Hydraulic converter

Abstract

A hydraulic transducer (1) comprises a housing (2) comprising a high pressure connection (3), a low pressure connection (4) and a working pressure connection (5), a cylinder (19, 20) rotatably mounted in the housing (2) and provided with compression chambers whose volume varies upon rotation of the cylinder (19, 20). The rear side (24) of the cylinder (19, 20) includes a cylinder port (27) in communication with the respective compression chamber. The hydraulic converter (1) has a valve plate (28, 29) supported by the housing (2) and provided with a front side (30) supporting the rear side (24) of the cylinder (19, 20), a rear side (31) facing the housing (2), a circumferential outer wall and a central bore (49) surrounded by a circumferential inner wall. The valve plate (28, 29) is rotatable within a predetermined angle relative to the housing (2), with the front side (30) being provided with three arcuate valve plate ports along which the cylinder ports (27) move as the cylinders (19, 20) rotate. The port of the valve plate is communicated with the high-pressure interface (3) through a first channel (35) in the valve plate (28, 29), is communicated with the low-pressure interface (4) through a second channel (36) in the valve plate (28, 29), and is communicated with the working pressure interface (5) through a third channel (37) in the valve plate (28, 29). One of the first to third channels (35, 36, 37) has an opening on a rear side (31) of the valve plate (28, 29), one of the first to third channels (35, 36, 37) has an opening on a circumferential outer wall of the valve plate (28, 29), and one of the first to third channels (35, 36, 37) has an opening on a circumferential inner wall of the valve plate (28, 29).

Description

[0001] This invention relates to a hydraulic converter, comprising: a housing including a high-pressure port, a low-pressure port, and a working pressure port; a cylinder rotatably mounted within the housing and having multiple compression chambers, the volume of which changes as the cylinder rotates, wherein the rear side of the cylinder includes a cylinder port communicating with a corresponding compression chamber; and a distribution plate supported by the housing and having a front side supporting the rear side of the cylinder, a rear side facing the housing, a circumferential outer wall, and a central hole surrounded by a circumferential inner wall. The distribution plate is rotatable relative to the housing within a predetermined angle, wherein the front side has three arc-shaped distribution plate ports, and the cylinder ports move along the arc-shaped distribution plate ports as the cylinder rotates. The distribution plate ports are respectively connected to the high-pressure port through a first channel in the distribution plate, to the low-pressure port through a second channel in the distribution plate, and to the working pressure port through a third channel in the distribution plate.

[0002] Such hydraulic converters are known in NL 1019736. While known hydraulic converters have advantages in terms of friction, their operating range is relatively narrow. High-pressure and low-pressure interfaces allow fluid connection to the high-pressure and low-pressure lines of a common rail pressure system, while the working pressure interface allows fluid connection to a load, such as a hydraulic cylinder or hydraulic motor. A general advantage of hydraulic converters is that, unlike throttling, they operate in a non-dissipative manner. Energy can be recovered and transferred to other loads or stored, for example, in a liquid-gas accumulator.

[0003] One object of the present invention is to provide an improved hydraulic transducer. This object is achieved by the hydraulic transducer of the present invention, characterized in that one of the first to third channels has an opening on the rear side of the distribution plate, one of the first to third channels has an opening on the outer circumferential wall of the distribution plate, and one of the first to third channels has an opening on the inner circumferential wall of the distribution plate.

[0004] One advantage of the hydraulic converter according to the invention is that the first to third channels have openings on different sides of the distribution plate, which allows the distribution plate to rotate at a relatively large angle relative to the housing without the risk of short circuits between the corresponding openings. This means that the hydraulic converter has a wide operating range.

[0005] In one specific embodiment, the hydraulic transducer includes a spindle through which a cylinder body is rotatable relative to a housing. The spindle is mounted within the housing and rotatable about a first axis of rotation. The spindle has a flange extending perpendicular to the first axis of rotation, and a plurality of pistons, each including a spherical piston head, are fixed to the flange at equal angular intervals around the first axis of rotation, with their centerlines parallel to the first axis of rotation. The cylinder body includes a plurality of individual sleeves in which each piston is movable to form a compression chamber. The cylinder body and its rear-facing support surface support the bottom of the sleeves. The cylinder body, including the sleeves, is rotatable about a second axis of rotation that intersects the first axis of rotation at an acute angle, such that as the spindle and the cylinder body including the sleeves rotate, each piston moves relative to the mating sleeve between bottom dead center and top dead center. The cylinder body ports communicate with the corresponding compression chambers through cylinder body channels in the cylinder body and through holes in the bottom of the sleeves. In this embodiment, the hydraulic transducer operates according to the so-called floating cup principle, which minimizes friction. The central hole in the distribution plate can be a through hole, which allows the central hole to be fluidly connected to the adjacent channel through openings on the front and rear sides of the distribution plate.

[0006] In one embodiment, the first channel has an opening on the rear side of the distribution plate, the second channel has an opening on the outer circumferential wall of the distribution plate, and the third channel has an opening on the inner circumferential wall of the distribution plate. This means that the opening on the rear side of the distribution plate is fluidly connected to the high-pressure interface, the opening on the outer circumferential wall of the distribution plate is fluidly connected to the low-pressure interface, and the opening on the inner circumferential wall of the distribution plate is fluidly connected to the working pressure interface.

[0007] Preferably, the opening on the rear side of the distributor plate is aligned with the port of the mating distributor plate, and preferably has substantially the same shape and size as the port of the mating distributor plate, because this minimizes the difference in pressure fields between the two sides of the distributor plate, thereby minimizing friction between the distributor plate and one of the cylinder blocks or the housing. Therefore, the rotation of the distributor plate relative to the housing requires relatively low power.

[0008] In one embodiment, one of the first to third channels, which has an opening on the outer circumferential wall of the distribution plate, also has an opening on the rear side of the distribution plate. This opening is aligned with the mating distribution plate port and closed by the inner wall of the housing, and preferably has a shape and size substantially the same as the mating distribution plate port. This minimizes the difference in pressure fields between the corresponding distribution plate port on the front side of the distribution plate and the opening on the rear side of the distribution plate. Notably, under operating conditions, hydraulic fluid does not flow through or only leaks very little through the opening on the rear side of the distribution plate.

[0009] Similarly, in one embodiment, one of the first to third channels, which has an opening on the inner wall of the distribution plate, also has an opening on the rear side of the distribution plate. This opening is aligned with the mating distribution plate port and closed by the inner wall of the housing, and preferably has a shape and size substantially the same as the mating distribution plate port. This minimizes the difference in pressure fields between the corresponding distribution plate port on the front side of the distribution plate and the opening on the rear side of the distribution plate. Notably, under operating conditions, hydraulic fluid does not flow through or only leaks very little through the opening on the rear side of the distribution plate.

[0010] The spindle can be a hollow spindle, its internal space communicating with the central hole of the distribution plate through a central hole in the cylinder block. Preferably, one of the central hole of the cylinder block and the spindle is provided with an inner sleeve including a spherical outer surface, while the other of the central hole of the cylinder block and the spindle is provided with an outer sleeve including a cylindrical inner surface, which fits around the spherical outer surface of the inner sleeve. This allows the central hole to be fluidly connected to a channel at a certain distance from the distribution plate in a direction away from its front side. The mating inner and outer sleeves can establish a sealed connection between the central hole of the cylinder block and the internal space of the spindle.

[0011] In one embodiment, the arc length of the distribution plate port connected to the high-pressure interface is greater than the arc length of the distribution plate port connected to the low-pressure interface, and also greater than the arc length of the distribution plate port connected to the working pressure interface. This provides opportunities to create a wide operating range.

[0012] The arc length of the distribution plate port connected to the working pressure interface can be smaller than the arc length of the distribution plate port connected to the low pressure interface.

[0013] In one embodiment, in the direction of rotation about the second axis of rotation, the ports of the distribution plate are separated by respective sealing strips, wherein at least one sealing strip is provided with a through-hole between the front and rear sides of the distribution plate. The flow area of ​​this through-hole is less than 5% of the flow area of ​​the first channel and widens from the front to the rear. Preferably, the sealing strip has multiple through-holes in the circumferential direction of the distribution plate. Under operating conditions, the relatively small and widening through-holes generate a force on the distribution plate that counteracts the pressure field on the corresponding sealing strip on the front side of the distribution plate. This results in minimized friction between the distribution plate and the housing, thereby facilitating the rotation of the distribution plate. The flow area of ​​the through-hole on the front side of the distribution plate can be smaller than the flow area of ​​each cylinder port passing through this through-hole.

[0014] The flow area behind the distributor plate can be formed by grooves. It is worth noting that although the term "flow area" is used, under operating conditions, hydraulic fluid does not flow through or only leaks very little through the flow area behind the distributor plate.

[0015] In one specific embodiment, the flange including the piston is a first flange including a first piston, and the main shaft is provided with a second flange extending perpendicular to the first axis of rotation. The hydraulic transducer is provided with a plurality of second pistons, each including a spherical piston head. These second pistons are fixed at equal angular distances to the second flanges around the first axis of rotation, and their centerlines are parallel to the first axis of rotation. The cylinder including the sleeve is a first cylinder including a first sleeve, and the compression chamber is a first compression chamber. The hydraulic transducer is provided with a plurality of individual second sleeves, each of which can move. The second cylinder body is rotatable relative to the housing and includes a plurality of individual second sleeves in which each second piston is movable to form a respective second compression chamber. The second cylinder body supports the bottom of the sleeves of the second sleeves via a rear-facing support surface. The second cylinder body, including the second sleeves, is rotatable about a third axis of rotation that intersects a first axis of rotation at an acute angle, such that each second piston moves relative to the mating second sleeve between bottom dead center and top dead center during rotation of the main shaft and the second cylinder body including the second sleeves. The rear side of the second cylinder body includes a second cylinder body port through which… The cylinder passage in the second cylinder and the through hole at the bottom of the second sleeve communicate with the corresponding second compression chamber. The distribution plate is a first distribution plate, and the hydraulic converter is equipped with a second distribution plate, which is supported by the outer shell and has a front side supporting the rear side of the second cylinder, a rear side facing the outer shell, a circumferential outer wall, and a central hole surrounded by an inner circumferential wall. This second distribution plate can rotate relative to the outer shell around a third rotation axis within a predetermined angle. The distribution plate port is the first distribution plate port, and the front side of the second distribution plate has three arc-shaped second distribution plate ports. The second cylinder port is located at the main shaft and the second sleeve... When the cylinder rotates, it moves along the port of the second distribution plate. The port of the second distribution plate is connected to the high-pressure interface through a first channel, to the low-pressure interface through a second channel, and to the working pressure interface through a third channel. One of the first to third channels in the second distribution plate has an opening on the rear side of the second distribution plate, another opening on the outer circumferential wall of the second distribution plate, and yet another opening on the inner circumferential wall of the second distribution plate. When the first and second pistons protrude from the first and second flanges in opposite directions, the forces acting on the first and second pistons cancel each other out through the main shaft.

[0016] In the case of a hollow spindle, its internal space can communicate with the center hole of the second distribution plate, which means that it is connected with the center holes of both the first and second distribution plates.

[0017] The first and second distribution plates can be mechanically coupled to each other via an auxiliary shaft extending through the internal space of the main shaft, allowing the first and second distribution plates to rotate synchronously. This auxiliary shaft can also be hollow, allowing hydraulic fluid to flow through it.

[0018] With the spindle having a first flange and a second flange, the spindle can be rotatably mounted in the housing via a bearing located between the first flange and the second flange.

[0019] The invention will now be illustrated with reference to the accompanying drawings, which illustrate one embodiment of the invention by way of example.

[0020] Figure 1 This is a perspective view of an embodiment of a hydraulic converter according to the present invention.

[0021] Figure 2 Is with Figure 1 A similar view shows the hydraulic converter from different sides.

[0022] Figure 3 Is it like this? Figure 1 An enlarged cross-sectional view of the hydraulic converter shown.

[0023] Figure 4 Is it like this? Figure 1 The enlarged cross-sectional view of the hydraulic converter is shown.

[0024] Figure 5 Is with Figure 4 A similar view, showing a portion of it at a larger scale.

[0025] Figure 6 It is shown from the opposite sides as follows Figure 1 The diagram shows a perspective cross-sectional view of the first cylinder of the hydraulic converter.

[0026] Figure 7 Is it like this? Figure 1 A front view of the front side of the second distributor plate of the hydraulic converter shown.

[0027] Figure 8 Is it like this? Figure 7 The perspective view of the second distribution plate shown indicates its rear side.

[0028] Figure 9 Is it like this? Figure 1 The perspective view of a portion of the hydraulic converter housing shown illustrates two different operating states.

[0029] Figure 10 This is a schematic diagram showing the flow of hydraulic fluid through... Figure 1 The high-pressure channel of the hydraulic converter is shown.

[0030] Figure 11 Is with Figure 10 A similar view shows hydraulic fluid flowing through, such as Figure 1 The low-pressure channel of the hydraulic converter is shown.

[0031] Figure 12 Is with Figure 10 A similar view shows hydraulic fluid flowing through, such as Figure 1 The working pressure channel of the hydraulic converter is shown.

[0032] Figure 13 This is a schematic diagram showing... Figure 1 The hydraulic circuit inside and around the hydraulic converter.

[0033] Figure 1 and Figure 2 The exterior of a hydraulic transducer 1 according to an embodiment of the present invention is shown. The hydraulic transducer 1 has a housing 2, which is provided with a high-pressure port 3, a low-pressure port 4, and two working pressure ports 5. The housing 2 is assembled from independent components to house the parts inside the housing 2. The hydraulic transducer 1 can be part of a hydraulic circuit including a high-pressure line communicating with the high-pressure port 3 and a low-pressure line communicating with the low-pressure port 4. The working pressure ports 5 can communicate with a hydraulic cylinder or a hydraulic motor, and the hydraulic cylinder or hydraulic motor can be operated by adjusting the hydraulic pressure at the working pressure ports 5. The flow direction of the hydraulic fluid flowing into and out of the working pressure ports 5 is controlled by valves, which will be referred to later. Figure 13 Describe it.

[0034] Figure 3-5 The interior of the hydraulic transducer 1 is shown. The hydraulic transducer 1 has a hollow spindle 6, which is supported in a housing 2 by a pair of angular contact roller bearings 7. The spindle 6 is rotatable relative to the housing 2 about a first axis of rotation 8. The bearings 7 are located in the central portion of the housing 2, as seen along the longitudinal direction of the first axis of rotation 8. The bearings 7 are fixed in position relative to the housing 2 in the longitudinal direction of the first axis of rotation 8 by means of a flange 9 and a sleeve 10 of the housing 2, with the outer circumferential edge of the bearing 7 sandwiched between the flange 9 and the sleeve 10.

[0035] The spindle 6 is provided with a first flange 11 and a second flange 12, which extend perpendicularly to the first axis of rotation 8 on both sides of the bearing 7. The inner circumferential edge of the bearing 7 is sandwiched between the first and second flanges 11 and 12. The second flange 12 is mounted to the spindle 6 as a separate component after the bearing 7 is placed next to the first flange 11. A key 13 locks the second flange 12 relative to the spindle 6 in the direction of rotation about the first axis of rotation 8. The second flange 12 has a toothed circumference for speed detection, see [link to relevant documentation]. Figure 3 .

[0036] On each of the first and second flanges 11, 12, a plurality of pistons 14 are fixed at equal angular intervals around the first axis of rotation 8; in this example, there are fifteen pistons 14. The pistons 14 project away from each other from their respective first and second flanges 11, 12. The centerline of the pistons 14 extends parallel to the first axis of rotation 8. In this example, they are fixed to their respective first and second flanges 11, 12 by screws, but other fixing methods are conceivable.

[0037] Each piston 14 mates with a separate sleeve 15 to form a variable-volume compression chamber. In this example, the hydraulic transducer 1 has 30 compression chambers. Each sleeve 15 includes a sleeve bottom 16 with a central through-hole 17 and a cylindrical sleeve jacket 18, see Figure 5 The sleeve 18 extends from the bottom 16 of the sleeve. Each piston 14 is directly sealed to the inner wall of the mating sleeve 18 by its piston head having a spherical outer side.

[0038] The bottom 16 of the sleeve is supported by the support surfaces of the first cylinder 19 and the second cylinder 20. The sleeve 15 can slide on the support surfaces of the first and second cylinders 19 and 20, which is known as the floating cup principle. The first and second cylinders 19 and 20 are mounted around the spindle 6 via their respective ball joints 21 and coupled to the spindle 6 via a key 22, see [link to relevant documentation]. Figure 5 Therefore, under operating conditions, the first and second cylinders 19 and 20 rotate together with the main shaft 6. The first and second cylinders 19 and 20 are identical.

[0039] Figure 6 The first cylinder body 19 is shown in more detail. The first cylinder body 19 has a front side 23 and a rear side 24. The rear side 24 is opposite to the front side 23 and the support surface. The front side 23 faces the first flange 11, and the rear side 24 faces away from the first flange 11. To maintain the position of the sleeve 15 during assembly, the first cylinder body 19 is provided with an inner ring 25 and an outer ring 26. Each compression chamber communicates with a cylinder port 27 on the rear side 24 of the first cylinder body 19 via a through hole 17 in the bottom 16 of the sleeve and a cylinder passage. In this example, each cylinder port 27 includes a pair of openings on the rear side 24 of the first cylinder body 19.

[0040] Reference Figure 3-5The hydraulic transducer 1 has a first distribution plate 28 sandwiched between the housing 2 and the first cylinder 19, and a second distribution plate 29 sandwiched between the housing 2 and the second cylinder 20. The first and second distribution plates 28 and 29 are functionally identical but are mirror-symmetrical with respect to a plane perpendicular to the first axis of rotation 8 and located between the first and second distribution plates 28 and 29. In the embodiment shown in the figures, the first distribution plate 28 includes a front portion 28a and a rear portion 28b with a fixed relative position. The front portion 28a and the rear portion 28b may be made of different materials, or the first distribution plate 28 may be a single component. Similarly, the second distribution plate 29 has a front portion 29a and a rear portion 29b. Hereinafter, the first and second distribution plates 28 and 29 will be described as if they were single components.

[0041] Figure 7 The front side 30 of the second distributor plate 29 is shown, which faces the rear side 24 of the second cylinder block 20. Figure 8 The rear side 31 of the second distributor plate 29 is shown, facing the wall of the housing 2. The wall of the housing 2 supports the second distributor plate 29, which in turn supports the second cylinder block 20. Similarly, the opposite wall of the housing 2 supports the first distributor plate 28, which in turn supports the first cylinder block 19.

[0042] The outer casing 2 is configured such that the first and second distribution discs 28, 29 have an inclined orientation, allowing the first cylinder 19 and the second cylinder 20 to rotate about a second rotation axis 32a and a third rotation axis 32b, respectively, which are inclined at acute angles relative to the first rotation axis 8. Therefore, the first and second cylinders 19, 20 pivot about their respective ball joints 21 during rotation with the main shaft 6. The sleeve 15 rotates about its respective second and third rotation axes 32a, 32b. Thus, the volume of the compression chamber changes during rotation of the main shaft 6. The angles between the first rotation axis 8 and the second rotation axis 32a, and between the first rotation axis 8 and the third rotation axis 32b, are practically about eight degrees, but can be smaller or larger.

[0043] The first and second cylinder bodies 19 and 20 are pressed against the first and second distribution plates 28 and 29 respectively by springs 33 installed in the main shaft 6 hole. These springs press their respective pressure blocks 34 against the first and second cylinder bodies 19 and 20. Figure 5 .

[0044] During the rotation of the first and second cylinders 19, 20, each sleeve 15 undergoes a combination of translational and oscillating motion around the mating piston 14. Therefore, the outer side of each piston head is spherical. This spherical shape forms a sealing line between the piston head and the sleeve jacket 18, perpendicular to the centerline of the mating sleeve 15. The diameter of each piston 14 near the corresponding first or second flange 11, 12 is smaller than the diameter at the piston head to allow relative movement of the mating sleeve 15 relative to the piston 14. Under operating conditions, each piston 14 moves within the mating sleeve 15 between bottom dead center and top dead center. Figure 5 In the attached diagram, the upper piston 14 at the first and second cylinders 19 and 20 is at top dead center, while the lower piston 14 at the first and second cylinders 19 and 20 is at bottom dead center.

[0045] Reference Figure 7 and Figure 8 The second distribution plate 29 is provided with a high-pressure channel 35, a low-pressure channel 36, and a working pressure channel 37. The high-pressure channel 35 includes eight through holes, forming a high-pressure port on its front side 30 and a high-pressure port on its rear side 31. The corresponding high-pressure port portions are circular and extend around the third rotation axis 32b within an angle of approximately 160°, but different arc lengths are conceivable. The low-pressure channel 36 includes four through holes, forming a low-pressure port on its front side 30 and a low-pressure port on its rear side 31. The low-pressure port portion is circular and shorter than the length of the high-pressure ports, as measured in the rotational direction around the third rotation axis 32b, both on the front side 30 and the rear side 31. The working pressure channel 37 includes three through holes, forming a working pressure port on its front side 30 and a working pressure port on its rear side 31. The working pressure port portion is circular and shorter than the low-pressure port, as measured in the rotational direction about the third rotation axis 32b, both on the front side 30 and the rear side 31.

[0046] When the spindle 6 rotates, the cylinder port 27 of the second cylinder 20 moves along the high-pressure port, low-pressure port, and working pressure port on the front side 30 of the second distribution plate 29. Similarly, when the spindle 6 rotates, the cylinder port 27 of the first cylinder 19 moves along the high-pressure port, low-pressure port, and working pressure port on the front side 30 of the first distribution plate 28.

[0047] The high-pressure channels 35 of the first and second distribution plates 28 and 29 are connected to the high-pressure interface 3 of the outer casing 2, the low-pressure channels 36 of the first and second distribution plates 28 and 29 are connected to the low-pressure interface 4 of the outer casing 2, and the working pressure channels 37 of the first and second distribution plates 28 and 29 are connected to the two working pressure interfaces 5 of the outer casing 2.

[0048] The first and second distribution disks 28 and 29 are respectively rotatable relative to the housing 2 around the second and third rotation axes 32a and 32b by a predetermined angle α, for example, 70°. In the illustrated embodiment, the second distribution disk 29 is rotated by a servo actuator 38, while the first distribution disk 28 rotates synchronously with the second distribution disk 29 via a hollow auxiliary shaft 39, which couples the first and second distribution disks 28 and 29 together via pins 40. Figure 3-5 .

[0049] Figure 9 An inner wall of the housing 2 is shown, which supports the rear side 31 of the second distribution plate 29. This inner wall is provided with a partially circular high-pressure port 41, which communicates with the high-pressure interface 3 of the housing 2. Figure 9 The dashed lines representing the projection A of the high-pressure port of the high-pressure channel 35 on the rear side 31 of the second distribution plate 29, the projection T of the low-pressure port of the low-pressure channel 36, and the projection B of the working pressure port of the working pressure channel 37 show two extreme rotational positions of the second distribution plate 29 relative to the housing 2 around the third rotation axis 32b. In these two extreme positions and between them, the high-pressure port 41 of the housing 2 communicates with the high-pressure port on the rear side 31 of the second distribution plate 29. It can be seen that the arc length of the high-pressure port 41 of the housing 2 is shorter than the arc length of the high-pressure port on the rear side 31 of the second distribution plate 29. This means that a portion of the high-pressure port on the rear side 31 of the second distribution plate 29 is always closed by the wall of the housing 2. To create sufficient flow area between the high-pressure port 41 of the second cylinder block 20 and the housing 2, the second distribution plate 29 can be positioned in the channel 42 between non-adjacent high-pressure channels 35, see... Figure 7 Channel 42 is drilled from the outer circumference of the second distribution plate 29, while insert 43 seals the respective channel 42. The walls of the first distribution plate 28 and the housing 2 supporting the first distribution plate 28 are similar to the walls of the second distribution plate 29 and the housing 2 supporting the second distribution plate 29. The housing 2 is provided with a high-pressure channel 44 through which the high-pressure ports on the rear side 31 of the respective first and second distribution plates 28, 29 communicate with the high-pressure interface 3 of the housing 2. This is in Figure 10 As shown in the figure, the dashed lines and arrows indicate that hydraulic fluid can flow in the opposite direction through the high-pressure channel 44.

[0050] Reference Figure 7 and Figure 8 The low-pressure channel 36 is formed by a through hole between the front side 30 and the rear side 31 of the second distribution plate 29 and a radial channel 45 drilled from the outer circumference of the second distribution plate 29 to the corresponding through hole. In the assembled state, the through hole is closed by the wall of the housing 2 at the rear side 31 of the second distribution plate 2, as shown in the image. Figure 9As shown in the projection T, this means that the low-pressure channel 36 forms a 90-degree bend in the first and second distribution plates 28 and 29. The low-pressure channel 36 is connected to the low-pressure interface 4 via a low-pressure channel 46 formed by the internal space of the housing 2. Figure 11 The flow pattern of hydraulic fluid through low-pressure channel 46 is shown by dashed lines and arrows, indicating that hydraulic fluid can flow in opposite directions.

[0051] Refer again Figure 7 and Figure 8 The working pressure channel 37 is formed by a through hole between the front side 30 and the rear side 31 of the second distribution plate 29 and a radial hole 48 drilled from the outer circumference of the second distribution plate 29 towards the central hole 49 of the second distribution plate 29, while passing through the corresponding through hole. The central hole 49 is a through hole. The insert 50 seals the respective radial holes 48 at the circumference of the second distribution plate 29. In the assembled state, the through hole of the working pressure channel 37 is closed by the wall of the housing 2 at the rear side 31 of the second distribution plate 2, as shown. Figure 9 As shown in projection B. This means that the working pressure channel 37 forms a 90-degree bend in the first and second distribution plates 28, 29.

[0052] Working pressure channel 37 is connected to working pressure interface 5 via a working pressure channel 51. This working pressure channel 51 is formed by the central holes 49 of the first and second distribution plates 28 and 29, the central holes in the first and second cylinder bodies 19 and 20, and the internal space of the main shaft 6. (See...) Figure 12 The working pressure channel 51 is sealed relative to the low-pressure channel 46, i.e., the internal space of the outer casing 2, through the inner sleeve 52 and the matching outer sleeve 53, as shown in the figure. Figure 5 Outer sleeves 53 are respectively mounted on the first and second cylinders 19 and 20. They are slidable relative to the first and second cylinders 19 and 20 along the second and third rotation axes 32a and 32b, respectively. Each inner sleeve 52 is fixed to the main shaft 6 and has a spherical outer surface portion that contacts the cylindrical inner wall of the mating outer sleeve 53. The center point of the spherical outer surface portion can coincide with the center point of the respective ball joint 21. Figure 12 The flow pattern of hydraulic fluid through working pressure channels 37 and 51 is shown by dashed lines and arrows. Although Figure 12 It is not shown in the figure, but the hydraulic fluid can also flow in the opposite direction.

[0053] Reference Figure 7 and Figure 8The high-pressure port on the front side 30 of the second distribution plate 29 is aligned with the high-pressure port on the rear side 31 of the second distribution plate 29 and has substantially the same shape and size. Similarly, the low-pressure port on the front side 30 of the second distribution plate 29 is aligned with the low-pressure port on the rear side 31 of the second distribution plate 29 and has substantially the same shape and size. Similarly, the working pressure port on the front side 30 of the second distribution plate 29 is aligned with the working pressure port on the rear side 31 of the second distribution plate 29 and has substantially the same shape and size.

[0054] Figure 7 As shown, the second distribution plate 29 has a series of small through holes 54 in the sealing strip between the high-pressure port and the low-pressure port, between the low-pressure port and the working pressure port, and between the high-pressure port and the working pressure port in the angular direction around the third rotation axis 32b. The flow area of ​​each through hole 54 on the front side 30 of the second distribution plate 29 is less than 5% of the flow area of ​​the first channel 35, and also less than the flow area of ​​each cylinder port 27 of the second cylinder 20 that moves along the through hole 54.

[0055] Figure 8 As shown, on the rear side 31 of the second distribution plate 29, the through hole 54 forms a groove 55, the cross-sectional area of ​​which is larger than the cross-sectional area of ​​the through hole 54 on the front side 30 of the second distribution plate 29. Under operating conditions, the cylinder port 27 of the second cylinder 20 moves along the through hole 54, thus generating a pressure field between the high-pressure port and the low-pressure port, between the low-pressure port and the working pressure port, and between the high-pressure port and the working pressure port on the front side 30 of the second distribution plate 29. Due to the presence of the through hole 54 and the groove 55, a reaction pressure field is generated on the rear side 31 of the second distribution plate 29. This results in minimized friction between the second distribution plate 29 and the housing 2, thereby facilitating adjustment of the rotational position of the second distribution plate 29 relative to the housing 2. It is worth noting that the first distribution plate 28 is also provided with a through hole 54 and a groove 55.

[0056] As previously described, the second distribution plate 29 is rotated by a servo actuator 38, which needs to overcome the torque load of the first and second distribution plates 28, 29. (Refer to...) Figure 4 The servo actuator 38 is coupled to an electric servo motor 56, which controls a control shaft 57, which includes ports communicating with a low-pressure channel 46 and a high-pressure channel 44, respectively. The hydraulic servo actuator 38 has a rotor and a stator, each with three ribs, forming six displacement chambers. The pressure in these chambers is controlled by the rotational position of the control shaft 57. The actual rotational position of the second distribution plate 29 relative to the housing 2 is determined by a position sensor 58.

[0057] The rotation angles of the first and second distribution plates 28 and 29 are defined by the corresponding arcuate grooves 59 in their rear sides 31, see Figure 5 and Figure 8 Pin 60 was stored in slot 59, see Figure 4 Pin 60 can be a bolt screwed into housing 2.

[0058] Figure 13 The hydraulic circuit inside and around the hydraulic transducer 1 is shown. The working pressure interface 5 is coupled to a hydraulic cylinder that can be extended and retracted via control valve 61, which also... Figure 1-4 As shown in Figures 10-11. High-pressure port 3 is connected to high-pressure line HP, and low-pressure port 4 is connected to low-pressure line LP. The hydraulic converter 1 also has two check valves 62 to prevent cavitation; these two check valves 62 are also... Figure 1 and Figure 11 As shown in the image.

[0059] Figure 11 and Figure 13 As shown, the low-pressure channel 46 is fluidly connected to the check valve 62 and the control valve 61. Figure 13 As shown, the working pressure passage 51 is fluidly connected to the control valve 61. The control valve 61 can be operated to allow hydraulic fluid to flow from the working pressure passage 51 to the lower side of the hydraulic cylinder and from the upper side of the hydraulic cylinder to the low-pressure passage 46, thereby extending the hydraulic cylinder. Similarly, the control valve 61 can be operated to allow hydraulic fluid to flow from the lower side of the hydraulic cylinder to the working pressure passage 51 and from the low-pressure passage 46 to the upper side of the hydraulic cylinder, thereby retracting the hydraulic cylinder.

[0060] For example, if an external load acts on the hydraulic cylinder during retraction, this load may force hydraulic fluid to flow through the working pressure channel 51. This causes the compressed hydraulic fluid to be delivered to the high-pressure line HP through the high-pressure channel 44 and the high-pressure port 3. This means that the energy from the external load causing the cylinder to retract is recovered and converted into hydraulic pressure in the high-pressure line HP. It is worth noting that pressure accumulators can be installed in both the high-pressure line HP and the low-pressure line LP.

[0061] The present invention is not limited to the embodiments shown in the accompanying drawings and described above, and may be varied in different ways within the scope of the claims and their technical equivalents.

Claims

1. A hydraulic converter (1) comprising a housing (2) including a high-pressure port (3), a low-pressure port (4), and a working pressure port (5), a cylinder (19, 20) rotatably mounted in the housing (2) and having a plurality of compression chambers, the volume of which changes when the cylinder (19, 20) rotates, wherein the rear side (24) of the cylinder (19, 20) includes a cylinder port (27) communicating with a corresponding compression chamber, and a distribution plate (28, 29) supported by the housing (2) and having a front side (30) supporting the rear side (24) of the cylinder (19, 20) and a rear side facing the housing (2). 31) A circumferential outer wall and a central hole (49) surrounded by a circumferential inner wall, wherein the distribution plate (28, 29) can rotate within a predetermined angle relative to the outer shell (2), wherein the front side (30) is provided with three arc-shaped distribution plate ports, and the cylinder port (27) moves along the arc-shaped distribution plate ports when the cylinder (19, 20) rotates, wherein the distribution plate ports are respectively connected to the high-pressure interface (3) through a first channel (35) in the distribution plate (28, 29), connected to the low-pressure interface (4) through a second channel (36) in the distribution plate (28, 29), and connected to the working pressure interface (5) through a third channel (37) in the distribution plate (28, 29), characterized in that, One of the first to the third channels (35, 36, 37) has an opening on the rear side (31) of the distribution plate (28, 29), one of the first to the third channels (35, 36, 37) has an opening on the outer circumferential wall of the distribution plate (28, 29), and one of the first to the third channels (35, 36, 37) has an opening on the inner circumferential wall of the distribution plate (28, 29).

2. The hydraulic converter (1) according to claim 1, characterized in that, The hydraulic transducer (1) includes a spindle (6) through which the cylinder body (19, 20) is rotatable relative to the housing (2). The spindle (6) is mounted in the housing (2) and is rotatable about a first axis of rotation (8). The spindle (6) has flanges (11, 12) extending perpendicular to the first axis of rotation (8), a plurality of pistons (14), each piston (14) including a spherical piston head. The plurality of pistons (14) are fixed at equal angular distances on the flanges (11, 12) about the first axis of rotation (8), and the centerlines of the plurality of pistons (14) are parallel to the first axis of rotation (8). The cylinder body (19, 20) includes a plurality of individual sleeves (15) in which each of the pistons (14) can move, thereby forming a... The compression chambers are described, wherein the support surface of the cylinder (19, 20) opposite to the rear side (24) of the cylinder (19, 20) supports the sleeve bottom (16) of the sleeve (15), wherein the cylinder (19, 20) including the sleeve (15) is rotatable about a second rotation axis (32a, 32b), the second rotation axis (32a, 32b) intersecting the first rotation axis (8) at an acute angle, such that when the main shaft (6) and the cylinder (19, 20) including the sleeve (15) are rotated, each piston (14) moves relative to the mating sleeve (15) between the bottom dead center and the top dead center, wherein the cylinder port (27) communicates with the corresponding compression chamber through a cylinder channel in the cylinder (19, 20) and a through hole (17) in the sleeve bottom (16).

3. The hydraulic converter (1) according to claim 1 or 2, characterized in that, The central hole (49) in the distribution plate (28, 29) is a through hole.

4. The hydraulic converter (1) according to any one of the preceding claims, characterized in that, The first channel (35) has an opening on the rear side of the distribution plate (28, 29), the second channel (36) has an opening on the outer circumferential wall of the distribution plate (28, 29), and the third channel (37) has an opening on the inner circumferential wall of the distribution plate (28, 29).

5. The hydraulic converter (1) according to any one of the preceding claims, characterized in that, The opening on the rear side (31) of the distribution plate (28, 29) is aligned with the port of the matching distribution plate and preferably has a shape and size substantially the same as the port of the matching distribution plate.

6. The hydraulic converter (1) according to any one of the preceding claims, characterized in that, One of the first to third channels (35, 36, 37) having an opening on the circumferential outer wall of the distribution plate (28, 29) also has an opening on the rear side (31) of the distribution plate (28, 29). The opening on the rear side (31) of the distribution plate (28, 29) is aligned with the port of the matching distribution plate and closed by the inner wall of the housing (2), and preferably has a shape and size substantially the same as the port of the matching distribution plate.

7. The hydraulic converter (1) according to any one of the preceding claims, characterized in that, One of the first to third channels (35, 36, 37) having an opening on the inner wall of the distribution plate (28, 29) also has an opening on the rear side (31) of the distribution plate (28, 29). The opening on the rear side (31) of the distribution plate (28, 29) is aligned with the port of the matching distribution plate and closed by the inner wall of the housing (2), and preferably has a shape and size substantially the same as the port of the matching distribution plate.

8. The hydraulic converter (1) according to any one of the preceding claims and claim 2, characterized in that, The main shaft (6) is a hollow main shaft, and its internal space is connected to the central hole (49) of the distribution plate (28,29) through the central hole in the cylinder (19,20). Preferably, one of the central hole of the cylinder (19,20) and the main shaft (6) is provided with an inner sleeve (52) including a spherical outer surface portion, while the other of the central hole of the cylinder (19,20) and the main shaft (6) is provided with an outer sleeve (53) including a cylindrical inner surface, the inner surface fitting around the spherical outer surface portion of the inner sleeve (52).

9. The hydraulic converter (1) according to any one of the preceding claims, characterized in that, The arc length of the distribution plate port connected to the high-pressure interface (3) is greater than the arc length of the distribution plate port connected to the low-pressure interface (4), and is also greater than the arc length of the distribution plate port connected to the working pressure interface (5).

10. The hydraulic converter (1) according to claim 9, characterized in that, The arc length of the distribution plate port connected to the working pressure interface (5) is less than the arc length of the distribution plate port connected to the low pressure interface (4).

11. The hydraulic converter (1) according to any one of the preceding claims, characterized in that, In the rotational direction about the second rotation axis (32a, 32b), the ports of the distribution plate are separated by respective sealing strips, wherein at least one sealing strip is provided with a through hole (54) between the front side (30) and the rear side (31) of the distribution plate (28, 29), the flow area of ​​the through hole (54) is less than 5% of the flow area of ​​the first channel (35), and widens in the direction from the front side to the rear side, wherein the sealing strip preferably has a plurality of through holes in the circumferential direction of the distribution plate (28, 29).

12. The hydraulic converter (1) according to claim 11, characterized in that, The flow area of ​​the rear side (31) of the distribution plate (28, 29) is formed by a groove.

13. The hydraulic converter (1) according to any one of the preceding claims and claim 2, characterized in that, The flange including the piston is a first flange (11) including a first piston (14), and the main shaft (6) is provided with a second flange (12) extending perpendicular to the first rotation axis (8), wherein the hydraulic transducer (1) is provided with a plurality of second pistons (14) including their respective spherical piston heads, the plurality of second pistons (14) being fixed at equal angular distances on the second flange (12) around the first rotation axis (8), and the center lines of the plurality of second pistons (14) being parallel to the first rotation axis (8), the cylinder including the sleeve is a first cylinder (19) including a first sleeve (15), and the compression chamber is a first compression chamber, wherein the hydraulic transducer (1) The hydraulic transducer (1) comprises a plurality of individual second sleeves (15) in which each second piston (14) is movable, wherein the hydraulic transducer (1) includes a second cylinder (20) rotatable relative to the housing (2) and comprising a plurality of individual second sleeves (15) in which each second piston (14) is movable to form a respective second compression chamber, wherein a support surface of the second cylinder (20) opposite to the rear side (24) of the second cylinder (20) supports the sleeve bottom (16) of the second sleeve (15), wherein the second cylinder (20) comprising the second sleeve (15) is rotatable about a third rotation axis (32b), the third rotation axis being perpendicular to the housing (2). The first rotation axis (8) intersects at an acute angle, such that when the main shaft (6) and the second cylinder (20) including the second sleeve (15) are rotated, each second piston (14) moves between the bottom dead center and the top dead center relative to the mating second sleeve (15), wherein the rear side (24) of the second cylinder (20) includes a second cylinder port (27), the second cylinder port (27) communicating with a corresponding second compression chamber through a cylinder channel in the second cylinder (20) and a through hole (17) in the sleeve bottom (16) of the second sleeve (15), wherein the distribution plate is a first distribution plate (28), and the hydraulic converter (1) is provided with a second distribution plate (29), the first The second distribution plate (29) is supported by the outer shell (2) and has a front side (30) supporting the rear side (24) of the second cylinder (20), a rear side (31) facing the outer shell (2), a circumferential outer wall, and a central hole (49) surrounded by the circumferential inner wall. The second distribution plate (29) can rotate relative to the outer shell (2) about the third rotation axis (32b) within a predetermined angle. The distribution plate port is the first distribution plate port, and the front side (30) of the second distribution plate is provided with three arc-shaped second distribution plate ports. The second cylinder port (27) moves along the second distribution plate port when the main shaft (6) and the second cylinder (20) including the second sleeve (15) are rotated.The second distribution plate port is connected to the high-pressure interface (3) through a first channel in the second distribution plate (29), to the low-pressure interface (4) through a second channel in the second distribution plate (29), and to the working pressure interface (5) through a third channel in the second distribution plate (29). One of the first to third channels (35, 36, 37) in the second distribution plate (29) has an opening on the rear side (31) of the second distribution plate (29), one of the first to third channels (35, 36, 37) in the second distribution plate (29) has an opening on the outer circumferential wall of the second distribution plate (29), and one of the first to third channels (35, 36, 37) in the second distribution plate (29) has an opening on the inner circumferential wall of the second distribution plate (29).

14. The hydraulic converter (1) according to claims 8 and 13, characterized in that, The internal space of the main shaft (6) is connected to the central hole (49) of the second distribution plate (29).

15. The hydraulic converter (1) according to claim 14, characterized in that, The first distribution plate (28) and the second distribution plate (29) are mechanically coupled to each other by an auxiliary shaft (39) extending through the internal space of the main shaft (6), wherein preferably, the auxiliary shaft (39) is a hollow shaft.

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