FR2498710A1 - MOTORCYCLE DISC BRAKE - Google Patents

Abstract

THIS DISC BRAKE FOR FRONT OR REAR WHEELS OF MOTORCYCLES INCLUDES A DISC 8 HAVING PAIRS OF PROJECTS 11 LOCATED ON ITS PERIPHERAL AND ALSO SPACED ANGULARLY 120. PAIRS OF PROJECTS 11 CAN BE FORMED EITHER ON THE EXTERNAL PERIPHERY OR ON THE INTERNAL PERIPHERY OF THE DISC. THE PROJECTS DELIMIT HOUSING 7 OPEN AT ONE END AND ADAPTED TO RECEIVE BOSSES 6 COME FROM MATERIAL WITH HUB 4, AND PARTIALLY SURROUNDED BY HARDENED OR SOAKED RETAINERS 13. A SCREW SCREWED IN EACH BOSS 6 PREVENTS SEPARATION OF THE BOSSES AND HOUSING BUT IS NOT SUBJECT TO FORCES CAUSED BY THERMAL EXPANSION OF THE DISC WHEN BRAKING. ONE OR MORE FIXED CALIPERS 18 APPLY NON-ROTATING GASKETS TO FRICTION AGAINST THE OPPOSITE FACES OF EACH DISC 8. MEANS 9, 10 ARE PROVIDED FOR COOLING THE DISC 8 BY MEANS OF ATMOSPHERIC AIR.

Description

The present invention relates to brakes

  discs for motorcycles and it concerns more particularly-

  the problem of fixing a brake disc on

  a wheel hub so as to tolerate satisfactorily

  health the thermal expansion and contraction of the disc, in service. The subject of the invention is a disc brake for a motorcycle, in which a brake disc is mounted on a hub by means of pairs of projections which are located t either on a periphery of the disc or on the hub of I the wheel at equidistant points so as to delimit J

  equally spaced dwellings, and several bos-

  wise men of matter with the other of these organs, and each projecting in one of said housings, the cooperation between said bosses and said housings being such that it allows thermal expansion;

of the brake disc.

  According to a preferred embodiment of the invention, a brake disc comprises pairs of projections located on its internal or external periphery and spaced apart

  intervals of 1200. The projections delimit boxes

  parts open at one end in which extend bosses which have come in one piece with the wheel hub. This construction uses a screw screwed into each of said bosses and preventing separation, but the screw is not subjected to forces caused by the thermal expansion of the brake disc. High adjustment accuracy is obtained with techniques that are easy to machine. A hardened or hardened retaining member partially surrounds each boss and this member may be of a

  type capable of developing elastic force for em-

  catch an unwanted organ shift. Disc I

  brake, which rotates with the wheel hub, is formed

  mé of annular plates comprising between them

  blades coming from material for cooling air.

  The blades serve to circulate atmospheric air through the interior of the brake disc, as well as to generate a stream of heated air back to

the atmosphere.

  Other features and advantages of the

  vention will appear during the description which goes

  follow made with reference to the accompanying drawings given solely by way of example and in which:

  - Fig. 1 is a detailed view in cross section

  trant an arrangement of a device of the technique an-

  Fig. 2 is a side elevational view with partial section and cutaway, showing a preferred embodiment of the invention;

  - Fig. 3 is a sectional view along the line

  gene 3-3 of FIG. 2; - Fig. 4 is a side elevational view of the brake disc shown in Ftg. 2 and 3; - Fig. 5 is a sectional view of a detail along line 5-5 of FIG. 4; - Fig. 6 is a view analogous to that

  Fig. 4, partially broken away, showing a

  laughing; - Figs. 7, 8 and 9 show another embodiment of the invention; - Fig. 7 is a view. in side elevation with partial cut and cut away; - Fig. 8 is a view in elevation and in section along line 8-8 of FIG. 7; - Fig. 9 shows a variant; - the Pig. 10 and 11 show a third embodiment of the invention; Fig. 10 is a side elevational view with partial section and cutaway; Fig. 11l is a sectional view along line 11-11 of FIG. 10; - Fig. 12 is a view in - FIG. 13 is a view in individual organs of the arrangement FIG. 12 before mounting; - Fig. 14 is a view showing part of FIG. 12 to - Fig. 15 is a retaining view shown in FIG. 12; - Figs. 16 to 21 show an embodiment of the invention; - the Pig. 16 is a view in partial section and cutaway; - Fig. 17 is a line view 17-17 of FIG. 16; - Fig. 18 is a sectional view of a detail; section showing the shown in section of a larger scale detail; plan of the member of a fourth lateral elevation mode section along the lateral elevation and in partial section showing a brake disc of the type shown in FIGS. 16 and 17; - Fig. 19 is a sectional view along line 19-19 of FIG. 18; - the FPg. 20 is a sectional view of a detail, according to a variant; - Fig. 21 is a sectional view of a detail

of another variant.

  Referring to the drawing, the device of the prior art shown in FIG. 1 comprises a wheel hub a on which is fixed by its periphery c a brake disc b. Several fixing holes d are provided in the peripheral part c of the disc b and a series of bolts e extends through the mounting holes d in aligned holes provided in the hub a. In this arrangement there is no play or freedom between the fixing holes d and the external surface of the bolts e, so that when the disc b is heated

  by the friction generated during braking, the di-

  thermal latation which results from the disc b in the direction i i j i I I radial generates forces which tend to deform the hub a. Stresses caused by the resistance of the hub a to deformation are likely to be

  develop in disk b in addition to ther-

  due to the uneven distribution of temperature. Since there is no play or degree of freedom between the fixing holes d and the peripheral surface of the bolts e, as described above, it

  results from a lack of precision in the machining of the

  ganes a lack of concidence of the fixing holes d with the holes f provided in the hub a. This can prevent or obstruct the introduction of the bolts e and

  this very high precision machining is necessary

  The invention relates to improvements in the manufacture of a brake disc for a motorcycle in which the assembly of the members is facilitated and the centering of the disc is obtained without limiting the radial displacement of the attachment of the disc, even if a displacement

  radial must occur due to thermal expansion

  that of the disc during braking. This reduces the

  development of internal stresses in the brake disc. Referring to Figs. 2 to 6, the axle 1 of the front wheel is fixed to the front fork 2 by its two ends, and the hub 4 of the front wheel is rotatably mounted on this axle 1 by means of spaced bearings

  3. The rim 5 is fixed to the hub 4 and constitutes a part

  tie of the latter. Bosses 6 coming from material on

  the hub 4 protrudes laterally and are angular-

  spaced 120 around the periphery of the hub 4.

  Pairs of projections 11 formed on the brake disc 8 project radially therefrom and delimit

  housings 7 which are open radially towards the ex-

II - J ...

  and which maintain each boss 6 by the inside

  through a retaining member 13.

  The three pairs of protrusions 11 of the disc of

  brake delimit the housings 7 open at one end

  mite between parallel walls 12. The walls 12 are parallel & straight lines extending radially from the center P of the brake disc 8 (Fig. 4). The pairs of projections 11 are engaged in releasable engagement with the fixing bosses 6 and retaining members 13 by an axial relative displacement of the brake disc 8, screws 14 extending axially fix caps 15 on the bosses 6 i A stationary lateral flange 16 has an orifice 17 for cooling air inlet and a stationary caliper 18 is fixed relative to the flange 16. Brake linings 19 are in contact with the opposite faces of the brake disc 8. The actuation of the pistons 20 of the caliper forces the linings 19 in contact under pressure with the two faces of the disc 8. When the fixing bosses 6 are engaged in engagement in the housings 7 delimited by the pairs of sablliea 11, no engagement or force adjustment is not necessary, although relative pitch errors are relatively large between the three bosses t

  fixing and the three housings 7. Thus considering

  deriving from Fig. 4, we assume that the engagement is made at points A and B, and we assume that the k

  fixing boss at point C is an imaginary point.

  The clearance existing between the width m of the housing, the width k

  geur p of the boss and double the thickness n of the gold-

  retaining gane determines the degree of offset w in

  direction XX at point C. Therefore, even when

  that there is a relative difference in position between

  the boss 6 at point C and the transmission surfaces 12

  torque of disc 8 in direction XX, p ^ ..

  disc 8 can easily be engaged without engagement

  cer on the fixing bosses 6 as far as exists

  te the degree of offset w. In addition, the games are sufficient

  to allow the tolerance necessary for machining on w. In addition a difference along the direction YY

  between the boss 6 and the bottom of the housing 7 is compensated

  sée by a specified clearance, provided that this clearance is provided between the boss 6 and the bottom of the housing 7,

  so this difference does not prevent

  the assembly operation. Consequently, a usi-

  relatively easy swimming allows the disc to be centered

  brake 8 to mount it with great precision.

  Even if disc 8 expands in the direction

  dial due to the heat given off by friction, or if it contracts as a result of cooling,

  thus causing relative displacement between the over-

  torque transmission faces of boss 6 and the pa-

  kings 12 of housing 7, expansion or contraction is not limited by bosses 6 and the appearance

  thermal stress can be reduced to a minimum

  mum, thus improving resistance. % The disc. 8 has a plurality of radial ribs 10 which delimit passages between them 9

for cooling air.

  The cooling air introduced through the orifice 17 of the flange 16 escapes into the atmosphere through the passages of cooling air due to the centrifugal force, so that the heat generated by the friction on the disc 8 during braking is dissipated by air, making it possible to obtain

  a considerable cooling effect.

  In the variant shown in FIG. 6, two

  bosses 21 arranged face to face are provided on the mo-

  eye of the wheel, and a projection 23 is provided on the device.

  than brake 8a. The bosses 21 and the projection 23 are t! I 2498710 j

7 I

  engaged in engagement through retaining bodies

  nude 13a. We thus obtain an equivalent result.

  According to the second embodiment shown

  tee in Figs. 7, 8 and 9, the rear wheel axle 1b is fixed to the rear torque assembly 2b. The rear wheel hub 4b is rotatably mounted on the axle lb by means of axially spaced bearings 3b. The rim of the wheel may have come in one piece with the external periphery of the hub 4b. A drive flange 24 is provided on one side of the hub 4b of the rear wheel, and a driven pinion 25 is fixed to this flange so

removable by screws 26.

  On the opposite side of the hub 4b with respect to the pinion 25 are provided three fixing bosses 6b which have come integrally with the hub 4b and are also angularly spaced by 120-. The disc 8b comprises three pairs of projections llb which delimit the housings 7b receiving the bosses 6b. The housings 7b receive the bosses 6b by means of a displacement

  relative ax1al between the disc 8b and the hub 4b.

  The brake disc 8b and the fixing bosses 6b are formed so as to provide a clearance at the bottom of each housing 7b. This arrangement allows a

  thermal expansion of the disc 8b in the radial direction.

  A cylindrical part 27, which is interrupted

  by the bosses 6b, is provided on the hub 4b of ma-

  in order to provide a game determined in relation to the

  disk array 8b. A flange 16b is formed so as to enclose the internal surface of the cylindrical part 27 and the brake disc 8b. This flange 16b is adapted to be removably mounted on the bosses 6b of the hub 4b by means of screws 14b so that its periphery 36b is disposed opposite the edge

  37b of the cylindrical part 27 of the hub 4b. A stirrup.

  18b is fixed on the flange 16b and overlaps the disc J 1I 8b from the inside. Two linings 19b come into contact with the two faces of the sliding disc 8b,

  following the actuation of the piston 20b of the caliper.

  The stirrup 18b is fixed on a support 28 so that the reaction force on the stirrup 18b is transmitted by the disc 28 and. Via an arm 29 to the frame

of the vehicle.

  Due to the fact that the disc 8b of the brake is covered by the hub 4b of the rear wheel and the flange 16b, this disc is prevented from receiving water, dust or the like on its surface and therefore

  the wear of the disc 8b and of the linings 19b is reduced.

  Similarly, due to the contact of the projection pairs llb provided on the periphery of the disc 8b with the fixing bosses 6b of the hub 4b of the rear wheel, the braking force exerted on the disc 8b is transmitted

  so to the hub 4b. In addition, the braking torque

  ge is supported by the bosses 6b and does not act on

  the screws 14b so that the screws maintain a connection

  its reliable and long lasting with the bosses 6b.

  In the variant shown in FIG. 9, the disc 8b has three projections 23b also spaced apart

  angularly. These projections are received between payments.

  res of bosses 30 which are fixed on the hub 4b, and clearances 31 are provided between the internal periphery of the

  retaining bosses 30 and the outer periphery of the device

  than 8b. This arrangement provides practically the same

  result that that shown in Figs. 7 and 8.

  The third embodiment of the invention which is shown in Figs. 10 to 15 uses a rear wheel axle lc which is fixed to the rear fork assembly 2c, and a rear wheel hub 4c carried by

  axially spaced 3c bearings. The ledge of-

  drag 24c is connected by means of screws 26c to the drive pinion 25c. On the side of the hub 4c opposite the pinion 25c are provided three bosses. 6c of fixing which came integrally with the hub 4c. The brake disc 8c has pairs of projections llc_ which

  receive a hardened or tempered retainer 13c.

  The disc 8c has radially extending ribs 10c which delimit between them passages 9c for the cooling air. A game is planned between

  the outer periphery of the disc 8c and the inter-

  of the retaining members 13c in order to absorb the

thermal expansion of the disc 8c.

  As seen in Figs. 12 and 13, each bos-

  sage 6c of the hub 4c receives with play the peripheral part

  u-shaped risk of the retaining member 13c, one side of which is designated by the reference 32 and the other side of which is designated by the reference 33. The side 33 is folded back so as to form an acute angle before the assembly, as shown in Fig. 13, while side 32

  is folded back to form a right angle. The par-

  tie 34 is adjacent to the end of the boss 6c which transmits the braking torque, and the part 35 is located on the opposite side thereof. The flange 16c does not rotate but has an opening 17c through which atmospheric air penetrates to cool the disc

  brake 8c. The flange is clamped in position by,.

  suitable means not shown.

  The cylindrical part 27c is shaped defaqon to provide a specified clearance relative to the periphery of the disc 8c. The flange 16c is shaped so as to enclose the internal surface of the cylindrical part 27c on the disc 8c. The stationary flange 16c comprises

  a peripheral part 36c which is spaced from a shoulder

  the annular part 37c of the hub 4c, defining a clearance

  38c for the outlet of the heated air.

  The stationary stirrup 18c carries fittings 19c which come into frictional contact with the two i-

  faces of the disc 8c under the action of the piston 20c of the caliper.

  The surface of the two lic projections is applied against the hub 4c by the elastic return movement

  of part 33 of the retaining member, preventing the dis-

  only 8c to loosen due to vibration or the like. Even when an impact force is applied to the disc 8c, the internal surface of the double projection 11c and the sides of the boss 6c limit the degree of wear of

  the presence of the retaining member 13c.

  The operating characteristics of the embodiment of the invention shown in FIGS. 10 to are similar to those described with reference to the embodiment shown in FIGS. 7, 8 and 9, with regard to cooling, thermal expansion and

other.

  In the fourth embodiment of the in-

  vention shown in Figs. 16 to 21, the members are similar to those shown in Figs. 2 to 6, except that only one brake disc 8d is used instead of two and that slightly different blades are used on the brake disc for cooling air,

  in the vicinity of the three bosses of the wheel hub.

  Thus the hub 4d is carried on 3d bearings spaced axially on a fixed axle ld fixed on the fork 2d. The single disc 8d has three pairs of projections lld which receive the three bosses 6d

  which came in one piece with the 4d hub of the wheel.

  Radial ribs 1Od delimit between them

  cooling passages 9d and an additional rib

  thicker mental 39 extends on either side of each boss 6d and its associated retaining member 13d. Atmospheric air for cooling enters the orifice 17d formed in the flange 16d and is evacuated through the interval 38d. The piston rod 20d of the caliper 18d tightens the linings

  19d against the external faces of the brake disc 8d.

  Fig. 20 shows a variant in which the disk 8e has pairs of inwardly extending projections to receive the three

  6th bosses which came from the material with the hub.

  A rib 40 plus shoulder extends on either side

of each of the 6th bosses.

  In the variant of FIG. 21 the disc 8f is analogous to the disc 8d shown in FIG. 18 except for the fact that the pairs of projections 11f carry thicker blades 14 delimiting between

they housing 7f.

i * It tI j

Claims (4)

CLAIMS i - Disc brake for motorcycle, characterized in that it comprises a brake disc (8, 8a-8f) which is mounted on a hub (4, 4a-4f) of wheels by means of pairs of projections (11 , lia-llf) located either on a periphery of the disc, or on the wheel hub at points also spaced angularly so as to delimit housings. (7, 7a-7f) also spaced angularly, and several bosses (6, 6a -6el which came integrally with the other of said members and each projecting in one of said housings, the arrangement between said bosses and said housings being adapted to allow a radial thermal expansion of the brake disc.   2 - Disc brake according to claim 1, characterized in that said pairs of projections (11, lla-llf) and said housings. (7, '7a7f) are located   on the outer periphery of the brake disc (8, 8a-8f).   3 - Disc brake according to claim 1, characterized in that said, pairs of projections - (11, 1la-11f) and said housings (7, 7a7f> are located   on the internal periphery of the brake disc (8, 8a-8f).   4 - Disc brake according to any one of   claims 2 or 3, characterized in that it comprises   means (15) screwed into said bosses (6, 6a-6f)   to maintain contact between said bosses and   said housing ,, - Disc brake according to any one of   previous claims, characterized in that said   bosses (6, 6a-6f) are partially surrounded each   by a hardened or hardened retainer (13, 13a-13d).   6 - Disc brake according to any one   of the preceding claims, characterized in that the   brake disc (8, 8a-8f) consists of plates   parallel annulars having vanes (10) coming from ma-   between them for cooling air   ment, and in that it comprises a stationary side flange (16) comprising an inlet orifice (17) for atmospheric air .. l i 'A> ..