FR2924152A1 - AXIAL PISTON MACHINE WITH SUPPORT OF PISTONS BY ROLLERS - Google Patents

Abstract

Hydrostatic axial piston machine comprising a roller drum rotatably mounted about an axis of rotation, this drum comprising piston bores each receiving a piston sliding longitudinally and supported by means of a shaped bearing member of pebble against a tray of uplift. A fixing device (25) for axially guiding the roller (5) in the longitudinal direction of the axis of rotation (R) of the roller (5) and fixing the roller (5) in rotation with respect to the axis longitudinal (K) piston.

Description

FIELD OF THE INVENTION The present invention relates to a hydrostatic axial piston machine comprising a roller drum rotatably mounted about an axis of rotation, this drum comprising piston bores, each receiving a piston sliding longitudinally and resting on the piston. intermediate roller bearing member against a lifting plate. STATE OF THE ART A multi-stroke oblique plate axial piston machine of the type defined above according to DE 10 2005 058 323 A1 is known. In such axial piston machines whose pistons are pressed against a plate As a result of the intermediate lifting of roller bearing members, it is necessary to align the axis of rotation of the rollers radially with respect to the axis of rotation of the roll drum. The rotational movement of the rollers with respect to the longitudinal axis of the piston may be limited by a piston denied by two faithfully shifted parts relative to each other. For such a stepped, eccentric, complicated to manufacture piston, it is also necessary to have a complicated stepped bore to be made in the roll drum. In addition, the rotational movement of the roller relative to the longitudinal axis of the piston can be limited by a radial pin provided in the roller drum, this pin cooperating with a corresponding axial groove of the piston. Such radial pins in a cylinder drum and cooperating with corresponding grooves of the piston also increase the complexity of cylinder drum and pistons manufacture and thus the overall manufacturing complexity of such an axial piston machine. . In summary, such means for fixing or locking in rotation of the roller 30 require implementation of significant construction means and thus cause high manufacturing costs for the axial piston machine. In addition, in the case of such an axial piston machine whose pistons are supported by a roller on a lifting path, it is necessary to ensure the lateral axial guidance of the rollers in the longitudinal direction of the axle. rotation of the rollers. For this, it is known from DE 10 2005 058 323 A1, to accommodate each roller in a front side cavity, a piston for radial and axial guidance of the roller. The cavity formed in the piston acts as a cage for the roller and functions as a lateral guide installation of the roller. Such a cavity in the piston is however complicated to achieve which further increases the cost of manufacturing an axial piston machine because of this roller guide installation.

OBJECT OF THE INVENTION The present invention aims to develop an axial piston machine of the type defined above, allowing a simpler manufacture. DESCRIPTION AND ADVANTAGES OF THE INVENTION For this purpose, the invention relates to a hydrostatic machine with axial pistons as defined above, characterized in that a fixing device for axial guidance of the roller in the longitudinal direction of the axis of rotation of the roller and a fixing in rotation of the roller with respect to the longitudinal axis of the piston.

Thus, the invention relates to a fastening installation which provides both the function of fixing or locking in rotation of the roller and also that of lateral guidance of the roller. This pez puts a simpler manufacturing of the cavity in the piston because the cavity will only have to ensure the radial guidance of the roller. In addition, neither eccentric, complicated, step-like pistons nor complicated cylindrical holes are required or complementary radial pins with grooves in the piston. Overall, the fastening installation according to the invention which ensures the fixation or locking in rotation and the lateral guidance of the rollers allows a simpler and less expensive embodiment of the axial piston machine. According to an advantageous embodiment of the invention, the fixing installation comprises at least one guide surface for each front face of the roller. Such guiding surfaces cooperating with the two front faces of the corresponding roller make it possible to perform both the rotational fixing of the roller and also its lateral guidance, in a simple manner and with reduced construction means. According to an advantageous development, the fixing device according to the invention comprises a guiding surface for the first end face of the roller and another guiding surface for the second end face of the roller, the guiding surfaces being lateral to each other with respect to to the axis of rotation of the roller. Thus, two such guiding surfaces each of which cooperates with a front face of the roller and which are laterally opposite the axis of rotation of the roller, lo make it possible to ensure lateral guidance and fixation or locking in rotation of the roller with reduced constructive means. According to another embodiment of the invention, the attachment installation comprises two guide surfaces for each front face of the roller, these guide surfaces being spaced apart from the axis of rotation of the roller. Thus, on each front face of the roller, there are two guide surfaces laterally spaced relative to the axis of the roller and facing each other. These guiding surfaces also make it possible to ensure lateral guidance and rotational fixing of the rollers with reduced constructive means. Particularly advantageous advantages result from an advantageous development of the invention, if the guide surfaces are made on extensions perpendicular to the axis of rotation of the rollers. Such extensions can be manufactured in a simple manner, for example by milling which results in reduced manufacturing costs for the fastening installation according to the invention. According to one embodiment of the invention, the fastening installation is provided in the region of the front side of the piston bore in the roll drum. The front face of the roll drum may simply have other extensions with guide surfaces at the piston bore of the roll drum, these other extensions being made for example by milling which allows easy manufacture of the roll. fastening system for lateral guidance and rotational fixing of the pistons. It is of particular interest that the fastening installation is provided on a fastener disk integrally connected in rotation with the roll drum and having through-holes, in particular through-holes for the pistons. The passage holes of the fixing disc, made in the form of through holes allow simply to achieve the extensions and thus the guide surfaces providing lateral guidance and fixing in rotation of the rollers. Such a fixing disk can be manufactured for example by stamping, sintering, extrusion press or creep or by broaching. The manufacturing means used for the roll drum and thus for the axial piston machine can be further reduced if, according to a development of the invention, the fastening disc comprises a drive installation by means of which the roll drum is in drive connection with a drive shaft. The drive installation can be carried out with reduced constructive means, by stamping, sintering, press extrusion or creep or pinning on the fixing disc. According to an advantageous embodiment of the invention, the drive installation comprises a toothing on the inner periphery of the fixing disc. This toothing of the fixing disc is produced simply by stamping, sintering, broaching or press extrusion or creep. Since, according to another advantageous embodiment of the invention, the fixing disk comprises a coding installation for a speed-sensing installation, it is possible to detect in a simple manner the speed of rotation of the drum. . The coding installation is advantageously carried out by radial extensions, in particular in the form of a toothing at the outer periphery of the fixing disc. This toothing can be made with only additional constructive means, reduced on the fixing disc, by stamping, sintering, broaching, press extrusion or press creep. According to an advantageous development of the invention, a brake disc of a brake installation for the drum drum 35 is formed on the fastening disc, which makes it possible to produce, with simple construction means, a brake installation for the drum. with cylinders of the axial piston machine according to the invention. The brake disk is advantageously formed by a radial extension of the fixing disc. It is possible to simply produce a radial extension on the fixing disc and thus have a fixing disc constituting the brake disk. A brake actuation installation is advantageously housed in the casing of the axial piston machine, this installation being placed in cooperative connection with at least 1 v an axial end face of the brake disc. The brake actuating system is preferably forearmed by a plurality of brake pistons connected to a brake line and each time at least one brake piston can be cooperatively connected to an opposite axial end face of the brake disc. Such brake pistons connected to a common brake line and acting on the two axial end faces of the brake disk simply brake the roll drum. Drawings The present invention will be described below in more detail with the aid of an exemplary embodiment shown in the accompanying drawings in which: - Figure 1 is a longitudinal section of an axial piston machine according to the FIG. 2 is a section on line AA of FIG. 1, FIG. 3 is an enlarged sectional view of FIG. 2, and FIG. 4 is a longitudinal section of a development of a machine. with axial pistons according to the invention. DESCRIPTION OF AN EMBODIMENT FIG. 1 shows a hydrostatic machine with axial pistons 1 according to the invention constituted for example by a slanting plate machine or inclined plate, presented in longitudinal section. The axial piston machine 1 comprises a cylindrical drum 2 mounted to rotate about an axis of rotation D and before several piston bores 3, distributed concentrically with respect to the axis of rotation D and each receiving a piston 4 sliding longitudinally . The pistons 4 each support by means of a rolling member in the form of a roller 5 against a lifting curve 6 secured to the housing. The drum drum 2 is supported in the axial direction against a control surface 7 integral with the housing. This surface is made on a control base (ice) 8 disk-shaped. The control bottom 8 is provided with kidney-shaped control slits constituting an inlet branch 10 and an outlet branch 11 for the axial piston machine 1. The roll drum 2 is provided with a connecting channel 12 associated with each piston bore 3 and for connecting the piston bore 3 to the inlet branch 10 and the outlet branch 11, when the roll drum 2 is rotated. The roll drum 2 is further integrally connected in rotation to a drive shaft 13 concentric with the axis of rotation D. For this, the roll drum 2 comprises a drive installation 14 made under the one of a toothing 15.

The cylinder drum 2 has a multi-part structure and is formed by a fixing disc 20 in the form of a plate and a member provided with piston bores. The member 21 comprises the piston bores 3 and the connecting panels 12.

The plate-shaped fixing disc has on its inner periphery the toothed drive installation 15 as shown in FIG. 1 taken in conjunction with FIGS. 2 and 3. In addition, the fixing disc 20 is provided for each piston 4, a through hole 23 in the form of a through bore which corresponds to the piston bores 3 of the piston boring member 21. The fixing disk 20 is fixed to the drill member of pistons 21 by a link by force. For this, a compression spring spring device 30 is provided which urges the fixing disc 20 in the axial direction, in the direction of the piston-piercing member 21. The drive of the compression member piston holes 21 by the drive shaft 13 and thus the integral connection in rotation between the piston-piercing member 21 and the drive shaft 13 is made by a connection by the shape, via the pistons 4 and through holes 23 made in the fixing disc 20 and the piston bores 3 made in the piston boring member 21. The axial piston machine 1 according to the invention may further comprise a gripping device of the invention. the rotational speed of the roll drum 2; this installation in the form of a rotational speed sensor is housed in the casing 36 of the axial piston machine 1. For this purpose the fixing disc 20 is provided for this purpose with a coding installation 37 which, as appears in Figures 2 and 3, is constituted by extensions 38 made radially and evenly distributed to the periphery of the fixing disc 20; these extensions can be for example a toothing. The pistons 4 are provided with a cavity 24 in their end face facing the lifting disc 6 to each receive a roller 5. The cavity 24 is formed in the form of a bore perpendicular to the longitudinal axis K of the piston and this cavity is arranged so that the roller 5 is held in the lateral segments 24a, 24b of the cavity 24 of the piston 4 which each overlap the equatorial plane of the roller to ensure its fixation while pei nieting the rotation about the axis of rotation R. According to the invention, the fixing disk 20 comprises a fixing installation 25 which ensures the function of fixing in rotation or locking in rotation of the rollers 5 limiting the rotational movement and thus the rotation of the rollers 5 with respect to the longitudinal axis K of the piston 4 and thus ensuring the radial alignment of the axis of rotation R of each roller 5 during the rotational movement of the drum cylinder 2 about the axis of rotation D; this installation also ensures the function of a lateral guidance of the rollers 5 guaranteeing the axial guidance of the rollers 5 in the longitudinal direction of the axis of rotation R of each roller 5 and preventing the rollers 5 from coming out laterally from the cavities 24. The fixing device 35 is formed by guide surfaces 25a, 25b, 25c, 25d provided on the through hole 23 corresponding to the piston bore 3. The guide surfaces 25a, 25b thus cooperate with the outer radial front face 5a of the roller 5 and these surfaces are spaced laterally from the axis of rotation R of the roller 5 facing each other. The guide surfaces 25c and 25d function correspondingly with the inner radial face 5b of the roller 5 and are also laterally spaced relative to the axis of rotation R of the roller 5 facing each other. The guide surfaces 25a, 25b, 25c, 25d are formed on finger-shaped extensions 26a, 26b, 26c, 26d perpendicular to the axis of rotation R of the roller 5 at the through hole 23. The guide surfaces 25a , 25b, 25c, 25d fix in a simple manner the roller 5 in the radial direction of the axis of rotation R thus avoiding that the roller 5 can be released from the cavity 24 of the piston by sliding on the side. In addition, the guiding surfaces 25a, 25b, 25c, 25d limit the rotational movement of the roller 5 with respect to the longitudinal axis K of the piston and thus the roller 5 is fixed or locked in rotation. of the axial piston machine 1 of the invention shown in FIG. 4, a brake disk 41 has been formed on the fixing disk 20. This brake disk is, for example, the disk of a brake installation 40 for the 2. The fixing disc 20 formed by a plate-shaped component is thus provided with a radial extension exceeding the outside diameter of the piston-piercing member 21 and acting as a brake disc 41.

The actuating or brake actuating installation 42 consisting of several brake pistons 43a, 43b is housed in the casing 36 of the axial piston machine 1. This installation can be connected to the two axial end faces 41a, 41b opposite the brake disc 41. The brake pistons 43a, 43b are connected to a common brake line 44 and thus constitute a floating assembly G of the brake pistons. Each time it is possible to provide a brake piston 43a, 43b which, when the brake pipe 44 is pressurized, cooperates with the corresponding axial end face 41a, 41b of the brake disc 41 and brakes the fastening disk 20 and thus the cylinder drum 2. But it is also possible to provide several brake pistons 43a, 43b distributed peripherally in place of each time a brake piston 43a or 43b; these different brake pistons, cooperate with the corresponding axial end face 41a, 41b of the brake disc 41 when the brake pipe 44 is pressurized.

The zone in which the brake disc 41 and the brake piston 43a, 43b (as shown in FIG. 4) are located can be opened in the direction of the internal volume of the casing of the axial piston machine 1 and thus have a management of common oil with the area of the drive mechanism. But it is also possible to seal the area in which the brake disk 41 and the brake pistons 43a, 43b are located by suitable sealing devices between the axial end faces 41a, 41b of the brake disk 41 and the housing. 36 relative to the interior volume of the housing and thus with respect to the region of the drive mechanism of the axial piston machine 1. The plate-shaped fixing disk 20 of the axial piston machine 20 according to the invention, provided with of the drive installation 14, the through-holes 23 as well as the fastening installation 25, which is defined by the extensions 26a, 26b, 26c, 26d and the coding installation 37 is, if appropriate, produced under the terms of brake disk 41 which is manufactured simply by stamping, sintering, extrusion press or creep. In addition, the fixing disc may also be manufactured by a machining process with chip removal such as for example the broaching; the complexity of manufacturing will be reduced by simultaneously manufacturing several fastening discs for several axial piston machines which will have been stacked in one package. The extensions 26a, 26b, 26c, 26d can then be manufactured simply by stamping, sintering, press extrusion or press creep or by milling.

The fixing device 25 according to the invention provides the function of fixing means or locking in rotation of the rollers 5 relative to the longitudinal axis K of the pistons and the axial guide function of the rollers 5 in the longitudinal direction of the rotation axis R; the fixing installation formed by the guide surfaces 25a, 25b, 25c, 25d provided on the extensions 26a, 26b, 26c, 26d of the through hole 23 makes it possible to obtain, by a simpler manufacturing process, the fixation in rotation and the lateral guidance of the rollers so that the axial piston machine 1 according to the invention is more simply realized.

The fixing disc 20 can also be connected to the piston boring member 21 by a connection by the material, for example by welding, brazing, gluing. In addition, the force connection of the fixing disc 20 and the piston boring member 21 can be done by a screw connection. In addition, the read connection of the fixing disc 20 and the piston-piercing member 20 can be done via a drive member such as for example with the aid of at least one a pin. The through orifices 23 may have a shape, for example rectangular, and the lateral surfaces of the rectangular-shaped through-orifice 23 comprise the guide surfaces 25a, 25b, 25c, 25d. In addition, the cylinder drum 2 can be made in one piece and the extensions 26a, 26b, 26c, 26d and thus the guide surfaces 25a, 25b, 25c, 25d of the piston bores 3 will be realized in a simple manner, for example by milling in the front zone of the drum drum 2. In place of the four guide surfaces 25a, 25b, 25c, 25d shown in the figures, it is also possible for each front face, only a guide surface, for example the guide surface 25a for the end face 5a and the guide surface 25c for the end face 5b or the guide surface 25b for the end face 5a and the guide surface 25d for the end face 5b, the two guide surfaces 25a. , 25c or 25b, 25d being opposed diagonally with respect to the axis of rotation R of the roller 5. A fixing installation thus formed with guide surfaces also makes it possible to fix it in rotation or to lock in rotation with mo yens of manufacturing reduced as well as the lateral guidance of the rollers. The axial piston machine according to the invention may be a single-stroke or multi-stroke machine.

Claims (6)

1 °) hydrostatic axial piston machine comprising a cylindrical drum rotatably mounted about an axis of rotation, the drum having piston bores each receiving a piston sliding longitudinally and supported by means of a piston member; roller bearing against a lifting plate, characterized by an attachment device (25) for axially guiding the roller (5)] o in the longitudinal direction of the axis of rotation (R) of the roller (5) and a fixing in rotation of the roller (5) with respect to the longitudinal axis (K) of the piston. 2) Hydrostatic axial piston machine according to claim 1, characterized in that the fixing device (25) has at least one guide surface (25a, 25b, 25c, 25d) for each end face (5a, 5b). ) of the roller (5). 3) A hydrostatic axial piston machine according to claim 2, characterized in that the fixing device (25) has a guide surface (25a, 25b) for the first end face (5a) of the roller (5), and another guiding surface (25c, 25d) for the second end surface (5b) of the roller (5), the guiding surfaces (25a, 25b, 25c, 25d) being laterally facing with respect to the axis rotation (R) of the roller (5). 4) A hydrostatic axial piston machine according to claim 2, characterized in that the fixing device (25) has two guide surfaces (25a, 25b, 25c, 25d) for each end face (5a, 5b) of roller (5), these guide surfaces being laterally spaced from the axis of rotation (R) of the roller (5). 5 °) hydrostatic axial piston machine according to claims 2 to 4, characterized in that the guide surfaces (25a, 25b, 25c, 25d) are formed on extensions (26a, 26b, 26c, 26d) located perpendicular to the axis of rotation (R) of the roller (5). 6. Hydrostatic axial piston machine according to claim 1, characterized in that the fixing device (25) is provided in the region of the front side of the piston bore (3) of the drum (2). Axial piston hydrostatic machine according to claim 1, characterized in that the fastening device (25) is provided on a fastening disc (20) integrally connected to the roll drum (2) and having openings (15). through (23) in particular in the form of through holes for the pistons (4). 8. Hydrostatic axial piston machine according to Claim 7, characterized in that the fixing disk (20) is provided with a drive unit (14) through which the cylinder drum (2) is connected to driving with a drive shaft (13). Axial piston hydrostatic machine according to claim 8, characterized in that the drive unit (14) is in the form of a toothing (15) on the inner periphery of the fixing disk (20). . 10 °) Axial piston hydrostatic machine according to claims 7 to 9, characterized in that the fixing disk (20) comprises a coding unit (37) for a rotational speed gripping system (35). Hydrostatic axial piston machine according to claim 10, characterized in that the coding device (37) is formed by radial extensions (38), in particular a toothing at the outer periphery of the fixing disk (20). . 12 °) Hydrostatic axial piston machine according to Claim 7, characterized in that a brake disc (41) of a brake system (40) for the roller drum (2) is formed on the mounting disk ( 20). 13 °) hydrostatic axial piston machine according to claim 12, characterized in that the brake disc (41) is formed by a radial extension of the fixing disc (20). 14 °) Hydrostatic axial piston machine according to Claim 12 or 13, characterized in that a brake actuating device (42) is provided in the housing (36) of the axial piston machine (1). which can be put into cooperative connection with at least one axial end face (41a, 41b) of the brake disk (41). Centrifugal hydrostatic machine according to Claim 14, characterized in that the brake actuating device (42) is formed by a plurality of brake pistons (43a, 43b) connected to a brake line (44) and each time at least one brake piston (43a, 43b) is cooperatively connected to the opposite axial end face (41a, 41b) of the brake disc (41).