the counter friction surface.

Figure 4a shows a view of a lining support 220, such as a support element which is angled in the axial direction in the radially outer area 221 and in the radially inner area 222. The angled areas 221 and 222 which are preferably angled in the axial direction correspond to the areas 103 and 104 in Figures 2a and 2b. Furthermore dished areas 223 with a central opening 224 are arranged spread out in the circumferential direction of the element 220. In addition to these dished areas 223 openings 225 are spread out over the circumference of the lining support element 220. The dished areas 223 with the central opening 224 of this area serve to rivet the friction lining on a friction lining support, such as for example spring segment wherein the openings 225 serve to fix or rivet an opposing friction lining. The rivet head of a rivet is housed in these areas.

The depth of the dished areas 223 corresponds substantially to the expansion of the axially angled areas 221 and 222 so that through the depth of the areas 223 and the expansion viewed in the axial direction of the areas 221 and 222 a spacer function is guaranteed which ensures during manufacture of the friction lining that the lining support element 220 is formed in a central area of the friction lining, viewed in the axial direction.

The depth of the dished area can however also be greater or smaller than the axial expansion of the angled areas so that the lining support such as support element on the one hand stands only on the dished areas or on the angled areas or on both when it lies on a supporting structure such as for example in a lining press.

Furthermore it can be seen on the radially outer circumference 220a and on the radially inner circumference 220b that openings 226 and 227 are arranged in a regular or irregular formation. These openings 226 and 227 are provided so that the friction lining layer of friction lining material can produce a connection between the friction lining layers in the axial direction right and left of the friction lining support. Thus a considerably improved connection can be achieved between the two sides and the element 220 can advantageously be stuck or connected to the friction lining material. The openings 226, 227 can also be arranged in the area of the angle corner.

Furthermore openings 230 are shown in the central area of the lining support which are formed corresponding to openings 226 and 227 and serve to provide a better connection of the friction lining layers in front of and behind and right and left of the friction lining support.

Openings 231 can also be seen with raised marginal areas which are provided so that the friction material can produce a better meshing with the friction lining support element.

The raised marginal areas can be raised so far that they have the same axial expansion as the areas 221, 222.

Figure 4b shows a cut-out section according to line I-I of Figure 4a wherein the marginal areas 221 and 222 are shown and the openings can be seen in section with raised marginal areas 231. Figure 4c shows a section of Figure 4a corresponding to line II-II wherein the marginal areas 221 and 222 as well as openings 227 and 226 are shown.

Furthermore the dished area 223 is shown with the opening 224.

Figure 4d shows a section corresponding to Figure 4a wherein the section was made along the line III-III. The marginal areas 221 and 222 as well as the opening 225 are shown.

Figure 5 shows a further design of a lining support element 300 with a radially outer marginal area 301 and a radially inner marginal area 302. Openings 303 are formed in the radially outer marginal area and openings 304 are formed such as punched, drilled or pierced in the radially inner marginal area.

The dished curved or deep-drawn areas 310 with their central openings 311 are arranged spread out over the circumference of the element 300 wherein furthermore openings 312 are formed in the central area. The dished areas 310 with their central openings 311 serve for fixing, such as for example rivetting the friction lining with a lining support, wherein the openings 312 are provided so that an opposing friction lining can be rivetted to a lining support wherein the ram for rivetting can project through the opening 312.

In addition to the openings 303, 304 and 312 further openings 313, 314 and 315 are provided which are formed in the lining support 300 to reduce the moment of inertia and reduce the weight. The marginal areas of the openings 312 to 315 can be raised like for example the marginal areas of the openings 231 of Figure 4a and 4b. These openings serve for a better connection between the material of the friction lining layer and the lining support 300.

The openings 312 to 315 can be formed substantially rectangular or rectangular with rounded corners wherein also a trapezoidal or parallelogram type opening can be formed with or without rounded corners.

Figure 6 shows furthermore a further design of a lining support 300 which has openings 303 in the outer marginal area 301 and openings 304 in the inner marginal area 302.

Furthermore the deepdrawn or curved areas 310 with their central opening 311 are arranged spread out over the circumference. The openings 312 corresponding to the openings 312 of Figure 5 have the same purpose wherein these openings are likewise arranged spread out over the circumference.

The openings 313 to 315 of Figure 5 are formed in the embodiment of Figure 6 as smaller divided openings 320, 321, 322, 324, 325 and 326. Furthermore oblong openings can also be formed viewed circumferentially which have for example the expansion of the openings 320 and 321.

The lining support such as support elements shown in Figures 4 to 6 are provided so that the friction lining undergoes a stabilizing effect wherein the friction lining material is arranged such as applied substantially on each side of the lining support and the lining support is arranged with its central area such as circular ring shaped area substantially in a central area of the friction lining. The thickness of the friction lining layer which enters into friction action with a counter friction face such as for example the thickness d1 as shown in Figure 2a can be greater than half the thickness of the friction lining wherein the thickness of the support element is substantially small compared to the overall thickness of the friction lining.

The thickness d1 of the lining support such as support element is preferably in the range from 0.1 to 2.0 mm wherein the thickness d1 is preferably in the range from 5.0 to 0.5 mm. The same applies for the thickness of the layer d2.

Figure 7a shows a plan view of a support element 400 of a friction lining which has a substantially circular ring shaped design. The circular ring shaped element 400 has a radially outer marginal area 401 and a radially inner marginal area 402 wherein the marginal area 401 and/or the marginal area 402 viewed in the axial direction is bent or angled or reformed so that this radially inner and/or radially outer marginal area 401, 402 protrudes in the axial direction. Furthermore openings 403 are formed in the radially outer marginal area 401 and openings 404 are formed, such as drilled, punched or otherwise in the radially inner marginal area 402. These openings 403, 404 serve for a better connection and bonding of the friction material with the lining support 400. Furthermore these openings have the advantage that they reduce the mass of the lining support 400 and reduce the mass inertia moment.

Openings 405 and 406 are formed in the central area of the support element 400. The openings 405 which can be formed over the entire circumferential area of the element serve for the connection of the friction element lying flat are supported on the underneath, ie that the lining support 400 is supported in the areas 407a of the raised marginal areas. The raised marginal areas 407 with their bearing areas 407a can have spacer function if the height of the raised area 407 viewed in the axial direction is at least equal to the height of the raised area of the marginal areas 401 and/or 402.

Figure 7a shows furthermore openings 408 which are formed so that a rivet head and rivet tool can pass through this opening in order to connect or rivet a second friction lining or further friction lining with a lining support on a fixing element. Furthermore areas 409 can be seen which have a dished design and a central opening 410. The dished design 409 serves for fixing such as rivetting the friction lining by means of a rivet wherein the rivet head comes to lie in the area of the dished indentation 409 and the rivet engages through the opening 410 in order to be connected with a fixing element.

The openings 405 can with a further advantageous design of the lining support 400 likewise like the openings 406 have raised marginal areas. Furthermore it can be advantageously expedient if the openings 408 have raised marginal areas.

Figure 7c shows a sectional view through the element 400 of Figure 7a along the line A-A. It is possible to see the radially outer marginal areas 401 and 402 which viewed in the axial direction are angled or reformed so that they protrude axially opposite the base area 400. Furthermore the openings 403 and 404 can be seen in the radially inner or radially outer marginal area of the element 400 wherein the openings extend over the angled area 420 and are located in the radially and also in the axial area of the element 400, 401. The area 409 such as a dished or shaped area with opening 410 shows that the depth of the dished area is smaller than the axial expansion of the areas 401, 402 which is clear through the area T in the lower half of the drawing. The area 409 serves in this embodiment not as a spacer but only as a fixing element. Furthermore a desig is possible wherein the axial expansion of the area 409 is greater than the axial expansion of the areas 401, 402 so that the area 409 undertakes a spacer function in comparison with the areas 401, 402.

Figure 7d shows a cut-out section of 7a wherein an area is shown around a dished formation 409. It is possible to see in the marginal areas the support element 400, the dished area 409 as well as the central opening 410. The central opening has in this embodiment not a circular or substantially circular design but additionally recesses such as arms 421 which are formed substantially star-shaped viewed in the radial direction of the opening. These arms 421 allows a formation of the area 409 into four partial areas 422 which are formed substantially as circular segments. Dividing up the base area 409 of the dished area into sub-areas 422 allows a resilient action of the segments 422 which is advantageous if the lining support 400 is rivetted by means of rivets in the area 409. The individual segments 422 can with such a design be stressed to different amounts wherein a slight tilting or displacement of the elements 422 in the axial direction is possible.

Figure 8 shows an element such as a lining support element 500 with a radially outer marginal area 501 and a radially inner marginal area 502 in which openings 503 and 504 are formed.

The dished areas 409 of Figure 7a which are formed substantially circular are connected in Figure 8 to a circular ring shaped area 505 which is displaced such as deep drawn opposite the area 506 of the element 500, viewed in the axial direction. In the area 505 which protrudes in the axial direction opposite the area 506 there are openings 507 and 508 which can be punched, pierced or drilled. The openings 507 serve to connect the element 500 to a fixing element such as for example a spring segment of a clutch disc wherein the openings 508 can be used for connecting such as rivetting an opposing friction lining.

Furthermore swages 510 and/or 511 can be formed in the lining support or in the support element in order to increase the bending stiffness of the lining support. The raised areas which can be formed on the radially inner or outer marginal areas 501, 502 viewed substantially in the axial direction of the friction lining likewise help to increase the bending stiffness.

The raised areas of the friction lining in the radially inner marginal area and/or in the radially outer marginal area can extend in the axial direction or be bent at an angle of between 0 and 90 degrees to the plane of the lining support. Similarly the raised area can be formed as a swage in the radially inner and/or outer marginal area.

The axially protruding marginal areas of the lining support as well as the dished areas which for example are also formed into a circular ring shaped area aligned in the circumferential direction of the friction lining, serve to increase the stiffness, such as bending stiffness of the support element, such as lining support wherein the bending stiffness of this element determines the bending stiffness of the friction lining. Furthermore it is advantageous if the bending stiffness assumes an increased value since distortion problems during the operation of the friction linings for example in a function of a clutch disc should be kept as small as possible.

The manufacture of such a friction lining as described above is achieved for example by measuring a dosed amount of a mixture of friction material into a heating press, then placing the lining support in the press and then adding further material before the material is formed with the lining support, for example by hot-pressing, into its end state.

It can likewise be advantageous if first the lining support provided with the spacer function is placed in the mould, then the friction material is added in a measured amount and then the material during the pressing process such as hot pressing process flows through the holes into the area underneath the lining support.

A friction lining according to the idea according to the invention can be finished, such as polished, on at least one side, such as surface, after the form-shaping process such as for example hot pressing process. Furthermore it can be expedient if both sides of the friction lining are polished.

A friction lining according to the invention is made from a friction material mixture of different for example organic and/or inorganic materials, such as plastics, resins, metals and fibres, such as for example glass fibres, carbon fibres, plastics fibres or ceramic fibres. This friction material mixture is mixed from the individual raw materials or premixtures wherein other residual substances such as for example grinding dust, drilling particles or pressing particles can be mixed in with this mixture. These residual substances can arise during the production or finishing of the friction linings so that through recycling in the production process they do not have to be disposed of separately. Furthermore reprocessing of old parts such as used and partly worn friction linings can be carried out so that for example after separating the recyclable and non recyclable parts of the friction lining the recyclable parts can be processed into a powder or granulate and then added to the friction lining mixture.

The friction lining can be formed so that the friction lining layer in front of the lining support (front side) has a quite different material mixture from the friction lining layer behind the lining support. The friction lining layer in front of the lining support (front side) provides the friction surface and the friction lining layer behind the lining support (reverse side) preferably does not serve as a friction surface.

A material can thereby be used for the lining mixture behind the lining support (reverse side) which need not meet the high demands regarding the friction value. This material can also preferably have a lower density so that the weight and moment of inertia of the friction lining is reduced.

Similarly the material can also be made from cost-effective constituent parts.

The materials of the front and reverse side of the friction lining are preferably selected so that a distortion of the lining through the influence of temperature or dampness does not or only slightly occur.

The back of the friction lining can also be chosen thinner or thicker than the front side in dependence on the choice of material. It is advantageous if the distortion properties of the front side and reverse side of the friction lining compensate one another so that no distortion of the lining results as a function of the temperature or moisture content.

With a friction lining according to the invention with each at least one friction material layer in front of and behind a lining support element it can be advantageous if materials of one sort are used without residual substances for the side of the friction lining which supports the friction surface. For the side of the friction lining which does not support the friction surface it is possible to use friction lining mixtures with residual substances. Such residual substances can be mixed together from grinding dust, grinding particles or recycled material.

The lining support elements such as the lining support plates can have between the lining material and the support element, such as support plate a mechanical connection for example through keyed engagement wherein this mechanical connection can be produced for example by lugs or other material connections or designs. These can be in the form of swages and/or collars on the marginal area and/or raised areas of parts of for example marginal areas of openings.

If the lining material is stuck for example to the support element, such as support plate, such as for example through resin parts in the lining support mixture, the lining support elements such as lining support plates can be surface treated. Through this roughness an improved connection is provided between the lining material and lining support.

If the support plates are made such as punched from rolled or non-rolled sheet metal then a surface treatment can be advantageous for better adhesion of the lining material.

The surface of the sheet metal can be roughened by a chemical pickling process. Furthermore the surface can be roughened by a particle jet process, such as for example a sand-blasting process or water jet process or by any other surface-clearing or deforming process.

The surface processing through for example pickling can take place in a suitable way in a phosphating plant.

The friction lining is preferably a mass-pressed friction lining which is made for example from a powder mixture in a mould with a hot press process.

Figures 9a to 9c each show a section through a friction lining according to the invention.

Figure 9a shows in a modification of the friction lining of Figure 2b a connection of the friction lining not with a rivet but with a keyed connection which is produced by reforming the material of the support element. The friction lining 600 consists basically of the support element 603 and the two friction lining layers 602 on the front side and 601 on the reverse side of the lining. The lining support 603 has in the radially inner marginal area 604 an axially raised marginal area 605. Furthermore the lining support 603 has in the radially outer marginal area 606 an axially raised area 607. The radially middle area 608 has a dished area which serves to connect the lining support 603 with a segment 609 of a clutch disc. The segment has in the connecting area an opening in which a collar 610 engages from the material of the dished area of the lining support which is in turn reshaped such as flanged over or bent round so that a keyed connection is formed. In the area 611 of the connection with the segment the friction lining layer can be recessed. Through this positive connection as an integrated rivet element it is possible to save an additional rivet. By raising and flanging or bending round the marginal area of the support element or by another design it is possible to form an integrated rivet element.

This fixing process can however not be carried out with all materials as a support element since not all materials can be deformed in the required manner. In such cases it is possible to provide a connection with a rivet.

Figure 9b shows a section through a friction lining 620 but at a different position so that the fixing with the segment of the clutch disc is not shown. Substantially circumferentially aligned grooves 623, 624 or indentations are formed or pressed In the friction lining 620 for example on the front side 622 supporting the friction surface and/or on the reverse side. These grooves 623, 624 run substantially circular or elliptical in the circumferential direction on the surface of the lining. Several grooves can also be formed or worked in side by side. These grooves 623, 624 can be formed in closed circular shape or the circular shapes of the grooves can be interrupted by webs.

It is thereby expedient if the webs are arranged in the area of the rivet edges or dished areas for rivetting or holding the rivets or the fixing means. The grooves can be formed by rams in the tool during the manufacturing process whereby a centring of the support can also be achieved.

Figure 9c shows a section through a friction lining 650 with a friction lining layer 651 on the front side supporting the friction face and a friction lining layer 652 on the reverse side. The support element 653 is arranged substantially central and has on at least one marginal area such as the radially inner marginal area and/or radially outer marginal area no raised areas. Nevertheless swages 654 can be formed in the support element to increase the bending strength.

Figure 10a shows a view of a friction lining from the side remote from the friction face. The friction lining 700 has a reverse side 702 which forms substantially no friction surface. Openings 703 and 704 are formed in the friction lining. The opening 703 with a deep drawn or raised area of the support plate serves to connect or rivet the friction lining with a fixing element and the opening 704 serves to rivet an opposing friction lining so that a tool can pass through this opening 704 for rivetting. In the radially inner area of the reverse friction lining is a circumferential groove 705 and in the radially outer of the friction lining is a circumferential groove 706 wherein the circumferential groove 706 is broken and the circumferential groove 705 is closed. The circumferential groove 705 can also be formed broken or the circumferential groove 706 can also be formed closed. Advantageously at least one broken or closed circumferential groove or another groove with for example radial alignment can be formed in the friction lining. Also more than one groove can be formed in the friction lining.

Figure 10b shows a cut out section of a friction lining 701 from the side of the friction surface 711 wherein openings 703 are formed in the friction lining for rivetting the friction lining and 704 for passing through tools. On the friction surface of the friction lining are indentations or grooves 712 and 713 worked in the circumferential direction wherein the grooves 712 and 713 can be formed circumferentially closed or broken. Providing grooves 705, 706 and 712, 713 causes a reduction in weight and thus a reduction in the moment of inertia of the friction lining.

Figure 10c shows a section through an arrangement of friction linings 700 and 701 which are connected in the central area through reforming of the support plate 720 with the fixing element 721. The central area 722 of the reformed area is designed as an integrated rivet element.

Figure 10d shows a connection of two friction linings 701 and 700 with a fixing element 710 which is connected to a rivet element 730 on an entrainment disc 711 of a clutch disc. The friction lining 700 is connected such as rivetted by the rivet element 731 to the element 710 wherein for rivetting the tool passes through the free areas 704.

Furthermore the grooves 706 , 705 and 712, 713 can be seen.

The patent claims filed with the application are proposed wordings without prejudice for achieving wider patent protection. The applicant retains the right to claim further features disclosed up until now only in the description and/or drawings.

References used in the sub-claims refer to the further design of the subject of the main claim through the features of each sub-claim; they are not to be understood as dispensing with obtaining an independent subject protection for the features of the sub-claims referred to.

The subjects of these sub-claims however also form independent inventions which have a configuration independent of the subjects of the preceding sub-claims.

The invention is not restricted to the embodiment of the description. Rather numerous modifications and alterations are possible within the framework of the invention, more particularly those variations, elements and combinations and/or materials which are inventive for example through combination or modification of individual features or elements or method steps contained in the drawings and described in connection with those in the general description and embodiments and claims and lead through combinable features to a new subject or to new method steps or sequence of method steps where they relate to manufacturing, testing and work processes.

Claims

PATENT CLAIMS

1. Friction lining, more particularly for clutch discs or brakes, by way of example for motor vehicles, which is designed substantially circular ring shaped and consists of a substantially circular ring shaped support element and a friction material substantially embedding this support element, the friction lining having receiving or shaping areas to fix the friction lining on a fixing element wherein the substantially circular ring shaped support element is mounted substantially in the middle of the friction lining, seen in the axial direction.

2. Friction lining according to claim 1 characterised in that the support element has a substantially circular ring shaped base area which is mounted substantially in the middle of the friction lining, seen in the axial direction.

3. Friction lining according to claim 1 or 2 characterised in that the friction material of the friction lining, viewed in the axial direction, is applied or provided both in front of and behind the substantially circular ring shaped base area of the support element.

4. Friction lining according to claim 1 or 2 characterised in that viewed in the axial direction one friction lining layer is applied in front of the support element and one friction lining layer is applied behind the support element.

5. Friction lining according to claim 1 or 2 characterised in that one friction lining layer is applied either side of the support element.

6. Friction lining according to claim 4 or 5 characterised in that the expansion, viewed in the axial direction, of the friction lining layer in front of the base area of the support element is substantially equal to the expansion, viewed in the axial direction, of the friction lining layer behind the base area of the support element.

7. Friction lining according to claim 4 or 5, characterised in that the expansion d1, viewed in the axial direction, of the friction lining layer in front of the base area of the support element is substantially larger than the expansion d2, viewed in the axial direction, of the friction lining layer behind the base area of the support element.

8. Friction lining according to claim 7 characterised in that the ratio of the expansion d1 to the expansion d2 is in the range from 4 to 1, preferably from 2 to 1.

9. Friction lining according to claim 7, characterised in that the expansion d1, viewed in the axial direction, of the friction lining layer in front of the base area of the support element is substantially smaller than the expansion d2 , viewed in the axial direction of the friction lining layer behind the support element.

10. Device according to claim 9, characterised in that the ratio of the expansion d1 to the expansion d2 is in the range from 1 to 0.3, preferably from 1 to 0.5.

11. Friction lining, more particularly for clutch discs or brakes, by way of example for motor vehicles, which is designed substantially circular ring shaped and consists of a substantially circular ring-shaped support element and a friction material substantially embedding this support element, with receiving or forming areas for fixing the friction lining on a fixing element, characterised in that the substantially circular ring-shaped support element has a circular ring shaped base area and at least one further area which has an expansion in the axial direction so that this area protrudes axially from the circular ring shaped base area of the support element.

12. Friction lining according to claim 11 characterised in that the radially outer marginal area of the circular ring shaped support element protrudes axially opposite the base area of the support element.

13. Friction lining according to claim 9 characterised in that the radially inner area of the circular ring shaped support element protrudes axially opposite the base area of the support element.

14. Friction lining according to claim 11 characterised in that in the base area of the circular ring shaped support element at least one zone is formed, such as curved, raised or dished so that it protrudes axially opposite the base area of the support element.

15. Friction lining according to claim 14 characterised in that at least two zones of the base area of the circular ring shaped support element, which protrude in the axial direction, are spread evenly, viewed over the circumference of the circular ring shaped support element.

16. Friction lining according to claim 14 characterised in that at least one zone in the base area of the circular ring shaped support element protrudes axially and is substantially circular ring shaped or oval.

17. Friction lining according to claim 14 characterised in that at least one zone in the base area of the circular ring shaped support element protrudes axially and is substantially angular such as square or rectangular.

18. Friction lining according to claim 14 characterised in that at least one zone in the base area of the circular ring shaped support element which protrudes axially, viewed circumferentially, has a circular ring-shaped contour.

19. Friction lining according to claim 14 characterised in that the at least one circular ring-shaped zone protruding axially is mounted coaxial with the axis of the friction lining.

20. Friction lining according to one of the preceding claims, characterised in that openings are formed, such as punched, pierced or drilled in the base area of the circular ring shaped support element.

21. Friction lining characterised in that marginal areas of at least one opening are raised in the axial direction in the circular ring shaped support element.

22. Friction lining according to one of the preceding claims, characterised in that in the base area of the circular ring shaped support element openings, such as holes, are formed with different cross-section or with different expansion.

23. Friction lining according to one of the preceding claims, characterised in that the areas or zones which protrude axially opposite the circular ring shaped base areas of the support element have openings.

24. Friction lining according to one of the preceding claims, characterised in that the expansion of the circular ring shaped support element, viewed in the radial direction, is less than the expansion of the friction lining, viewed in the radial direction.

25. Friction lining according to claim 24 characterised in that the expansion of the support element, viewed in the radial direction, is less than the radial expansion of the friction lining, but greater than a quarter of the radial expansion of the friction lining.

26. Friction lining according to one of the preceding claims, characterised in that the expansion of the circular ring shaped support element, viewed in the radial direction is equal to the expansion of the friction lining, viewed in the radial direction.

27. Friction lining according to one of the preceding claims, characterised in that the expansion of the circular ring shaped support element viewed in the radial direction is greater than the expansion of the friction lining, viewed in the radial direction.

28. Friction lining according to one of the preceding claims, characterised in that the substantially circular ring shaped support element is made of metal, such as for example steel or aluminium.

29. Friction lining according to one of the preceding claims, characterised in that the substantially circular ring shaped support element is made of plastics, such as for example fibre-reinforced such as glass fibre reinforced, plastics.

30. Clutch disc more particularly for a friction clutch which supports on its outer circumference at least one friction lining, with an input part, such as an entrainment disc, which where applicable is connected rotationally secured to a counter disc, and the entrainment and counter disc form the input part of a torsion vibration damper, wherein a circular ring shaped component part such as a flange serves as the output part of the torsion vibration damper and transfers a transferable torque on the output side directly or where applicable through a further torsion vibration damper to the hub of the clutch disc, wherein between the flange and the clutch disc hub can be provided a torsion vibration damper, for example for the idling area, characterised in that the friction linings of the clutch disc which serve as the input part consist of a support element and a friction lining layer and the support element is mounted substantially in the middle of the friction lining and the support element has areas which project radially opposite a base area of the support element.

31. Clutch disc more particularly for motor vehicles, characterised in that the friction linings of the clutch disc are formed according to one of claims 1 to 29.

32. A friction lining for a clutch or brake disc substantially as herein described with reference to the accompanying drawings.

33. A clutch disc substantially as herein described with reference to the accompanying drawings.