FR2529978A1 - DISC BRAKING DEVICE WITH PRESSURE FLUID DEFREINING CONTROL - Google Patents

Abstract

THE INVENTION RELATES TO A BRAKING DEVICE WITH A ROTATING BODY 1 BY SPRINGS 18 AND HYDRAULIC BRAKING 10, INCLUDING A BRAKING CHAMBER 26, AN ENCLOSURE 11 CONTAINING BRAKE DISCS 12, A COVER 10 CLOSING THE ENCLOSURE 11 AND PRESSING ON BRAKE LININGS 13 AND A BRAKE PISTON 10. IN THIS DEVICE: A. THE BRAKE CHAMBER AND THE CLOSED ENCLOSURE ARE IN PERMANENT COMMUNICATION; AND B. A GASKET (IN ROTATION) IS PROVIDED BETWEEN THE BODY AND THE ENTIRE FRAME AND THE CRANKCASE, JOINT IN ROTATION. ONE APPLICATION IS THE REALIZATION OF A SAFETY BRAKE FOR A HYDRAULIC MOTOR.

Description

Disc braking device with brake release control

by fluid under pressure.

  Multidisk brakes in mechanically braking oil

  nique (under the action of return springs) and release brake fluid under pressure are already known and today include: a chamber containing oil at atmospheric pressure and brake discs a room in the open air containing the springs necessary for mechanical braking a chamber in excess pressure with respect to the preceding chamber, which is separated by the brake piston, allowing

  hydraulic brake release in operation.

  The chamber containing the discs is distinct from that in which the piston moves, which implies a certain

  number of consequences, considered, in fact, as inconveniences

  Thus, the brake release piston has a relative dimension-

  low, hence the need, to be able to release, with a determined pressure, to initially provide springs of

  brake control with return forces also relatively

  The corresponding braking may then be insufficient

  unless, of course, an increase in the diameter of

  be the brake release piston, and therefore the size of the brake.

  Increasing the pressure itself is not a simple operation as it usually leads to a necessary increase

  dimensions of the various constituents.

  The object of the invention is to remedy its disadvantages of the known brakes, as well as to propose a simplification thereof.

of their constitution.

  The invention therefore relates to a device for braking the relative rotation about an axis of a body and a frame mounted relative rotation, this braking device being constituted by: a housing integral in rotation with the frame and in a sealed manner with this frame, -2 a suitable housing cover with sealing to this housing so as to carry with it a closed enclosure, at least part of this cover being axially movable relative to the frame, at least one disk brake arranged transversely to said axis of rotation and integral in rotation with a first of two parts mounted relative rotation -body and frame,

  at least one integral brake lining

  tion of the second of said two parts -bâti and body-, the brake disc (s) and the brake lining (s) being disposed inside the enclosure, alternately facing one another, respectively, so as to cooperate in braking the relative rotation, the axially movable portion of the cover being axially aligned with said disk (s) and brake linings, resilient return members arranged between

  said axially movable portion of the lid and one of the two

  your parts mounted relative rotation - body and frame and apt,

  by pushing this axially mobile part and by its intermediary

  diary, to put in support the brake linings on the disks, a release chamber formed in the housing and containing a sliding piston, coupled to the axially movable portion of the cover, the brake release chamber being capable of containing a fluid under pressure of which the pressure has an antagonistic effect of that of the elastic return members, and a source * of pressure release fluid,

  to which said brake release chamber is selectively connected

  being supplied. In this device a) the brake release chamber and the closed chamber are in permanent communication, and, b) a seal (in rotation) is disposed between the body and the assembly of the frame and the housing, secured

in rotation.

  -3 The following advantageous provisions are, in

in addition, preferably adopted: -

  the piston is constituted at least by a portion of the cover, one of the ends of the housing is formed in a bore inside which at least a portion of the lid

  is slidably mounted with sealing ,.

  the lid is rigid, while the elastic return members are distinct from this lid ;,

  the body passes through the lid, the elastic organs

  These return elements are arranged between said bodies and cover, and a rotational sealing device is disposed between said bore and cover.

  a passage is provided between the body and the cover

  key, while the elastic return members include

  at least one elastic spring washer, watertight seals

  the interplay between this washer and, on the one hand, the body, on the other hand, the lid, a sealing device between the body and the lid; the elastic return members are arranged between the housing and the cover; the cover is constituted by a single piece shaped as a solid web not crossed by the body; the cover is a composite assembly consisting of a central thrust piece and a spring washer of revolution, the seals being arranged between -ladite

  spring washer, and on the one hand, said thrust piece, on the other

  on the other hand, the casing passes through the cover, while a rotational sealing device is disposed between said bodies and the cover the cover has an axial elasticity, the central part of this cover being, therefore, movable by relative to the periphery of said cover, while this periphery is in abutment on the housing and remains there by a holding means 4, such as a removable segment engaged in a groove of the housing the elastic return members are constituted

by the lid itself.

  The invention will be better understood, and secondary features and advantages will become apparent in the course of

  the description of achievements given below as examples

ple.

  It is understood that the description and drawings

  are only indicative and not limiting.

  Reference will be made to the accompanying drawings, in which: Figure 1 is a view, partly schematic, and partly in axial section, of a braking device according to the invention; and, FIGS. 2 to 6 are axial sections, similar to that of FIG. 1, of variant embodiments according to

to the invention.

  Each braking device of FIGS. 1 to 6 is adapted to the braking of a shaft 1 rotatably mounted relative to a frame 2, in a rotation of axis 3. In the example shown, the frame 2 constitutes the body of a hydraulic motor and shaft

  1 is an extension of the shaft of this engine.

  The casing 4 of the braking device comprises a planar face 5 which is applied on a flat transverse face 6, which comprises the frame 2, this casing being secured to the frame by means of screws 7, a seal 8, housed in a * groove of the frame and maintained in support on the face 5 of the housing,

  sealing the assembly plane 9 of the housing on the frame.

  In all six embodiments, the casing 4 is hollow and is closed, either by a cover 10 (FIGS. 1 to 3, and 6), or by the cover 10 and an associated spring washer 46, 47 (FIGS. 4 and 5). A closed enclosure 11 is thus provided

  in this housing, inside which are arranged

  brake shoes 12, integral in rotation with the shaft 1, as well as brake linings 13, integral in rotation with the inner wall of the casing, a lining being placed between two successive disks, and, in known manner, the axial succession of discs and brake linings starting at one end and ending at the other end of the stack by a brake lining 13. A boss 14 of the lid 10, in the form of a crown, is arranged facing, and is support on the brake lining 1-3 of one of the ends of said stack A to observe that, in FIGS. 1, 2, 4 and 6, the cover 10 has its periphery 15 introduced with axial sliding in a bore 16, of 3, formed in the end of the housing 4 opposite the face 5 A

  seal (sliding) 17 is disposed between the bore

  ge 16 and the periphery 15 of the lid -

  In the embodiments of Figures 1 and 2, a compression spring 18, consisting of a washer 'Belleville', is held in abutment on the outer side 19 of the cover 10 by a holding segment 20 removably inserted in a groove 21 formed in the end of the casing The effect of the spring 18 is to eliminate the clearances between the discs 12 and the brake linings 13, and by keeping the latter bearing on them, to immobilize the shaft 1 relative to to the casing 4

(and therefore with respect to the frame 2).

  In the embodiments of Figures 1 and 6, the shaft 1 through a central orifice 22, which is provided with the lid 10, with the interposition of a seal (in rotation) 23. In the embodiment of Figure 4, the shaft 1 also passes through a central orifice 37 of the cover 10, but with a

  large gap 38, so that no gasket

  placed between the orifice 37 and the shaft 1 A ring 39 is immobilized axially relative to the shaft by a segment 40 introduced into a groove 41 of the shaft A spring washer 46, type "Belleville" for example, orend support on a segment 42 introduced into a groove 43 of the shaft 1; on the cover 10 to put it itself in support, on the brake linings 13 finally,

252 E 978

* - 6: 9 9

  on two interposed O-rings, one 44 between itself, the ring 39 and the shaft 1, the other 45,

  between itself and the lid 10.

  In the embodiments of FIGS. 2, 3 and 5, the circular neck 10 is a solid web, which the shaft 1 does not cross.

  In FIGS. 2 and 3, this cover completely closes the opening

  On the other hand, in FIG. 5, the cover 10 occupies only the central part of this opening, the remainder thereof being closed off by an elastic washer 47 for supporting the cover on the brake linings. 13 At this

  end, the spring washer 47 is supported on a segment 48 containing

  naked in a groove 49 of the opening of the housing 4 Two seals 50 and 51 are interposed between the washer 47, and, on the one hand, the housing 4 with respect to the seal 50, other

  on the other hand, the cover 10 with respect to the seal 51.

  It should be noted that in the embodiment of FIG.

  the shaft 1 passes through the lid 10 with watertightness <23);

  elastic delle 18 bearing on a segment 52 introduced into a groove 53 of the shaft 1 to push the lid 10

  resting on the brake linings 13, without it being necessary

  re interpose any seal between this

washer 18 and the other pieces.

  In all cases, the shaft 1 passes through the frame 2 with the interposition of a seal (in rotation).

  the enclosure 11 is completely isolated from the outside.

  In the embodiments of Figures 1, 2, 3 and 5, a connector 25 opens into a peripheral chamber 26 of the housing, and allows to selectively connect the enclosure 11 to a pump 27, the peripheral chamber 26 and the enclosure 11 being in communication

  permanent and forming two parts of the same room.

  The pump 27 has its suction duct 35 connected to a tank 28 of fluid without pressure, and its delivery duct 29 connected to a fluid distributor 30 A duct 31 connects the distributor 30 to the tank 28, another duct 32 connecting the discharge pipe 29 to this reservoir 28, and

  a calibrated discharge valve 33 being disposed on this duct 32.

-7-

  Finally, a duct 34 connects the distributor 30 to the connector 25.

  This distributor 30 has three positions which correspond to

  at the first position, at the placing of the ducts 29 and 34 in communication, and at the closing of the duct 31 at the second position, at the placing in communication of the ducts 29 and 31, and at the closing of the duct 34; and, the third position, to the porting

ducts 29, 31 and 34.

  The device for supplying pressurized fluid comprising the pump 27, the reservoir 28 and the distributor 30

  is preserved (but not represented, because identical) in the reali-

  4 and 6 The only difference lies in the fact that the duct 34 is connected to a duct 54 formed in the shaft 1 itself, and opening directly into the enclosure

  11 (in Figure 4, in the area of space 38 of this enclosure

te 11).

  The cover 10 of the embodiments of Figures 1, 2, 4, 5 and 6 is rigid, substantially indeformable and its boss 14 bears against one of the brake linings 13 quo under the effect of elastic return of the washer elastic (18, 46, 47). In the embodiment of FIG. 3, the cover

  has an axial elasticity and is therefore

  same, the return spring whose effect is to support the boss 14 of this cover on one of the brake linings 13 Thus, there is no need to provide a separate spring 18 Of course, it remains necessary to provide a support element on the housing to the element providing the elastic function, that is to say at the periphery 15 of the cover 10 the removable holding segment 20 and the groove 21 realize this support element It should also be noted that the periphery 15 of the lid 10 is no longer slidably mounted relative to the

  casing 4, whose end therefore does not have to be machined into a bore

  On the other hand, a seal 36 (in compression) is interposed between the casing 4 and the periphery 15 of the cover 10.

: 8

  8- I 1 must finally be noted that if, in the embodiments shown, the casing 4 constitutes a separate piece of the frame

  2 to which it is assembled with the interposition of a sealing gasket

  8, an obviously equivalent achievement would be to

  fit the monobloc housing with the frame. The advantages of the provisions which have just been

  described will be noted below.

  First, the permanent communication of the

  11 and Chamber 26, or their confusion in one room.

  single operation, the release fluid, coming from the pump 27 when the distributor 30 is placed in its first position, acts on the entire cross-section of the

  cover 10 (FIGS. 1, 2, 3 and 6), or on the cross-section

  the lid 10 completed by the section of the elastic washer

  46, 47 (Figures 4 and 5), which constitutes a clear section

  higher than that of the brake release piston of previous achievements.

  It becomes possible, therefore, to realize the

  swimming using the same fluid pressure as the previously used pressure, ie using a lower pressure than the one previously used.

  is the same as before, the effort of defreindge e Bt superior

  better than it was previously, which makes it possible to

  a spring (18, 46, 47) having a greater restoring force

  In this case, the braking force is improved (higher than it was previously). But it is also possible by keeping the same braking force, and therefore the same braking force.

  than before, to adopt a lower brake release pressure

  to the previously-used pressure, which can sometimes

be interesting.

  When the cover 10 is traversed by the shaft 1 (FIGS. 1, 4, 6), the above advantage is already clearly obtained. This advantage is even more significant when the cover 10 is not traversed by the shaft (Figures 2, 3,) and that then the complete cross-section acts as a piston

of release -

  9 - It should also be noted the isolation of the enclosure 11 relative to the mechanism contained in the frame 2, by means of the seal 24 Thus, in a new way, the fluid (the oil) which is contained in the 11 enclosure, and wherein abrasive particles of brake linings and / or brake discs can be in suspension, does not risk polluting the mechanism housed by the frame 2 This is particularly interesting when this frame is that of a hydraulic motor,

  whose functioning does not support a possible pollution.

  Moreover, the brake and motor fluids being isolated from each other may be different and specific to each of them.

corresponding functions.

  The embodiment of FIG. 3, in which the

  vercle 10 also provides the elastic return function, is

advantageous by its simplicity.

  Finally, it must be observed that, on the face 19 of the cov-

  cle 10 being in free communication with the atmosphere, the

  10 of the cover 10, during a release, is performed without back pressure No transit out of or to the enclosure 11,

  of a volume of oil equal to the volume displaced by the piston of

  braking during its active run does not occur, which contributes

  to reduce the response times of the device both in braking

age, only in skidding.

  The brake operation is further fully

  independent of the mechanism on which this brake is mounted.

  The invention is not limited to the achievements described above.

  on the contrary, all the variants which

  They should be brought to them without leaving their frame or mind. -

Claims (9)

R E V E N D 1 C A T I 0 N S-   1 device for braking the relative rotation about an axis (3) of a body (1) and a frame (2) mounted relative rotation, this braking device being constituted by: -   a housing (4) integral in rotation with the frame (2) and sealingly (24) with this frame, a cover (10, or 10-46, or 10-47) suitable housing with sealing (17, 36, 50 ) to this casing so as to produce therewith a closed enclosure (11), at least a portion (14) of this cover being axially movable relative to the frame (2),   at least one brake disk (12) arranged transversely   salement with respect to said axis of rotation (3) and integral in rotation with a first (1) of the two parts mounted relative rotation -body (1) and frame, at least one brake lining (13) integral in rotation of the second (2) of the two said parts -bâti and body-, the brake disc (s) (12) and the brake lining (s) (13) being disposed inside the enclosure (11), alternatively facing each other, respectively, so as to cooperate with the braking of the relative rotation, the   axially movable portion (14) of the cover being axially   generated with said discs (12) and brake linings (13),   resilient return members (18, 46, 47) are provided   sés between said axially movable portion of the cover and one of said two parts mounted relative rotation -body (1) and frame (2) and adapted, by pushing this axially movable portion (14) and through it, to put in support the brake linings (13) on the discs (12), a release chamber (11, 26) formed in the housing and containing a sliding piston, coupled to the axially movable portion (14) of the cover, the brake release chamber being capable of containing a pressurized fluid (27) whose pressure has an antagonistic effect with that of the elastic return members, and a source of brake release fluid (27) under   pressure, to which said brake release chamber is selectively   connected device, characterized in that a) the brake release chamber (26) and the closed enclosure (11) are in permanent communication, and   (b) a (rotating) gasket (24) is   se between the body (1) and the assembly of the frame (2) and the housing (4), integral in rotation.   Braking device according to Claim 1, characterized in that the piston is constituted at least by part of the lid (10).   3 Braking device according to any one   Claims 1 and 2, characterized in that one of the ends   of the casing (4) is formed into a bore (16) inside which at least a portion (15) of the cover (10) is slidably mounted with sealing (17). 4 Braking device according to claim 3, characterized in that that the lid is rigid, while the elastic return members (18, 46, 47) are distinct of this lid (10).   Braking device according to claim 4, characterized in that the body (1) passes through the cover, the elastic return members (46, 18) are arranged between   said body (1) and cover (10), and a sealing device   rotating part (17) is arranged between said bore (16) and cover (10).   Braking device according to claim 1, characterized in that a passage (38) is provided between the body (1) and the cover (10), while the elastic members   with at least one elastic washer of revolu-   tion (46), seals (44, 45) being interposed between this washer (46) and, on the one hand, the body (1), on the other hand the cover (10).   Braking device according to Claim 5, characterized in that a sealing device   (23) is disposed between the body (1) and the lid (10).   12 - 8 Braking device according to claim 4, characterized in that the resilient-biasing members I 8,   47) are arranged between the housing (4) and the cover (10).   Braking device according to Claim 8, characterized in that the cover consists of a part   single (10) shaped as a solid web not traversed by the body.   Braking device according to claim 8, characterized in that the cover is a composite assembly constituted by a central thrust piece (10) and a spring washer (47), the seals (51, 50) being disposed between said spring washer and, on the one   said thrust piece (10), on the other hand the housing (4).   Braking device according to Claim 8, characterized in that the body (1) passes through the cover (10), whereas a rotational sealing device (23) is   disposed between said bodies (1) and cover (10).   Braking device according to any one of   Claims 1 and 2, characterized in that the cover   (10) has an axial elasticity, the central portion (14) of this cover being thereby movable relative to the periphery (15) of said cover, while this periphery (15) bears on the housing (4) and remains there by a holding means (20), such as a removable segment (20) engaged in a groove (21) of the housing.   Braking device according to Claim 12, characterized in that the elastic return members are   constituted by the cover (10) itself.