Source: http://www.docstoc.com/docs/50705484/Hydraulically-Controlled-Clutch-Release-Bearing-For-A-Motor-vehicle-Diaphragm-Clutch---Patent-5865288
Timestamp: 2015-07-31 00:28:02
Document Index: 599088227

Matched Legal Cases: ['arts 5', 'art 100', 'arts 5', 'art 21', 'art 132', 'art\n152', 'art 131', 'art 83']

Hydraulically Controlled Clutch Release Bearing For A Motor-vehicle Diaphragm Clutch - Patent 5865288 by Patents-332
50705484
Thepresent invention concerns hydraulically controlled clutch release bearings for a diaphragm clutch, notably for a motor vehicle.The invention concerns more particularly a clutch release bearing having a fixed portion comprising an outer body and a concentric inner support tube distinct from the outer body, defining a blind annular cavity of axial orientation capable ofbeing supplied with fluid and inside which is mounted an axially movable tubular piston carrying a drive member capable of acting on the diaphragm of a clutch.Such a bearing is described for example in the document FR-A-2 682 950.This bearing can be supplied by a fluid of the gaseous or liquid type and this is the reason why it is usually referred to as a hydraulically controlled clutch release bearing.According to various known designs, means are provided for fixing the inner support tube to a fixed element, for example to the casing of the gearbox equipped with a clutch having such a concentric hydraulically controlled clutch release bearing,and means are also provided for fixing the outer body to this same fixed part, the most precise concentricity possible also having to be ensured between these two elements of the fixed portion of the bearing.The aim of the present invention is to propose a novel design of a hydraulic bearing which makes it possible to simplify the fixing and relative positioning of the two components of the fixed portion of the bearing.To this end, the invention proposes a clutch release bearing of the type mentioned above, characterised in that the inner support tube has at its rear end an annular flange of transverse orientation, by means of which it bears on a fixed portion,notably on a gearbox, and in that the rear end of the body in indented in order to clamp the flange between the body and the said fixed portion.Thus the fixing of the outer body makes it possible simultaneously to ensure the fixing of the inner support tube and to reduce the cost price of the clutch rele
United States Patent: 5865288
5,865,288
Hydraulically controlled clutch release bearing for a motor-vehicle
A clutch release bearing comprising a fixed portion (5, 6) including an
outer body (5) and an inner support tube (6) concentric therewith and
separated therefrom, and defining an axially extending blind ring-shaped
cavity (50) capable of being supplied with a fluid and housing an axially
movable tubular piston (4) supporting a drive member (3) engageable with
the diaphragm (13) of a clutch (1). The rear end (100) of the support tube
(6) has a transversely extending ring-shaped flange (61) by means of which
it engage a fixed portion (21), particularly the gearbox, and the rear end
of the body (5) is recessed for clamping the flange (61) between the body
(5) and the fixed portion (21).
Thomire; Sylvain (Levallois, FR), Giroire; Jean-Pierre (St Germain En Laye, FR)
08/722,230
PCT/FR96/00192
WO96/24782
95 01700
95 10750
192/91A,85CA,98 92/169.1
0 095 841
0 168 932
35 04 086
43 13 346
1.  Hydraulically controlled clutch release bearing for a clutch (1) with a diaphragm (13) having a fixed portion (5, 6) comprising an outer body (5) in a mouldable material and a
concentric inner support tube (6), distinct from the outer body (5) and defining a blind annular cavity (50) of axial orientation capable of being supplied with fluid and inside which is mounted an axially movable tubular piston (4) carrying a drive
member (3) capable of acting on the diaphragm (13) of a clutch (1), wherein the inner support tube (6) has at its rear end (100) opposite the diaphragm (13) an annular flange (61) of transverse orientation by means of which it bears on a fixed part (21),
and wherein the rear end of the body (5) opposite the diaphragm (13) is indented (112, 124) for clamping the flange (61) between the body (5) and the said fixed part (21), and wherein the annular flange (61) has an annular centering rim (62, 162) of
axial orientation for centering the inner support tube (6) in a fixed portion, and the annular centering rim (162) extends axially from the outer peripheral edge of the annular flange (61).
2.  Bearing according to claim 1, wherein the flange (61) has an axial offset (120, 122) which serves as a centering device for the outer body (5).
3.  Bearing according to claim 1, wherein an annular sealing joint (104) is interposed between the annular flange (61) and the outer body (5, 108).
4.  Bearing according to claim 1, wherein the inner support tube (6) is a metallic element produced by one of pressing and stamping deformation.
5.  Bearing according to claim 1, wherein the outer body (5) is stepped with a transverse shoulder (54) being formed and has a tubular portion (52) serving to center a pre-loading spring (7) acting between the shoulder (54) on the outer body (5)
and a shoulder on an annular flange (41) belonging to the piston (41).
6.  Bearing according to claim 1, wherein the inner tube (6) has a stop (9, 190) for limiting the movement of the piston (4) and for forming, prior to the mounting of the clutch release bearing (2) on said fixed part (21), a unitary assembly by
virtue of the pre-loading spring (7) holding the piston (4) in contact with the said stop (9, 190) and the outer body (5) in contact with the flange (61) of the inner support tube (6).  Description
present invention concerns hydraulically controlled clutch release bearings for a diaphragm clutch, notably for a motor vehicle.
The invention concerns more particularly a clutch release bearing having a fixed portion comprising an outer body and a concentric inner support tube distinct from the outer body, defining a blind annular cavity of axial orientation capable of
being supplied with fluid and inside which is mounted an axially movable tubular piston carrying a drive member capable of acting on the diaphragm of a clutch.
According to various known designs, means are provided for fixing the inner support tube to a fixed element, for example to the casing of the gearbox equipped with a clutch having such a concentric hydraulically controlled clutch release bearing,
and means are also provided for fixing the outer body to this same fixed part, the most precise concentricity possible also having to be ensured between these two elements of the fixed portion of the bearing.
To this end, the invention proposes a clutch release bearing of the type mentioned above, characterised in that the inner support tube has at its rear end an annular flange of transverse orientation, by means of which it bears on a fixed portion,
notably on a gearbox, and in that the rear end of the body in indented in order to clamp the flange between the body and the said fixed portion.
Other characteristics and advantages of the invention will emerge from the reading of the detailed description which follows, for an understanding of which
In FIG. 1, a clutch can be seen at 1 having, in succession axially, a reaction plate 10, a friction disc 11, a thrust plate 12, a diaphragm 13 and a cover 14 in the
form of a hollow dish.
The reaction plate 10 is designed to be fixed, here by screws, to a driving shaft, not visible, here the crankshaft of the engine of the motor vehicle, and offers up a friction face to the friction linings 16 which the friction disc 11 has at its
The thrust plate 12 offers up a friction face to the friction disc 11 and is connected in rotation to the cover 14, being mounted so as to be able to move axially in relation to the latter, and in a manner known per se, by means of tangential
tongues (not visible).
The diaphragm 13 has, in a manner known per se, an outer peripheral part in the form of a Belleville washer and a central part divided into radial fingers by slits opening out internally in the central aperture of the diaphragm and externally in
broadened orifices located at the inner periphery of the Belleville washer of the diaphragm.
Thus, by virtue of the small columns 20 the diaphragm 13 is mounted pivotally on the cover 14 between its primary and secondary supports and the clutch is normally engaged, the diaphragm 13 resting on the primary support of the cover 14 in order
to force the thrust plate 12 in the direction of the reaction plate 10 so as to clamp the friction linings 16 of the disc 11 between the thrust plate 12 and reaction plate 10.
In order to disengage the clutch, in a manner known per se, it is necessary to act here by pushing by means of the clutch release bearing 2 on the inner end of the fingers of the diaphragm 13 in order to make the latter pivot and to cancel the
load exerted by the diaphragm 13 on the thrust plate 12, the elastic tongues then returning the thrust plate 12 in the direction of the base of the cover 14 so as to release the friction linings 16 of the disc 11.
Here, the clutch release bearing 2 has a drive member 3 capable of acting on the inner end of the fingers of the diaphragm 13, a movable part, namely an axially movable piston 4, acting on the drive member 3 in order to manoeuvre the latter, a
fixed portion 5, 6, here in two pieces 5, 6, defining with the piston 4 a control chamber 50, elastic preloading means 7 interposed between the fixed portion 5, 6 and the piston 4 in order to permanently force the drive member 3 into contact with the
fingers of the diaphragm 13 so as to exert a small initial load on the diaphragm 13, a protective bellows 8 and a guide sleeve 9 for guiding the piston 4 during its axial movement.
Here, the self-centering washer 32 is a washer of tapered shape whose inner periphery is divided into inclined lugs which bear against the side, furthest away from the flange 41, of a groove 42 made in the piston 4, between the free end of the
latter and the flange 41.
The washer 32 thus has a dihedral cross-section and enables the edge 31 to be clamped in contact with the flange 41.  Here, the height of the edge 31 is greater than the diameter of the balls of the bearing 3.
A self-centering clutch release bearing is thus created in a manner known per se, enabling the bearing 3 to travel radially in order to center itself in relation to the diaphragm 13, the clamping force exerted by the washer 32 depending on
application while being calibrated so that the bearing does not fall under the effect of its own weight.
This tube 6, in this case metallic, which is produced, for example, by pressing or stamping, has at its rear end 100 an annular flange 61 of transverse orientation, radially towards the outside, by means of which it bears on the gearbox 21, being
thus contiguous with the latter against an annular transverse surface 102 arranged opposite the gearbox.
This tube 6 has an annular centering rim 62 produced in its flange 61 by folding.  Here, the rim 62 extends roughly from a median part of the flange 61.
The rear end of the body 5 is indented, that is to say a countersink 112 is provided, produced by milling, in its rear annular transverse face 108, having a right-angled cross-section for the centering of the body 5 on the outer periphery of the
flange 61, in this case metallic, and for the clamping of the flange 61 between the body 5 and the casing of the gearbox 21.
At the same time as the parts 5, 6 are fixed simultaneously, a centering of the inner tube 6 is assured by means of its rim 62 in the bore 63, and a relative centering of the outer body 5 on the inner tube 6 assured by means of the countersink
112 which receives the transverse side 61.
Thus the chamber 50 is of annular, cylindrical shape and of axial orientation, being delimited at its outer periphery by the tubular body 5, at its inner periphery by the tube 6, at one of its axial ends by the flange 61, forming the base of the
chamber 50, and at its other axial end by the movable piston 4.
This piece 46 is metallic and has a right-angled cross-section with a transverse part anchored (embedded) in the joint 45 and an axial part engaged on the outer periphery of the piston and provided with inclined, serrated lugs obtained by cutting
As will have been understood, the joint 45 equipped with its piece 46 is installed by being snapped into place, the lugs of the piece 46 spreading in order to then come into engagement with the side of the groove in the piston 4 nearest the rear
face of the piston 4.
The pre-loading spring 7, the piston 4 with its flange 41, the sleeve 9, the tube 6 and the tubular portion 52 are located radially below the main part of the non-rotating inner raceway 34 of the bearing 3, the said raceway 34 being of roughly
axial orientation, being equipped at its inner periphery with the edge 31 and at its outer periphery with the edge 35.
Thus the piston 4 has at its front end a tubular nose 40 projecting axially in relation to its flange 41 and enabling, by virtue of the groove 42, the self-centering washer 32 to be installed and the movement of the edge 31 and bearing 3 to be
limited, a predetermined radial clearance existing between the internal bore of the edge 31 and the outer periphery of the nose 40.
This arrangement allows the available space to be used optimally and the axial dimension of the bearing 2 to be reduced, each nozzle 56, 57 thus having a transversely orientated part extended by an inclined part for connection to the thicker rear
end in the form of a collar 53 on the body 5.
Here the control fluid is oil.  Naturally the fluid can be gaseous in nature.
The catch 92, forming a tenon, is engaged in the indentation 55 forming a mortice, contact being made between the catch and the base of the indentation 65, then locking is effected by producing laterally a crimp causing the material of the
lateral edges of the indentation 55 (FIG. 4), whose edges have a U-shaped cross-section, to yield.
It will be appreciated that the body 5 does not need to be machined in a precise manner, the areas for guiding the piston 4 being formed by the outer periphery of the sleeve 9 and by the outer periphery 116 of the tube 6, the joint 45 being
guided by the tube 6 and the internal bore 114 of the body 5.
In addition, with a fixed portion in two parts, it is easy to produce supply and drainage channels associated with the nozzles 56 and 57, for example by drilling, given the fact that the said channels are installed at the rear of the outer body 5
and are partially inclined.
As can be seen in this figure, the transverse flange 61, which extends the inner tube 6 at its rear part 100, has, in transverse section, an annular offset 120 of annular orientation which delimits an area 122 for centering the body 5 on the tube
6 and which is received in an indentation 124 of complementary shape formed in the annular rear transverse face 108 of the body 5.
The flange 61, beyond its offset 120 of axial orientation, is extended, in the opposite direction to the piston 4, by an axially orientated part in the form of a bush 162 which provides a centering function equivalent to that of the rim 62
produced by folding in the first embodiment illustrated in FIGS. 1 and 3.
The simultaneous mounting and clamping of the fixed parts 5 and 6 are provided, as in the case of the first embodiment, by the clamping in position by its flanges (not depicted) of the outer body 5 on the fixed part 21 of the casing of the
It will be noted that the supply nozzles 156 and drainage nozzles (not visible) extend here in an inclined manner and that the piston 4 has two rings 192 split for sliding along the outer periphery of the inner tube.  In this case the sleeve 9 of
FIG. 1 is omitted and the piston 4 has at its free end a scraper joint 191 mounted in a housing 193 produced at the free end of the piston 4 by virtue of a change in the diameter of its internal bore.  The joint 191 prevents oil leaking in the direction
notably of the friction linings of the disc 11.  A ring 190 masks the housing 193.
This ring is mounted on the tube 6, for example, in the same way as the sleeve 9 of FIG. 1, that is to say notably as in FIG. 4.  Here, mounting is effected by snapping in, the ring 193 having at its inner periphery a rim engaging in a groove
produced at the free end of the tube 6.
By virtue of the stop 5, 190, it is possible to form, prior to mounting the clutch release bearing 2 on the fixed portion 21 of the vehicle, a manipulatable and portable unitary assembly by virtue of the pre-loading spring 7 acting between the
piston 4 and the body 5 while allowing a contact between the piston 4 and its associated stop 9, 190 and a contact between the support tube 6 and the rear face 108 of the collar 53 of the body 5, the latter then being centered by the outer periphery of
the flange 61 or by the return 120.
Given that the bellows 8 delimits, with the piston 4, the body 5 and the bearing 3, a sealed housing, it is possible to drill a channel 160 (FIG. 7) in the piston to collect the oil leaks present between the inner bore of the piston 4 and the
outer periphery of the tube 6.
By virtue of the scraper joint 191 the oil leaks enter the sealed housing and can be discharged via a channel 150.  This L-shaped channel 150 is then produced in the rear portion 53 of the body 5 and has an axial part 132 and a transverse part
152 produced in a nozzle 76 in one piece, by moulding, with the rear portion 53.  A conduit is connected to the nozzle 76 in order to discharge the oil.
The part 131 serves to house with clearance the axially oriented end strand 130 of the pre-loading spring 7 thus fixed with respect to rotation to the body 5.  The other end of the spring 7 has an inclined strand in contact with the flange 41,
hollowed to receive this strand.
The piston 4 is thus fixed in rotation.  Naturally, for example in FIG. 3, an axial drilling can be produced in the portion 53 for mounting the axial strand of the end of the spring 7.
In a general manner, the installation of the clutch release bearing is simple.  This is because the support 6 is placed on the body 5 or vice versa, then the part 83 is fitted and the bellows 8 put in place, and afterwards the spring 7 is fitted,
followed by the sleeve 9 or the stop 190.  Finally the bearing 3, the washer 32 and the other end of the bellows are installed.
Naturally the bearing can first be mounted on the piston.  In operation the piston 4 moves along the inner tube 6 when the chamber 50 is pressurised.  It returns to its retracted position under the action of the diaphragm 13 (lower part of FIG.
1, chamber 50 depressurised).
It thus emerges from the description and the drawings that the clutch release bearing 2 forms a receiver of the concentric type controlled by a master cylinder operated by the clutch pedal and that the piston 4 projects axially in relation to the
outer body 5, sliding axially along the inner support tube 6 mounted in a concentric manner in relation to the outer body 5, extending in axial projection in relation thereto.
"Hydraulically Controlled Clutch Release Bearing For A Motor-vehicle Diaphragm Clutch - Patent 5865288"
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