Sealing member and sealing concept for hydraulic axial piston machine

Abstract

The invention relates to a thrust pad for a port flange of a hydraulic axial piston machine. Thrust pads are used to improve the sealing concept of a hydraulic axial piston machine. The thrust pad includes a top surface, a side surface, and a bottom surface. Further, the thrust pad includes a curved shape configured to be at least partially disposed between the port flange and a port plate of the hydraulic axial piston machine. The thrust pad extends in a first direction, a second direction, and a third direction. The second direction is defined to be orthogonal to the first direction, and the third direction is defined to be orthogonal to the first direction and the second direction. In addition, the extension amount of the thrust pad in the third direction is smaller than the extension amount in the first direction and the second direction, and the extension amount of the thrust pad in the first direction is larger than the extension amount in the second direction. The thrust pad includes a through hole configured to fluidly connect the first port of the port flange to the control hole of the port plate. Furthermore, the invention relates to a port flange, an assembly and a hydraulic axial piston machine.

Description

Technical Field

[0001] This invention relates to a thrust pad for a port flange of a hydraulic axial piston press. Furthermore, this invention relates to a port flange, an assembly of a port plate, a thrust pad, and a port flange, and a hydraulic axial piston press. Background Technology

[0002] Hydraulic axial piston presses are well known in the art. In a hydraulic axial piston press, pistons are guided within a cylinder and rotate about the drive shaft of the press. Furthermore, each piston is coupled to a sliding shoe, which is held in a retainer plate, whereby the piston performs one full stroke per revolution of the cylinder. The term "hydraulic axial piston press" refers to both a hydraulic axial piston pump and a hydraulic axial piston motor. A hydraulic axial piston pump converts mechanical energy into hydraulic energy, while a hydraulic axial piston motor converts hydraulic energy into mechanical energy. Therefore, hydraulic axial piston presses are frequently used in hydraulic systems, such as those in construction machinery, agricultural machinery, and factories. Their excellent reliability, high power density, and precise controllability make hydraulic axial piston presses a preferred choice for hydraulic systems.

[0003] Typically, hydraulic axial piston presses are thus integrated into complex hydraulic fluid systems, with fluid connections to conduits, pipes, channels, tubes, etc., which deliver high-pressure or low-pressure fluid to and from the hydraulic axial piston press. Leakage in the hydraulic fluid system (particularly in the transition region between the fluid delivery device and, for example, the cylinder of the hydraulic axial piston press) can lead to energy loss. Therefore, hydraulic axial piston presses known in the art are equipped with sealing concepts to allow high-pressure fluid to enter or leave the hydraulic axial piston press preferably without leakage; however, limited leakage is often present, which reduces the efficiency of the hydraulic axial piston press. In other words, leakage during the supply and discharge of fluid into and from the cylinder can lead to a loss of efficiency in the hydraulic axial piston press.

[0004] Therefore, sealing elements are known to be arranged in hydraulic axial piston presses to prevent excessive leakage. However, known sealing concepts often require alternating seals (i.e., sealing elements or sealing surfaces alternate between the high-pressure and low-pressure sides), are large in size, require many parts, are complex, heavy, or are simply unsuitable for high pressure. In particular, handling high pressures that deform sealing surfaces (such as the sealing surfaces of port flanges or port plates in hydraulic axial piston presses) can be difficult. Summary of the Invention

[0005] Therefore, an improved sealing concept is needed for hydraulic axial piston presses. Thus, the object of this invention is to improve the sealing concept for hydraulic axial piston presses. In particular, the object of this invention is to provide an improved sealing concept for hydraulic axial piston presses that allows for reduced leakage while operating the system at, for example, higher pressures and higher flow rates.

[0006] The above objectives are achieved by the thrust pad, component, or hydraulic axial piston mechanism according to the present invention.

[0007] Typically, a hydraulic axial piston press includes a port plate (also referred to as a valve plate, distributor plate, or control plate). The port plate includes control holes that allow fluid to flow, for example via the port plate, from a port flange into the cylinder of the hydraulic axial piston press. The thrust pad according to the invention is suitable for the port flange of a hydraulic axial piston press; in other words, the thrust pad is configured to mate with the port flange to improve sealing.

[0008] The thrust pad includes a top surface, a bottom surface, and side surfaces. The top surface may be disposed opposite to the bottom surface. When the thrust pad is disposed within a recess of a port flange, the bottom surface may face the port flange, while the top surface may face the port plate. The bottom surface may include a first aperture. When the thrust pad is disposed within a recess of the port flange, the first aperture may align with a second aperture of the port flange. In one aspect, the thrust pad includes two apertures, each located at each end portion of the thrust pad.

[0009] The first and second holes can be provided by blind holes. An elastic element (e.g., a spring element) can be arranged within the first and second holes to push the thrust pad against the port plate. Furthermore, the top surface can be a generally flat surface and, when used, for example, in an assembly according to the invention, can at least partially abut against the port plate, for example, against a protrusion of the port plate as described below.

[0010] According to one aspect of the invention, the top surface of the thrust pad in the region surrounding the through-hole can protrude from a region not directly adjacent to the through-hole. The protrusion can contact or abut against the thrust pad. In this respect, for example, by means of a spring in a hydraulic axial piston mechanism, the port plate can also be pushed toward the thrust pad, as described below.

[0011] Furthermore, the thrust pad includes a curved shape configured to be at least partially disposed between the port flange and the port plate of the hydraulic axial piston machine. The curvature of the thrust pad may correspond to an arc, at least in some regions.

[0012] In one aspect, the thrust pad can be at least substantially a semilunar shape. According to the invention, a "semilunar shape" can include a crescent shape or a croissant-like shape. In another aspect, the thrust pad can include an axisymmetric shape.

[0013] The lateral surfaces of the thrust pad may extend between the bottom and top surfaces. The distance between the top and bottom surfaces of the thrust pad may be the same for all areas of the thrust pad (excluding any possible first opening), or it may be different, meaning the distance between the top and bottom surfaces may vary in different areas of the thrust pad, for example, due to protrusions on the top and / or bottom surfaces. Therefore, the distance between the top and bottom surfaces may be smaller in some areas of the thrust pad compared to other areas.

[0014] Furthermore, the thrust pad extends in a first direction (e.g., a first planar direction), a second direction (e.g., a second planar direction), and a third direction (e.g., a third normal direction). In other words, the first and second directions can be arranged in a plane, and the third direction can be oriented perpendicular to that plane. Therefore, the second direction is defined as orthogonal to the first direction, and the third direction is defined as orthogonal to both the first and second directions. The curvature of the thrust pad can lie in the plane formed by the first and second directions. In one aspect, the curvature can be analyzed by projecting the thrust pad parallel to the plane formed by the first and second directions.

[0015] According to one aspect, "curved shape" may mean that the thrust pad bulges to different degrees from a plane formed by a third direction and the first direction, or a plane formed by a third direction and the second direction, at different locations along a first direction or a second direction, and wherein the first direction or the second direction extends through the thrust pad. In another aspect, the third direction may be at least partially parallel to the lateral surface.

[0016] Furthermore, the thrust pad's extension in the third direction is less than its extension in the first direction, and the thrust pad's extension in the third direction is less than its extension in the second direction. In other words, the thrust pad may be thinner compared to its width and length. Furthermore, the thrust pad's extension in the first direction is greater than its extension in the second direction. In other words, the thrust pad's extension in the third direction is less than its extension in the first direction, and the thrust pad's extension in the third direction is less than its extension in the second direction. Furthermore, the thrust pad's extension in the first direction is greater than its extension in the second direction.

[0017] In addition, the thrust pad includes a through-hole. The through-hole may include a shape at least similar to that of the thrust pad. In one aspect, the through-hole may include the same shape as the thrust pad. However, the size of the through-hole may be smaller than the size of the thrust pad. The through-hole may extend in a third direction, such that fluid flows through the through-hole of the thrust pad from the top surface of the thrust pad to the bottom surface of the thrust pad, and vice versa.

[0018] When the thrust pad is arranged between the port flange and the port plate, i.e., when the thrust pad is used in the assembly according to the invention, the through-hole is configured to fluidly connect the port (especially the first port) of the port flange to a control hole in the port plate. In this respect, the through-hole of the thrust pad (i.e., the cross-section of the through-hole), the first port of the port flange (i.e., the cross-section of the first port), and the control hole of the port plate (i.e., the cross-section of the control hole) can overlap. Therefore, the thrust pad can be configured to supply and discharge hydraulic fluid into and out of the cylinder through the control hole of the port plate. In this respect, the port plate may include at least two control holes.

[0019] Therefore, the thrust pad can be a flow guiding element located between the port plate and the port flange, while also achieving a seal.

[0020] Therefore, the arrangement of thrust pads (e.g., thrust pads located at least partially between the port plate and the port flange) can allow for improved sealing of the hydraulic axial piston press. Consequently, thrust pads can improve the cost-to-flow ratio because they reduce leakage in the hydraulic axial piston press compared to known sealing concepts and elements. Furthermore, when arranged in a hydraulic axial piston press, thrust pads allow for increased efficiency.

[0021] For example, in one aspect, the thrust pad can be configured to transmit an axial force parallel to the longitudinal axis between the port plate and the port flange during sealing.

[0022] In one embodiment, the lateral surface of the thrust pad may be provided partly by an inner curved profile and partly by an outer curved profile extending between a first end portion and a second end portion. The radius of curvature of the inner or outer curved profile may vary along the respective profile. The inner and outer curved profiles may converge at the first and second endpoints of the respective end portions of the thrust pad, respectively. Therefore, the thrust pad may be configured to be disposed on a port flange of a hydraulic axial piston machine, for example, disposed in a recess in the port flange, such that the thrust pad at least partially surrounds, encloses, or surrounds a rotational axis that defines the rotational axis of the cylinder and / or the drive shaft of the hydraulic axial piston machine. The rotational axis may be collinear with the longitudinal axis described below. Therefore, the shape of the thrust pad may allow for optimization of the thrust pad's sealing function (relative to the contact surface between the thrust pad and, for example, a port plate and / or a port flange). Therefore, the thrust pad may allow for a reduction in the diameter of the port plate, which allows for reductions in the material, weight, and cost of the port plate and corresponding other components.

[0023] Alternatively, and as described above, the thrust pad may include a crescent-shaped bend. The shape of the thrust pad, the shape of the groove in the port flange and / or the shape of the control hole in the port plate, and the shape of the through hole in the thrust pad may be matched to each other.

[0024] Furthermore, in one embodiment, the through-hole may extend partially along the curved shape of the thrust pad. In one aspect, the extension of the through-hole in a first direction may be greater than the extension in a second direction. Therefore, the through-hole may extend along the curved shape of the thrust pad. Thus, the through-hole may comprise a curved shape or a crescent-shaped curved shape. In one aspect, the through-hole of the thrust pad according to the invention (particularly the shape and size of the through-hole relative to the thrust pad) can facilitate the provision of a channel (i.e., a cylinder or cylinder channel) on a larger area end face of the cylinder barrel (i.e., the face of the cylinder barrel facing the port plate and port flange), which can reduce the weight of the cylinder barrel. Furthermore, the number of cylinders in the cylinder barrel can be increased, wherein the cross-section of each cylinder can be reduced, thus preventing cavitation even when each cylinder barrel is used under high pressure.

[0025] Alternatively, in one embodiment, the through-hole may be a curved slot. In other words, the through-hole may be a slot that is curved. The curvature of the through-hole can be selected based on the curvature of the thrust pad. Using a curved slot can enhance the advantages described above and particularly helps to ensure that the thrust pad, and therefore the seal, has little effect on the flow of fluid into and out of the cylinder cavity, while providing improved sealing.

[0026] Furthermore, in another embodiment, the thrust pad may have a thickness defined by the amount of extension of the thrust pad along a third direction. In this respect, the thickness (i.e., the amount of extension along the third direction) may be at least 10 times smaller than the amount of extension of the thrust pad in the first direction (i.e., the thickness is at most one-tenth of the amount of extension of the thrust pad in the first direction). The size of the thrust pad allows for improved sealing when the thrust pad is used under high pressure.

[0027] In addition, according to one aspect, the thrust pad can be made of ceramic.

[0028] The object of the invention is also achieved by a port flange of a hydraulic axial piston machine according to the above aspects. The port flange extends along a longitudinal axis between a cylinder side surface and an opposite surface (i.e., a surface facing away from the cylinder). In one aspect, the port flange may be generally cylindrical. The cylinder side surface and the opposite surface can provide end faces for the generally cylindrical port flange.

[0029] Furthermore, the port flange may include a first port and a second port, each configured to fluidly connect the port flange to a cylinder (i.e., cylinder chamber or (cylinder) passage) of the cylinder barrel of a hydraulic axial piston machine. In this regard, the first and second ports may be arranged on the side surface of the cylinder barrel. Additionally, the port flange may be fluidly connected to the hydraulic system via additional ports fluidly connected to the first and / or second ports, wherein the additional ports are, for example, arranged on the side surface of the generally cylindrical port flange. Thus, fluid can flow from these ports located on the side surface of the port flange to the first and second ports on the cylinder barrel side surface of the port flange, respectively.

[0030] Furthermore, the cylinder side surface of the port flange may also include a groove that at least partially surrounds one of the ports on the cylinder side surface, such as the first port. In other words, the cylinder side surface may have a groove in the region of the first port such that the first port on the cylinder side surface is larger than the pipe at a point offset along the longitudinal axis toward the opposite surface (i.e., the inside of the port flange). In one aspect, the groove may therefore include a stepped portion having a contact surface offset along the longitudinal axis relative to the cylinder side surface of the port flange. Furthermore, the groove may be configured to at least partially receive a thrust pad according to the above aspects. In other words, the thrust pad may at least partially sink into the groove of the port flange. Thus, the contact surface may be configured to abut against the thrust pad along the longitudinal axis when the thrust pad is received in the groove of the port flange, or at least limit possible movement of the thrust pad along the longitudinal axis. For example, the contact surface may limit relative movement of the thrust pad with respect to the port flange in the direction toward the opposite surface (i.e., away from the cylinder side surface).

[0031] Furthermore, when the thrust pad is received in the groove of the port flange, the through-hole of the thrust pad at least partially overlaps with the first port, such that when the port flange is fluidly connected to the cylinder of the hydraulic axial piston press, the first port is fluidly connected to the through-hole of the thrust pad. In other words, the cross-sections of the respective ports can overlap. In other words, fluid can enter the inside of the port flange through the through-hole. Providing a groove for the thrust pad allows for a reduction in the size of the hydraulic axial piston press when using a port flange according to the above aspects. This is particularly true because the thrust pad is actually at least partially recessed into the port flange. Therefore, the port flange can achieve a simple structure while still being particularly suitable for hydraulic axial piston presses operating under high pressure.

[0032] In one embodiment, the groove may include a channel extending orthogonally to the longitudinal axis. Therefore, the channel may extend into the groove in a circumferential direction toward the port flange, i.e., toward the side surface of the port flange. In this respect, the groove may provide sidewalls, and the channel may be arranged in the sidewalls. To allow the thrust pad to be fully received in the groove, the sidewalls of the groove may be longer than the thickness of the thrust pad, i.e., longer than the amount of extension of the thrust pad in a third direction. Therefore, the gap between the contact surface and the bottom surface of the thrust pad may be filled with fluid, causing the thrust pad to move toward the port plate, i.e., away from the opposite side of the port flange. In this respect, a spring element, for example, arranged in a hole in the thrust pad, may provide clearance. Furthermore, due to the arrangement of the channel on the sidewalls of the groove, the channel may not be directly visible in a top view of the cylinder side surface of the port flange. The groove may be configured to receive a sealing element. The sealing element may be an O-ring. Therefore, a sealing element such as an O-ring may be arranged, for example, within the groove. Furthermore, when the thrust pad is at least partially received in the groove, the sealing element may be configured to abut against the side surface of the thrust pad. In other words, when the port flange is used with an assembly including a port plate, a thrust pad, and the port flange itself, the sealing element can be configured to form a seal between the port plate and the thrust pad. Furthermore, when the thrust pad is inserted into a groove and the sealing element may contact the thrust pad, the thrust pad can be held in place within the groove by the frictional force generated by the surface contact between the sealing element and the thrust pad. Additionally, the sealing element contributes to the sealing performance of the thrust pad and can further prevent fluid from flowing through the contours of the thrust pad, i.e., through the lateral surfaces of the thrust pad.

[0033] Furthermore, according to one aspect of the invention, the first port can provide a high-pressure port configured to supply or discharge a high-pressure fluid into or from the cylinder of the hydraulic axial piston machine. Therefore, in one aspect, since the first port is used in conjunction with a thrust pad, the thrust pad is preferably used in conjunction with the high-pressure side of the hydraulic axial piston machine. This is primarily because the thrust pad, due to its shape and design, deforms only slightly, thus providing a sufficient seal without deformation even under high pressure. It can also be used to compensate for deformation in other components of the hydraulic axial piston machine, particularly deformation caused by high pressure on the port flange and / or port plate.

[0034] According to another aspect of the invention, the object of the invention is achieved by a component comprising, for example, a port plate according to the above aspects, a thrust pad according to the above aspects, and a port flange according to the above aspects. In this respect, the thrust pad may be at least partially received (e.g., recessed) within a groove of the port flange, such that a third direction of the thrust pad is parallel to the longitudinal axis of the port flange. Furthermore, the cylinder side surface of the port flange may be arranged to abut against the port plate, and / or the port plate may be arranged to abut against the thrust pad, such that when the thrust pad is received in the groove, the thrust pad is at least partially disposed between the port flange and the port plate. The groove in the port flange allows for limited axial movement of the thrust pad relative to the port flange, i.e., movement, for example, along the longitudinal axis of the port flange toward the other side of the port flange. In this respect, the port plate may move together with the thrust pad to keep the thrust pad and the port plate in abutment. The thrust pad can seal the port flange. Therefore, the (high) hydraulic pressure acting on the thrust pad and the pressure causing deformation of the port flange and / or port plate can be compensated by the thrust pad (e.g., together with a sealing element disposed in the groove).

[0035] In one aspect of the invention, the thrust pad is axially movable relative to the port flange along the longitudinal axis of the port flange, at least when no port plate is disposed on the cylinder side surface of the port flange. In other words, the thrust pad is not fixed to the port flange. Furthermore, the thrust pad is provided as a separate component from the port flange.

[0036] In one embodiment, the recess of the port flange may form a stepped portion having a contact surface offset along a longitudinal axis relative to the cylinder side surface of the port flange. When the thrust pad is received in the recess, the contact surface can thus restrict axial movement of the thrust pad along the longitudinal axis relative to the port flange. Furthermore, the offset between the contact surface and the cylinder side surface can be greater than the extension of the thrust pad along a third direction. Therefore, the thrust pad can be configured to be fully received in the recess. In other words, the thrust pad can be recessed into the port flange such that the top surface of the thrust pad does not bulge from the cylinder side surface toward the port plate. The port plate can have a corresponding protrusion such that even when the thrust pad is fully recessed into the port flange recess and the port plate abuts against the cylinder side surface of the port flange, the port plate with the protrusion also abuts against the thrust pad. In other words, if the port flange is correspondingly raised, the protrusion can protrude into the recess. This ensures improved sealing.

[0037] According to a further embodiment, the assembly may also include a sealing element disposed within a groove in the recess of the port flange as described above. In one aspect, the sealing element may be configured to seal between the port plate and the thrust pad. Therefore, this improved sealing concept allows for the use of port plates that are less complex to manufacture, as they require only a single material and are thus less expensive, while still allowing for a adequate seal under high pressure.

[0038] According to a further aspect of the invention, the aforementioned objective can be achieved by a hydraulic axial piston machine comprising components according to the foregoing aspects. Furthermore, the hydraulic axial piston machine may include: a cylinder having at least one cylinder housing a piston, a retainer plate mechanically coupled to the piston in the cylinder, and a drive shaft mechanically coupled to the cylinder. The piston can move along a longitudinal axis in at least one cylinder of the cylinder and can transmit force from hydraulic fluid to the drive shaft or from the drive shaft to hydraulic fluid. Furthermore, a port plate (i.e., a control plate or valve plate) can control the flow of hydraulic fluid to at least one cylinder of the cylinder, thereby determining, for example, the direction of rotation of the drive shaft. The drive shaft can transmit power from the piston to a connecting element connected to the drive shaft, or for rotating the cylinder. In this regard, for example, the drive shaft may be splined to the cylinder. Furthermore, bearings may be provided to support the drive shaft. Furthermore, a housing (at least partially) provided, for example, by a port flange, may house the aforementioned components. Due to the corresponding arrangement of the thrust pads as described above, the sealing performance of the hydraulic axial piston machine can be improved, and the aforementioned advantages can be achieved.

[0039] According to one embodiment, the hydraulic axial piston press may further include a pressure plate and at least one spring (i.e., one or more springs) configured to abut the pressure plate against a port plate. Thus, the port plate can abut against the side surface of the cylinder of the port flange. In other words, at least one spring and the pressure plate can be configured to provide a seal between the port plate and the cylinder side surface of the port flange. The cylinder can rotate relative to the port plate and the port flange. In one aspect, the cylinder can rotate with the pressure plate. The pressure plate and the port plate, or the cylinder and the port plate, can provide a sliding seal. The force acting on the sliding seal can be substantially toward the port flange. Furthermore, a force acting on a thrust pad in the opposite direction to the force acting toward the port flange, for example due to hydraulic pressure, can be transmitted to the port plate by the thrust pad. These forces acting in opposite directions can keep the fluid system closed and sealed. Therefore, the thrust pad can be used to seal the hydraulic axial piston press.

[0040] According to a further embodiment, in a first mode, when the drive shaft can be rotated by a drive motor, the hydraulic axial piston press can be configured to draw low-pressure fluid into at least one cylinder of the cylinder barrel via a second port of the port flange, and can be configured to discharge high-pressure fluid via a first port of the port flange. In the first mode, the hydraulic axial piston press can be considered as a hydraulic axial piston pump.

[0041] Furthermore, in the second mode, when the drive shaft can be rotated by the rotation of the cylinder, the hydraulic axial piston press can be configured to supply high-pressure fluid to at least one cylinder of the cylinder via a first port of the port flange, and can be configured to discharge low-pressure fluid via a second port of the port flange. In this regard, the retainer plate can rotate. Therefore, the high-pressure fluid entering the cylinder via the first port of the port flange and discharging as low-pressure fluid via the second port of the port flange drives the cylinder and thus drives the drive shaft connected to the drive motor. In the second mode, the hydraulic axial piston press can be considered as a hydraulic axial piston motor, wherein the drive motor acts as a generator.

[0042] Therefore, regardless of the aforementioned usage scenario, i.e., the aforementioned usage mode, the thrust pad can be placed at the high-pressure port of the port flange to improve the corresponding sealing performance. In one aspect of the invention, no sealing element is provided between the port flange and the port plate at the low-pressure port. In other words, the seal at the low-pressure port can be provided purely through surface contact between the port plate and the port flange. Therefore, sealing of the interface between the port plate and the port flange can be achieved solely with the thrust pad, which can reduce the cost and complexity of the hydraulic axial piston press.

[0043] In particular, the thrust pad provided according to the present invention makes this inventive sealing concept for hydraulic axial piston machines possible. Therefore, it can bring about several improvements, especially making the structure of hydraulic axial piston machines more economical.

[0044] Although not described in more detail, a sealing concept similar to providing a thrust pad between the port plate and the port flange can also be used in pressure exchangers, such as those used in seawater reverse osmosis systems. Attached Figure Description

[0045] Additional features, advantages, and possible applications of the present invention arise from the following description of exemplary embodiments and the accompanying drawings. All features described herein and / or illustrated graphically, whether independent or in a desired combination, and regardless of how they are combined in the claims or referenced in prior claims, form the technical subject matter of the present invention.

[0046] Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0047] Figure 1A A top perspective view of the thrust pad according to the present invention is shown;

[0048] Figure 1B It shows that according to Figure 1A Bottom perspective view of the thrust pad;

[0049] Figure 2A An exploded top view of an assembly according to the invention is shown, the assembly including a port plate, a thrust pad, and a port flange.

[0050] Figure 2B It shows that according to Figure 2A The exploded bottom view of the component;

[0051] Figure 3A A cross-sectional view of the components is shown, illustrating the arrangement of the thrust pads;

[0052] Figure 3B Additional sectional views of the components are shown; and

[0053] Figure 4 A hydraulic axial piston machine is shown.

[0054] In the accompanying drawings, the same elements and components, as well as the same elements and components in different examples or embodiments (i.e., elements and components that have the same purpose or are provided for the same purpose but belong to different examples), are given the same reference numerals. Detailed Implementation

[0055] exist Figure 1A and Figure 1BThe diagram illustrates a thrust pad 1 according to the present invention. The thrust pad 1 extends in a first direction X and a second direction Y, which are arranged in the same plane and orthogonal to each other. Furthermore, the thrust pad 1 extends in a third direction Z, which is orthogonal to the first direction X and the second direction Y. The extension of the thrust pad 1 in the third direction Z is less than the extension of the thrust pad 1 in the first direction X and less than the extension of the thrust pad 1 in the second direction Y. In other words, the thrust pad 1 is thinner compared to its width and length.

[0056] As can be seen from the figure, the thickness of thrust pad 1 is at least 10 times smaller than its extension in the first direction X (i.e., the thickness is at most one-tenth of the extension of the thrust pad in the first direction). The first direction X, the second direction Y, and the third direction Z are indicated by corresponding arrows.

[0057] Furthermore, the thrust pad 1 includes a top surface 2, a side surface 3, and a bottom surface 4. In the third direction Z, the bottom surface 4 is disposed opposite to the top surface 2. The side surface 3 extends parallel to the third direction Z.

[0058] Furthermore, the thrust pad 1 includes a curved shape. In this respect, the thrust pad 1 includes two end portions, each end portion including a corresponding endpoint, namely a first endpoint 5 and a second endpoint 6. An inner curved profile 7 and an outer curved profile 8 are formed between the two endpoints 5 and 6, for example, these profiles are defined by the edge of the thrust pad 1 near the top surface 2. In this respect, the inner curved profile 7 can be considered as a profile with a smaller radius compared to the outer curved profile 8. Furthermore, the inner curved profile 7 and the outer curved profile 8 meet at the first endpoint 5 and the second endpoint 6 of the respective end portions.

[0059] Furthermore, the thrust pad 1 includes a through hole 9, the shape of which is at least substantially the same as the shape of the thrust pad 1. In the figure, the through hole 9 is a curved slot.

[0060] As can be seen from the figure, the through hole 9 can cover more than 60% of the area of ​​the bottom surface 4.

[0061] Furthermore, the through-hole 9 is configured to allow fluid to flow from the top surface 2 of the thrust pad 1 to the bottom surface 4, and vice versa. When the thrust pad 1 is used for example... Figure 2A , Figure 2B , Figure 3A or Figure 3B In the component 100 shown, or used for, for example Figure 4 In the hydraulic axial piston machine 1000 shown, the through hole 9 allows fluid to flow from the port flange 101 to the control hole 102 of the port plate 103, and vice versa.

[0062] from Figure 1AIt can be noted that in the region surrounding the through-hole 9, the top surface 2 protrudes from the area not directly adjacent to the through-hole 9 (i.e., immediately adjacent to the inner curved profile 7 and the outer curved profile 8 of the thrust pad 1). Furthermore, a first hole 10 is arranged in the region at the end portion of each thrust pad 1. Therefore, two first holes 10 are thus arranged on the bottom surface 4 of the thrust pad 1. Figure 2A and Figure 2B It can be noted that the first hole 10 is arranged on the bottom surface 4 and aligned with the second hole 104 of the port flange 101. Here, the first hole 10 and the second hole 104 are blind holes. Although not shown, a spring element can be arranged in the first hole 10 and the second hole 104, i.e., in the corresponding openings formed by the first hole 10 and the second hole 104, so as to push the thrust pad 1 away from the port flange 101 and abut against the port plate 103.

[0063] like Figure 2A and Figure 2B The corresponding port flange 101 shown extends along the longitudinal axis XL between the cylinder side surface 105 and the opposite side 106 opposite to the cylinder side surface 105. For example, when with, for example Figure 4 When the cylinder 107 shown is used together, the cylinder side surface 105 of the port flange 101 faces the cylinder 107. In this respect, a port plate 103 and, on the other hand, a pressure plate 108 are arranged between the cylinder side surface 105 and the cylinder 107.

[0064] Furthermore, port flange 101 includes a first port 109 and a second port 110, each of which is configured to fluidly connect port flange 101 to cylinder 111 of cylinder 107 of hydraulic axial piston press 1000. The first port 109 may be a high-pressure port, and the second port may be a low-pressure port. Moreover, rotation of cylinder 107 fluidly connects cylinder 111 to the corresponding first port 109 and second port 110, and this fluid connection alternates according to the rotational position of cylinder 107.

[0065] Furthermore, the port flange 101, and therefore the hydraulic axial piston 1000, can be fluidly connected to a hydraulic system (not shown) via additional ports arranged on the side surface of the port flange 101. Thus, fluid can flow from the ports of the port flange 101 to the first port 109 and the second port 110 on the cylinder side surface 105. In other words, the ports on the side surface of the port flange 101 can be used to supply and discharge fluid into and from the cylinder 111 of the cylinder 107.

[0066] Furthermore, the cylinder side surface 105 of the port flange 101 also includes a groove 112 that at least partially surrounds the first port 109 on the cylinder side surface 105. The groove 112 forms a stepped portion with a contact surface 113 offset relative to the cylinder side surface 105 of the port flange 101 along the longitudinal axis XL. Figure 3A and Figure 3B The stepped portion and contact surface 113 are best viewed from the center.

[0067] In addition, Figure 3A and Figure 3B In this configuration, the thrust pad 1 is received or recessed into the groove 112. More specifically, the thrust pad 1 is partially recessed into the groove 112 of the port flange 101, wherein the contact surface 113 is configured to abut against the thrust pad 1 or restrict possible movement of the thrust pad 1 along the longitudinal axis XL toward the opposite side 106 (i.e., away from the cylinder side surface 105). Furthermore, a gap is formed between the contact surface 113 and the thrust pad 1, which is filled with fluid, such that the thrust pad 1 abuts against the port plate 103, i.e., the opposite side away from the port flange 101. In other words, the aim is to eliminate contact between the contact surface 113 and the thrust pad 1. In this regard, a spring element (not shown) can be provided for this gap, which can be arranged, for example, in the hole 10.

[0068] exist Figure 3A and Figure 3B In the component 100 shown, the through hole 9 of the thrust pad 1 at least partially overlaps with the first port 109.

[0069] Furthermore, the recess 112 of the port flange 101 includes a groove 114 extending orthogonally to the longitudinal axis XL. Thus, the groove 114 extends radially toward the outer periphery of the port flange 101 from within the recess 112. In this respect, the recess 112 provides a sidewall 115 in which the groove 114 is disposed. The groove 114 is configured to receive a sealing element (not shown). The sealing element may be an O-ring. When the thrust pad 1 is partially received within the recess 112, the sealing element is configured to abut against the lateral surface 3 of the thrust pad 1.

[0070] The above-mentioned component 100 can be used as follows: Figure 4In the hydraulic axial piston press 1000 shown, hydraulic fluid is fed into cylinder 111 via two ports 109 and 110, and flows out of cylinder 111 via through hole 9 of thrust pad 1, port plate 103, and control hole 102 of pressure plate 108. When piston 116 retracts inside cylinder 111 and moves axially inside cylinder barrel 107, for example, low-pressure hydraulic oil can be drawn into cylinder 111 via second port 110. In other words, piston 116 can move away from port flange 101 to draw fluid into piston 111. In this respect, piston 116, connected via ball joint 117, is connected to slip shoe 118 and thus to retainer plate 119. Due to the rotation of drive shaft 120 in hydraulic axial piston press 1000, piston 116 can be pulled away from port flange 101 by retainer plate 119. Furthermore, slip shoe 118 can slide or move on swing plate 119A. Furthermore, the retainer plate 119 can hold the sliding shoe 118 on the swing plate 119A. In this mode, the hydraulic axial piston machine 1000 can be used as a hydraulic axial piston pump. Additionally, when the cylinder 107 rotates such that the cylinder 111 containing the intake fluid reaches a rotational position where liquid can be discharged via the first port 109, the liquid has high pressure. Then, the empty cylinder 111 rotates back to the second port 110 position, so that new fluid at a lower pressure is drawn in again. The rotation of the cylinder 107 is provided by the drive shaft 120 and therefore by the drive motor connected thereto.

[0071] In this respect, torque (and thus rotation) is applied to the drive shaft 120 of the hydraulic axial piston machine 1000 via a drive motor (not shown). The drive shaft 120 is mechanically connected to the cylinder 107, for example, via a spline connection to the cylinder 107. Therefore, rotation of the drive shaft 120 is transmitted to the cylinder 107, resulting in rotation of the cylinder 107 due to the rotation of the drive shaft 120. Thus, hydraulic fluid can flow into the cylinder 111, for example, when the piston 116 retracts on the intake side (low-pressure side). Simultaneously, hydraulic fluid is pushed out of the cylinder 111 by the piston 116 located on the high-pressure side and enters the hydraulic system, for example, via the first port 109 of the port flange 101. Thus, the thrust pad 1 can seal the high-pressure side of the hydraulic axial piston machine 1000. However, the hydraulic axial piston machine 1000 can also be used as a hydraulic axial piston motor.

[0072] Furthermore, the hydraulic axial piston press 1000 includes at least one spring 121 that applies a force toward the port flange 101. In this respect, at least one spring 121 abuts a pressure plate 108 against the port plate 103. Therefore, the port plate 103 can abut against the cylinder side surface 105 of the port flange 101. In other words, at least one spring 121 and the pressure plate 108 can provide a seal between the port plate 103 and the cylinder side surface 105 of the port flange 101. In other words, the pressure plate 108 abuts against the port plate 103 under the force of the spring 121. The pressure plate 108 can rotate together with the cylinder 107. Furthermore, the cylinder 107 can rotate relative to the port plate 103 and the port flange 101, i.e., rotate relative to the port plate 103 and the port flange 101. Therefore, the pressure plate 108 and the port plate 103 can provide a sliding seal.

[0073] When the drive shaft 120 is rotated by the drive motor, the hydraulic axial piston press 1000 can thus draw low-pressure fluid into the cylinder 111 of the cylinder 107 via the second port 110 of the port flange 101, and can be configured to discharge high-pressure fluid via the first port 109 of the port flange 101. The sealing of the low-pressure port (i.e., the second port 110) is provided purely through surface contact between the port plate 103 and the port flange 101, and between the port flange 103 and the pressure plate 108. Therefore, no sealing element is provided associated with the second port 110.

[0074] Furthermore, to maintain contact between the thrust pad 1 and the port plate 103, particularly when the thrust pad 1 is recessed into the groove 112 of the port flange 101, as shown, the port plate 103 has a corresponding protrusion 122, such that even when the thrust pad 1 is fully recessed into the groove 112 of the port flange 101, and even when the port plate 103 abuts against the cylinder side surface 105 of the port flange 101, the port plate 103 with the protrusion 122 still abuts against the thrust pad 1. Furthermore, the protrusion 122 ensures that pressure is formed between the thrust pad 1 and the port plate 103. Therefore, if the port plate 103 contacts the port flange 101, i.e., contacts the cylinder side surface 105 of the port flange 101, the protrusion 122 partially protrudes into the groove 112.

[0075] In addition to the components described above, the hydraulic axial piston mechanism 1000 includes a housing 123 that at least partially houses further components and elements of the hydraulic axial piston mechanism 1000. For example, the housing can be used to protect components and prevent leakage.

[0076] Furthermore, a bearing 124, such as a radial bearing, is provided inside the housing 123 to support the cylinder 107 and thus the drive shaft 120 of the hydraulic axial piston machine 1000. Therefore, the cylinder 107 can rotate together with the drive shaft 120 to which it is splined.

[0077] Therefore, when the hydraulic axial piston press 1000 is used and when fluid is supplied or discharged from the cylinder 111 of the cylinder 107, the thrust pad 1 arranged between the port flange 101 and the port plate 103, especially the thrust pad 1 sandwiched between the port flange 101 and the port plate 103, can improve the sealing performance of the hydraulic axial piston press 1000.

[0078] List of reference numerals

[0079] 1. Thrust pad

[0080] 2 Top surface

[0081] 3. Side surfaces

[0082] 4 Bottom surface

[0083] 5 First endpoint

[0084] 6 Second endpoint

[0085] 7. Inner Curved Profile

[0086] 8. Outer curved profile

[0087] 9 Through holes

[0088] 10 First Hole

[0089] 100 components

[0090] 101 Port Flange

[0091] 102 Control Hole

[0092] 103-port board

[0093] 104 Second Hole

[0094] 105 Cylinder side surface

[0095] 106 Opposite side

[0096] 107 cylinder barrel

[0097] 108 pressure plate

[0098] 109 First Port

[0099] 110 Second Port

[0100] 111 cylinders

[0101] 112 Groove

[0102] 113 Contact Surface

[0103] 114 Trench

[0104] 115 Sidewall

[0105] 116 Piston

[0106] 117 Ball Joint

[0107] 118 Sliding Boots

[0108] 119 Retainer Plate

[0109] 119A Swing Plate

[0110] 120 drive shaft

[0111] 121 Spring

[0112] 122 Protrusion

[0113] 123 Outer shell

[0114] 124 bearing

[0115] 1000 Hydraulic Axial Piston Press

[0116] X First Direction

[0117] Y Second Direction

[0118] Z Third Direction

[0119] XL (longitudinal axis of the port flange).

Claims

1. A thrust pad (1) for a port flange (101) of a hydraulic axial piston machine (1000). in, The thrust pad (1) includes a top surface (2), a side surface (3) and a bottom surface (4). The thrust pad (1) includes a curved shape configured to be at least partially disposed between the port flange (101) and the port plate (103) of the hydraulic axial piston machine (1000). The thrust pad (1) extends in a first direction (X), a second direction (Y), and a third direction (Z), wherein the second direction (Y) is defined as orthogonal to the first direction (X), and the third direction (Z) is defined as orthogonal to both the first direction (X) and the second direction (Y). Wherein, the extension amount of the thrust pad (1) in the third direction (Z) is less than the extension amount in the first direction (X) and the second direction (Y), wherein the extension amount of the thrust pad (1) in the first direction (X) is greater than the extension amount in the second direction (Y). The thrust pad (1) includes a through hole (9), and The through hole (9) is configured to fluidly connect the first port (109) of the port flange (101) to the control hole (102) of the port plate (103).

2. The thrust pad (1) according to claim 1, wherein, The lateral surface (3) is provided in part by an inner curved profile (7) and in part by an outer curved profile (8) extending between a first end portion and a second end portion, wherein the inner curved profile (7) and the outer curved profile (8) intersect at a first end point (5) and a second end point (6) of the respective end portions, and / or wherein the thrust pad (1) comprises a crescent-shaped curved shape.

3. The thrust pad (1) according to any one of the preceding claims, wherein, The through hole (9) extends partially along the curved shape of the thrust pad (1), and wherein the through hole (9) extends more in the first direction (X) than it extends in the second direction (Y).

4. The thrust pad (1) according to any one of the preceding claims, wherein, The through hole (9) is a curved slot.

5. The thrust pad (1) according to any one of the preceding claims, wherein, The thickness of the thrust pad (1) is defined by the amount of the thrust pad extending along the third direction (Z), wherein the thickness is smaller than the amount of the thrust pad (1) extending in the first direction (X) and is at most one-tenth of the amount of the thrust pad (1) extending in the first direction (X).

6. A port flange (101) for a hydraulic axial piston press (1000). in, The port flange (101) extends along the longitudinal axis (XL) between the cylinder side surface (105) and the opposite surface (106). The port flange (101) includes a first port (109) and a second port (110), each of which is configured to fluidly connect the port flange (101) to the cylinder (111) of the cylinder (107) of the hydraulic axial piston machine (1000). The cylinder side surface (105) of the port flange (101) further includes a groove (112) that at least partially surrounds the first port (109), wherein the groove (112) is configured to at least partially receive the thrust pad (1) according to any one of claims 1 to 5. When the thrust pad (1) is received in the groove (112) of the port flange (101), the through hole (9) of the thrust pad (1) at least partially overlaps with the first port (109), such that when the port flange (101) is fluidly connected to the cylinder (111) of the cylinder (107) of the hydraulic axial piston machine (1000), the first port (109) is fluidly connected to the through hole (9) of the thrust pad (1).

7. The port flange (101) according to claim 6, wherein, The groove (112) includes a channel (114) extending orthogonally to the longitudinal axis (XL), wherein the channel (114) is configured to receive a sealing element, and wherein the sealing element is configured to abut against the lateral surface (3) of the thrust pad (1) when the thrust pad (1) is at least partially received within the groove (112).

8. The port flange (101) according to claim 6 or 7, wherein, The first port (109) provides a high-pressure port, which is configured to supply a high-pressure fluid to the cylinder (111) of the cylinder (107) of the hydraulic axial piston machine (1000), or the high-pressure port is configured to discharge a high-pressure fluid from the cylinder (111) of the cylinder (107) of the hydraulic axial piston machine (1000).

9. An assembly (100) comprising a port plate (103), a thrust pad (1) according to any one of claims 1 to 5, and a port flange (101) according to any one of claims 6 to 8. in, The thrust pad (1) is at least partially received in a groove (112) of the port flange (101) such that the third direction (Z) of the thrust pad (1) is parallel to the longitudinal axis (XL) of the port flange (101). The cylinder side surface (105) of the port flange (101) is arranged to abut against the port plate (103), and / or the port plate (103) is arranged to abut against the thrust pad (1), such that when the thrust pad (1) is received in the groove (112), the thrust pad (1) is at least partially arranged between the port flange (101) and the port plate (103).

10. The component (100) according to claim 9, wherein, The groove (112) of the port flange (101) forms a stepped portion having a contact surface (113) offset relative to the cylinder side surface (105) of the port flange (101) along the longitudinal axis (XL), wherein the offset between the contact surface (113) and the cylinder side surface (105) is greater than the extension of the thrust pad (1) along the third direction (Z).

11. The component (100) according to claim 9 or 10, wherein, The component (100) also includes a sealing element disposed inside the groove (114) of the recess (112) of the port flange (101).

12. A hydraulic axial piston press (1000), comprising: The component according to any one of claims 9 to 11; Cylinder (107), the cylinder having at least one cylinder (111), the at least one cylinder having a piston (116). Retainer plate (119), said retainer plate being mechanically connected to piston (116) of cylinder (107); and A drive shaft (120) is mechanically connected to the cylinder (107).

13. The hydraulic axial piston machine (1000) according to claim 12, wherein, The hydraulic axial piston machine (1000) also includes a pressure plate (108) and at least one spring (120) configured to press the pressure plate (108) against the port plate (103), thereby providing a seal between the port plate (103) and the cylinder side surface (105) of the port flange (101).

14. The hydraulic axial piston machine (1000) according to claim 12 or 13, wherein, When the drive shaft (120) is rotated by the drive motor, the hydraulic axial piston (1000) is configured to draw low-pressure fluid into at least one cylinder (111) of the cylinder (107) via a second port (110) of the port flange (101), and to discharge high-pressure fluid via a first port (109) of the port flange (101). When the drive shaft (120) rotates due to the rotation of the cylinder (107), the hydraulic axial piston (1000) is configured to supply high-pressure fluid to at least one cylinder (111) of the cylinder (107) via a first port (109) of the port flange (101) and discharge low-pressure fluid via a second port (110) of the port flange (101).

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