HYDRAULIC DEVICE INCLUDING A FACE PLATE
The invention is related to a hydraulic device comprising a housing including pipe ports, a rotor (14) having rotor chambers (9) which are formed by a cylinder (11) and a piston (12) which rotate about a first axis of rotation (m1) and a second axis of rotation (m2). Both axes of rotation extend within a common plane and intersect each other. A face plate (4) including a face plate centre line which coincides with the second axis of rotation (ml) has two or more face plate ports (3) which are each communicating with a pipe port for communicating the pipe port with the rotor chambers (9). An adjustment device adjusts the mutual positions of the face plate (4) and the common plane. Corresponding to the invention a face plate bearing (30, 32) between the face plate (4) and the housing has at least two axes of rotation which intersect the face plate centre line preferably perpendicularly and upon rotating the face plate (4) the common plane rotates with respect to the housing.
Latest INNAS BV Patents:
The invention is related to a device according to the preamble of claim 1. Such devices are known as a pump or hydraulic motor in which rotation of the face plate is used to adjust the swept volume, or as a hydraulic transformer wherein rotation of the face plate is used for adjusting the hydraulic transformer.
The disadvantage of the known devices is that inter alia upon application in the hydraulic transformer it is necessary to rotate the face plate about a wide angle, which causes problems in respect of the connection of the face plate ports to the pipe ports in the housing. Furthermore, high friction occurs upon rotating the face plate such that driving of the face plate must be sufficiently powerful and which makes accurate and/or quickly adjusting difficult.
In order to avoid this disadvantage the hydraulic device is according to claim 1. As a consequence, adjusting the face plate quickly and accurately is possible in a simple manner.
An embodiment of the hydraulic device is according to claim 2. As a consequence, the relative movement between the pistons and cylinders and the face plate remains unchanged upon adjusting the face plate.
An embodiment of the hydraulic device is according to claim 3. As a consequence, the face plate can be adjusted in a simple manner wherein the face plate port only has a small displacement with respect to the ports in the housing.
An embodiment of the hydraulic device is according to claim 4. As a consequence, a little force is required to adjust the face plate.
An embodiment of the hydraulic device is according to claim 5. As a consequence, the angle of stroke can be limited in a simple manner.
An embodiment of the hydraulic device is according to claim 6. As a consequence, rotation of the face plate about the face plate centre line is limited in a simple manner.
An embodiment of the hydraulic device is according to claim 7. As a consequence, a force which has risen between the spherical surface of the face plate and the concave surface of the housing and which is directed perpendicular to the face plate centre line, is compensated and reduces friction in the ball bearing.
An embodiment of the hydraulic device is according to claim 8. As a consequence, the location of the force at the face plate port between the face plate and the concave surface is determined accurately, such that accurate compensation of this force is possible.
An embodiment of the hydraulic device is according to claim 9. As a consequence, the direction of the force exerted by the support cylinder onto the face plate is always perpendicular to the face plate centre line and directed to the same location on the face plate, independent from the rotational position of the face plate.
An embodiment of the hydraulic device is according to claim 10. As a consequence, the face plate is balanced in relation to the forces that are caused by oil pressure such that the face plate can be moved easily.
An embodiment of the hydraulic device is according to claim 11. As a consequence, deformations of the face plate caused by oil pressure in the channels through the face plate are avoided as much as possible, such that leakages along sealing surfaces will be minimized.
The invention will be elucidated hereinafter by means of some embodiments by means of a drawing. The drawing includes a number of figures, in which similar components in the different figures have the same reference signs.
The parts as shown in
A centring surface 22 about which the drum plate 7 can swivel is formed on the rotor shaft 2. The centring surface 22 is spherical and the intersection M forms the centre of the sphere. The rotation of the drum plate 7 is coupled to a rotation of the rotor shaft 2 by means of a key 16 which engages in a key path. The key 16 has a radius of curvature in the plane of the surface of the shaft which is smaller than the radius of the centring surface 22, such that the key 16 does not clamp in the key path upon rotation of the drum plate 7. Possibly more than one key 16 is present. It is also possible that the key 16 is mounted in the rotor shaft 2 and the key path is provided in the drum plate 7.
The drum plate 7 is provided with drum bushes 11 at the side which is directed to the pistons 12, which drum bushes 11 are clamped against the drum plate 7 by a bush holder 18. The drum bush 11 has a cylindrical wall 23 at its inner side. Each piston 12 is enveloped by a drum bush 11 wherein the piston ring 10 can move along the cylindrical wall 23 in a sealing manner. The piston 12 and the cylindrical bush 11 thus form a chamber 9 of which the volume changes upon rotation of the rotor shaft 2. As a consequence of the volume change, oil flows into and out of the chamber 9 via a drum bush opening 24, a drum port 6, wherein each chamber 9 has its own drum bush opening 24 and drum port 6. The drum plate 7 including the drum ports 6 rotate along a face plate 4 which is at a stand still in the housing and the oil flows through the drum port 6 via one of the kidney-shaped face plate ports 3 to a pipe connection (not shown) in the housing. The face plate 4 has three kidney-shaped face plate ports 3 which together form a ring which is discontinuous between the different face plate ports 3. For other applications each face plate 4 may have two or four face plate ports 3. Each face plate port 3 has its own pipe connection wherein corresponding face plate ports 3 at both sides of the rotor 14 are connected to the same pipe connection, for example due to the fact that they are coupled to each other in the housing.
Since the shafts of rotations of the rotor 14 and the drum plate 7 are angled by an angle of stroke α, the pistons follow an elliptical path in the plane of the drum plate 7 and the drum bushes 11 will slide over a contact surface 8 of the drum plate 7. The holder 18 is provided with openings which allow this sliding and serves to limit the gap between the drum plate 7 and drum bush 11 such that a pressure can arise in the chamber 9 upon starting.
The face plate port 3 is a kidney-shaped opening in the face plate 4 which is supported by a surface of the housing. This surface does not extend perpendicular to the rotor centre line l but is angled to that rotor centre line and hence defines the direction of the drum plate centre line m1 or m2 and also the rotational position where the volume in the chamber 9 is minimal or maximal. In the known hydraulic transformer as shown in
In the position of the drum plate 7 with respect to the rotor shaft 2 as shown in
Upon rotating the face plate 4 the settings of the hydraulic transformer changes as described in the above identified patent applications. The rotation of the face plate 4 is limited since each face plate port 3 communicates with a port in the housing which communicates with a pipe connection and upon rotating the face plate 4 about a too large angle a face plate port 3 would possibly communicate with a different pipe connection. As a consequence, not all of the setting possibilities of the hydraulic transformer are applied.
In the embodiment of
In an alternative embodiment (not shown) in the ball pivot on the spherical surface of the face plate 34 a pin is provided and in the opposite concave surface of the housing a slit is provided in a plane through the rotor centre line l. In this way the pin limits one of the three possible rotations of the face plate 34 whereas the pin in the split can move and a rotation about the axis of the pin in the slit is possible such that the face plate 34 can rotate about two remaining axes of rotation. The face plate ports 3 communicate with openings in the housing via connection openings 33.
In the face plate port 3 and the associated connection opening 33 the oil pressure is the same for each face plate port 3, and this oil pressure will be different for the different face plate ports 3. In the area where oil pressure is present around the connection opening 33 between the housing and the face plate 34 the oil pressure exerts a port force 38 on the face plate 34 which is directed to the intersection M, see
The adjustment device of the face plates 25, 34 of
The bearings 47 are mounted in a central housing 48 and the covers 51 are mounted at the ends of the central housing 48. The inner side of the cover 51 forms a concave surface 53 along which the face plate 50 can move in the way as described in relation to
As described earlier, a pin which is mounted to the face plate 50 and moves within a slit, wherein the face plate 50 can rotate about the rotation shaft of the pin, can serve to limit the rotation of the face plate 50 in one axis of rotation. This means that the exact position of the face plate in respect of the angle of stroke α and setting angle δ can be set by means of two actuators. It is possible for example to guide one of the pistons 58 in a slit 65 in the concave inner surface 53 of the face plate 50. Possibly the slit 65 can be oval and in that case the rotation is limited by guiding two pistons 58 within a slit 65. If the slit 65 lies in a plane in which the rotor shaft 1 lies, the face plate 50 will not rotate about the rotor shaft 1.
The embodiments as described hereinbefore describe the adjustment of the face plate of a hydraulic transformer. The face plate of a pump of a hydraulic motor can be adjusted in a comparable manner, such that this obtains an adjustable swept volume in a simple way.
The invention is described by means of a hydraulic device wherein the pistons move within bushes which are supported by a drum plate and wherein the drum plate rotates along the face plate. It may be clear that the invention can also be applied in hydraulic devices which do not have separate bushes but wherein a rotor in which pistons move rotates against the face plate or wherein the chambers that have varying volumes are formed with other components in another way.
Claims
1. A hydraulic device comprising:
- a housing,
- two or more pipe ports in the housing,
- a rotor including a plurality of rotor chambers which are each formed by a cylinder and a piston which rotate about a first axis of rotation and a second axis of rotation, respectively, wherein both axes of rotation extend in a common plane and intersect each other by an acute angle such that upon rotating the rotor the volume of the rotor chambers changes,
- a face plate including a face plate centre line which coincides with the second axis of rotation, wherein the face plate comprises two or more face plate ports which each connect with a pipe port in the housing for connecting the pipe port with the rotor chambers,
- an adjustment device for adjusting the mutual positions of the face plate and the common plane, and
- wherein a face plate bearing, between the face plate and the housing, has at least two axes of rotation which intersect the face plate centre line, and
- wherein upon rotating the face plate the common plane rotates with respect to the housing.
2. The hydraulic device according to claim 1, wherein two axes of rotation of the face plate bearing intersect the face plate centre line in the intersection point of the first axis of rotation and the second axis of rotation.
3. The hydraulic device according to claim 1, wherein the face plate bearing comprises a spherical surface of the face plate and a concave surface of the housing, in which the spherical surface can rotate.
4. The hydraulic device according to claim 1, wherein the face plate bearing comprises cylindrical bearings having non-parallel axes of rotation.
5. The hydraulic device according to claim 1, wherein the housing is provided with a limiting edge which limits rotation of the face plate with respect to the housing.
6. The hydraulic device according to claim 3, wherein the face plate and the housing are provided with meshing teeth.
7. The hydraulic device according to claim 3, wherein support cylinders are provided between the housing and the face plate and wherein via a channel the support cylinder(s) communicates with the face plate port which is located diametrically opposite to the support cylinder(s).
8. The hydraulic device according to claim 7, wherein the face plate port has a connection opening at the side of the spherical surface and wherein the face plate around the connection opening has a sealing ridge which seals against the concave surface of the housing.
9. The hydraulic device according to claim 7, wherein each support cylinder is supported by a support surface of the housing wherein the support surface forms a part of a cylinder of which the centre line intersects the axis of rotation perpendicularly.
10. The hydraulic device according to claim 8, wherein the projection of the connection opening on a plane perpendicular to the face plate centre line has the same surface area and centre of gravity at the same location as the projection of the face plate port on the plane perpendicular to the face plate centre line and wherein the projection of the connection opening on a plane through the face plate centre line and extending perpendicular to a line through the centre of gravity of the surface of the connection opening and the face plate centre line has the same surface area and centre of gravity in the same location as the projection of the contact surfaces of the support cylinder(s) with the housing on the plane.
11. The hydraulic device according to claim 3, wherein the face plate port is provided with ridges such that the largest dimension of a channel through the face plate is smaller than three times the width of the face plate port.
12. The hydraulic device according to claim 1, wherein the at least two axes of rotation of the face plate bearing intersect the face plate centre line perpendicularly.
13. The hydraulic device according to claim 2, wherein the face plate bearing comprises a spherical surface of the face plate and a concave surface of the housing, in which the spherical surface can rotate.
14. The hydraulic device according to claim 2, wherein the face plate bearing comprises cylindrical bearings having non-parallel axes of rotation.
15. The hydraulic device according to claim 8, wherein each support cylinder is supported by a support surface of the housing wherein the support surface forms a part of a cylinder of which the centre line intersects the axis of rotation perpendicularly.
16. The hydraulic device according to claim 9, wherein the projection of the connection opening on a plane perpendicular to the face plate centre line has the same surface area and centre of gravity at the same location as the projection of the face plate port on the plane perpendicular to the face plate centre line and wherein the projection of the connection opening on a plane through the face plate centre line and extending perpendicular to a line through the centre of gravity of the surface of the connection opening and the face plate centre line has the same surface area and centre of gravity in the same location as the projection of the contact surfaces of the support cylinder(s) with the housing on the plane.
Type: Application
Filed: Oct 12, 2011
Publication Date: Aug 1, 2013
Applicant: INNAS BV (Breda)
Inventors: Peter Augustinus Johannes Achten (Eindhoven), Titus Van Den Brink (Breda)
Application Number: 13/877,938