NL2005504C2 - HYDRAULIC DEVICE WITH A MIRROR PLATE. - Google Patents

Description

Hydraulic device with a mirror plate

The invention relates to a device according to the preamble of claim 1. Such devices are known as a pump or hydraulic motor in which the rotation of the mirror plate is used to adjust the stroke volume, or as a hydraulic transformer in which the rotation of the mirror plate is used for setting the hydraulic transformer.

The drawback of the known devices is that the mirror plate is rotated through a large angle, so that the connection of the mirror plate ports to the housing causes problems. Also, a lot of friction occurs with the rotation of the mirror plate, as a result of which the drive of the mirror plate must be powerful and whereby accurate adjustment is difficult.

In order to avoid this drawback, the hydraulic device is according to claim 1. This makes adjustment of the mirror plate possible in a simple manner.

In accordance with an embodiment, the hydraulic device is according to claim 2. As a result, the relative movement between the pistons and cylinders and the mirror plate remains unchanged when the mirror plate is adjusted.

According to an embodiment, the hydraulic device is according to claim 3. As a result, the mirror plate can be adjusted in a simple manner, the mirror plate port having only a small displacement relative to the ports in the housing.

In accordance with an embodiment, the hydraulic device is according to claim 4. As a result, little force is required to adjust the mirror plate.

2

According to an embodiment, the hydraulic device is according to claim 5. This makes it possible to limit the impact angle in a simple manner.

In accordance with an embodiment, the hydraulic device is according to claim 6. Hereby, the rotation of the mirror plate about the mirror plate axis is limited in a simple manner.

According to an embodiment the hydraulic device is according to claim 7. This reduces the friction in the ball bearing.

According to an embodiment, the hydraulic device is according to claim 8. As a result

According to an embodiment, the hydraulic device is according to claim 9. The invention is explained below with reference to a few exemplary embodiments with the aid of a drawing. The drawing has a number of figures in which corresponding parts in the various figures have the same reference numerals.

Figures 1 and 2 show parts of a known hydraulic device,

Figure 3 shows a method of adjusting a hydraulic device according to the invention,

Figure 4 shows a first embodiment of the adjustment method discussed in Figure 3,

Figure 5 shows a second embodiment of the adjustment method discussed in Figure 3,

Figure 6 shows a perspective view of the mirror plate of Figure 5, Figure 7 shows schematically the forces on the mirror plate of Figure 5, and

Figure 8 shows an arrangement of compensation cylinders in combination with the mirror plate of Figure 5.

3

The parts shown in Figures 1 and 2 are the parts of a hydraulic transformer mounted in a housing. Such a hydraulic transformer is described, for example, in the published applications WO 9731185 5 and WO 9940318, the contents of which are considered to be known. Rotor bearings 1 are mounted in the housing in a known manner, in which a rotor shaft 2 with a rotor shaft member 1 can rotate. A rotor 14 with rotor holes 15 is mounted on the rotor shaft 2. Rod-shaped parts 10 are mounted in the rotor holes 15 which form pistons 12 on either side of the rotor 14. The pistons 12 are provided with piston rings 10, the outer surface of the piston rings 10 having the shape of a sphere and the center of these spheres for all pistons on one side of the rotor 14 lying in one plane. The left side and the right side of the rotor 14 are symmetrical with respect to the center of the rotor 14. Each side of the rotor 14 cooperates with a drum plate 7 with drum bushes 11 that rotate about a drum plate center line mi and drum plate center line m2, the rotor center line Line 1 and drum plate center mi and respectively rotor center line 1 and drum plate center m2 intersect each other under an angle of impact α at an intersection point M which lies in the plane perpendicular to the rotor center line 1 and in which the centers of the spherical outer surfaces of the piston rings 10 for the pistons 12 located on that side. In the exemplary embodiment shown, the impact angle α is approximately 8 °.

A centering surface 22 is formed on the rotor shaft 2 around which the drum plate 7 can pivot. The centering surface 22 is spherical, the intersection point M forming the center of the sphere 30. The rotation of the drum plate 7 is coupled to the rotation of rotor shaft 2 by means of a key 16 which engages in a keyway. The key 16 has a rounding radius in the plane of the surface of the shaft that is smaller than 4 the radius of the centering surface 22, so that the key 16 does not decrease in the keyway when the drum plate 7 rotates. Optionally there is more than one key 16. The key 16 can also be mounted in the rotor shaft 2 and the key way 5 is arranged in the drum plate 7.

The drum plate 7 is provided on the side facing the pistons 12 with drum sleeves 11 which are clamped against the drum plate 7 with a bush holder 18. The drum sleeve 11 has a cylindrical wall 23 on the inside.

Each piston 12 is enclosed by a drum sleeve 11 whereby the piston ring 10 can move sealingly along the cylindrical wall 23. The piston 12 and the cylindrical bush 11 thus form a chamber 9, the volume of which changes with respect to rotation of rotor shaft 2. As a result of the change in volume, oil flows into and out of the chamber 9 via a drum sleeve opening 24, a drum gate 6 and a mirror plate gate 3 to a pipe connection (not shown) in the housing. The mirror plate 4 has mirror plate ports 3 which are each connected to their own pipe connection, corresponding mirror plate ports 3 on either side of the rotor 14 which are connected to the same pipe connection are coupled to each other in the housing.

Because the rotational axes of the rotor 14 and the drum plate 7 make the impact angle α together, the pistons 12 in the plane of the drum plate 7 describe an elliptical path and the drum bushes 11 will slide over a contact surface 8 of the drum plate 7. The holder 18 is provided with openings that make this sliding possible and also ensures that the gap between the drum plate 7 and the drum sleeve 11 remains limited, so that pressure can be created in the chamber 9 upon starting.

The mirror plate port 3 is an opening in a mirror plate 4 that rests against a surface of the housing. This plane is not at right angles to the rotor center line 1 but makes an angle therewith and thus determines the direction of the drum plate center line mi or m2 and thus also the rotation position at which the volume in the chamber 9 is minimal or maximum. In the known hydraulic transformer shown in Figs. 1 and 2, the mirror plate 4 is rotatably mounted in the housing about the drum plate center line m1 or m2. In order to be able to rotate the mirror plate 4 about the drum plate axis mx, m2, the mirror plate 4 is provided over a part of its circumference with a toothing 5 which cooperates with a pinion driven by a drive.

By rotating the mirror plate 4, the setting of the hydraulic transformer as described in the aforementioned patent applications changes. The rotation of the mirror plate 4 is limited because each mirror plate port 3 cooperates with a port in the housing which is connected to a pipe connection and when the mirror plate 4 is rotated through too great an angle, a mirror plate port 3 would be connected may come up with another leadership closure. As a result, not all setting options of the hydraulic transformer are utilized.

Figure 3 shows schematically another way of changing the setting of the hydraulic transformer in which the mirror plate is not rotated around the drum plate center line m2, 25 m2. The rotor center line 1 intersects the drum plate center m2 in M. The mirror plate 25 has a center line perpendicular to the drum plate center m2. The mirror plate 25 has two or more mirror plate openings and one of them is a central mirror plate opening 26 and a axis of symmetry 30 s. The drum plate center line m2 and the axis of symmetry intersect in a center C. The rotor center line 1 and the drum plate heartline lie in a plane that intersects the mirror plate 25 in a plane V. The plane V makes an adjustment angle δ with the axis of symmetry s. As described above, the adjusting angle δ of the device according to figures 1 and 2 is adjusted by rotating the mirror plate 25 about an axis of rotation Revi, which corresponds to the drum plate center line mi.

In the embodiment of Figure 3, the mirror plate 25 is adjusted by rotating the mirror plate 25 about a second axis of rotation Rev2 and a third axis of rotation Rev3, which axis of rotation are perpendicular to the first axis of rotation Revi. The rotation axis Revi is not rotated. The center 10C of the mirror plate 25 then follows a path p to a position C 'and the new position of the drum plate center line mi is drawn as m' i. The plane through the drum plate center line m 'i and the rotor shaft 1 intersects the rotated mirror plate 25' in a plane V '. The plane V 'makes an adjustment angle 5' with the axis of symmetry. As can be seen in figure 3, the adjustment angle δ changes because the plane in which the rotor axis 1 and the drum axis mi lie rotates relative to the mirror plate 25, while the mirror plate 25 itself does not rotate about the drum axis mi. In the embodiment of Figure 20 shown, the first rotation axis Rev1 intersects the second rotation axis

Rev2 and the third axis of rotation Rev3 each other at the intersection point M, in another embodiment that may be other points such as the center C. However, this will affect the relative movement of the pistons 12 relative to the drum bushing 11. The rotation of the second rotation axis Rev2 and the third rotation axis Rev3 are limited and coupled such that the angle of impact α has a constant or adjustable value.

Figure 4 shows the hydraulic device as shown in figures 1 and 2 with a mirror plate 29 which is adjusted in the manner as described in figure 3. The device with which the mirror plate 29 is adjusted is not shown. The mirror plate 29 is rotatably mounted in a cardan ring 27 with a bearing pin 30 and can rotate about a first cardan shaft 31. Between the cardan ring 27 and the housing is a second bearing with a second cardan shaft (not shown). The first cardan shaft 31 and the second cardan shaft intersect the rotor shaft 1 at the intersection point M. The mirror plate 29 has mirror plate ports 3 which are connected via connection ports 28 to the line connections in the housing. Between the housing and the mirror plate 29 is a flexible connection, such as a flexible conduit or a hose. In the embodiment shown, the cardan ring 27 is provided with cylindrical bearings, other bearings are also possible, for example because there is a small rotation of cross-spring hinges or knife bearings are used. For limiting the angle of impact α there is an edge in the housing which limits the rotation of the mirror plate 25. This edge can form a flat plane and then the angle of impact α is constant at each angle of adjustment δ. In another embodiment, the edge is corrugated, so that the angle of impact α is dependent on the angle of adjustment δ.

Figure 5 shows a hydraulic device as shown in figures 1 and 2 with a mirror plate 34 which is adjusted in the manner as described in figure 3. The device with which the mirror plate 34 is adjusted is not shown. The side of the mirror plate 34 remote from the pistons 12 is provided with a convex surface with a radius, which convex surface forms a convex bearing 32 with a concave surface with the same radius in the housing. The center of the hollow surface in the housing is on the rotor shaft 1 at the intersection point M and the center of the sphere is on the drum plate center line mi. As a result, the intersection point M forms the center of the spherical bearing 32 and the mirror plate 34 can rotate about this point in three directions. In order to limit the rotation of the mirror plate 34 to two axes of rotation, the mirror plate 34 is provided with toothing 35 which cooperates with a toothing 37 in the housing (see figure 6).

8

The mirror plate ports 3 are connected via connection openings 33 to openings in the housing.

Figure 6 shows the mirror plate 34 in a perspective view wherein the mirror plate 34 is supported on an edge 36 of the housing with toothing 37 which cooperates with toothing 35 of the mirror plate 34. The mirror plate 34 is drawn in three positions, the first position being indicated with continuous lines and shows the position in which the mirror plate 34 in point A is supported on the housing 36. The second position is indicated by dot-and-dash lines in which the mirror plate 34 in point B is supported on the housing 36. The third position is indicated by broken lines wherein the mirror plate 34 in point C is supported on the housing 36. The points A, B and C describe an arc of more than 180 degrees, so that the hydraulic device has a large adjustment range and the adjustment angle can be more than 90 °. The figure shows that the gates 33 only make small movements with respect to the housing, so that the gates in the housing (not shown) are small.

The area where oil pressure is around the ports 33 between the housing and the mirror plate 34 results in a gate force 38 directed to the intersection point M on the mirror plate 34, see figure 7. The component 39 directed in the direction of the drum center line mi is compensated by the tooth force 41. The component 40 directed perpendicularly in the direction of the drum axis would lead to high forces in the spherical bearing 32, as a result of which this would yield too much resistance on adjustment and is therefore compensated by a support cylinder force 42. The support cylinder force 42 is generated by oil pressure between a piston 44 attached to the mirror plate 34 and a sleeve 43 that rests on a convex surface 45 in the housing. Optionally, two pistons 44 are arranged in the mirror plate 34, such as in the case that the mirror plate 34 has an opening for an axis, see figure 8.

The adjusting device of the mirror plates 25, 34 of figures 4, 5 can consist of two hydraulic cylinders diagonally placed on view 5 of the rotor shaft 1 which exert a force on the mirror plate 24, 34 in the direction of the rotor shaft 1. mirror plate to the desired tilt position.

The embodiments given above describe the adjustment of the mirror plate of a hydraulic transformer. The mirror plate of a pump or a hydraulic motor can be adjusted in a similar manner, as a result of which it obtains a stroke volume that can be adjusted in a simple manner.

Claims (7)

A hydraulic device comprising a housing, two or more conduit ports in the housing, a rotor (14) with a number of rotor chambers (9) each formed by a cylinder (11) and a piston (12) arranged around a first rotation. The axis of rotation (1) and a second axis of rotation (m1, m2) rotate, both axes of rotation lying in a plane of symmetry (V) and intersecting each other at an acute angle (a) so that the volume of the rotor chambers during rotation of the rotor changes, a mirror plate (4) with a mirror plate center line (m 1, m 2) corresponding to one of the rotation axes, in the mirror plate two or more mirror plate ports (3) which are each connected to a conduit port for connecting of the conduit port with the rotary chambers and an adjusting device for rotating the mirror plate and the plane of symmetry relative to each other, characterized in that the mirror plate (25; 34) is offset by a mirror plate bearing (30; 32) from the housing can rotate and the s mirror plate bearing has at least two rotational axes (Rev2, Revs) that perpendicularly intersect the mirror plate axis (mi, m2). 2. Hydraulic device according to claim 1, wherein two rotation axes (Rev2, Revs) of the mirror plate bearing (30; 32) intersect the mirror plate axis (mi, m2) at the intersection (M) of the first rotation axis (1) and the second rotation axis ( mi, m2). 3. Hydraulic device according to claim 1, or 2, wherein the mirror plate bearing is a sphere. The hydraulic device according to claim 1 or 2, wherein the mirror plate bearing comprises two cylindrical bearings. 5. Hydraulic device according to any one of the preceding claims, wherein the housing is provided with a boundary edge that limits the rotation of the mirror plate (25; 34) relative to the housing. 6. Hydraulic device according to claim 3, wherein the mirror plate and the housing are provided with interlocking teeth (35, 37). Hydraulic device according to claim 3, wherein support cylinders (43, 44) are arranged between the housing and the mirror plate (25) in three directions and preferably perpendicular to the mirror plate center line (m 1, m 2).