FR3048473B1 - ENGINE FOR EXTERNAL BRAKE RELIEF SYSTEM, ASSOCIATED SYSTEMS, AND ASSOCIATED METHODS - Google Patents

Abstract

The invention proposes a hydraulic motor (100) comprising a cylinder block (106) and a motor shaft (120), the cylinder block (106) being configured to drive in rotation the motor shaft (120), said motor shaft ( 120) comprising: - an outer end (124) forming the motor output shaft (120), - an inner end (126), the motor shaft (120) extending in a longitudinal direction (X) the engine comprising a hydraulic brake system (200) configured to: - allow rotation of the motor shaft (120) when hydraulic release pressure is provided, and - keep the motor shaft (120) stationary otherwise the braking system (200) comprising a brake piston (220) located in the extension of the inner end (126) of the shaft (120) and movable in translation in the longitudinal direction (X), the motor (100) ) being characterized in that the drive shaft (120) comprises a longitudinal through duct (128) for access control of the longitudinal position of the brake piston (220).

Description

Motor for external brake release system, associated systems, and related methods

GENERAL TECHNICAL FIELD The invention relates to the field of vehicles comprising hydraulic assistance in the form of a motor mounted on an axle. In particular, the vehicles concerned are construction site, mining or agricultural vehicles.

More specifically, the invention relates to hydraulic machines, such as radial piston engines, installed on the vehicles mentioned above and the associated brake system.

In the following, we speak indistinctly machine or engine.

STATE OF THE ART

As shown in FIGS. 1 and 2, the hydraulic motors 100 comprise a shaft 120 to which is affixed the hub of a wheel R, and a brake system 200 configured to block the rotation of the shaft when said brake system is not not powered. Thus, by default, the shaft 120 is immobilized. The shaft 120 extends along a longitudinal axis X and rotates about this axis. The drive shaft 120 is rotated by splines (not shown in the figures).

The motor 100 comprises a casing 105 generally comprising a bearing cover 103 and a dispensing cover 104, a cylinder block 106 inside which is disposed a plurality of radial pistons 108 (dashed) which slide at the inside their respective cylinder, a lobed cam 110 on which the pistons 108 roll, thus moving back and forth inside their cylinder. The cylinders are fed with pressurized oil (more than 300 bars) and rotates the cylinder block 106. High pressure and low pressure supplies 116, 118 are typically located in the dispensing cover 104.

The cylinder block 106 is integral in rotation with the shaft 120, either by a fixed connection or by a clutch. Grooves, not shown, can form such a connection. The oil supply is performed for a distributor 112 which has high and low pressure supply lines. The dispensing cover 104 covers the dispenser being located radially outwardly. On the other side of the cylinder block 106, the bearing cover 103 protects bearings 114 which allow rotation of the shaft while acting as transmission of the force to the motor housing, the housing being secured to the frame of the vehicle.

Several types of motors exist with regard to the architecture of the bearings (force recovery via the shaft or the hub of the wheel) and will not be detailed here. The shaft 120 is for example connected to the wheel R. by means of a hub / flare 122 located at the outer end 124 of the shaft 120 and having orifices for receiving screws securing the wheel.

More generally, the outer end 124 serves as an output for the motor shaft 120, and is the point of recovery of the torque produced by the motor 100.

Existing brake systems are generally positioned at the inner end of the shaft. By internal, we mean the end which is located the most inside the vehicle.

It is also possible that the shaft 120 stops at the cylinder block and is extended by a brake shaft 130, itself driven by the cylinder block. This allows the so-called modular motors to easily have alternating motors with or without brake. The brake shaft 130 may therefore be distinct from the drive shaft 120.

We will therefore speak later internal end 126, 136 designating the inner end of the shaft 120 or the brake shaft 130 which comes into contact with the brake system 200.

The brake system 200 comprises a brake cover 202 integral with the casing, in particular here the dispensing cover 104, which houses an oil inlet 204 and a brake piston 220 movable in translation along the longitudinal axis X to immobilize the casing. 120. For this, the brake piston bears on a series of disks or pads 225 located radially around the inner end of the shaft 120 and interposed between a series of disc 125 integral in rotation with the shaft 120. When the brake piston 220 approaches the shaft 120, it comes to tighten the discs 225 and therefore the discs 125, causing the immobilization of the shaft 120. In practice, the discs 125 can be housed in a groove longitudinal axis of the shaft 120, 130 to allow relative axial displacement. The oil inlet 204 feeds a thrust chamber 206 (between the brake piston 220 and the brake cover 202) configured so that the pressurized oil pushes the brake piston 220 away from the shaft 120. the other side of the piston, recall means 208 generate a counterforce that tends to maintain the piston 220 in the braking position, that is to say the discs 125, 225 pinched. The recall means abuts a ring 209. When the brake system 200 is not supplied with oil under pressure, the recall means 208 immobilize the shaft 120 via the piston 220 and the disks 225, 125.

The recall means 208 take the form of, for example, a washer.

A cover 210 covers the return means 208 and the brake piston 220 longitudinally. The cover 210 bears against the brake cover 202. The cover 210 comprises a generally central orifice 212 which makes it possible to access a tapping. 222, generally central, present in the brake piston 220. A cap 214, bearing on the cover 210, in the cover 210 makes it possible to close this orifice 212 and to protect the tapping 222.

Seals are provided to prevent leakage of pressurized oil. For example, between the brake cover 202 and the distribution cover 104, at the discs 125, 225, oil leaks may occur (the discs are immersed in the oil), so an annular seal 213 is provided radially around the shaft 120, 130. Another seal 215 is provided in the brake cover 202, between said cover and the brake piston 220 which is movable in translation.

As previously indicated, by default, the brake system 200 is in the default braking position, when no pressurized oil is injected. Once pressurized oil is injected, the brake piston 220 is translated away from the shaft 120 (see arrow in Figure 1) and allows the rotation of the shaft. This is a "hydraulic brake release", used by safety, to see an automatic action of the brake in case of hydraulic failure or when the vehicle is These brakes can be designated as "negative brakes" or "parking brakes" or "Emergency brakes".

On the other hand, it is possible that one wishes to deactivate this "default" braking, for example when towing. For this, a holding device 230 must be inserted into the orifice 212 to be screwed into the tapping 222. The holding device 230 is typically in the form of a screw 232 with head 234, the screw 232 to screw itself in the tapping 222 and a nut 236 inside which is screwed the screw 234 and being abutted against the cover 210. A rotation of the head makes it possible to pull the piston towards the cover 210 (see FIG. 2) and it is thus possible to compress the brake piston 220 against the return means 208 and thus move the disks 225 to release the shaft 120, 130 in rotation, even in the absence of any hydraulic supply. This is a "mechanical release", usually used during vehicle assembly, maintenance or breakdown.

Thus, to activate the mechanical release, it is necessary to perform manipulations on the inner side of the machine 100, that is to say in a place often not accessible when the vehicle is placed on the ground. It is therefore necessary to lift the vehicle or disassemble the wheel and / or the machine to perform these manipulations.

In addition, the same problems arise when it is desired to measure the state of wear of the brakes, including 225 discs. However, some standards require frequent checks. The current architecture complicates the use and maintenance.

PRESENTATION OF THE INVENTION The invention proposes a hydraulic motor comprising a cylinder block and a motor shaft, the cylinder block being configured to rotate the motor shaft, said motor shaft comprising: an outer end forming the drive shaft; motor output, - an inner end, the motor shaft extending in a longitudinal direction, the motor comprising a hydraulic braking system configured to: - allow rotation of the motor shaft when a hydraulic release pressure is provided, and - keep the motor shaft stationary otherwise, the braking system comprising a brake piston located in the extension of the inner end of the shaft and movable in translation in the longitudinal direction, the motor being characterized in that that the motor shaft comprises a longitudinal through duct to access the control of the longitudinal position of the brake piston.

The hydraulic motor as shown here is designed so that it can receive a push rod disposed in the longitudinal duct and translationally controlled within said duct by means of adjustment means.

Advantageously, the engine is radial pistons. The invention also proposes a system comprising a motor as described above and comprising a push rod and means for adjusting the rod, said rod being insertable in said longitudinal duct and comprising: an external end configured to be accessible from the external shaft when installed in the longitudinal conduit, and a pusher end configured to apply a force to the brake piston when positioned in a release position within the longitudinal conduit.

This system may comprise the following features, taken alone or in combination depending on the compatibilities between the embodiments: the push rod is removable, the push rod is disposed in said longitudinal duct, the motor shaft extends longitudinally to the brake system and said brake system is configured to act directly on the motor shaft; - the thrust rod passes entirely through the motor shaft, so that it can cause the brake piston to move by contact,

The system further comprising a brake shaft disposed in the longitudinal extension of the drive shaft and drivable in rotation by the cylinder block, said brake shaft being located longitudinally between the motor shaft and the brake piston, the shaft brake comprises a longitudinal duct through and said rod passes through the longitudinal ducts of the motor shaft and the brake shaft, so that the push rod can cause by contact the translation of the brake piston, the brake shaft comprises a longitudinal through duct and in that it comprises a second rod disposed in the longitudinal duct passing through the brake shaft, said second rod comprising a pusher end configured to abut against the pushing end of the push rod and having an inner end configured to transmit a force to the brake piston, the pusher end of the second rod reaches an end 1 of the brake shaft, the push rod or the second rod comprises a longitudinal stop, such as a flare at its inner end, to limit the longitudinal translation towards the outside of the engine, the system comprising a seal radial annulus housed in the longitudinal duct between the second rod and the brake shaft, for sealing the clearance between the brake shaft and the second rod, the pushing end of the motor shaft and / or brake have surfaces of contact convex to allow a centered contact regardless of the longitudinal misalignment, the brake shaft is movable in translation along the longitudinal axis and is configured to transmit the force of the push rod to the brake piston , the hydraulic motor comprises a bearing disposed between on the one hand an inner end of the push rod or the second rod and on the other hand the brake piston to facilitate relative rotation By maintaining contact, the bearing is lubricated by the oil from the hydraulic brake system, an inner end of the thrust rod or the second rod includes a friction pad configured to facilitate relative rotation while maintaining contact. , the system comprises a radial annular seal housed in the longitudinal duct between the push rod and the drive shaft, to seal the clearance between the drive shaft and the push rod, the push rod comprises two positions, a position of braking in which the brake piston is in the braked position and a braking position in which no force is applied to the brake piston via the push rod, the adjusting means comprise a reversible nut, said nut comprising a skirt cylindrical barrel shape integral with a body, said skirt having a diameter greater than that of the outer end of the push rod, the body comprises nt a through hole configured to transmit a moment by a tool, and the adjusting means comprising a thread on the outer surface of the reversible nut, adapted to cooperate with a thread inside the longitudinal conduit, the reversible nut being insertable in both directions within the longitudinal conduit, the adjusting means comprises a thrust screw integrated with the outer end of the rod and a nut, the push rod comprises an anti-rotation finger configured to prevent rotation of said rod relative to the longitudinal duct, the second rod comprises an anti-rotation finger configured to prevent the rotation of said rod relative to the longitudinal duct, the second rod or the push rod comprises a longitudinal stop, in order to limit the translation towards the outside of the engine. The invention also proposes an assembly comprising a motor or a system as described above, and a gauge, said gauge: - being configured to be positioned along the longitudinal direction and, - including indications making it possible to know the relative longitudinal position. of the brake piston, so as to be able to know the state of wear of the brake system.

In one embodiment, the gauge comes into contact with the brake piston.

In one embodiment, the gauge comes into contact with the push rod. The invention also provides a brake control method using a motor, system, or assembly, said method comprising a step of measuring the position of the brake piston.

Advantageously, the method comprises the following characteristics, taken alone or in combination: the gauge comes into contact with the brake piston,

The method comprises a step of moving the push rod within the longitudinal duct,

The method comprises a step of measuring (E2) the position of the push rod within the conduit during the braking position and a step of analyzing the measurement to determine the wear of the brake system. the measuring step (E2) is performed using a gauge positioned in abutment against the outer end of the push rod, the measuring step (E2) is performed by counting the number of turns to reach the braking position, the adjusting rod is not inserted into the longitudinal duct, said method comprising a step of measuring (E2) the position of a gauge inserted in the longitudinal duct,

The method comprises comprising a measuring step (E2) performed by counting the number of turns of the push rod between a reference position and a stop position on the brake piston in the braking position,

The method comprises a step (E21) of setting brake position of the brake system, and a step (E22) of setting brake braking stop position, going from one to the other to the help setting means. the measuring step (E2) is performed by counting the number of turns of the push rod to change position. the measurement step comprises the following substeps: - (E21) screwing the thrust screw to a pre-tightening position or a maximum position, respectively, - (E22) screwing the thrust screw up to at the maximum or pre-tightening position, respectively, of the brake piston, counting the number of revolutions.

The method comprises an intermediate step of writing on the hydraulic machine the value recorded in the measuring step (E2), in order to serve as a reference for the posterior measurements.

PRESENTATION OF THE FIGURES Other features, objects and advantages of the invention will emerge from the description which follows, which is purely illustrative and nonlimiting, and which should be read with reference to the appended drawings, in which: FIGS. 1 and 2 represent a hydraulic machine according to the prior art, - Figures 3 to 6 show different embodiments of the invention, - Figures 7 and 8 illustrate measurement embodiments, - Figures 9 and 10 illustrate a reversible nut. , according to two opposite front views, - Figures 11 and 12 illustrate this nut in position, in a side view.

DETAILED DESCRIPTION

The description of the hydraulic machine 100 and the brake system 200 was made in introduction.

An axial piston hydraulic motor can also be used.

In order to access the brake system from outside the vehicle, the drive shaft 120 includes an outer end 124 to which is typically attached a wheel, typically by screw-nut, or other torque recovery device, and a internal end 126, located inside the hydraulic machine 100. The outer end 124 is accessible from outside the vehicle, either by removing the wheel or being in the middle of the wheel hub. As in introduction, we define a longitudinal direction X which extends the drive shaft 120 and around which it is substantially rotating (with the games).

The braking system is typically negative type as introduced in introduction, that is to say that when a hydraulic pressure called "release", the brake system 200 is in the released position and the brake piston 220 allows the rotation of the motor shaft 120. When no hydraulic pressure is applied, the recall means 208 move the brake piston 220 which blocks the motor shaft 120. It will be seen later that various intermediate elements can be provided. .

The braking system 200 is located in the longitudinal extension of the shaft 126, towards the inside of the vehicle from the inner end 126 of the shaft 120. The driving shaft 120 comprises a duct 128 extending according to the invention. longitudinal axis X and passing through the motor shaft 120 from one side. For balancing reasons (even if the rotation of the shaft is generally small, especially in the case of a radial motor), the duct 128 is centered in the motor shaft 120, that is to say that the longitudinal axis X, which is also the axis of rotation, is in the center of the motor shaft 120 and the duct 128.

The conduit 128 is a bore made in the motor shaft 128, which is generally made of metal.

The duct 128 makes it possible to control the longitudinal position of the brake piston 220. In certain embodiments that will be described, this duct 128 opens out facing the brake piston 220. In other embodiments, this duct 128 opens out against of the brake shaft 130. In a general embodiment, the conduit 128 opens into the thrust chamber 206, that is to say that it is in fluid communication therewith.

The motor is thus defined as comprising said duct 128.

Axially, the shaft 120 and / or the brake shaft 130, if present, is surrounded radially and successively from the outside towards the inside, bearings 114, the cylinder block 106 and a distributor 112.

This duct 128 is adapted to receive a push rod 300, movable in translation. The translation is controlled by means of adjustment means 310 which will be detailed later.

The thrust rod 300 therefore also extends along the longitudinal axis X, within the drive shaft 120.

The push rod 300 is defined as an outer end 304 and a push-on end 302. The outer end 304 is the end that is accessible from outside the vehicle, that is, it can be manipulated from the level of the outer end 124 of the motor shaft 120. Handling means either manipulating by hand or manipulating with a conventional tool (Allen key, etc.). The pusher end 302 is intended to allow the translation of a contact element 350, the contact element 350 being intended to come into contact with the brake piston 220 of the braking system 200 to cause (or not) its translation along the longitudinal axis X and thus activate or deactivate braking.

The push rod can either be permanently in the machine, or be supplied separately and inserted by the user when he needs it. For this purpose, we define a system comprising the engine as shown here in all its variants and the rod as shown here in all variants, within the limit of compatibility variants. The rod can be removable, being either out of the engine or in the engine, or be inserted during assembly in the engine. The rod can then be supplied in an accessory kit.

In the same way, the adjustment means 310 or certain parts of adjustment means can be permanently or separately supplied. At present, particular embodiments will be detailed.

The arrows in the figures indicate the main elements movable in translation along the longitudinal axis X.

First embodiment

This embodiment is shown in FIG. 3. The drive shaft 120 extends along the longitudinal axis X to the brake system 200. The drive shaft 120 thus itself comprises the discs 125 which cooperate with the discs. 225 of the brake system 200. The brake system 200 thus acts directly on the drive shaft 120. The contact element 350 is here formed by push rod 300. For this, the push rod 300 extends according to the invention. longitudinal axis X, in its duct 128, to the brake system 200, and passes entirely through the drive shaft 120. The push rod 300 is configured for, under the effect of a translation of the adjustment means 310, cause the translation of the brake piston 220.

Radially around the rod 300 are therefore, in a successive manner in the longitudinal direction X, the bearings 114, the cylinder block 106 and a distributor 112. The brake shaft

In the following embodiments, the hydraulic machine 100 further comprises a brake shaft 130 disposed in the longitudinal extension X of the drive shaft 120, on the inner side. This brake shaft 130, distinct from the drive shaft 120, is provided to simplify the modularity of the various models of hydraulic machine 100. When it is provided, the brake shaft 130 comprises the discs 125 which will cooperate with the disks. 225 of the brake system 200. The brake shaft 130 is rotated by the cylinder block 106, typically using the same splines as those which drive the drive shaft 120.

Longitudinally, the brake shaft 130 is disposed between the brake piston 220 and the drive shaft 120.

The motor shafts 120 and brake 130 are in contact at the inner end 126 of the drive shaft 120, but as the two shafts rotate at the same speed, no significant problem of friction arises. In addition, the interface between the two shafts 120, 130 is in fluid communication with the casing 105 which is under oil pressure. The interface is lubricated with oil.

A recess E may be provided at the central portion of the inner end 126 to receive oil and act as a local reservoir for lubrication, or to allow assembly of the system more easily.

This recess can also be made on the brake shaft 130.

Second embodiment

This embodiment is shown in FIG.

Here, similarly to the drive shaft 120, the brake shaft 130 comprises a conduit 138 extending along the longitudinal axis X and through the brake shaft 130 from one side.

The duct 138 is centered in the brake shaft 130, that is to say that the longitudinal axis X, which is also the axis of rotation, is in the center of the brake shaft 130 and the duct 138. .

The conduit 138 is a bore made in the brake shaft 130, which is generally made of metal. The contact element 350 is formed by the push rod 300. For this, the push rod 300 extends along the longitudinal axis X, in the conduits 128 and 138, to the brake system 200, and passes through integrally the two shafts 120, 130.

The thrust rod 300 is configured for, under the effect of a translation of the adjustment means 310, cause the translation of the brake piston 220.

This embodiment requires that the longitudinal ducts 128, 138 are perfectly aligned at all times, which can lead to costly constraints in terms of sealing, maintenance and manufacturing, such as the need for greater play. for the push rod 300.

Radially around the rod 300, 350 are therefore, successively in the longitudinal direction X, the bearings 114, the cylinder block 106 and a distributor 112. Radially between the bearings 114 and the cylinder block 106 of on the one hand, and the rod 300 on the other hand, is the motor shaft 120. Radially between the cylinder block 106 and the distributor 112 on the one hand, and the rod 300 on the other hand, is the shaft brake 130.

Third embodiment

This embodiment is shown in FIG. 5. The brake shaft 130 comprises the longitudinal duct 138 as defined previously.

On the other hand, the contact element 350 is a second, independent rod disposed in the longitudinal longitudinal duct 138 of the brake shaft 130. The push rod 300 only passes through the motor shaft 120. rods 300, 350 are substantially aligned, that is to say that at play near the brake shaft 130 relative to the motor shaft 120, they are aligned.

The second rod 350 comprises a pusher end 354, configured to abut against the pusher end 302 of the push rod 300. The second rod 350 is movable in translation in the conduit 138 of the brake shaft 130.

In this embodiment, in particular because of the play in the splines, the motor shaft 120 and the brake shaft 130 may have a slight misalignment without the risk of damaging the hydraulic machine 100. This means that the pushing end 302 of the push rod 300 appears substantially at the inner end 126 of the motor shaft 120 and does not enter the longitudinal conduit 138 of the brake shaft 130. The same reasoning applies to the pusher end 354 of the second rod. The recess E here also serves to locally release the push rod 300 to limit undesirable contacts and to ensure that each rod only abuts against the other rod. For example, a slight misalignment could cause the push rod 300 to abut against the brake shaft 130 which is not movable in translation.

In the same way, a recess 139 is provided in the brake shaft 130.

The surface S of the pusher end 354 of the brake shaft 130 is curved, to allow a centered and effective contact between the two rods 300, 350.

Alternatively or additionally (but not shown in the figures), the surface S of the pusher end 354 of the brake shaft is curved.

By convex, we mean convex.

Radially around the thrust rod 300 are therefore, in a successive manner in the longitudinal direction X, the bearings 114, the cylinder block 106. Radially between the bearings 114 and the cylinder block 106 on the one hand, and the rod 300 on the other hand, is the motor shaft 120.

Radially around the second rod 350 are thus, successively in the longitudinal direction X, the cylinder block 106 and the distributor 112. Radially between the cylinder block 106 and the distributor 112 on the one hand, and the second rod 350 on the other hand, is the brake shaft 130.

Fourth embodiment

This embodiment is shown in FIG. 6. The brake shaft 130 does not here comprise longitudinal duct 128 as defined previously. The contact element 350 is formed by the brake shaft 130 itself which is configured to be movable in translation along the longitudinal axis. The pusher end 302 of the push rod 300 comes into direct contact with the brake shaft 130 which itself comes into contact with the brake piston 220.

This embodiment requires that the discs 125 be movable in translation longitudinally with respect to the brake shaft 130 which carry them.

Radially around the thrust rod 300 are therefore, in a successive manner in the longitudinal direction X, the bearings 114, the cylinder block 106. Radially between the bearings 114 and the cylinder block 106 on the one hand, and the rod 300 on the other hand, is the motor shaft 120.

Means of adjustment

The push rod 300 is controlled in translation by adjustment means 310 which make it possible to modify the position of said rod 350 and therefore in fine of the brake piston 220 between several positions. A braking position is identified in which, in the absence of hydraulic pressure in the thrust chamber 206, the brake piston 220 blocks the driving shaft and a brake release position, in which the return means 208 abut against the washer 209 and the brake system 200 is disabled.

The adjustment means 310 can take several forms.

In a preferred embodiment, the longitudinal conduit 128 has a thread 129 of a given length at its outer end and the adjusting means 310 comprises a reversible nut 315 comprising a thread on the outer surface. The thread 129 may extend to the outer end emerging from the conduit 128 or be located strictly within said conduit. The reversible nut 315 comprises a skirt 316 in the shape of a cylindrical barrel within which the outer end 304 of the push rod 300 can be inserted. As indicated above, the outside of the skirt 316 is provided with also a thread complementary to that 129 of the longitudinal channel 128. The outer end 304 of the push rod 300 may comprise a portion of smaller diameter. The skirt 316 can not cause the translation of the rod 300 since said skirt 316 will be inserted, by longitudinal translation, radially between the portion of smaller diameter and the shaft 120. One end of the skirt 316 is secured to a body 317 forming a pushing surface and being able to receive a tool in both directions, as shown in FIGS. 9 and 10 (for example by means of a through hole 319 of non-circular shape, which can receive a moment by one 'tool). The reversible nut 315 can be put in place in both directions: in a first direction called "in free position" (FIG. 11), the skirt 316 is oriented inward: when it is put in place, the nut 315 can be screwed with the tool into the thread 129 so that the skirt 316 slides around the outer end 304 of the rod 300. On the other hand, the end of the thread is reached with the skirt (by a stop or other) before the body 317 comes into contact with the push rod 300. Thus, even when screwing to the maximum, or conversely by screwing almost, it is ensured not to maintain the brake system in position released, - In a second direction (inverted direction) said "in free position" (Figure 12), the skirt 316 is oriented outwardly: when it is put in place, the nut 315 can be screwed to the of the tool in the thread 129 to a position further inland than before, since the upe is located on the other side, which allows the body 317 to come into contact with the rod 300 and cause its longitudinal translation.

In another embodiment not shown, the adjustment means 310 comprise a set screw which comes into a thread in the conduit 128 and the screw causes the translation of the push rod 300.

Any means known in mechanics for carrying out the desired translation can be used here.

The adjustment means 310 are preferably configured so that in the maximum position it does not deteriorate the braking system 200 causing excessive translation or transmitting too much force (especially on the recall means 208 and the stop 209). For example, the threading of the duct 128 is suitably dimensioned, so that in the free position, the maximum screwing of the reversible nut 315 does not make it possible to cause the translation of the brake piston 220 but that it is possible in said position of release.

To protect the nut 315 or more generally the adjustment means 310, a protective cap 318 is provided which protects the adjustment means 310 and the thrust rod 300 from the outside environment. Due to the low rotational speed in the case of radial motors, a simple clipping may be suitable.

Complementarily, the protective cap 318 can be used to plug the longitudinal conduit 128 when the push rod 300 is not in position. It then has a sealing role of the conduit 218, inside which can be oil under pressure.

In the case of the reversible nut, the protective cap 318 may not be insertable when the nut is in the release position. This gives a visual or practical indicator to remember that the brake system 200 is disengaged, even when the hydraulic pressure system stops. The reversible nut can also wear a particular color face to identify that the engine is in a situation of brake release.

General embodiments

Several conduits 128 may be provided, each with a push rod 300.

In the case of embodiments where the contact element 350 is a rod, a flare 353 may be provided at the inner end 352, and a recess 121, 131 complementary to this flare 353 may also be provided in the motor shaft 120 or the brake shaft 130. This flare provides a stop in translation of either the thrust rod 300 or the second rod 350 towards the outside of the vehicle, for safety reasons: Indeed, if a sudden pressure is applied in the thrust chamber 206 and assuming nothing holds it (no cap, or thread, or other), the rod could be ejected violently. This embodiment has the advantage that the push rod remains trapped in the engine and can not be lost. The flare 353 may be in the form of a screw, a pin or a pin. We will speak more generally of longitudinal stop.

In contrast, the longitudinal stop 353 requires the insertion of the rod concerned from the internal side of the engine and thus prevents its removal, without dismantling the engine. Figures 5 and 8 illustrate this embodiment.

Alternatively, a simpler assembly consists of not having a flare 353 at the end of the rod. The rod or rods can be removed if necessary, without dismantling the engine. The motor can be delivered with or without rod (s). The rod or rods, depending on the embodiments, may be part of a machine edge lot. The assembly of the rod is then made by the outer side, which does not require disassembly of the engine.

The presence or absence of the flare is related to the choice of mounting the motor and whether or not to have a push rod 300 removable once the engine mounted. The interface of the two shafts is bathed in crankcase pressurized oil. However, between the push rod 300 and the motor shaft 120 is necessarily a clearance within which pressurized oil is inserted. To overcome this, an annular radial seal is provided in the longitudinal duct 128 between the thrust rod 300 and the drive shaft 130.

The brake piston 220 is immersed in the oil of the thrust chamber 206. When the contact element 350 is a rod, there necessarily is a clearance between the longitudinal duct and said rod inside which the oil pressure can fit.

It is then advantageously provided a radial annular seal disposed between the rod and the shaft, to seal the conduit.

In the case of the first embodiment, a single seal 306, 356 prevents oil from the brake system 200 from reaching the outer end 124 of the motor shaft 120 and maintains the pressure in the thrust chamber 206 There is no interface here between the two trees.

In the case of the second embodiment, a seal 356 is provided between the push rod 300 and the brake shaft 130, for the same reasons as above. In addition, the location of this seal is to choose to prevent the brake pressure oil from reaching the interface between the two shafts, which is at a different crankcase oil pressure.

In the case of the third embodiment, the seal 356 is provided on between the second rod 350 and the brake shaft 130.

In the case of the third embodiment, the seal was provided by the seal 213 around the brake shaft 130. It must nevertheless be adapted to remain tight even in the event of translation of the brake shaft 130. The contact element 350 is configured to cause the translation of the brake piston 220. However, when using the hydraulic machine 100, the contact element 350 rotates but the brake piston 220 does not rotate. There is therefore a friction which can generate wear and / or undesirable heating.

For this, several alternatives are possible.

At an inner end 352 of the contact member 350 (i.e., the pusher end 302 of the push rod 300 for some embodiments, or an inner end 352 of the second shank 350 ), it can be provided a friction pad 358 which ensures the transmission of the translation while facilitating friction by reducing the friction (see Figures 3 to 5). The friction pad 358 is in a suitable material, such as brass, phosphor bronze, or a friction material used for the pads, distinct from that of the rod and can be assembled therein.

It can also be provided a bearing 356, which provides the same functions (see Figure 6). The bearing 356 is advantageously lubricated by the oil present in the thrust chamber 206. The bearing is typically a ball stop, comprising at least one ball, which makes it possible to ensure the translation and the rotation at the same time, or a bearing conical.

The friction pad and the bearing 356 can be used indifferently.

Despite the friction pad 358 or the bearing 356, the resistive torque is transmitted by the brake piston 220, immobile, to the contact member 350, in rotation. Therefore, the contact element 350 may be slightly slowed down and not rotate at the same speed as the drive shaft 120. Now, the contact element 350 will transmit this resisting torque to the push rod 300. To avoid any relative (unwanted) rotation between the push rod 300 and the drive shaft 120, an anti-rotation finger 308 is provided on the push rod 300. Such a rotation could cause the disruption, or at worst the complete unscrewing , adjustment means 310.

Alternatively, the anti-rotation finger is provided on the second rod 350.

It is recalled that when the vehicle is in motion, there is no desirable relative rotation between said thrust rod 300 and the drive shaft 120.

Method of moving the adjusting rod, setting the brake position and measuring brake wear

Will now be described a method of setting release position, to which may be added steps of measuring the wear of the brake system, with corresponding sets.

As indicated in the introduction, the brake system 200 includes a plurality of discs 225 enclosing another plurality of discs 125 on the brake shaft 130 (or the motor shaft 120 according to the embodiments). If the discs 225 are worn, their thickness will be less and the longitudinal translation necessary to pinch the discs 125 will be greater than for discs 225 in good condition. Due to a series of contact, the δ between two new / worn positions is the same at the level of the brake piston 220 as the thrust rod 300.

It is possible that the δ at the discs is different, if effort / distance conversion devices are provided between the brake piston 220 and the discs 225. In this case, the ratios are known and it is possible in the same way to know the relevant information by measuring the δ of the translation of the push rod. In general, if the stop position of the brake piston 220 under pressure remains constant, the stop position of the brake piston 220 without pressure and resting on the discs varies according to the wear thereof.

The methods and assemblies aim at measuring the δ between the two positions (see FIG. 7).

In an embodiment shown in FIG. 8, a gauge 400 is provided. The gauge 400 includes a main body configured to abut another element and includes markers for measuring relative translation deviations.

The gauge 400 is inserted longitudinally at the outer end 304 of the thrust rod 300. The gauge 400 is positioned in abutment with either the brake piston 220, the thrust rod 300, or the thrust screw 312 or a movable portion of the adjustment means 310 as the reversible nut 315 or the adjusting screw. With the aid of indications 402, 404 appearing on the gauge 400, and with reference to a surface of the motor shaft 120, the position of the object touched by the gauge 400 may be known. At the very least, the relative position can be known, that is to say that from an initial position (for example a dimension define, or an individual measurement of the engine at the factory exit, when the system brake 200 is new, or when the latter has been replaced), it is possible to determine the δ.

Two process families will be detailed.

A first family of methods consists in measuring the position of the brake piston 220 in the braking position, and comparing it with an acceptable limit or a reference value.

A first method, without rod, of this first family is to measure with the help of the gauge the position of the brake piston 220, without any contact element being present the conduits 128, 238. In a step E2, the gauge then comes into contact with the brake piston 220. This is a simple measurement of position in support. This method can be implemented simply with the aid of the motor as described above, or with the aid of a system in which the rod or rods 300, 350 are removable. For this first method, no pressure is required in the thrust chamber 206 and prior emptying operations may be necessary.

Either the push rod 300 has been removed beforehand, so that the longitudinal duct is empty, or it must be removed especially for the measurement.

Finally, in an analysis step E3, the value of the measurement is recorded and analyzed.

A second method, with the second rod 350, of this first family is to introduce in a step E2 the depth gauge 400 which will go to touch the brake piston 220 via the longitudinal duct 128 and the second rod 350. This makes it possible to measure, still in step E2 its position relative to an external surface of the motor, for example a planar surface towards the center of the outer surface of the motor shaft 120.

This is followed by a first measurement step with the gauge 400, then a step E3 of analysis of this measurement to determine the state of wear of the brake system 200.

A third method of this first family is to keep the push rod 300 in place, with second rod 350 when provided.

Another method, in addition to the third method of this first family, can use this gauge 400, and during the measuring step E2, it comprises a substep of screwing E21 of the push rod 300 into an effortless contact position. which corresponds to the position of the brake piston 220 in the braking position, then a substep E22 of actual measurement of the position of the push rod 300, then a step E3 of analysis of this measurement to determine the state This method is advantageously applied for engines equipped with a thrust rod 300 having a flare 353, said rod 300 can not be removed by the outer side of the engine.

A fourth method consists in not using a gauge 400, but in measuring the position of the brake piston 220 by counting the number of revolutions of the thrust screw 312.

A step E2 consists of carrying out the measurement by the following substeps: E21: placing the thrust screw in reference with respect to an external surface of the motor, for example a flat surface towards the center of the outer surface of the shaft 122, either by flush with the screw head, or by aligning an engraved mark on the screw head. E22: Tighten the turns to a clamping position without effort.

A step E3 consists of the analysis of this measurement.

A second family of methods consists in measuring the position of the brake piston in the braking position, with reference to the stop position of the brake piston 220 at the end of the stroke, and comparing this difference with an acceptable limit or reference value.

This second family can be implemented using a system (motor and rod 300 as described above, that the rod or rods 300 and 350 are removable or not).

This method eliminates the dispersion of length and stacking of many parts, and is more accurate. Since it is necessary to compress the thrust means 208, this second family requires a large thrust force, and it is necessary to use a thrust screw.

A method of this second family can use counting of the number of turns of the thrust screw 312. The measurement step E2 then comprises the following substeps: E21: screwing the movable member 302 to a position pre-clamping, for example using a tool 500, - E22: screwing the movable member 302 to a clamping position, counting the number of turns of the movable member 302, c ' that is, a release position.

The method can be done in the direction of a position to another, that is to say from the brake position clamped to the stop position of the brake released, or vice versa, depending on whether it is done by screwing, or by unscrewing.

For example, knowing the pitch of the control means 210 and the number of turn, we go back without difficulty to the δ. The longer the discs are used, the higher the number of revolutions.

Finally, an analysis step E3 is performed.

The pre-tightening position corresponds for example to the moment when the contact element 350 comes into exact contact with the brake piston 220 but without transmitting any force or force. The engine is in the braked position. As the return means 208 have a large force, it is possible to tighten the screw with the hand until contact, without it moves the brake piston 220, because the force on the brake piston 220 is negligible.

The clamping position corresponds for example to the moment when the brake system 200 is in the maximum position, that is to say that the brake piston 220 is in abutment (the return means 208 are compressed against the abutment 208). The engine is therefore in the released position. The tool 500 is for example a Allen key, or a torque wrench, to establish precisely the pre-tightening position or the clamping position, according to manufacturer data. The analysis step E3 of the described methods may comprise a comparison of data with a limit value, with a table, or with a stop on the gauge. The limit value or the table can be a general data indicated in a maintenance manual. It can also be an individual data attached to the engine, for example a value measured on it, and which remains attached to it individually, for example by being noted in a tracking document, or engraved on the engine.

The methods may comprise an additional step E4, in which the value established in the measuring step E2 or the analysis established in the step E3 is written on the machine 100, in order to serve as a reference point for the measurements and the later tests.

This measurement can be made at the output of the production line, at first time on the machine and / or at each change of the brake discs. The advantage of such a process, with the inscription of a reference value, is that it avoids measuring variations due to the rib chains.

Finally, the processes may comprise an earlier step El of removing the protective cap 318. The step E1 may also comprise a substep of draining the oil that flows after opening the cap 318, for the engines whose thrust rod 300 does not have a flare 353, and whose rod 300 is stored as a machine batch tool of the machine.

Claims (19)

claims A hydraulic motor (100) comprising a cylinder block (106) and a drive shaft (120), the cylinder block (106) being configured to rotate the drive shaft (120), said drive shaft (120) comprising - an outer end (124) forming the motor output shaft (120), - an inner end (126), the motor shaft (120) extending in a longitudinal direction (X), the motor comprising a hydraulic braking system (200) configured to: - allow rotation of the motor shaft (120) when a release hydraulic pressure is applied, and - keep the motor shaft (120) stationary otherwise, the braking (200) comprising a brake piston (220) located in the extension of the inner end (126) of the shaft (120) and movable in translation in the longitudinal direction (X), the motor (100) being characterized in that the drive shaft (120) comprises a longitudinal through conduit (128) for accessing the controller the longitudinal position of the brake piston (220), the hydraulic motor being configured to receive a thrust rod (300) disposed in the longitudinal duct (128) and translationally controlled within said duct (128) at the using adjustment means (310). 2. System comprising an engine according to claim 1 and comprising a push rod (300) and rod adjustment means (310), said rod (300) being insertable into said longitudinal duct (128), in particular removably and comprising: - an outer end (304) configured to be accessible from the outer (124) of the shaft (120) when installed in the longitudinal conduit (128), and - a pusher end (302) configured to applying a force to the brake piston (220) when positioned in a brake release position within the longitudinal conduit (128). 3. System according to claim 2, wherein: the driving shaft extends longitudinally to the brake system (200) and the brake system (200) is configured to act directly on the motor shaft. (120), - the thrust rod (300) completely traverses the motor shaft (120), so that it can cause by contact the translation of the brake piston (220). 4. System according to claim 2, further comprising a brake shaft (130) disposed in the longitudinal extension (X) of the drive shaft (120) and drivable in rotation by the cylinder block (106), said shaft of brake (130) being located longitudinally between the drive shaft (120) and the brake piston (220), the system being characterized in that the brake shaft (130) comprises a longitudinal through conduit (138) and said rod (300) passes through the longitudinal ducts (128, 138) of the drive shaft (120) and the brake shaft (130), so that the push rod (350) can contact the piston brake (220). 5. System according to claim 2, further comprising a brake shaft (130) arranged in the longitudinal extension (X) of the motor shaft (120) and drivable in rotation by the cylinder block (106), said shaft of brake (130) being located longitudinally between the drive shaft (120) and the brake piston (220), the system being characterized in that the brake shaft (130) comprises a longitudinal through conduit (138) and in that that the motor comprises a second rod (350) disposed in the longitudinal longitudinal duct (138) of the brake shaft (130), said second rod comprising a pusher end (354) configured to abut against the pusher end ( 302) of the push rod (300) and having an inner end (352) configured to transmit a force to the brake piston (220), 6. System according to one of the preceding claims, wherein the push rod (350) or the second rod (350, 130) comprises a longitudinal stop, such as a flare (353) at its inner end (352), to limit the longitudinal translation towards the outside of the engine. The system of claim 6, comprising a radial annular seal (356) housed in the longitudinal duct (138) between the second rod and the brake shaft (130), to seal the clearance between the brake shaft (130). ) and the second rod (130). 8. The system of claim 2, further comprising a brake shaft (130) disposed in the longitudinal extension (X) of the drive shaft (120) and drivable in rotation by the cylinder block (106), said shaft of brake (130) being located longitudinally between the drive shaft (120) and the brake piston (220), characterized in that the brake shaft (130) is movable in translation along the longitudinal axis (X) and is configured to transmit the force of the push rod (300) to the brake piston (220) by contact. 9. System according to any one of claims 2 to 8, wherein the push rod (300) comprises two positions, a braking position in which the brake piston (20) is in the braked position and a braking position in which no force is applied to the brake piston (220) via the push rod (300). An assembly comprising an engine according to claim 1, or a system according to any one of claims 2 to 9, and a gauge (400), said gauge (400) being configured to be positioned along the longitudinal direction (X) and, - comprising indications (402, 404) for knowing the relative longitudinal position of the brake piston (220), so as to be able to know the state of wear of the brake system (200). An engine brake control method according to claim 1, or a system according to any one of claims 2 to 9, or an assembly according to claim 11, said method comprising a step measuring the position of the brake piston (220). 12. The method of claim 11, wherein the gauge (400) engages the brake piston (220). The method of claim 11 including a step of moving the push rod (300) within the longitudinal conduit (128). 14. The method of claim 13, comprising a step of measuring (E2) the position of the push rod (300) within the duct (128) during the braking position and an analysis step (E3) of the measurement for determining the wear of the brake system (200), in which the measuring step (E2) is performed by means of a gauge positioned in abutment against the outer end (304) of the rod of thrust (300). 15. A method according to claim 13, comprising a step of measuring (E2) the position of the push rod (300) within the duct (128) during the braking position and an analyzing step (E3) of the measurement for determining the wear of the brake system (200), wherein the measuring step (E2) is performed by counting the number of revolutions to reach the braking position. The method of claim 15, wherein the adjusting rod (300) is not inserted into the longitudinal conduit (128), said method comprising a step (E2) of measuring the position of a gauge (400). inserted into the longitudinal duct (128). The method of claim 13, comprising a measuring step (E2) performed by counting the number of turns of the push rod (300) between a reference position and a stop position on the brake piston (220). braking position. 18. A brake control method according to claim 13, comprising a step (E21) for setting the brake system in the braking position (200), and a step (E22) for setting the braking system brake release stop position. (200), from one to the other using the setting means (310). 19. Method according to any one of claims 13 to 18, comprising an intermediate step of writing on the hydraulic machine the value recorded in the measuring step (E2), to serve as a reference for the posterior measurements.