Patent Application
20110189045
The invention refers to mechanical engineering and can be used in rotor vane pumps, hydraulic motors, hydrostatic differential units and transmission systems with increased effectiveness at high pressure.
There are rotor vane machines containing two units installed with the possibility of reciprocal rotation, namely a housing with inlet and outlet ports and a rotor with vane chambers enclosing vanes with the possibility of movement relative to the rotor: axial (U.S. Pat. No. 570,584), radial (U.S. Pat. No. 894,391) or rotary (U.S. Pat. No. 1,096,804 and U.S. Pat. No. 2,341,710), with the working chamber in them being limited by the face surfaces of the rotor and the housing.
In the working chamber the inlet cavity hydraulically connected to the inlet port and the outlet cavity hydraulically connected to the outlet port are divided by two insulating dams of the housing. One of them has a sliding insulating contact with the vanes moving from the inlet to the outlet cavity during the rotor rotation and is further called a forward transfer limiter. The other one is further called a backward transfer limiter.
The embodiment of the working chamber in the annular groove in the face of the rotor unit U.S. Pat. No. 1,096,804, U.S. Pat. No. 3,348,494, U.S. Pat. No. 894,391, U.S. Pat. No. 2,341,710 provides the radial unloading of the rotor and improves insulation of the working chamber through the sliding insulating contact between the face surface of the working part of the rotor enclosing the annular groove and the face surface of the working part of the housing. The flat insulating face surfaces of the working parts of the rotor and the housing being pressed together provide good insulation at no deformations.
However, the pressure force of the working fluid contained in the working chamber pushes the working parts of the rotor and the housing away from each other and deform their insulting surfaces, which results in considerable increase of leakages at pressure increase.
There is disclosed the hydrostatic component EP0269474 taken by us as the closest analog with reduced deforming influence of the working fluid pressure on the surfaces of the sliding insulating contact between the working parts of both units. It consists of two units, namely the housing and the rotor installed with the possibility of reciprocal rotation. The housing with the inlet and outlet ports (called “channels for fluid feed and removal” by the authors) contains the working part of the housing called by the authors “the trackway carriers”, the way enclosing the forward transfer limiter and the backward transfer limiter in the form of the rim sections with a trackway between the inlet and outlet cavities. The rim with the trackway also performs the function of the guide cam of the vane drive.
The rotor consists of two parts: the working part of the rotor called a “plate holder” and the supporting part called a “supporting flange”. The working face surface of the plate holder has an annular groove connected to the vane chambers enclosing the vanes installed with the possibility of varying the degree of extension into the annular groove. The authors have provided for the embodiment when the supporting part also has the vane chambers and the annular groove. In this case the supporting part of the rotor contacts with the supporting part of the housing in the form of the second trackway carrier.
Having a sliding contact with the working part of the rotor (the plate holder) the working part of the housing (the trackway carrier) insulates the working chamber in the annular groove. The working chamber is divided by the backward transfer limiter (the rim section overlapping the annular groove the most) and the forward transfer limiter (the rim section overlapping the annular groove the least) having a sliding insulting contact with the vanes into the inlet cavity of the working chamber hydraulically connected to the inlet port and the outlet cavity of the working chamber hydraulically connected to the outlet port.
The authors provide for the possibility of using a pair of hydrostatic components of the described type in rotor vane machines either in the embodiment where the working and supporting parts of the rotor are located between the working and supporting parts of the housing connected by the connecting part of the housing in the form of a shaft or in the embodiment where the working and supporting parts of the housing are located between the working and supporting parts of the rotor connected by the connecting part of the rotor in the form of an outer casing.
To ensure insulation of the working chamber the authors provide for an adaptive embodiment of one of the units, rotor or housing, that is an embodiment including force chambers of variable length kinematically connecting the working and supporting parts of the adaptive unit with the possibility of their reciprocal axial displacements and tilts at least sufficient to bring the blade holder to the trackway carrier, i.e. to ensure the sliding insulating contact between the working parts of both units of hydrostatic component during their reciprocal rotation while every force chamber includes a load-bearing cavity hydraulically connected to the working chamber and the means of its insulation. The change of the length of these force chambers results in the mentioned reciprocal displacements of the working and supporting parts of the given unit while the working fluid pressure forces in the load-bearing cavities are directed so that to draw apart the force chambers and to bring the working part of the housing closer to the working part of the rotor.
In the first embodiment the rotor is adaptive, that is it includes force chambers of variable length kinematically connecting its working and supporting parts, i.e. the plate holder with the supporting flange, with the possibility of their reciprocal axial displacements. The cylindrical load-bearing cavities communicating with the working chamber have an oval section and are made on the face of the plate holder on the reverse side from the annular groove. They contain means of insulation in the form of cylindrical piston-like elements moving in the axial direction and called “sealing cups” by the authors. These elements thrust against the supporting flange and press the face surface of the plate holder to the face surface of the trackway carrier thus sealing the working chamber.
The authors point out that the fluid pressure forces pushing the plate holder away from the trackway carrier are transferred through the force chambers to the static contact between the piston-like moving element and deformable supporting flange, which relieves the mentioned face insulating surfaces of the plate holder from axial deformations. The pressing force of the working part of the rotor to the working part of the housing depends on the force chambers size and determines the level of friction losses between these working parts.
Despite the synchronous rotation of the working and supporting parts of the rotor this contact of the piston-like moving element with the supporting flange is not absolutely static as the disalignment of the rotation axes of the working and supporting parts causes the face surface of the moving element to move along the supporting flange surface. To reduce friction between the piston-like moving element and the supporting flange there are cavities on the faces of the moving elements that are hydraulically connected to the load-bearing cavities in the plate holder. To prevent leakages from both cavities of the force chamber it is necessary to provide good insulation simultaneously in two sliding insulating contacts of the surfaces of every moving element both from the inner cylindrical surface of the force chamber cavity and the flat surface of the supporting flange. For that purpose it is necessary to ensure high precision perpendicularity between the generatrix of the cylindrical insulating surface of the force chamber cavity and the flat insulating surface of the supporting flange at any pressure and any rotor rotation angle.
However, for technological reasons and due to the deformations of the housing under the action of the working fluid pressure the axis of rotation of the plate holder can deflect from the axis of rotation of supporting flange by a certain angle. This angle determines the angular amplitude of the cyclic tilts performed by the insulating surface of the supporting flange relative to the face surface of the moving element during rotation of the rotor unit. The supporting flange deformation under the action of the working fluid pressure increases the cyclic tilts amplitude considerably and causes distortion of its flat insulating surface. All this destroys the sliding insulating contact between the mentioned insulating surfaces and results in considerable increase of the leakages, which is a significant shortcoming of the hydrostatic component described above.
Besides, the trackway carrier is hydrostatically unbalanced. Therefore, its flat insulating surfaces deform at high pressure, which further increases the leakages.
The EP0269474 also described the embodiment of the hydrostatic component where it is the housing rather than the rotor that is adaptive, i.e. the force chambers of variable length with moving elements are located in the housing unit between the working part of the housing, i.e. the trackway carrier and the supporting part of the housing. In this embodiment the tilts of the supporting part of the housing relative to the working part of the housing conditioned by deformations and technological reasons as well as the distortion of the flat insulating surface will result in leakage growth.
The elastic elements sealing the contact between the walls of the moving element and the walls of the load-bearing cavity in the form of flexible peripheral rims of the moving piston-like elements or in the form of toroidal sealing gaskets partly improve the insulation in case of the above-described reciprocal tilts of the working and supporting of the relevant unit of the hydrostatic component; however, they result in considerable increase of the frictional forces preventing movement of the moving elements in the cavities of the force chambers. To overcome these forces it is necessary to increase the section of the force chambers, which results in increased forces pressing the rotor to the housing and higher friction losses.
Thus, the hydrostatic component described in EP0269474 requires high precision of manufacture, fails to provide insulation of the force chambers and the working chamber in case of deformations and prevents achieving a low level of leakages and low friction losses together at high pressure.
The objective of the present invention is to provide insulation of the working chamber and force chambers of variable length in a wide range of deformations and technological tolerances and related reciprocal tilted and transverse movements of the working and supporting parts of the adaptive unit and to increase the efficiency of rotor vane machines at high pressure.
It is proposed to solve the task by means of a rotor vane machine consisting of two units, namely a housing and a rotor installed with the possibility of reciprocal rotation. The housing with the inlet and outlet ports contains the supporting part of the housing and the working part of the housing with a forward transfer limiter and a backward transfer limiter. The rotor includes the supporting part of the rotor and the working part of the rotor. The working face surface has an annular groove connected with the vane chambers enclosing the vanes installed with the possibility of changing the degree of extension into the annular groove. The working and supporting parts of one unit are located between the working and supporting parts of another unit joined by the connecting part. The supporting part of the housing contacts the supporting part of the rotor while the working part of the part of the housing contacts with sliding the working face surface of the working part of the rotor and insulates the working chamber in the annular groove. The backward transfer limiter and the forward transfer limiter being in sliding insulating contact with the vanes divide the working chamber into the inlet cavity hydraulically connected to the inlet port and the outlet cavity hydraulically connected to the outlet port.
At least one of the two units of the rotor vane machine, the rotor or the housing are made adaptive, that is it includes the force chambers of variable length kinematically joining the working and supporting parts of the adaptive unit with the possibility of their reciprocal axial displacements and tilts. The amplitude of these axial displacements is at least sufficient to ensure a sliding insulating contact between the working parts of both units of the rotor vane machine during their reciprocal rotation. The change of the length of these force chambers results in these reciprocal movements of the working and supporting parts of the adaptive unit. Each force chamber of variable length (hereinafter in the text—the force chamber) includes a load-bearing cavity of variable length (hereinafter in the text—the load-bearing cavity) hydraulically connected to the working chamber and the means of its insulation. The pressure forces of the working fluid in the load-bearing cavities are directed so as to draw the force chambers apart and to bring the working part of the housing closer to the working part of the rotor.
In every force chamber the means of insulation of its load-bearing cavity include two moving elements at least. These moving elements are installed forming sliding insulating contacts between the following pairs of the surfaces: the insulating surface of one of the moving elements and the insulating surface of one part of the adaptive unit, the insulating surface of another moving element and the insulating surface of the other part of the adaptive unit and between the insulating surfaces of the moving elements. At least in one of these contacts both insulating surfaces are cylindrical and at least in one of them they are spherical while in the other contacts mentioned the shapes of the pairs of the contacting surfaces are chosen so as to keep the sliding insulating contact during such reciprocal movements of the working and supporting parts of the adaptive unit. The reciprocal sliding of the cylindrical surfaces provides insulation during reciprocal axial movements of the working and supporting parts of the adaptive unit while the reciprocal sliding of the spherical surfaces provides insulation during reciprocal tilted movements of these parts. To keep insulation during reciprocal transverse movements of these parts at least in one more of the other insulating contacts both insulating surfaces are made either flat or spherical.
To improve insulation of the force chambers at high pressure the spherical and flat insulating surfaces should be preferably made on the hydrostatically unloaded part of the adaptive unit and on the hydrostatically unloaded moving elements. In the embodiments where one part of the adaptive unit, the supporting or the connecting one, is not unloaded and is deformable under pressure it is preferable to make cylindrical surfaces on this deformable part and the gap clearance between them and the respective cylindrical surfaces of the moving elements, if required, should be sealed with cylindrical self-adjusting spring rings. In the embodiments where the force chambers are located between two hydrostatically balanced parts of a unit the cylindrical surfaces are made on moving elements and on any of the mentioned parts or between the moving elements. The cylindrical surface is interpreted here in its most general sense as a surface formed by parallel displacement of a straight line along the set closed circuit. If necessary the cylindrical surfaces can be made with an oval or another transverse section. The examples of the invention implementation given below show the preferable embodiment of cylindrical surfaces with a round cross-section.
The pressing of the working part of the rotor to the working part of the housing at no pressure is provided by the fact that the force chambers include elastic elements. For hydrostatic unloading of the working part of the adaptive unit the shapes, sizes and location of the load-bearing cavities are chosen so that the sum of elastic forces of these elastic elements and the forces of the working fluid pressure in the force chambers pressing the working part of the rotor to the working part of the housing exceeds the sum of the pressure forces of the working fluid in the working chamber pushing the working part of the rotor away from the working part of the housing and the friction forces in said rotor elements preventing the working part of the rotor from approaching the working part of the housing by the set value, preferably not exceeding 5% of said sum of the pressure forces repelling the working part of the rotor from the working part of the housing.
For the embodiments where the force of the elastic reaction of the elastics elements is small or has no influence on the pressing force of the parts of the rotor to the parts of the housing, shapes and sizes of the load-bearing cavities are chosen so that to provide hydrostatic pressing of the working parts to each other, namely the shapes, sizes and location of the load-bearing cavities are chosen so that the sum of the working fluid pressure forces in the force chambers pressing the working part of the rotor to the working part of the housing should exceed the sum of the working fluid pressure forces repelling the working part of the rotor from the working part of the housing by a preset value preferably not exceeding 5% of said sum of the pressure forces repelling the working part of the rotor from the working part of the housing. In particular for the embodiments where the guides of the cylindrical surfaces of the load-bearing cavities are parallel with the axis of the rotor rotation said exceeding is provided for example by the fact that the total area of the sections of the load-bearing cavities by the plane perpendicular to the axis of the rotor rotation exceed the area of the projection of the annular groove to the same plane at least by 50% of the area of the projection of the sliding insulating contact of the working part of the rotor with the working part of the housing to said plane.
The supporting cavities for the hydrostatic unloading of the supporting part of the adaptive unit are made between the supporting parts of the rotor and the housing being in sliding insulating contact, their shapes, sizes, number and location are chosen so that the difference between the working fluid pressure forces repelling the working parts of the rotor and the housing from each other and the working fluid pressure forces repelling the supporting parts of the rotor and the housing from each other should not exceed the set value preferably small. Hydrostatic unloading of a part of the adaptive unit prevents it from axial deformations under working fluid pressure and reduces substantially the losses on friction between it and corresponding part of the other unit.
For hydrostatic pressing of the moving elements of the insulating means of the force cavities for every pair of the contacting spherical insulating surfaces and for every pair of the contacting flat surfaces the shapes and sizes of said pairs of insulating surfaces are chosen so that the sum of the working fluid pressure forces that pressing these surfaces to each other exceeds the sum of the counter forces of the working fluid pressure pushing these surfaces apart. For hydrostatic unloading of the moving elements it is preferably to choose said value of excess small i.e. not exceeding 10% of the product of the pressure in the force cavity and the area of the cross section of it's cylindrical insulating surfaces.
In the preferable embodiment said hydrostatic pressing of the moving elements is provided by the fact that for every pair of said insulating surfaces the area of the cross section of the load-bearing cavity by the plane passing through the inner boundary of the sliding insulating contact of these surfaces is chosen to be less than the area of the cross section of the cylindrical insulating surfaces of the load-bearing cavity by at least 50% of the area of projection of said sliding insulating contact to said plane.
For stabilization of the force of the hydrostatic pressing for every pair of said contacting insulating surfaces the area of one insulating surface exceeds the area of the other insulating surface so that every section of the surface of the smaller area keeps the sliding insulating contact with the surface of the larger area at any angle of the rotor rotation throughout the whole range of reciprocal displacements of the working and supporting parts of the adaptive unit.
The proposed solution for insulation of the force chambers and the working chamber of the rotor vane machine can be embodied in various designs. They differ by which unit of the rotor vane machine, the rotor or the housing, is made adaptive and by the type of the force closure, i.e. by which of the two units includes the connecting part sustaining the axial tensile of the working fluid pressure forces compensating them with its elastic strain. The rotor vane machines with the force closure to the housing correspond to traditional configurations where the rotor unit is located between the working and supporting parts of the housing. In the rotor vane machines with the force closure to the rotor we will further call the assembly of the working and supporting part of the housing located between the working and supporting parts of the rotor the operational unit of the housing.
In the rotor vane machines with the force closure to the rotor the assemblage of the working and supporting parts of the housing located between the working and supporting parts of the rotor is called further the operational unit of the housing.
In the embodiments with the force closure to the rotor and the adaptive rotor the working and supporting parts of the housing are located between the working and supporting parts of the rotor which includes the connecting part of the rotor wherein at least one of said parts of the rotor is installed with the possibility of axial displacements and tilts relative to the connecting part while the force chambers of variable length are made between said part of the rotor and the connecting part of the rotor and kinematically connect said part of the rotor to the connecting part, wherein the surfaces of the sliding insulating contact between the connecting part of the rotor and the moving element are cylindrical. In the embodiments with the force closure to the rotor and the adaptive housing the force chambers of variable length are made between the supporting and working parts of the housing joined into the operational unit of the housing located between the working and supporting parts of the rotor connected by the connecting part of the rotor.
The insulation of the working chamber at high pressure can be improved by hydrostatic means preventing deformations of the housing insulating surfaces, their embodiment depending on the type of the force closure.
In rotor vane machines with the force closure to the housing the working or supporting parts of the housing are composite, namely they are assembled from the external load-bearing and internal functional elements. Between them opposite the annular groove there is at least one antideformation chamber hydraulically connected to the working chamber. The number, location, shape and sizes of the antideformation chambers are chosen so that the resultant of the fluid pressure forces acting on the internal functional element of the part of the housing from the rotor side and the fluid pressure forces from the side of the antideformation chambers should not exceed the set value, preferably not exceeding 20% of said pressure forces acting from the rotor.
In rotor vane machine with the force closure to the housing and adaptive rotor where the unit of the housing made with possibility of changing the angle of the reciprocal tilt of the axes of rotation of the supporting and working parts of rotors, the antideformation cavities of variable length also can be made similar to above mentioned force chambers where the insulating at the reciprocal tilts is provided by combination of the three types of sliding movement of the moving elements: axial movement at the reciprocal axial sliding of the cylindrical insulating surfaces, tilted movement at the reciprocal sliding of the spherical insulating surfaces as well as transverse movement at reciprocal sliding of the flat or other spherical surface.
In this case the antideformation chamber has the antideformation cavity with variable length and the insulating means with at least, two moving elements installed with formation of sliding insulating contacts between the following pairs of the surfaces: the insulating surface of one of the moving elements and the insulating surface of the functional element of the part of the housing, the insulating surface of the other moving element and the insulating surface of the load-bearing element of the part of the housing and between the insulating surfaces of the moving elements, while at least in one of the contacts both insulating surfaces are cylindrical and at least in one of them they are spherical and in the rest of said contacts the shapes of the pairs of the contact surfaces are chosen so as to keep said sliding insulating contact at said variation of the angle of the reciprocal tilt. At that at least in one of said contacts both insulating surfaces are flat or at least in two of said contacts the insulating surfaces are spherical.
In rotor vane machines with the force closure to the rotor the working and supporting parts of the housing are connected into the operational unit of the housing. Between the supporting parts of the housing and the rotor opposite the annular groove there are supporting cavities hydraulically connected to it so that the pressure in every supporting cavity is equal to that in the cavity in the annular groove that is located opposite, wherein the shape, sizes and location of the supporting cavities are chosen so that the resultant of the pressure forces acting on the supporting part of the housing from the supporting part of the rotor and the pressure forces acting on the working part of the housing from the working part of the rotor does not exceed the set value preferably not exceeding 5% of said pressure forces repelling the working parts of the rotor and housing from each other.
In the embodiment with an adaptive operational unit of the housing said transfer of the balancing pressure forces between the working and supporting parts of the housing is provided by the above mentioned force chambers. In the embodiment with an adaptive rotor said transfer of the balancing pressure forces between the parts of the housing is provided either by means of their rigid joint or by means of antideformation chambers made either directly between the parts of the housing or between the functional and load-bearing elements of the parts of the operational unit of the housing.
In rotor vane machines with the force closure to the rotor and adaptive rotor where the supporting part of the housing is made with the possibility of variable tilt relative to the working part of the housing the antideformation chambers of variable length can be made similar to the force chambers described above where insulation during reciprocal tilts of the parts of the unit is provided by combination of three kinds of sliding movements of the moving elements: axial movement at reciprocal axial sliding of the cylindrical insulating surfaces, tilted movement at reciprocal sliding of the spherical insulating surfaces as well as transverse movement at reciprocal sliding of the flat or other spherical surfaces
In this case the antideformation chamber includes the antideformation cavity of variable length and the means of it's insulation with at least, two moving elements installed with formation of the sliding insulating contacts between the following pairs of the surfaces: the insulating surface of one moving element and the insulating surface of the working part of the housing, the insulating surface of another moving element and the insulating surface of the supporting part of the housing and between the insulating surfaces of the moving elements wherein at least in one of the contacts both insulating surfaces are cylindrical and at least in one of them they are spherical while in the other said contacts the shapes of the pairs of the contacting surfaces are chosen so as to keep the sliding insulating contact at said variation of the angle of the reciprocal tilt. At that at least in one of said contacts both insulating surfaces are flat or at least in two of said contacts the insulating surfaces are spherical.
The particulars of the invention are described in more detail in the examples given below and illustrated by drawing presenting:
The rotor vane machine in
The rotor vane machine in
The rotor vane machine in
The flat insulating surfaces of the supporting part 2 of the rotor and the supporting part 4 of the housing have a sliding insulating contact. Between them are supporting cavities 15 hydraulically connected to the load-bearing cavities 8 by channels 16 in the supporting part 2 of the rotor and hydraulically connected to the working chamber by channels 17 in the operational unit 12 of the housing. The shape and sizes of the supporting cavities 15 are chosen so that the pressure forces acting on the supporting part of the rotor from the side of the force chambers 7 should exceed the pressure forces pushing the supporting part 2 of the rotor from the supporting part 4 of the operational unit 12 of the housing by the preset value, preferably small, not exceeding 5% of the given repelling forces. Thus, the supporting part 2 of the rotor is hydrostatically balanced and is saved from deformations. These structures with hydrostatic balancing of the working and supporting parts of the adaptive rotor are described in more detail in RU 2005113098.
The force flange 14 is subject to axial deformations. It has cylindrical load-bearing cavities 8. Every load-bearing cavity has a cylindrical moving element 9 installed with formation of a sliding insulating contact. Its spherical surface has a sliding insulating contact with the spherical surface of another moving element 10 with its flat surface having a sliding insulating contact with the flat surface on the supporting part 2 of the rotor.
In the embodiment of
In all the embodiments described above the cylindrical, spherical and flat insulating surfaces are made with reasonable accuracy allowing deviations from the ideal cylindrical, spherical or flat shapes within the limits conditioned by the viscosity of the applied fluids and the range of working pressures. In the preferred embodiments designed for work with hydraulic fluids with the viscosity of centistokes and pressures of up to 30-50 MPa these deviation values do not exceed 2-5 microns for spherical or flat insulating surfaces and 5-15 micron for cylindrical undistorted surfaces. Embodiment of the cylindrical insulating surfaces on self-adjusting spring sealing rings (similar to piston-like rings) allows considerable (dozens of times) increase of the permissible deviations.
In all the described embodiments of the rotor vane machine the working part 3 of the housing having a sliding contact with the working face surface 18 of the working part 1 of the rotor insulates the working chamber in the annular groove 19. The backward transfer limiter 20 and the forward transfer limiter 22 having a sliding insulating contact with the vanes 21 divide the working chamber into the inlet cavity 23 hydraulically connected to the inlet port 24 and the outlet cavity 25 hydraulically connected to the outlet port 26. The vanes 21 located in the vane chambers 27 are kinematically connected to the cam mechanism 28 of the vane drive installed on the housing and specifying the character of the cyclic movement of the vanes 21 relative to the annular groove 19 during reciprocal rotation of the units of the rotor and the housing. In
During reciprocal rotation of the rotor and the housing the vanes 21 kinematically connected to the mechanism 28 of the vane drive move cyclically relative to the annular groove 19 in the following way: they move from the outlet cavity 25 into the vane chambers 27 as far as the position when they move past the backward transfer limiter 20, then they move from the vane chambers 27 into the inlet cavity 23 as far as the position when they move towards the outlet cavity 25 having a sliding insulating contact with the forward transfer limiter 22 and overlapping the annular groove 19. Sliding along the forward transfer limiter 22 the vanes 21 provide cyclic variation of the inlet 23 and outlet 25 cavities, inflow of the working fluid through the inlet port 24, its transfer from the inlet cavity 23 to the outlet cavity 25 and its displacement into the outlet port 26. High pressure is set in the pump mode in the inlet cavity 25 (in the hydraulic motor mode—in the inlet cavity 23) and in the load-bearing cavities 8 communicating to it under load.
The pressure forces of the working fluid in the load-bearing cavities 8 tend to expand the force chambers, i.e. to press the moving elements 9 out of the cylindrical load-bearing cavities 8 and to bring the working part 3 of the housing closer to the working part 1 of the rotor. Thus, the flat insulating surfaces 18 of the working parts of the rotor and the housing are pressed together ensuring insulation of the working chamber. The moving elements 9 are pressed against the moving elements 10 that are pressed against the respective part of the adaptive unit (for example, to the working part 1 of the rotor in the embodiment of
During reciprocal rotation of the rotor and the housing the parts of the adaptive unit with the force chambers 7 between them move in the axial, tilted and transverse direction relative one another. In this case the moving elements 9 perform axial movement relative to the load-bearing cavities 8 during reciprocal axial sliding of their cylindrical insulating surfaces while the moving elements 10 perform tilted movement relative to the moving elements 9 with reciprocal sliding of their spherical insulating surfaces and transverse movement relative to the respective part of the adaptive unit with reciprocal sliding of their flat insulating surfaces. The combination of these three kinds of sliding movements in pairs of the cylindrical, spherical and flat insulating surfaces keeps insulation of the load-bearing cavities 8 during these movements of the parts of the adaptive unit.
To improve insulation of the force chambers at high pressure the spherical or flat surfaces of the sliding insulating contact should be preferably made between the hydrostatically unloaded part of the adaptive unit and the moving element as well as between the hydrostatically unloaded moving elements.
For the aforesaid hydrostatic tightening of each pair of the flat 30 and spherical 31 insulating surfaces the areas of the cross section of the load-bearing cavity 8 by planes R1 and R2 (
To ensure synchronism of the axial, tilted and transverse sliding movements in pairs of the cylindrical, spherical and flat insulating surfaces required to preserve the insulation at reduced friction provision is made for axial hydrostatic unloading of the moving elements of the insulation means of the load-bearing cavities. This unloading is achieved by choosing the value of the mentioned hydrostatic tightening, namely by choosing the shapes and sizes of the pairs of the spherical and flat insulating surfaces in such a way that the sum of the working fluid pressure forces pressing these surfaces to each other should exceed the sum of counter forces of the working fluid pressure pushing them apart by the preset value, preferably small, i.e. not exceeding 10% of the product of the pressure in the load-bearing cavity by the cross-sectional area of its cylindrical insulating surfaces.
To ensure the mentioned synchronism of movements of the moving elements the shapes of the contacting spherical insulating surfaces of the insulation means of the load-bearing cavities are selected so as to ensure no self-stopping or no jamming of the moving elements at the set friction ratios in pairs of the sliding insulating contacts. In the preferable variant the curvature radius and the radii of the internal and external boundaries of the spherical surfaces are chosen in such a way that the angles “γ” in
Due to the hydrostatic unloading of the moving elements and the respective part of the adaptive unit described above the flat 30 and spherical 31 insulating surfaces are not subject of deformations under pressure and ensure insulation during reciprocal radial and tilted movements of the working and supporting parts. Deformations of the supporting part or the connecting part under pressure, as shown below, do not destroy insulation between the cylindrical insulating surfaces 33.
In the designs in
It can be seen that the initially flat face surface of the deformable part bends under the action of the pressure forces turning in
The invention also provides for an embodiment of the rotor vane machine where both parts of the adaptive unit are hydrostatically unloaded.
The hydrostatic balance of both parts of the rotor allows to make flat or spherical insulating surfaces on any of these parts and ensures free choice of the load-bearing cavity location.
In
The working part 3 of the adaptive housing in
As an example
The position of the insulating bushing 32 of the working part of the rotor relative to the functional element 51 of the working part of the rotor depends on the position of the vane 21 only and does not change at the given reciprocal movements of the parts of the adaptive rotor. Therefore, it is not necessary to synchronize the movements of the bushing 32 and the moving elements 9 and 10 and, accordingly, there is no need for axial hydrostatic unloading of the bushing 32. The contact of the flat surfaces of the functional element 51 and bushings 32 of the working part of the rotor transfers the pressure of the working fluid from the force chambers 7 to the functional element 51 thus hydrostatically balancing the working part of the rotor in general and preventing axial deformations both of the functional element 51 and bushings 32 of the working part of the rotor. The position of the moving elements 9 and 10 relative to one another as well as relative to the working and supporting parts of the adaptive rotor changes at reciprocal axial and tilted movements of these parts of the adaptive rotor. The moving elements 9 and 10, as shown above, are hydrostatically unloaded in the axial direction; hence, the axial movements of the element 9 relative to the supporting part 2 of the rotor cause synchronous, insulation-preserving, tilted and transverse movements of the element 10 relative to the bushing 32 and functional element 51 of the working part 1 of the rotor and, vice versa, the movements of element 10 cause synchronous movements of the element 9.
To ensure insulation of the working chamber at no pressure and to overcome friction forces, including those preventing the working parts from getting closer to one another, the adaptive unit includes elastic elements pressing the face insulating surfaces of the parts of the adaptive unit to the face insulating surfaces of the parts of another unit. In the embodiments of
To ensure a sliding insulating contact between the working parts of the rotor and the housing at high pressure the shapes, sizes and location of the load-bearing cavities 8 are chosen so that the sum of the elastic forces of the mentioned elastic elements 36 and the working fluid pressure forces in the force chambers 7 pressing the working part 1 of the rotor to the working part 3 of the housing should exceed by the preset value the sum of the working fluid pressure forces (in the working chamber and in the gap clearances between the face insulating surfaces of the rotor and the housing) pushing the working part 1 of the rotor from the working part 3 of the housing and the friction forces preventing the working part of the rotor from getting close to the working part of the housing. To reduce friction losses it is preferable to choose a small value of the said excess, namely not mare than 5% of the sum of the pressure forces pushing the working part 1 of the rotor from the working part 3 of the housing. (These repelling forces oscillate during rotor rotation, especially for the embodiment with an adaptive housing; therefore, the excess is determined against the maximum value of the repelling forces.) Thus, the working part of the adaptive unit supported by the force chambers is hydrostatically unloaded, not subject to deformations at high pressure while the losses of friction between the face insulating surfaces of the working parts of both units are small.
The present invention supposes that any unit of the rotor vane machine, the rotor or the housing, can rotate relative to the chassis of the aggregate on which another unit of the rotor vane machine is fixed. It is possible to provide an embodiment where both the rotor and the housing rotate relative to the chassis of the aggregate, for example, if the rotor vane machine is an element of hydrostatic differential or hydromechanical transmission.
If the unit fixed on the chassis is adaptive, to reduce friction losses at small pressure it is preferable to reduce the elastic forces of elastic elements 36 down to the minimal necessary level chosen considering the friction forces in the force chambers 7 at no pressure.
If the unit rotating relative to the chassis of the aggregate is adaptive, the shape of the spherical surfaces and the elastic forces of the elastic elements 36 are chosen so as to prevent the sliding insulating contact between the spherical surfaces and between the flat surfaces at the maximum rotation speed from being broken by centrifugal forces. At the rotation speed of several thousands revolutions per minute the centrifugal forces acting on the moving elements of dozens of grams can achieve hundreds of newtons. The correlation between the centrifugal force and the tightening force balancing it acting on the moving element 10 from the side of the elastic element 36 is determined by the shapes of the insulating surfaces, for example, for the embodiment of
To avoid the increase of pressing of the rotor parts to the housing parts and increase of the friction losses at the increased elastic reaction forces of the elastic elements the designs of the force chambers 7 shown in
In
For the embodiments where the elastic reaction force of the elastic elements is either small or does not affect the force of pressing of the rotor parts to the housing parts, the shape and sizes of the load-bearing cavities 8 are chosen so as to ensure hydrostatic pressing of the working parts together, namely so that the overall area of the sections of the load-bearing cavities 8 by the plane perpendicular to the rotor rotation axis should exceed the area of the annular groove projection to the same plane by at least 50% of the area of projection of the sliding insulating contact of the working part of the rotor with the working part of the housing to the said plane. To reduce friction losses between the face insulating surfaces of the working parts of both units it is preferable to choose the said excess value so that the mentioned hydrostatic pressing should be small, namely not exceeding 5% of the given sum of the pressure forces pushing the working part of the rotor away from the working part of the housing.
The necessary range of the said reciprocal axial, transverse and tilted movements of the working and supporting parts is determined considering technological tolerances, expansion clearances and deformations of the elements under the action of the working fluid pressure. The invention also provides for an embodiment of rotor vane machines described below with an adaptive rotor where the range of these reciprocal movements of the working and supporting parts is chosen based on the preset value of variation of the force chamber volumes during reciprocal rotation of the rotor and housing.
In the embodiments preferable for generation of a uniform working fluid flow the volume of the force chambers connecting the working and supporting parts of the rotor is changed during rotor rotation so that the pressure of the working fluid separated in the force chamber from the inlet cavity with the inlet pressure should reach the value of the outlet pressure by the moment the force chamber is merged the outlet cavity. For that purpose the axis of rotation of the supporting part of the rotor is tilted relative to the axis of rotation of the working part of the rotor by an angle depending on the difference between the inlet and outlet pressure. This method and design for its implementation are described in detail in the application “Method of creating a uniform working fluid flow and the device for its implementation” RU 2005129000. We consider here such embodiments from the point of view of solving the task of the present invention, namely ensuring insulation of the force chambers and the working chamber in wide range of amplitudes of reciprocal movements of parts of an adaptive rotor both at fixed and variable angle of reciprocal tilt of the axes of rotation of the working and supporting parts of the adaptive rotor.
In the embodiment of
In
Similar way for the embodiments with force closure to the rotor in order to implement this method of creating a uniform flow the working and supporting parts of the operational unit of the housing are made either with a fixed reciprocal tilt or, as shown in
Variation of the said tilt angle results in change of the amplitude of reciprocal axial, transverse and tilted displacements both in pairs of the cylindrical surfaces 33 and in pairs of the flat 30 and spherical 31 insulating surfaces.
At the pressure of dozens MPa the necessary degree of variation of the force chambers volumes reaches several percents while the angle of reciprocal tilt reaches units of degrees. In this case the reciprocal axial displacements of the cylindrical insulating surfaces reach units of millimeters while the reciprocal transverse displacements in pairs of the spherical and flat insulating surfaces reach hundreds microns.
The sizes of the insulating surfaces are chosen so that in the preset range of reciprocal axial, transverse and tilted displacements of the working and supporting parts of the adaptive unit the sliding insulating contact should be maintained in all pairs of the contacting insulating surfaces between means of insulation of the load-bearing cavities. To stabilize the pressing forces in every pair of the flat or spherical insulating surfaces the area of one of them exceeds the area of the other by the set value chosen so that every section of the surface of the less area should keep a sliding contact with the surface of a larger area at any angle of the rotor rotation throughout the range of the said reciprocal displacements,
The pressing of the face insulating surfaces of the adaptive unit to the respective insulating surfaces of another unit ensures good insulation of the working chamber in the absence of deformations of these face insulating surfaces, generally flat ones. Deformations of the face insulating surfaces of the rotor are small due to the massiveness and high rigidity of the working part of the rotor and due to the hydrostatic unloading of the supporting part of the adaptive rotor. In the embodiments of the rotor vane machine with an adaptive housing the part of the housing supported by the force chambers is hydrostatically balanced and is not subject to axial deformations under the action of the working fluid pressure forces. The parts of non-adaptive housing or the part of adaptive housing that is not supported by the force chambers can be made rather massive and rigid; however, this increases considerably the sizes and weight of the rotor vane machine. To reduce the size and weight of the parts of the housing that are not supported by the force chambers and to improve the insulation of the working chamber at high pressure the invention provides for hydrostatic means of prevention of deformations of the housing insulating surfaces having a sliding insulating contact with the flat face surfaces of the working and supporting parts of the rotor.
In the embodiments with force closure to the housing to prevent defortmations of the flat insulating surfaces the working 3 part of the housing (
For rotor vane machines with an adaptive rotor where the working 3 and supporting 4 parts of the housing are connected with the possibility of varying the reciprocal tilt of the rotation axes of the working and supporting parts of the rotor the preferred embodiment according to the technology and overall size supposes provision of the antideformation chambers between the functional and load-bearing elements of the part of the housing, preferably the supporting part of the housing in
The above-described reduction of the fluid pressure forces on the functional element results in proportional reduction of deformations of the housing insulating surfaces and the gap clearances between them and the respective rotor insulating surfaces. The leakage through these gap clearances at the set pressure is proportional to the third power of the clearance size. Therefore, reduction of the forces even by 2-3 times reduces the leakages substantionally while the preferred embodiment reducing these pressure forces by 5 and more times ensures leakage reduction at the set pressure by 100 and more times, which improves the insulation of the working chamber considerably.
In the embodiments with force closure to the rotor (
In case of the rigid joint of the working 3 and supporting 4 parts of the housing into the operational unit 12 of the housing, for example, in the embodiment of the operational unit 12 of the housing in the form of a single part like in
For the embodiments where the working and supporting parts of the non-adaptive operational unit of the housing are not rigidly connected, the invention provides for antideformation chambers between the working and supporting parts of the operational unit of the housing. The number, location, sizes and shape of the antideformation chambers are chosen so that the resultant of the fluid pressure forces acting on the parts of the housing from the side of the rotor and the fluid pressure forces acting from the side of the antideformation chambers should not exceed 20% of the pressure forces acting from the side of the rotor. For the embodiments with an adaptive rotor where the working and supporting parts of the operational unit of the housing are connected with the possibility of reciprocal movements, for example, with the possibility of a variable reciprocal tilt by means of the tilt angle variator, each part of the operational unit is supposed to be made from two elements, the functional one and the load-bearing one, with antideformation chambers between them similar to the embodiment described above for force closure to the housing.
For rotor vane machines with an adaptive rotor where the working 3 and supporting 4 parts of the operational unit 12 of the housing are connected with the possibility of varying the reciprocal tilt of the axes of rotation of the working and supporting parts of the rotor the embodiment preferable for manufacturability and overall dimensions supposes to locate antideformational chambers between the working and supporting parts of the operational unit of the housing
This hydrostatic balancing of the working and supporting parts of the operational unit of the housing reduces substantionally deformations of the housing insulating surfaces and improves considerably the insulation of the working chamber.
Thus, the proposed rotor vane machine ensures:
The said insulation of the working chamber and force chambers ensures high volume efficiency and in combination with hydrostatic unloading of the friction pairs high total efficiency at high pressure of the working fluid.
The embodiments described above are examples of implementation of the main idea of the present invention that also supposes a variety of other embodiments that were not described here in detail, for example: the rotor vane machine with the second working chamber in the annular groove in the supporting part of the rotor, an embodiment with several forward and backward transfer limiters in one annular groove as well as various installations of the rotor vane machine into hydrostatic differentials and transmissions or embodiments of the rotor vane machine connecting differently its units with the inlet or outlet shaft, chassis of the hydromechanical agregate or with units of another rotor vane machine.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006138903 | Oct 2006 | RU | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/RU07/00534 | 10/2/2007 | WO | 00 | 4/29/2009 |
