Hydraulic rotating machine

Abstract

Hydraulic rotating machine with pistons, comprising: a casing (102); an inclined plate (130) mounted in the casing; a drive shaft (100) and a barrel (104) which are mounted in the casing; a plurality of pistons (106) which are situated in bores formed in the barrel, the plurality of pistons bearing at a first end against the inclined plate; and a delivery head (110) against which the barrel bears opposite the inclined plate. The delivery of the hydraulic rotating machine is ensured by the delivery head, the delivery head comprising two crescent ports permitting the aspiration and the delivery of a liquid in the hydraulic rotating machine. The delivery head (110) is a cast iron component comprising a surface on which a coating of soft metal (111) has been deposited, the coating of soft metal being in contact with the barrel (104). The soft metal is a non-ferrous metal alloy comprising at least 51% copper relative to the total weight of the non-ferrous metal alloy. The thickness of the coating of soft metal (111) is between 0.5 and 3.5 mm. A method for preparing the two-material delivery head (110) is also proposed.

Description

Hydraulic rotating machine

[0001] The invention relates generally to the field of hydraulic piston rotating machines. More particularly, the invention relates to hydraulic piston pumps and hydraulic piston motors. Technological background

[0002] There are different types of hydraulic rotating machines. They mainly consist of a housing, a bias plate and a barrel mounted in the housing as well as a plurality of pistons integrated into the barrel.

[0003] In DE102010046216A1 or in US2009120278, distribution is enabled by means of a distribution glass which is an added part between the barrel and the cylinder head which closes the pump casing. The distribution glass has a through passage formed by two lunules which allow the passage of the liquid and more particularly the suction and discharge of the liquid into the hydraulic pump.

[0004] The timing glass is an added part that plays an important role because it must allow, in particular, the sealing of the interface between the barrel and the cylinder head. The timing glass has a sliding surface in contact with the barrel to limit the friction forces against the barrel.

[0005] The dispensing ice is a removable part which can be replaced if worn.

[0006] However, the distribution ice can cause hydraulic fluid leaks and therefore damage or reduce the performance of the hydraulic rotating machine. Summary

[0007] An idea at the basis of the invention is to propose a hydraulic rotating piston machine with low wear in operation and whose number of constituent parts is reduced to reduce manufacturing costs.

[0008] A basic idea of ​​the invention is to improve the energy performance of the hydraulic rotating machine by eliminating the areas of hydraulic leaks linked to the use of a distribution ice.

[0009] Another idea underlying the invention is to propose a hydraulic piston pump and / or a reciprocating hydraulic piston motor.

[0010] Another idea underlying the invention is to propose a method for preparing a two-material distribution cylinder head intended to be integrated into a hydraulic rotating machine.

[0011] According to one embodiment, the invention provides a hydraulic rotating piston machine comprising: a casing, a bias plate mounted in the casing, a drive shaft and a barrel rotatably mounted in the casing, a plurality of sliding axial pistons located in bores provided in the barrel, the plurality of axial pistons bearing at a first end against the bias plate, a distribution cylinder head arranged to close the casing, against which the barrel bears opposite the bias plate, the distribution cylinder head being located opposite the drive shaft, in which the distribution of the hydraulic rotating machine is ensured by the distribution cylinder head, the distribution cylinder head comprising two lunules allowing the suction and discharge of a liquid into the hydraulic rotating machine,and wherein the timing cylinder head is a cast iron part comprising a surface on which a soft metal coating has been deposited, the soft metal coating being in contact with the barrel,

[0012] Thanks to these characteristics, the hydraulic rotating machine has good efficiency with good tolerance to high rotation speeds without the discharge pressure causing the separation of the barrel and the distribution cylinder head.

[0013] According to embodiments, such a hydraulic rotating machine may comprise one or more of the following characteristics.

[0014] The term "soft metal" is defined in this text as being a malleable and ductile metal, that is to say capable of being deformed, extended without fragmenting or breaking under pressure conditions of approximately 10x10 4 Pa and temperature between 10°C and 60°C.

[0015] According to one embodiment, the soft metal is a non-ferrous metal alloy.

[0016] According to one embodiment, the soft metal is a non-ferrous metal alloy comprising gold, silver, copper, aluminum, tin, platinum, palladium, lead, zinc or a mixture of these metals.

[0017] According to one embodiment, the non-ferrous metal alloy comprises at least 51% copper relative to the total weight of the non-ferrous metal alloy.

[0018] According to one embodiment, the soft metal is chosen from: bronze or brass.

[0019] According to one embodiment, the thickness of the soft metal coating is between 0.5 and 3.5 mm, preferably between 1 and 2 mm.

[0020] According to one embodiment, the soft metal coating was deposited directly on the cast iron part using a technique chosen from: brazing, cold spraying, vacuum deposition and additive production.

[0021] In one embodiment, the soft metal coating was deposited directly onto the cast iron part by powder spraying with laser beam fusion. Thanks to these characteristics, the soft metal coating can be formed in a well-controlled and precise manner and offer excellent long-term resistance. In addition, this allows for the formation of a deposit with little loss of raw material and therefore a lower-cost deposit.

[0022] According to one embodiment, the soft metal coating is located only on the surface of the cast iron part intended to be in contact with the barrel.

[0023] According to one embodiment, the hydraulic rotating machine is a hydraulic pump.

[0024] According to one embodiment, the hydraulic rotating machine is a hydraulic motor.

[0025] According to one embodiment, the hydraulic rotating machine is reversible and operates either as a hydraulic pump or as a hydraulic motor.

[0026] According to one embodiment, the hydraulic rotating piston machine comprises between 2 and 12 pistons, preferably between 4 and 8 pistons, for example 6 pistons.

[0027] According to one embodiment, the shaft and the barrel have two directions of rotation.

[0028] Generally, the present invention is designed to operate on a plurality of hydraulic rotating machines, in particular hydraulic piston motors or pumps of the following types: one-way rotation, two-way rotation, fixed displacement, variable displacement, broken axis, or any combination of one or more of these characteristics.

[0029] According to one embodiment, the invention has as a second subject a method for preparing a two-material distribution cylinder head, the distribution cylinder head being intended to be integrated into a hydraulic piston machine, the method comprising a step of depositing a layer of a soft metal directly on a surface of a cast iron part forming a cylinder head in order to form a two-material part.

[0030] According to one embodiment, the deposition is carried out by powder projection with laser beam fusion.

[0031] According to one embodiment of the method, the powder intended to form the soft metal layer is projected in the solid state and is fused via the laser beam before touching the surface of the cast iron part. That is to say, the soft metal is in the liquid state when it comes into contact with the surface of the cast iron part.

[0032] Thanks to this process, the cylinder head obtained has the advantage of significantly reducing or completely eliminating the release of cast iron nodules at the connection zone between the cast iron part and the soft metal layer. In addition, when the cylinder head obtained by this process is integrated into a hydraulic rotating machine, it helps to achieve a reduction in noise, an improvement in admissible pressure levels and an improvement in rotation speeds when the hydraulic rotating machine is in operating condition.

[0033] According to one embodiment, the projected powder is a non-ferrous metal alloy comprising at least 51% copper relative to the total weight of the powder, preferably the powder is brass or bronze.

[0034] According to one embodiment, the method comprises an operation of melting the surface of the cast iron part. According to a preferred embodiment, said operation of melting the surface of the cast iron part and the deposition of the metal layer by powder spraying are carried out at the same time.

[0035] According to one embodiment, the layer of soft metal deposited during the deposition step is between 0.5 and 3.5 mm, preferably between 1 and 2 mm.

[0036] According to one embodiment, the soft metal coating layer is deposited only on a surface of the cast iron part intended to be in contact with a rotating barrel.

[0037] Thanks to these characteristics, the amount of soft metal used is reduced. Thus, the process is economical.

[0038] According to one embodiment, the method further comprises a step of machining at least one distribution channel in the cast iron part forming the cylinder head before or after the deposition of the soft metal layer.

[0039] According to one embodiment, the method further comprises a step of assembling the two-material distribution cylinder head to a casing in order to form a hydraulic rotating machine.

[0040] According to one embodiment, the distribution cylinder head of the hydraulic rotating machine is obtained by one or more of the aforementioned steps of the method for preparing a two-material distribution cylinder head. Brief description of the figures

[0041] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings.

[0042] The figure represents a sectional view of a rotating machine according to one embodiment.

[0043] This is an enlarged view of Zone II shown on the.

[0044] This is a sectional view of a rotating machine with a broken axis, according to another embodiment.

[0045] This is a perspective view of a timing belt suitable for the machine.

[0046] It represents a rotating piston machine I, of the hydraulic pump / motor type with reversible bias plate and variable displacement.

[0047] The rotating piston machine I consists of the following elements:

[0048] a casing 2 in which are arranged a drive shaft 1 and a barrel 4 mounted in rotation in the casing 2 via a ball bearing system. The barrel 4 has bores forming cylinders in which a plurality of axial pistons 6 are slidably housed.

[0049] These axial pistons 6 come to bear by their heads 6a against a biased plate 30 which is in an oblique position and which is fixed in rotation so that, when the barrel 4 rotates via the action of the drive shaft 1, the axial pistons 6 are animated by a back and forth movement.

[0050] A cylindrical timing head 10 is threaded into the cylindrical end 21 of the casing 2 and is arranged to close the casing 2.

[0051] The distribution cylinder head 10 is blocked against any axial movement by a stop edge 23 of the end 21 of the casing 2 and is immobilized in rotation by a screw 18, the sealing being ensured by one or more seals 19.

[0052] The distribution cylinder head 10 has two lunules forming the ports 12 and 13 allowing the suction and discharge of a liquid into the hydraulic rotating machine.

[0053] Furthermore, the distribution cylinder head 10 comprises a first cylinder head bore 14 and a second cylinder head bore 15. The bore 15 made in the distribution cylinder head 10 communicates with the port 13 and the bore 14 communicates with the port 12.

[0054] For one direction of rotation of shaft 1, port 12 is the suction port and port 13 is the discharge port.

[0055] If the direction of rotation of shaft 1 is reversed, port 13 becomes the suction port and port 12 the discharge port.

[0056] In order to reverse the direction of rotation, simply unscrew screw 18 and rotate the distribution cylinder head 10 about 180 degrees to reverse the direction of rotation of the rotating piston machine I.

[0057] The hydraulic rotating machine I comprises an internal volume 20 located in the casing 2. The internal volume is filled with the hydraulic oil being pumped and thus makes it possible to lubricate the moving parts. The hydraulic oil is not under pressure so that the sealing of the internal volume 20 is easily ensured by seals.

[0058] In the example shown, the bias plate 30 is a variable tilt plate, but it could be fixed tilt.

[0059] At the rear of each bore of the barrel 4 is arranged a bore 8 which opens against the front face 11 of the distribution cylinder head 10.

[0060] This is an enlarged view of zone II shown in FIG. 1, it illustrates the contact area between the barrel 4 and the distribution cylinder head 10.

[0061] The timing belt 10 is formed by a cast iron part coated with a soft metal surface, for example bronze or brass. The thickness of this surface is approximately 1 to 2 mm.

[0062] The barrel 4 bears directly against the soft metal coating 11 of the distribution cylinder head 10. This support is maintained by means of a spring 40. The soft metal surface is a glazed surface allowing the rotation of the barrel 4 while preserving the sealing of the barrel / cylinder head junction and limiting the friction forces.

[0063] The soft metal coating was deposited directly onto the cast iron part using a technique chosen from: brazing, cold spraying, vacuum deposition. Preferably, the soft metal coating was deposited directly onto the cast iron part by powder projection with laser beam fusion.

[0064] Such powder projection with laser beam melting is carried out by means of a laser metal deposition machine.

[0065] The soft metal laser deposition machine may have the following characteristics: - a laser head for performing powder metal deposition (LMD), the laser head being movable within a determined working volume in order to allow the deposition to be carried out on the desired surface.For example, the laser head can travel along X (abscissa) up to 800 mm, along Y (ordinate) up to 550 mm and along Z (coordinate) up to 400 mm, - a dynamic axis system, including a rotation and pivot axis for 3-dimensional deposition, - a dynamic axis system with a linear drive, - an intelligent image processing system to perform deposition with high precision, the image processing allows automatic detection of the position of the cast part and thus ensures that the deposit is always positioned in the right place, - a laser power sensor system, and - a capacity to deliver power greater than between 2000W.

[0066] An example of a powder-blasting laser soft metal deposition machine suitable for carrying out the soft metal deposition process has the following technical data:

[0067] Axis travel range X-axis travel range800 mmY-axis travel range600 mmZ-axis travel range400 mmB-axis travel range± 135 °Maximum axis speeds Maximum axial speed parallel to the X axes50 m / minMaximum axial speed parallel to the Y axes50 m / minMaximum axial speed parallel to the Z axes50 m / minMaximum simultaneous axial speed85 m / minMaximum axial speed B-axis120 rpmMaximum axis accelerations Maximum axis acceleration parallel to the X axes10 m / s 2 Maximum axis acceleration parallel to Y axes 10 m / s 2 Maximum axis acceleration parallel to the Z axes 10 m / s 2 Maximum simultaneous axis acceleration 17 m / s 2 Maximum axis acceleration axis B130 rad / s 2 Positioning accuracy Positioning accuracy linear axes (X, Y, Z)0.015 mmPositioning accuracy rotation axes (B)0.02 °Lasers Maximum laser power8000 WLaser parametersSolid-state, diode or fiber laser

[0068] The process of depositing the soft metal coating is, for example, bronze deposition. The process includes a step of melting bronze powder using a laser, with an average power of 2500W. This step allows a layer of bronze to be deposited on a surface of the cast iron part with a thickness of between 0.5 and 3.5mm.

[0069] This soft metal deposition process is particularly advantageous because it allows control of the production time and the quantity of soft metal to be used depending on the desired deposit on the cast part. It also allows control of the intrinsic quality of the component by guaranteeing repeatability of the process ensured by the machine indicated above.

[0070] On average, the time to deposit a soft metal using this process on a cast iron piece is 8 minutes to deposit 107 grams of soft metal to a thickness of 3.5 mm.

[0071] The deposition process may also include a step of machining the soft metal coating layer in order to reduce the thickness of the coating, for example to go from an initial thickness after deposition of 3.5 mm to a thickness of 2 mm.

[0072] As previously indicated, the present invention is designed to operate on a plurality of hydraulic rotating machines.

[0073] It is illustrated in a sectional view of a rotating machine. The hydraulic rotating machine differs from that of the in that it has a broken axis.

[0074] Inside the casing 102 are arranged: on the one hand a motor shaft 100, carrying a drive plate 130, perpendicular to the motor shaft 100; on the other hand, a barrel 104 pivotally mounted on a fixed shaft 5 whose axis makes an angle, of approximately 30 to 40 degrees, with that of the motor shaft 1. The spherical head 5a of the shaft 5 is engaged in a corresponding spherical housing provided in the center of the drive plate 130; while its other end is engaged and fixed in a cylindrical housing 5b provided in the center of a distribution cylinder head 110, constituting the bottom of the oblique part of the casing 102.

[0075] A compression spring 140 holds the barrel 104 in contact with the soft metal coating 111 of the distribution cylinder head 110. The barrel 104 comprises, in a similar manner to the pistons 106 slidably housed in bores.

[0076] Illustrates the distribution cylinder head 110 comprising a cast iron part 150 on which a soft metal coating 111 has been deposited, for example by powder spraying with laser beam fusion. The soft metal coating 111 has a circular strip shape with a width of approximately 20 mm. The soft metal coating 111 forms a sliding surface for the barrel 104. In this embodiment, the coating is located on the contour of the first lunule 112 used for delivery and between the first lunule 112 and the second lunule 113 used for suction.

[0077] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention. Indeed, the present invention is designed to operate on a plurality of hydraulic rotating machines.

[0078] The use of the verb "comport" or "comprendre" and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0079] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Hydraulic rotating machine (I) with pistons comprising: a housing (2, 102), a slant plate (30, 130) mounted in the housing (2, 102), a drive shaft (1, 100) and a cylinder (4, 104) mounted for rotation in the housing (2, 102), a plurality of sliding axial pistons (6, 106) located in bores formed in the cylinder (4, 104), the plurality of axial pistons (6, 106) bearing at one end against the slant plate (30, 130), a distribution cylinder head (10, 110) arranged to close the housing (2, 102), against which the cylinder (4, 104) bears on the opposite side of the slant plate (30, 130), the distribution cylinder head (10, 110) being located opposite the drive shaft (1, 100), in which the distribution of the rotating hydraulic machine (I) is ensured by the distribution cylinder head (10, 110), the distribution cylinder head (10, 110) comprising two crescents (12, 112, 13,113) allowing the suction and discharge of a liquid in the rotating hydraulic machine (I), and in which the distribution cylinder head (10, 110) is a cast iron part comprising a surface on which a soft metal coating (11, 111) has been deposited, the soft metal coating (11, 111) being in contact with the barrel (4, 104), in which the soft metal is a non-ferrous metal alloy comprising at least 51% copper by weight of the total non-ferrous metal alloy, in which the thickness of the soft metal coating (11, 111) is between 0.5 and 3.5 mm. Hydraulic rotating machine according to claim 1, in which the soft metal (11, 111) is chosen from: bronze or brass. Hydraulic rotating machine according to any one of the preceding claims, in which the soft metal coating (11, 111) was deposited directly onto the cast iron part by a technique selected from: brazing, cold spraying, vacuum deposition and additive manufacturing. Hydraulic rotating machine according to any one of the preceding claims, in which the soft metal coating (11, 111) was deposited directly onto the cast part by powder spraying with laser beam fusion. hydraulic rotating machine according to any one of the preceding claims, wherein the hydraulic rotating machine (I) is a hydraulic pump. hydraulic rotating machine according to any one of the preceding claims, wherein the hydraulic rotating machine (I) is a hydraulic motor. hydraulic rotating machine according to any one of the preceding claims, wherein the hydraulic rotating machine (I) is reversible and operates either as a hydraulic pump or as a hydraulic motor. Method for preparing a two-material distribution cylinder head, the distribution cylinder head being intended to be integrated into a hydraulic piston machine (I), the method comprising a step of depositing a layer of a soft metal (11) directly onto a surface of a cast iron part in order to form a two-material part, in which the deposition is carried out by powder projection with laser beam melting, in which the layer of soft metal deposited during the deposition step is between 0.5 and 3.5 mm and in which the soft metal is a non-ferrous metal alloy comprising at least 51% copper relative to the total weight of the non-ferrous metal alloy. Method for preparing a two-material distribution cylinder head according to the preceding claim, wherein the soft metal coating layer is deposited only on a surface of the cast iron part intended to be in contact with a rotating barrel. Method for preparing a bi-material distribution cylinder head according to claim 8 or 9, wherein the powder intended to form the soft metal layer is projected in solid state and is fused via the laser beam before touching the surface of the cast part. Method for preparing a bi-material distribution cylinder head according to any one of claims 8 to 10, the method comprises an operation of melting the surface of the cast iron part at the same time as the projection of powder with laser beam fusion.

Images