Hydraulic device

Abstract

A hydraulic device includes a rotor and port members including a high-pressure port and a low-pressure port. The rotor has a plurality of cylinders spaced at an angle about an axis of rotation and mating pistons movable within each cylinder. Each cylinder communicates with an open end at an outer surface of the rotor, and under operating conditions, each open end alternately communicates with the high-pressure port and the low-pressure port. Every two consecutive cylinders are interconnected via a fluid displacement member having a first opening and a second opening, and a closing element that is freely movable between the first and second openings and substantially blocks either the first or second opening if, under operating conditions, the pressure in the cylinder communicating with the second opening is higher or lower than that in the cylinder communicating with the first opening. Flow resistance is provided in the rotor at a distance from each open end, and the first and second openings of every two fluid displacement members communicating with a cylinder are fluidly connected to that cylinder on opposite sides of the flow resistance.

Description

Technical Field

[0001] This invention specifically relates to a hydraulic device. Background Technology

[0002] This invention relates to a hydraulic device comprising a rotor and a port member including a high-pressure port and a low-pressure port, wherein the outer surface of the rotor faces the outer surface of the port member and is rotatable relative to the port member about a rotation axis in a rotational direction, wherein the rotor is provided with a plurality of cylinders spaced angularly apart about the rotation axis and mating pistons movable within each cylinder, wherein the cylinders communicate with their respective open ends at the outer surface of the rotor, wherein under operating conditions each open end alternately communicates with the high-pressure port and the low-pressure port, wherein every two consecutive cylinders of the plurality of cylinders are interconnected via a fluid displacement member having a first opening communicating with one of the two consecutive cylinders, a second opening communicating with the other of the two consecutive cylinders, and a closing element movable freely between the first and second openings and configured such that if, under operating conditions, the pressure in the cylinder communicating with the second opening is higher or lower than the pressure in the cylinder communicating with the first opening, the first opening or the second opening is substantially blocked, respectively.

[0003] Such a hydraulic device is known from NL 1016738. The known hydraulic device has a rotor connected to a rotating swashplate such that during rotor rotation, each piston in its respective cylinder moves between bottom dead center and top dead center. Under operating conditions, some cylinders are in communication with a high-pressure port, and other cylinders are in communication with a low-pressure port. Each cylinder is connected to its successive, adjacent, or neighboring cylinders via a fluid displacement member. The fluid displacement member is provided with a closing element that can move freely between its first and second openings. If, under operating conditions, the pressure of the hydraulic fluid in the cylinder communicating with the second opening is higher than the pressure of the hydraulic fluid in the cylinder communicating with the first opening, the closing element can move to the first opening and substantially block the first opening; and if the pressure in the cylinder communicating with the first opening is higher than the pressure in the cylinder communicating with the second opening, the closing element can move to the second opening and substantially block the second opening. During the movement of the closing element from the first opening to the second opening, a finite volume of hydraulic fluid flows between the two successive cylinders, and vice versa.

[0004] When one of the open ends on the outer surface of the rotor travels between the high-pressure port and the low-pressure port, i.e., along the sealing surface of the port member, under operating conditions, the pressure of the hydraulic fluid in the cylinder connected to that open end changes due to the change in the piston's position within the cylinder, while the open end is closed by the sealing surface. If the pressure at the high-pressure port differs from the pressure within the cylinder when the corresponding open end begins to connect with the high-pressure port, and / or if the pressure at the low-pressure port differs from the pressure within the cylinder when the corresponding open end begins to connect with the low-pressure port, this pressure change, known as commutation, can lead to increased noise and vibration. Known hydraulic devices suppress excessive pressure differences through fluid displacement members, also known as shuttles, which can transfer excessive hydraulic fluid between successive cylinders.

[0005] For example, consider one of the open ends traveling from the low-pressure port to the high-pressure port, which is closed by a sealing surface between the low-pressure and high-pressure ports. The piston in the cylinder connected to the open end in question moves from bottom dead center to top dead center, and during this travel, the pressure in the cylinder connected to the open end in question increases. The successive cylinders still connected to the low-pressure port will remain at a lower pressure, such that the closing element of the fluid displacement member connecting these cylinders will substantially block one of its first and second openings, preventing any or a limited amount of hydraulic fluid from flowing into the successive cylinders. The other successive cylinder already connected to the high-pressure port will initially have a higher pressure than the cylinder connected to that open end as it travels along the sealing surface at the open end in question, such that the closing element of the fluid displacement member connecting these cylinders will also substantially block one of its first and second openings. During the travel of the open end along the sealing surface, if the pressure in the corresponding cylinder exceeds the pressure at the high-pressure port, and this pressure equals the pressure in the successive cylinders already connected to the high-pressure port, the closing element of the fluid displacement member connecting these cylinders will move from one of the first and second openings to the other. During this movement, hydraulic fluid will flow from the cylinder connected to the open end to the fluid displacement member and displace its closing element, thereby preventing further pressure increases.

[0006] If the open end in question begins to connect to the high-pressure port before the closing element of the fluid displacement member begins to connect to the high-pressure port, the continuous cylinders connected to the fluid displacement member (in this case, all continuous cylinders are connected to the high-pressure port) substantially block the other of the first and second openings. The pressure in the cylinder connected to the open end in question is balanced with the pressure at the high-pressure port, and a significant pressure difference is avoided. If the closing element substantially blocks the other of the first and second openings before the open end in question begins to connect to the high-pressure port, the pressure in the cylinder connected to the open end in question will further increase to a level higher than the pressure at the high-pressure port. Since the pressure in the cylinder will reach the high-pressure port earlier as the pressure at the high-pressure port decreases, the distance between the first and second openings should ensure that the travel distance of the closing element is sufficient to avoid an undesirable pressure difference at the relatively low pressure at the high-pressure port.

[0007] When the open end travels from the high-voltage port to the low-voltage port, a similar effect as described above will occur. Summary of the Invention

[0008] The purpose of this invention is to provide an improved hydraulic device.

[0009] This objective is achieved by a hydraulic device according to the invention, characterized in that a flow resistance is provided in the rotor at a certain distance from each open end, wherein the first and second openings of every two fluid displacement members communicating with a cylinder are fluidly connected to the cylinder on opposite sides of the flow resistance.

[0010] The advantage of this invention is that the closing element of the fluid displacement member is forced to a predetermined position before the open end of the rotor reaches the sealing surface between the low-pressure port and the high-pressure port. Under operating conditions, the continuous cylinder communicating with the low-pressure port generates a hydraulic fluid flow that causes a pressure drop across its respective flow resistance in the direction from the corresponding open end to the cylinder, while the continuous cylinder communicating with the high-pressure port generates a hydraulic fluid flow that causes a pressure drop across its respective flow resistance in the direction from the corresponding cylinder to the open end. Since the first and second openings of each fluid displacement member communicate with two consecutive or adjacent cylinders on opposite sides of the corresponding flow resistance, the closing element of the fluid displacement member interconnected with the two consecutive cylinders communicating with the low-pressure port or the high-pressure port will be forced in the same direction. Therefore, when the open end communicating with the cylinder reaches the sealing surface, the closing element of the fluid displacement member interconnected with the cylinder and the subsequent continuous cylinders reaching the sealing surface will always substantially block its first or second opening. This provides the opportunity for compression or expansion to begin at the sealing surface under fixed reference conditions of the fluid displacement member. This prevents the closing element from being positioned by, for example, centrifugal force.

[0011] It should be noted that when the closing element of the fluid displacement member substantially blocks the first or second opening, it minimizes the fluid flow through the first or second opening, respectively. This means that the first or second opening is either completely closed, or a very small amount of fluid still flows through it. In the latter case, the fluid flow will typically be much smaller than the fluid flow through the first and second openings when the closing element moves between them.

[0012] In one practical embodiment, each cylinder is connected to a corresponding open end via a channel that provides flow resistance. The cross-sectional area of ​​this channel may be smaller than the cross-sectional area of ​​the respective cylinder. The channel and the fluid displacement member may be formed within a rigid element.

[0013] Flow resistance can be created by localized narrowing of the channel.

[0014] In one embodiment, a first opening of each fluid displacement member communicates with a corresponding cylinder via a first hole in a channel, and a second opening of each fluid displacement member communicates with a corresponding cylinder via a second hole in a channel. In a more specific embodiment, for one of the fluid displacement members, under operating conditions, its first opening is fluidly connected to a first hole in a channel corresponding to a first cylinder in the cylinder, and its second opening is fluidly connected to a second hole in a channel corresponding to a successive cylinder following the first cylinder in the cylinder.

[0015] Preferably, the distance between the first orifice and the open end is greater than that between the second orifice, because in this embodiment, the flow resistance can be formed by the length of the channel between the first and second orifices. This provides simple flow resistance, making it possible to omit the local narrowing of the channel.

[0016] Each of the fluid displacement components may include a straight passage between a first opening in one of two consecutive channels and a second opening in the other of the two consecutive channels, wherein the passage has a cylindrical portion between the first and second openings. Thus, the closing element travels within the cylindrical portion.

[0017] In one practical embodiment, the closing element is a ball, and the first and second openings are surrounded by respective seats that mate with the ball, such that when the ball is pressed against the seat at the first opening, fluid flow through the first opening is substantially blocked, and when the ball is pressed against the seat at the second opening, fluid flow through the second opening is substantially blocked. This is a simple and effective fluid displacement component structure. The ball can be made of ceramic. Furthermore, the ball of the fluid displacement component can be smaller than the diameter of the cylindrical portion between the first and second openings, as long as the ball substantially blocks the first or second opening when pressed against the respective seat. However, other shapes of the closing element and / or seat, such as a small piston, are also conceivable. In an alternative embodiment, the closing element fits tightly against the cylindrical portion between the first and second openings. In this case, the respective seats at the first and second openings can be omitted, because the tightly fitted closing element, when in its respective opposite end position within the cylindrical portion, automatically substantially blocks the first and second openings. As previously stated, when the closing element substantially blocks the first or second opening, minimal leakage is allowed through the first or second opening.

[0018] The cylindrical portion has a centerline, which may lie in a plane extending tangentially to the axis of rotation relative to the rotational position of the cylindrical portion, or may be inclined at an angle of less than 45°, preferably less than 25°, relative to this plane. This minimizes the influence of centrifugal force on the closing element, which may counteract displacement of the closing element through the pressure difference in flow resistance.

[0019] In a preferred embodiment, the channel extends imaginarily through the open end of the channel where its second hole is located in the direction from the rotor to the port member, as this provides the opportunity to drill the channel from the open end. Therefore, it is unnecessary to drill a separate hole that requires partial closure and subsequent sealing.

[0020] In one specific embodiment, the outer surfaces lie in a common plane, the axis of rotation extends perpendicular to the outer surfaces, the centerline of the cylinder extends parallel to the axis of rotation, and the high-pressure port and the low-pressure port are arc-shaped around the axis of rotation.

[0021] In a more specific embodiment, the axis of rotation is a first axis of rotation, and the rotor also includes a shaft rotatable about a second axis of rotation and having a flange extending perpendicular to the second axis of rotation. The plurality of pistons are fixed to the flange at equal angular distances about the second axis of rotation. The cylinders are individual sleeves fitted onto a cylindrical plate having a channel. The second axis of rotation intersects the first axis of rotation at an acute angle, such that when the shaft is rotated, each piston reciprocates within a mating cylinder. This configuration can be referred to as a float cup hydraulic system because the position of the cylinder on the cylindrical plate is determined by the actual position of the mating piston. In this embodiment, the channel may have an imaginary extension in the direction from the port member to the cylinder, passing through an inlet opposite to the open end of the channel, as this provides an opportunity to drill out of the channel through the inlet.

[0022] In one embodiment, the outer surface of the port member has a first sealing surface between the low-pressure port and the high-pressure port, which reaches the bottom dead center via a mating piston at the open end, and a second sealing surface between the low-pressure port and the high-pressure port, which reaches the top dead center via a mating piston at the open end, wherein when measured in the rotational direction, the length of each of the first and second sealing surfaces is greater than the length of each of the open ends.

[0023] When measured in the rotational direction, the distance between the edge of the first sealing surface adjacent to the low-pressure port and the position of the piston at the first sealing surface when it reaches bottom dead center can be half the length of each open end, and / or when measured in the rotational direction, the distance between the edge of the second sealing surface adjacent to the high-pressure port and the position of the piston at the second sealing surface when it reaches top dead center can be half the length of each open end. This means that bottom dead center and top dead center are reached when the first and second sealing surfaces begin to close their respective open ends.

[0024] When measured in the direction of rotation, the length of the first sealing surface can be greater than the length of the second sealing surface, because after leaving the top dead center, only the dead volume in the cylinder must be expanded by the corresponding piston, while after leaving the bottom dead center, both the dead volume and the volume to be replaced by the piston must be compressed by the corresponding piston.

[0025] The hydraulic device can be a pump, motor, or transformer. Attached Figure Description

[0026] The invention will now be described with reference to the accompanying drawings, which illustrate embodiments of the invention by way of example.

[0027] Figure 1 This is a cross-sectional view of an embodiment of the hydraulic device according to the present invention;

[0028] Figure 2 yes Figure 1Front view of the distribution plate of the hydraulic unit;

[0029] Figure 3 yes Figure 1 Enlarged perspective view of the cylindrical plate in the embodiment;

[0030] Figure 4 Is with Figure 3 A similar view, showing a portion of it at a larger scale;

[0031] Figure 5 yes Figure 4 Cross-sectional view of the middle section;

[0032] Figure 6 This is an explanation Figure 1 A schematic diagram illustrating the function of the embodiment shown;

[0033] Figure 7 Is with Figure 6 A similar view illustrates the functionality of another embodiment;

[0034] Figure 8 Is with Figure 6 A similar view illustrates the functionality of another embodiment. Detailed Implementation

[0035] Figure 1 The internal components of a hydraulic device 1, such as a pump or hydraulic motor, are shown, mounted in a known manner within a housing 2. The hydraulic device 1 is provided with a shaft 3, which is rotatably supported by the housing 2. One side of the housing 2 is provided with an opening through which a toothed end 4 of the shaft 3 protrudes from the housing 2. If the hydraulic device 1 is a pump, a motor can be coupled to the toothed end 4, and if the hydraulic device is a motor, a driven tool can be coupled to it.

[0036] The hydraulic device 1 includes port components in the form of distribution plates 5 installed inside the housing 2 at a certain distance from each other. Figure 2 One of the distribution plates 5 is shown in more detail. Each distribution plate 5 includes an arc-shaped high-pressure port 6 and an arc-shaped low-pressure port 7. A first sealing surface 8a and a second sealing surface 8b are located between the high-pressure port 6 and the low-pressure port 7. The distribution plate 5 has a fixed position relative to the housing 2 in the direction of rotation of the housing 2, but in an alternative embodiment (not shown), the distribution plate 5 can rotate relative to the housing 2. A shaft 3 extends through a respective central through-hole in the distribution plate 5.

[0037] Shaft 3 is provided with flange 9. On both sides of flange 9, a plurality of pistons 10 are fixed by their respective crimp fittings, in this case, there are fourteen pistons 10 on both sides. Figure 1The pistons 10 shown are made from individual parts, but they can also be a single unit. Each of the pistons 10 mates with a separate cylinder 11 to form a variable-volume compression chamber 12. Figure 1 The hydraulic device 1 shown has 28 compression chambers 12. Each of the cylinders 11 includes a cylinder bottom 13 and a cylinder liner 14 extending from the cylinder bottom 13.

[0038] Each cylinder 11 has its cylinder bottom 13 supported by two cylindrical plates 16, which are mounted around the shaft 3 via respective ball joints 17 and coupled to the shaft 3 via keys 18. Therefore, under operating conditions, the cylindrical plates 16 rotate together with the shaft 3. Figure 3 One of the cylinder plates 16 is shown in more detail. It should be noted that the cylinder bottoms 13 rest on their respective cylinder plates 16, but they are not fixed in position relative to their respective cylinder plates 16.

[0039] Figure 1 The diagram shows cylindrical plates 16 rotating about their respective first axes of rotation 19, which are angled relative to a second axis of rotation 20. A shaft 3 is rotatable about the second axis of rotation 20, and a flange 9 extends perpendicular to the second axis of rotation 20. A piston 10 is positioned at equiangular distances about the second axis of rotation 20. The piston 10 has a centerline extending parallel to the second axis of rotation 20. An arcuate low-pressure port 7 and an arcuate high-pressure port 6 of each panel 5 extend about their respective first axes of rotation 19. The angle between the second axis of rotation 20 and the respective first axes of rotation 19 is practically approximately 9 degrees, but can be smaller or larger.

[0040] When rotating shaft 3, cylinder plate 16 and cylinder 11 rotate about their respective first rotation axes 19. Each cylinder 11 undergoes combined translational and rotational movements about its mating piston 10. Each piston 10 moves relative to its mating cylinder 11 between bottom dead center (BDC) and top dead center (TDC). As a result, the volume of the corresponding compression chamber 12 changes.

[0041] like Figure 1 As shown in Figure 3, each of the cylindrical plates 16 has an outer surface 21 that is away from the flange 9 and faces the outer surface 22 of the mating distribution plate 5. The cylindrical plates 16 are pressed against their respective distribution plates 5 by springs 23 installed in holes in the shaft 3. The outer surfaces 21, 22 extend perpendicular to their respective first axes of rotation 19. Due to the inclination direction of the outer surface 22 of the distribution plate 5 relative to the flange 9, the cylindrical plates 16 pivot about the ball joint 17 as they rotate together with the shaft 3.

[0042] With regard to one of the cylinder plates 16, the cylinder 11 resting on the cylinder plate 16 communicates with the mating channel 24 in the cylinder plate 16 via a central through hole in the bottom 13 of the respective cylinder. The channel 24 has its own open end 25 at the outer surface 21 of the cylinder plate 16, see... Figure 3 and Figure 4 In this configuration, each cylinder plate 16 has fourteen consecutive open ends 25, which communicate with fourteen consecutive cylinders 11. Under operating conditions, the open ends 25 are alternately connected to high-pressure lines and low-pressure lines (not shown) provided in the housing 2 via high-pressure port 6 and low-pressure port 7, respectively.

[0043] In fact, Figure 1 In the embodiment shown, shaft 3, cylinder plate 16, piston 10, cylinder 11, ball hinge 17, key 18 and spring 23 can be regarded as parts of the rotor, which has opposing outer surfaces 21 facing the outer surfaces 22 of their respective distribution disks 5.

[0044] Figure 3-5 It is shown that each pair of consecutive channels 24 are interconnected via fluid displacement members 26, which means that each pair of consecutive cylinders 11 are also interconnected via fluid displacement members 26. Therefore, each cylinder plate 16 is also provided with fourteen consecutive fluid displacement members 26. Each of the fluid displacement members 26 includes a channel between each pair of consecutive channels 24 and has a first opening 27 and a second opening 28 spaced apart from each other. The channel has a cylindrical portion between the first opening 27 and the second opening 28. A closing element in the form of a ball 29 is freely movable between the first opening 27 and the second opening 28. For illustrative purposes, Figure 3-5 Two balls are shown on a fluid displacement member 26, but in reality each fluid displacement member 26 has a single ball 29.

[0045] See Figure 4 The first opening 27 communicates with the right channel of a pair of consecutive channels 24, and the second opening 28 communicates with the left channel of the pair of consecutive channels 24. The first opening 27, the second opening 28, and the ball 29 are configured such that, under operating conditions, the channel 24 communicating with the second opening 28, i.e. Figure 4 The pressure in the left channel is higher than that in the channel 24 connected to the first opening 27, i.e. Figure 4 If the pressure in the right channel is such that ball 29 essentially blocks the first opening 27, while under operating conditions, channel 24, which is connected to the first opening 27, ... Figure 4 The pressure in the right channel is higher than that in the channel 24, which is connected to the second opening 28. Figure 4 The pressure in the left channel of the ball 29 essentially blocked the second opening 28.

[0046] As ball 29 moves from the first opening 27 to the second opening 28, it displaces the fluid toward the channel 24 communicating with the second opening 28, and as ball 29 moves from the second opening 28 to the first opening 27, it displaces the fluid toward the channel 24 communicating with the first opening 27. Therefore, the greater distance between the first opening 27 and the second opening 28 results in a larger volume of fluid displaced between each pair of consecutive channels 24.

[0047] With regard to one of the channels 24, it communicates with a first opening 27 and a second opening 28 of two consecutive fluid displacement members 26 located on opposite sides of the channel 24. The first opening 27 of one of the two consecutive fluid displacement members 26 is fluidly connected to the channel 24 via a first hole 31 in the channel 24, and the second opening 28 of the other of the two consecutive fluid displacement members 26 is fluidly connected to the channel 24 via a second hole 32 within the channel 24. The distance between the first hole 31 and the open end 25 of the channel 24 discussed is greater than that of the second hole 32, see [link to relevant documentation]. Figure 4 and Figure 5 The distance between the first orifice 31 and the second orifice 32 in channel 24 creates a flow resistance 30 between the first orifice 31 and the second orifice 32 under operating conditions, the effect of which will be explained below. In an alternative embodiment (not shown), each of the channels 24 is provided with a flow resistance in the form of a constraint having a locally narrowed cross-sectional area of ​​the channel 24.

[0048] Figure 4 The arrows illustrate how the fluid displacement component 26 is manufactured by drilling channels in the form of elongated stepped holes between every two consecutive channels 24, by inserting a drill bit into the open end 25 and drilling in the direction of the arrow. An advantage of this manufacturing method is that the fluid displacement component 26 is entirely within the cylindrical plate 26, meaning that sealing between different components is not necessary.

[0049] Figure 5 A first opening 27 is shown adjacent to a first hole 31. The first opening 27 is surrounded by a seat that mates with a ball 29, such that fluid flow through the first opening 27 is impeded when the ball 29 is pressed against the seat at the first opening 27. Similarly, a second opening 28 is surrounded by a seat that mates with a ball 29, such that fluid flow through the second opening 28 is impeded when the ball 29 is pressed against the seat at the second opening 28. The seat at the second opening 28 is formed by the tapered end of an internal hexagonal screw 32 that includes a through-hole screw screwed into the drilled hole after the ball 29 is introduced into the cylindrical portion of the stepped hole. Optional structural designs are conceivable, such as a seat that is crimped, clamped, or glued into the drilled hole.

[0050] Each of the elongated stepped holes has a centerline that is slightly inclined relative to a plane that extends tangentially relative to the first axis of rotation 19 at the rotational position where the cylindrical portion of the fluid displacement member 26 is located. This means that the effect of centrifugal force on the ball 29 is limited. Therefore, the rotational speed of the shaft 3 has a limited impact on the function of the fluid displacement member 26. It is worth noting that in Figure 1-5 In the illustrated embodiment, with Figure 4 In contrast to the direction indicated by the middle arrow, a long, narrow stepped hole can also be drilled from the other side of the cylinder plate 16, preferably through the entrance of the respective channel 24 away from the open end 25, that is, on the side of the cylinder plate 16 where the cylinder bottom 13 is placed.

[0051] The ball 29 does not need to fit tightly within the cylindrical portion of the fluid displacement member 26; it is sufficient that the ball 29 substantially blocks fluid flow when it is adjacent to the seat of the first opening 27 or the second opening 28 to minimize leakage.

[0052] The working principle of hydraulic device 1 is as follows: Figure 6 As shown, for illustrative purposes, Figure 6 The distribution plate 5, including the high-pressure port 6 and the low-pressure port 7, is shown linearly. Furthermore, only eleven pistons 10, cylinders 11, channels 24, flow resistance 30, open ends 25, and fluid displacement members 26 are shown. The channels 24, cylinders 11, and fluid displacement members 26, including the flow resistance 30 and open ends 25, are represented as a portion of a unit moving along the linear distribution plate 5. The direction of movement of this unit relative to the distribution plate 5 is as follows... Figure 6 As indicated by arrow X. During the movement of the corresponding open end 25 along the first sealing surface 8a between the low-pressure port 7 and the high-pressure port 6 and the second sealing surface 8b between the high-pressure port 6 and the low-pressure port 7, each of the pistons 10 passes the bottom dead center (BDC) and the top dead center (TDC). The length of each open end 25 in the direction of movement X is less than the length of each of the first sealing surface 8a and the second sealing surface 8b in that direction, which means that during the passage of each sealing surface of the first sealing surface 8a and the second sealing surface 8b, the open end 25 is closed by one of the first sealing surface 8a and the second sealing surface 8b within a certain period.

[0053] Preferably, the distance between the edge of the first sealing surface 8a adjacent to the low-pressure port 7 and the position of the piston 10 at the first sealing surface 8a when it reaches the bottom dead center BDC is approximately half the length of the open end 25 in the direction of movement X, because compression in each of the cylinders 11 passes through essentially begins at the bottom dead center BDC of the corresponding piston 10. Similarly, the distance between the edge of the second sealing surface 8b adjacent to the high-pressure port 6 and the position of the piston 10 at the second sealing surface 8b when it reaches the top dead center TDC is preferably approximately half the length of the open end 25 in the direction of movement X, because expansion in each of the cylinders 11 passes through essentially begins at the top dead center TDC of the corresponding piston 10. Figure 2 The semi-length is represented by angle α. This semi-length is measured in the direction of rotation about the first axis of rotation 19.

[0054] Furthermore, the distance between the position of piston 10 at the bottom dead center (BDC) on the first sealing surface 8a and the edge of the adjacent high-pressure port 6 of the first sealing surface 8a is greater than the distance between the position of piston 10 at the top dead center (TDC) on the second sealing surface 8b and the edge of the adjacent low-pressure port 7 of the second sealing surface 8b. The distances measured in the rotational direction are respectively... Figure 2 The angles β1 and β2 in the figure represent this. The reason why β1 is greater than β2 is that after leaving the top dead center (TDC), only the dead volume in cylinder 11 must expand, while after leaving the bottom dead center (BDC), both the dead volume and the stroke volume to be replaced by piston 10 must be compressed.

[0055] When the open end 25 passes the first sealing surface 8a or the second sealing surface 8b and is closed by it, the pressure in the cylinder 11 communicating with the open end 25 will change because the piston 10 is still moving during this period. When the open end 25 reaches the high-pressure port 6 or the low-pressure port 7, the pressure in the cylinder 11 and the pressure at the high-pressure port 6 or the low-pressure port 7 should preferably be the same as or close to each other to avoid excessive pressure difference leading to noise emissions. This is achieved by the fluid displacement member 26 between each pair of consecutive channels 24, and will be described below. Figure 6 The arrow at the piston 10 indicates the direction of movement of the piston 10 and also indicates the direction of flow of hydraulic fluid through the channel 24 when the open end 25 is connected to the high-pressure port 6 or the low-pressure port 7.

[0056] exist Figure 6 In the figure, one piston 10, the cylinder 11 that mates with it, the passage 24, and the open end 25 are indicated by reference numerals 10', 11', 24', and 25', respectively. Figure 6In the illustrated configuration, piston 10' is near bottom dead center (BDC), and cylinder 11' remains connected to low-pressure port 7 via channel 24' and open end 25'. The fluid displacement member 26 and its ball 29 located to the left of channel 24' are indicated by reference numerals 26' and 29', respectively, while the continuous fluid displacement member 26 and its ball 29 located to the right are indicated by reference numerals 26” and 29”, respectively. The continuous channel 24 of channel 24' that mates with the fluid displacement member 26' is indicated by reference numeral 24”, and the continuous channel 24 of channel 24' that mates with the fluid displacement member 26” is indicated by reference numeral 24”'. Further continuous channels 24 of channel 24”' are indicated by 24””.

[0057] In such Figure 6 In the illustrated case, fluid displacement member 26' blocks the flow from channel 24' to channel 24" by closing its first opening 27, while fluid displacement member 26" blocks the flow from channel 24"' to channel 24' by closing its first opening 27. Due to the increased pressure at the high-pressure port 6 communicating with channel 24"', the ball 29" of fluid displacement member 26" remains in that position. According to the invention, the ball 29' of fluid displacement member 26' remains in its position due to the presence of flow resistance 30; the flow resistance 30 in channel 24' is denoted by 30', and the flow resistance 30 in channel 24" is denoted by 30"".

[0058] Since the open end 25, which is connected to the low-pressure port 7, is also connected to the cylinder 11, in which the piston 10 moves from the top dead center (TDC) to the bottom dead center (BDC), under operating conditions, hydraulic fluid flows from the low-pressure port 7 to the respective cylinder 11 through their respective mating passages 24. This generates a lower pressure on the downstream side of each flow resistance 30, i.e., on the side where the corresponding cylinder 11 is located, than on its upstream side, i.e., on the side where the open end 25 is located. Therefore, as Figure 6 As shown, fluid displacement members 26 are arranged to connect with the open end 25, which communicates with the low-pressure port 7, forcing each ball 29 of the fluid displacement members 26 to reach its respective first opening 27 in an upward direction. In other words, the balls 29' of the fluid displacement members 26' are always in a predefined position before the open end 25' reaches the first sealing surface 8a.

[0059] It should be noted that, in the absence of local narrowing of the channel 24, the distance between the first hole 31 and the second hole 32 along the channel 24 may only cause a small pressure drop, but due to the low weight of the ball 29, for example, the ball 29 may have a diameter of 4 mm and a weight of 0.1 g, this may be sufficient to displace the ball 29 of the fluid displacement member 26.

[0060] Refer again Figure 6When the open end 25' moves further in the direction of motion X, the piston 10' in the corresponding cylinder 11' will be completely closed by the first sealing surface 8a when it reaches the bottom dead center BDC. As long as the open end 25' is closed, the pressure in the cylinder 11' will increase after passing the bottom dead center BDC. Due to the increased pressure, the first opening 27 of the fluid displacement member 26' will remain blocked. However, when the pressure in the cylinder 11' exceeds the pressure at the high-pressure port 6, the ball 29' of the fluid displacement member 26' will move in the direction from the channel 24' toward the continuous channel 24'', causing the pressure in the cylinder 11' to no longer rise or only rise slightly. Therefore, when the open end 25' begins to connect with the high-pressure port 6, the pressure in the cylinder 11' is essentially equal to the pressure at the high-pressure port 6. The travel distance of the ball 29' of the fluid displacement member 26' depends on the pressure level at the high-pressure port 6. The relatively low pressure at the high-pressure port 6 requires a relatively long travel distance because the cylinder 11 will quickly reach a low pressure level during the movement of the open end 25' along the first sealing surface 8a.

[0061] After the open end 25' has passed the first sealing surface 8a and moved along the high-pressure port 6, the ball 29' will automatically move to or remain in the desired position and then reach the second sealing surface 8b, on which the piston 10' passes the top dead center TDC. On the downstream side of each flow resistance 30, i.e., on the side where the open end 25 is located, the pressure is lower than on the upstream side, i.e., on the side where the cylinder 11 is located. This forces the ball 29' to be in a position such that... Figure 6 The lower position shown allows it to block the flow from channel 24”' to continuous channel 24”” by blocking its second opening 28.

[0062] Importantly, each of the balls 29 of the respective fluid displacement members 26 has a predefined position before the open end 25 reaches its respective first sealing surface 8a and second sealing surface 8b. For example, if before reaching the first sealing surface 8a, Figure 6 If the ball 29' has an intermediate position at any position between the first opening 27 and the second opening 28, then the ball 29' will first move to its correct upper position when the open end 25' is closed, which will cause compression to subsequently begin in the cylinder 11', thus creating an undetermined compression initiation condition in the cylinder 11' after the corresponding piston 10' has passed the bottom dead center BDC.

[0063] When the open end 25 passes through the second sealing surface 8b and the piston 10 of the cylinder 11 connected to the open end 25 passes the top dead center TDC, a similar effect as described above occurs when the open end 25 passes through the first sealing surface 8a. When the open end 25 is closed by the second sealing surface 8b and the piston 10 moves from the top dead center TDC to the bottom dead center BDC, the pressure in the cylinder 11 decreases, causing the ball 29 of the fluid displacement member 26, which connects the cylinder 11 to the continuous cylinder 11 under operating conditions, to remain in the same position, i.e., close the second opening 28. Once the pressure in the cylinder 11 becomes lower than the pressure at the low-pressure port 7, the ball 29 of the other fluid displacement member 26 can move toward the first opening 27. Before reaching the first sealing surface 8a, the ball 29 will automatically move to or remain at the first opening 27, i.e. Figure 6 The upper part of the middle.

[0064] Figure 7 An alternative embodiment is shown in which the arrangement of the fluid displacement member 26 is different, but the function is the same. Figure 6 The embodiment shown is similar. In this case, the open end 25, which is connected to the low-pressure port 7, forces the ball 29 of the corresponding fluid displacement member 26 upward. Figure 7 As shown, when the open end 25' reaches the first sealing surface 8a, the ball 29' of the fluid displacement member 26' blocks the first opening 27. Since the open end 25' is already connected to the high-pressure port 6, the ball 29' of the fluid displacement member 26' is forced to a lower position and blocks its second opening 28. Once the open end 25' is closed by the first sealing surface 8a, the piston 10' will begin to move from the bottom dead center BDC, and the pressure in the cylinder 11 will begin to rise. Therefore, the ball 29' will immediately move downward and block the flow from channel 24' to channel 24'". Subsequently, when the pressure in the cylinder 11' exceeds the pressure at the high-pressure port 6, the ball 29' of the fluid displacement member 26' will move upward in the direction from channel 24' toward the continuous channel 24'', but once the open end 25' is connected to the high-pressure port 6, the ball 29' will be forced downward due to the arrangement of the fluid displacement member 26.

[0065] The opposite effect was achieved at the second sealing surface 8b. (Reference) Figure 7 Ball 29”' remains in the lower position until piston 10”' reaches top dead center TDC, while open end 25”' is closed by second sealing surface 8b. After passing top dead center TDC, ball 29”' will immediately move upward.

[0066] Because the ball 29 of the fluid displacement member 26 must immediately shift between the first opening 27 and the second opening 28 after passing the top dead center TDC or the bottom dead center BDC, in order to begin expansion or compression respectively, when measured in the direction of motion X... Figure 7The first sealing surface 8a and the second sealing surface 8b of the fluid displacement member 26 shown in the diagram will be greater than Figure 6 The fluid displacement member 26 shown has a first sealing surface 8a and a second sealing surface 8b.

[0067] Figure 8 Another alternative embodiment is shown, in which the hydraulic device 1 is used as a motor. Figure 7 and Figure 8 In the illustrated embodiment, the channel 24 and open end 25, including the flow resistance 30, the cylinder 11, and the fluid displacement member 26 are represented as a portion of a unit that moves along the linear distribution plate 5 in a movement direction Y opposite to the movement direction X. The function of the fluid displacement member 26 is similar to... Figure 6 and Figure 7 The illustrated embodiments are quite similar.

[0068] This invention is not limited to the embodiments shown in the accompanying drawings and described above, and can be varied in different ways within the scope of the claims and their technical equivalents. For example, the hydraulic device may be a slider axial pump or a motor with a cylinder in the cylinder body, or the hydraulic device may be a transformer.

Claims

1. A hydraulic device (1) comprising a rotor (3, 9, 10, 11, 16-18, 23) and a port member (5) including a high-pressure port (6) and a low-pressure port (7), wherein the outer surface (21) of the rotor faces the outer surface (22) of the port member (5) and is rotatable relative to the port member (5) about a rotation axis (19) in a rotational direction, wherein the rotor is provided with a plurality of cylinders (11) spaced angularly apart from each other about the rotation axis (19) and mating pistons (10) movable within each of the respective cylinders (11), wherein the cylinders (11) communicate with a respective open end (25) at the outer surface (21) of the rotor, wherein under operating conditions each of the open ends (25) alternately communicates with the high-pressure port (6) and the low-pressure port (7), wherein... Each pair of consecutive cylinders (11) in a plurality of cylinders (11) is interconnected via a fluid displacement member (26), the fluid displacement member (26) having a first opening (27) communicating with one of the two consecutive cylinders (11), a second opening (28) communicating with the other of the two consecutive cylinders (11), and a closing element (29) movable freely between the first opening (27) and the second opening (28) and configured such that if, under operating conditions, the pressure in the cylinder (11) communicating with the second opening (28) is higher or lower than the pressure in the cylinder (11) communicating with the first opening (27), the first opening (27) or the second opening (28) is substantially blocked, respectively. The flow resistance (30) is provided in the rotors (3, 9, 10, 11, 16 - 18, 23) at a distance from each open end (25), wherein the first opening (27) and the second opening (28) of every two fluid displacement members (26) communicating with a cylinder (11) are fluidly connected to the cylinder (11) on the opposite side of the flow resistance (30).

2. The hydraulic device (1) according to claim 1, characterized in that, Each cylinder in the cylinder (11) is connected to a corresponding open end (25) through a channel (24) in which the flow resistance (30) is provided.

3. The hydraulic device (1) according to claim 2, characterized in that, The flow resistance (30) is formed by the local narrowing of the channel (24).

4. The hydraulic device (1) according to claim 2 or 3, characterized in that, The first opening (27) of each fluid displacement member (26) is connected to the corresponding cylinder (11) via a first hole (31) in the channel (24), and the second opening (28) of each fluid displacement member (26) is connected to the corresponding cylinder (11) via a second hole (32) in the channel (24).

5. The hydraulic device (1) according to claim 4, characterized in that, The distance between the first hole (31) and the open end (25) is greater than the distance between the second hole (32) and the open end (25).

6. The hydraulic device (1) according to claim 5, characterized in that, Each fluid displacement component in the fluid displacement component (26) includes a straight passage between a first hole (31) in one of two consecutive channels (24) and a second hole (32) in the other of the two consecutive channels (24), wherein the straight passage has a cylindrical portion between the first opening (27) and the second opening (28).

7. The hydraulic device (1) according to claim 6, characterized in that, The closing element is a ball (29), and the first opening (27) and the second opening (28) are surrounded by respective seats that mate with the ball (29), such that when the ball (29) is pressed against the seat at the first opening (27), the fluid flow through the first opening (27) is substantially blocked, and when the ball (29) is pressed against the seat at the second opening (28), the fluid flow through the second opening (28) is substantially blocked.

8. The hydraulic device (1) according to claim 6 or 7, characterized in that, The cylindrical portion has a center line that lies in a plane or is inclined at less than 45° relative to the plane, and the plane extends tangentially relative to the axis of rotation (19) at the rotational position of the cylindrical portion.

9. The hydraulic device (1) according to claim 8, characterized in that, The centerline is inclined at less than 25° relative to the plane.

10. The hydraulic device (1) according to claim 6 or 7, characterized in that, An imaginary extension of the channel in the direction from the rotor to the port member (5) passes through the open end (25) of the channel (24), and the second hole (32) of the channel (24) is located in the open end (25).

11. The hydraulic device (1) according to any one of claims 1-3, characterized in that, The outer surfaces (21, 22) are located in a common plane, the rotation axis (19) extends perpendicular to the outer surfaces (21, 22), the center line of the cylinder (11) extends parallel to the rotation axis (19), and the high-pressure port (6) and the low-pressure port (7) are arc-shaped around the rotation axis (19).

12. The hydraulic device (1) according to claim 11, characterized in that, The rotation axis is a first rotation axis (19), and the rotor also includes a shaft (3) that can rotate about a second rotation axis (20) and has a flange (9) extending perpendicular to the second rotation axis (20), wherein the plurality of pistons (10) are fixed on the flange (9) at equal angular distances about the second rotation axis (20), wherein the cylinder is an independent sleeve (11) that is fitted on a cylindrical plate (16) having a channel (24), wherein the second rotation axis (20) intersects the first rotation axis (19) at an acute angle, such that when the shaft (3) is rotated, each piston of the piston (10) reciprocates within the mating cylinder (11).

13. The hydraulic device (1) according to any one of claims 1-3, characterized in that, The outer surface (22) of the port member (5) has a first sealing surface (8a) and a second sealing surface (8b); the first sealing surface (8a) is between the low-pressure port (7) and the high-pressure port (6); at the first sealing surface (8a), the piston (10) corresponding to the open end (25) reaches the bottom dead center (BDC); the second sealing surface (8b) is between the low-pressure port (7) and the high-pressure port (6); at the second sealing surface (8b), the piston (10) corresponding to the open end (25) reaches the top dead center (TDC); wherein, when measured in the rotational direction, the length of each of the first sealing surface (8a) and the second sealing surface (8b) is greater than the length of each of the open ends (25).

14. The hydraulic device (1) according to claim 13, characterized in that, When measured in the direction of rotation, the distance between the edge of the first sealing surface (8a) adjacent to the low-pressure port (7) and the position of the piston at the first sealing surface (8a) when it reaches the bottom dead center (BDC) is half the length of each open end (25), and / or when measured in the direction of rotation, the distance between the edge of the second sealing surface (8b) adjacent to the high-pressure port (6) and the position of the piston (10) at the second sealing surface (8b) when it reaches the top dead center (TDC) is half the length of each open end (25).

15. The hydraulic device (1) according to claim 13, characterized in that, When measured in the rotational direction, the length of the first sealing surface (8a) is greater than the length of the second sealing surface (8b).

16. The hydraulic device (1) according to any one of claims 1-3, characterized in that, The hydraulic device is a pump, motor, or transformer.

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