FR2702519A1 - Hydraulic mechanism comprising an assembly of at least two parts, intended to transmit a torque. - Google Patents

Abstract

The invention relates to a hydraulic mechanism comprising a first structure with two assembled elements (1A, 1B) and a second structure (20-17-41), a determined torque being transmitted between these structures. According to the invention: A) a first element (1A) comprises a thread (4) and a first transverse face; B) the second element (1B) comprises an internal thread (5), and, a second transverse face; C) the thread (4) is screwed into the internal thread (5) until the transverse faces come into mutual contact with the application of a tightening torque. One application is the production of a hydraulic motor at low machining cost.

Description

1 2702519

  A hydraulic mechanism, such as a motor or a piston pump, is already known, comprising a first structure, itself comprising at least two initially distinct elements and subsequently assembled to form said first structure, and, a second structure, a pair being able to be transmitted between said first and second structures and to have a value

  maximum constituting a specific torque.

  In this known mechanism, the assembly of the two elements is achieved by means of a plurality of screws cooperating with tapped holes formed in one of the elements. Such a structure is satisfactory as regards the mechanical strength obtained: it is less regarding its cost price, which is high. The invention intends to remedy this drawback by proposing a new

  design, much simpler to achieve and just as resistant.

  For this purpose, according to the invention, the following provisions are concomitantly adopted: A) a first of the two said elements comprises a thread and a first transverse face; B) the second of said two elements comprises a tapping, which is complementary to said thread, and a second transverse face, which is capable of being brought into contact with said first transverse face; O) the threading of the first element is screwed into the tapping of the second element until the first and second transverse faces are brought into mutual contact and is continued, by application of a tightening torque between the two said elements, until obtaining an assembly of these two elements with clamping of the first and second transverse faces one on the other. The following advantageous provisions are furthermore preferably adopted: the tightening torque is greater than said determined torque; depending on the application, the tightening torque is equal to at least 1.1 times or 1.5 times the determined torque; this mechanism further comprises complementary means for blocking the two said elements in the configuration in which they are assembled; the complementary blocking means comprises an adhesive film interposed between said first and second transverse faces, and / or an adhesive film interposed between the thread and the tapping; the complementary locking means may also comprise at least one pin, which is inserted between the two said transverse faces and which is partially contained both in a first housing that comprises the first element and in a second housing that comprises the second element, said housings opening into the respective transverse faces of said elements; this mechanism comprises, on the one hand, a fastening flange, which is integral with one of the elements of the first structure, on the other hand, ducts of

  hydraulic fluid, which are formed in the same said element.

  The main advantage of the invention lies in the simplicity of assembling the structures: a thread and a tapping are sufficient, whereas previously it was necessary to provide a large number of precision screws and as many holes and tapping This simplicity assembly is also accompanied by a gain in weight that of the screws removed - and a reduction in the cost of

manufacturing.

  The invention will be better understood, and secondary characteristics and

  their advantages will become apparent during the description of achievements given below.

below as an example.

  It is understood that the description and drawings are given only as

indicative and not limiting.

  Reference is made to the accompanying drawings, in which: Figure 1 is an axial section of an assembly according to the invention, comprising a hydraulic motor and a disc brake; and, Figures 2 and 3 are enlargements of detail A of Figure 1,

  realized in two variants according to the invention.

  The assembly represented in FIG. 1 is that of a hydraulic motor associated with a multiple disk brake, and comprises: an engine casing comprising a first part 1A, provided with a thread 4 and a fastening flange 301 A, a second portion 1 B, provided with a first thread 5 and a second thread 6, and a third portion 1 C, provided with a thread 7 and flats 101 C, the thread 4 and the first thread 5 cooperating to perform the assembly of the first 1A and second 1B parts, and the thread 7 and the second tapping 6 cooperating to achieve the assembly of the second 1B and third 1C parts; a brake casing 8, provided with a fletcher 9 which cooperates with a tapping, which is provided with the first part AA of the motor casing, to achieve the assembly of the brake casing 8 with the motor casing, by means of the first part l A thereof; a cover 11 for closing the brake casing 8, slidably mounted in a bore 12 of the brake casing 8, with sealing being effected between these two

  parts by means of a gasket 13.

  The internal constitutions of the hydraulic motor 14 and the multiple disk brake 15, known in themselves, except precisely the means of assembly of the crankcase and brake housing, which will be described in detail later, are

briefly described below.

  The crankcase 1 A-1 B-1 C defines an enclosure 16 containing: a motor shaft 17, rotatably mounted relative to the crankcase, about an axis of rotation 18, by means of roller bearings 19 interposed between the motor shaft 17 and the part 1 C of the crankcase, a cylinder block 20, in which cylinders 21 are arranged radially with respect to the axis of rotation 18, is integral with the drive shaft 17 vis-à- screw rotation of the axis 18, by means of splines 22 and 23, which are respectively provided with the motor shaft 17 and the cylinder block 20; a piston 24 is slidably mounted in each cylinder 21, defines a chamber 25 communicating via a cylinder duct 26 with a communication face 27 of the cylinder block 20, perpendicular to the axis of rotation 18, and carries at its outer end a roll 28, cylindrical, of axis parallel to the axis of rotation 18, placed in abutment on a corrugated cam 29, constituted by the internal periphery of the part 1 B of the motor casing, an internal fluid distributor 30, integral, relative to the rotation of the part A of the crankcase by means of a set of pins and notches 31, has a distribution face 32 perpendicular to the axis of rotation 18, bearing on the communication face 27, in which distribution ducts 33, 34 are connected to revolution grooves 35, 36 formed between the internal fluid distributor 30 and the part 1A of the motor casing, communicating via ducts 37, 38 arranged in this part l A crankcase with external conduits 39, 40 for supplying fluid under pressure and

  exhausting fluid to a pressure-free fluid reservoir, respectively.

  In addition, each cylinder duct 26 alternately communicates with the distribution ducts 33, 34 during the rotation of the bloccylindres 20 relative to the engine casing 1 Al Bl C. The internal fluid distributor 30 comprises a central recess allowing the passage of the brake shaft 41 This is provided with splines 42, which cooperate with splines 43, which is provided with the cylinder block 20, to make it integral, vis-à-vis the rotation of axis 18, said cylinder block 20 The brake shaft 41 extends to the inside of the brake housing 8; The disc brake comprises, in addition to the brake casing 8: disks 44, integral with the rotation of the axis 18 of the brake casing 8, by means of splines 144 integral with said brake casing; discs 45, integral with the rotation of the axis 18 of the brake shaft 41, the brake discs 44, 45 being arranged alternately and constituting a

stacking of brake disks.

  an integral appendix of the cover 11 having an end 46 resting on the stack of the brake disks to perform mutual braking against each other; a groove 47 formed in the wall delimiting the bore 12, receiving a stop segment 48; an elastic washer 49, forming a spring, bearing on the stop segment 48 and tending to push on a face of the cover 11 in the direction causing the support of this cover on the stack of the brake discs and obtaining the braking of the brake shaft 41 with respect to the brake casing 8; a duct 50, passing through the wall of the part 1A of the motor casing, connecting the chamber 51 containing the brake discs to an external duct 52 that can be selectively connected to either a pressure-free fluid reservoir or a source When the external pipe 52 is connected to the source of pressurized fluid, the effect of the pressure on the inner face of the lid 11 is predominant over the effect of the washer 49, and allows to exclude the end 46 of the cover relative to the stacking of the brake discs, and thus, to suppress the braking. Of course, the hydraulic motor 14 has a motor torque whose maximum value is equal to a determined torque. Similarly, the brake 15 generates a braking torque, the maximum value of which is equal to another determined torque. The determined torque of the hydraulic motor 14 and the determined torque of the brake have similar values As an example, existing assemblies have the following values (in meters x deca Newton): 1st set, determined torque of the hydraulic motor = 296 mx da N; determined torque of the brake = 248 m x da N; 2 nd set determined torque of the hydraulic motor = 1112 m x da N; determined brake torque = 928 m x da N; 3rd set torque of the hydraulic motor = 1588 m x da N; determined torque of the brake = 1876 mx da N. Thus, the determined torque of the hydraulic motor can be either lower or greater than that of the brake, both having similar values For each set, it is possible to define the determined torque which has the largest value, which will be hereinafter referred to as "specified couple", without specifying whether it is the

  hydraulic motor torque or brake torque.

  The assemblies of the various crankcases or casing parts 1A, 1B, 1C, 8 must withstand said determined torque, without unscrewing a crankcase or a crankcase portion relative to the other. Each assembly is, for this purpose, realized as that of parts 1 A and 1 B of the hydraulic motor housing, shown in detail at

  as an example in Figures 2 and 3.

  The following characteristics should be noted with reference to FIGS. 2 and 3: each of the parts 1A, 1B of the housing of the hydraulic motor has a flat transverse face 10A, 101B, perpendicular to the axis of rotation 18; the screwing of the thread 4 into the tapping 5 has been carried out until the two transverse faces 101 A and 101 B bear in mutual abutment; this screwing has been achieved with application of a tightening torque, of course at least equal to the aforementioned determined torque, and therefore with clamping of said transverse faces 101 A and 101 B on one another, and a part of the profile of the thread 4 on the corresponding part of the thread profile 5; for reasons of safety of maintaining the assembly, this tightening torque has been chosen, in the embodiments described, so as to be greater than said determined torque; s the value of the tightening torque relative to that of the determined torque depends on the use of the mechanism; a hydraulic motor not associated with a brake, or an assembly of a hydraulic motor and a brake, operating smoothly, without sudden abruptness, shall be assembled with application of a tightening torque equal to or greater than 1, 1 times the determined torque; the same hydraulic motor or the same unit operating under severe conditions of use, subjected to sudden jolts and / or numerous, and / or large amplitudes, will be assembled against the application of an equal torque or greater than 1.5 times the determined torque; it is furthermore preferred to complete the effect of the screwing by means of adhesive films interposed between the transverse faces 101 A, 101 B, and / or between the threading 4 and the threading 5; it is even advantageous to provide in each of the assembled portions 1A, 1B one or more housings 201A, 201B, which open into the transverse faces 101A, 101B, respectively, and in each of which a pin 53 is introduced , prohibiting after its introduction any relative rotation of the part l A relative to the part 1 B. The fastening flange 301 A mainly allows the attachment of the engine housing assembled on the chassis of a machine, for example In addition, at the moment of assembly of the parts 1A and 1B of the housing, it allows a mounting tool generating the tightening torque -a hydraulic motor with high torque, or a hydraulic jack, for example to take support on the one hand on this flange, on the other hand on the profile of the cam 29, before the assembly of the cylinder block, and to transmit the

  tightening torque between parts 1A and 1B of the housing.

  Similarly, the part 1 C of the housing will be fixed on the part 1 B by interposition of the same mounting tool which bears on the cam 29 and on the flats 101 C. Finally, the mounting tool, interposed between the flange 301 A and the grooves 144 of the brake housing 8, before mounting the brake discs 44 and 45, allows the

  tightening of parts l A of crankcase and brake housing 8.

  From the foregoing description, follows the observation of the achievement of

  assemblies without the use of numerous screws or the like formerly required.

  The gain therefore concerns both machining a single thread and a single thread replace all the tapped holes in one of the elements to be assembled and all the corresponding screws-, that the weight of the screws - that

  the size, and of course also the cost of the realization.

  Note that the profiles of the threads 4 and tapping 5 are easily obtained

  by turning, with turning tools, at a low machining cost.

  It should also be observed that the presence of the flange 301 A on the part IA of the crankcase, which already comprises the conduits 37, 38 for supplying fluid 24 fluid exhaust, allows to define with respect to the same part 1 A of the crankcase the position of the crankcase of the engine and said orifices

  compared to the frame on which this engine will be fixed later.

  For the same reason, it is interesting to spare the conduit 50 in this

same part 1A of the crankcase.

  Thus it is possible to dispense with the relative final positions, which are slightly variable, of the various parts assembled relative to each other. The invention is not limited to the embodiments described and shown, but covers all the variants that could be made without them.

  out of their frame, or out of their minds.

Claims (7)

  A hydraulic mechanism, such as a motor or a piston pump, comprising a first structure, itself comprising at least two elements (8-1 A-1 B-1 C) initially distinct and subsequently assembled to form said first structure and, a second structure (20-17-45-41), a torque being capable of being transmitted between said first and second structures and having a maximum value constituting a determined torque; characterized in that: A) a first (1A) of said two elements has a thread (4) and a first transverse face (1L A); B) the second (1 B) of the two said elements comprises a tapping (5), which is complementary to said thread, and a second transverse face (10 i B), which is capable of being brought into contact with said first transverse face (10 l A); C) the thread (4) of the first element is screwed into the tapping (5) of the second element until the first (1 OA) and second (1 01 B) transverse faces are brought into mutual contact and is continued, by applying a tightening torque between the two said elements, until an assembly of these two elements is obtained with clamping of the first and second faces transverse to each other.   2 Mechanism according to claim 1, characterized in that the determined tightening torque. 3 Mechanism according to claim 2, characterized in that the tightening torque is determined couple.   4 Mechanism according to claim 2, characterized in that the tightening torque is determined couple.   is greater than said pair equal to at least 1.1 times equal to at least 1, 5 times the   Mechanism according to one of Claims 1 to 4,   characterized in that it comprises a complementary means of blocking the   two said elements in the configuration in which they are assembled.   6 Mechanism according to claim 5, characterized in that the complementary blocking means comprises at least one glue film interposed between said first (10 l A) and second (101 B) transverse faces.   Mechanism according to one of Claims 5 and 6,   characterized in that the complementary blocking means comprises a   adhesive film interposed between the thread (4) and the thread (5).   Mechanism according to one of Claims 5 to 7,   characterized in that the complementary locking means comprises at least one pin (53), which is inserted between the two said transverse faces (101 A, 101 B) and which is partially contained in a first housing (201 A) that comprises the first element (1 A) and in a second housing (201 B) that includes the second element (1 B), said housing opening   in the respective transverse faces (101 A, 101 B) of said elements.   Mechanism according to one of Claims 1 to 8,   characterized in that it comprises, on the one hand, a fastening flange (301A), which is integral with one (1A) of the elements of the first structure, on the other hand, hydraulic fluid conduits ( 37, 38, 50), which are provided in the same element (l A).