US3348494A

US3348494A - Rotary piston machine

Info

Publication number: US3348494A
Application number: US611133A
Authority: US
Inventors: Fischer Arno
Original assignee: Halbergerhutte GmbH
Current assignee: Halbergerhutte GmbH
Priority date: 1967-01-23
Filing date: 1967-01-23
Publication date: 1967-10-24
Anticipated expiration: 1984-10-24

Description

Oct. 24, 1967 A. FISCHER ROTARY PISTON MACHINE Filed Jan. 23, 1967 4 Sheets-Sheet 1 jOct. 24, 1967 AQFISCHER ROTARY PISTON MACHINE 4 Sheets-Sheet 2 Filed Jan. 23, 1967 A- FISCHER ROTARY PISTON MACHINE Oct. 24, 1967 4 Sheets-Sheet 5 Filed Jan. 23, 1967 \m J x Em QM m m i mm 3 7./ 7 mm mm, km Qm mm mm m6? Oct. 24, 1967 A. FISCHER 3,348,494

ROTARY PISTON-MACHINE Filed Jan. 23, 1967 4 Sheets-Sheet 4 United States Patent 3,348,494 ROTARY PISTON MACHIN Arno Fischer, Rottenbuch, Upper Bavaria, Ammermuhle,

Germany, assignor to Halbergerhutte G.m.b.H., Brebach, Germany, a corporation of Germany Filed Jan. 23, 1967, Ser. No. 611,133 13 Claims. (Cl. 103-136) ABSTRACT OF THE DISCLOSURE A rotary piston machine of the parallel axes type includes a working chamber within which is at least one piston consisting of a piston hub and a tubular vane or slide member, said slide member lying against a running surface of the peripheral wall of the working chamber.

The invention relates to a rotary piston machine, particularly a parallel axis rotary piston machine having a peripheral wall which is provided with running surfaces, which possess zones near the axis and zones remote from the axis, and having a piston consisting of a piston hub and at least one slide member, wherein in each case a working chamber is formed between two zones near the axis. The invention consists in that in the working chamber bounded by running surfaces of the peripheral wall, the piston and the side parts at least one slide member lies against a running surface on the peripheral wall, while the side parts are joined fast to the piston, and the slide members have the form of open-ended tubes and are guided in the side parts.

According to another aspect of the invention, the principle of the construction of the working chambers and of the slide members may be applied to crossed axis rotary piston machines having running surfaces extending at any desired angle to the axis of rotation of the machine.

Another construction according to the present invention provides for the axis of the slide members to extend at an angle to the radial plane.

According to the invention the tubular slide members may be so constructed that they are reinforced, for example by bridges or ribs, on their interior. In some cases it is advantageous for the slide members to be composed of at least two tubes disposed side by side.

One embodiment of the invention, moreover, consists in that the tubular slide member has at its end a seal associated with the running surface.

A further advantageous form of construction also consists in that the working chambers in their succession form an annular chamber subdivided by partitions, the width of the tubesor, in the case of circular piston tubes, their diameter-being greater than the respective dimension of the annular chamber measured in a plane laid through the axis of the machine and the axis of the tube, in such a manner that in the region in which the tubes cooperate with the peripheral wall carrying the partitions the tubes are adapted to said wall in a formlocking manner.

According to the invention, provision is also made for each slide member to be slidable under the control of a self-contained control cam adapted to the path of the running surface by guide elements connected to it and cooperating with the control cam, the latter and the guide elements being situated outside the working chambers. Moreover, control may also be effected by means of other kinematic elements. The control may also be so arranged that the control cam is formed as a curved slot in which running rollers engage, which rollers are mounted on the end of links 'rockably connected to the slide members. The control cam may be constructed as a curved slot only in the region of the zones of the running surface 3,348,494 Patented Oct. 24, 1967 ice which lie near the axis, While elsewhere it has the form of an outwardly curved path.

In some cases it is advantageous for the control cam to be made elastic in some regions of the running surface.

Another form of construction according to the invention provides for the sliding path of the slide members to be limited by stops in the case of guide elements which do not cooperate positively.

According to the invention a machine of this type may also be so arranged that at least two individual machines are disposed allochirally and combined to form a constructional unit which is a single annular chamber, and are operated after the style of a boxer engine having opposed pistons. A plurality of such machines may also be disposed on a common shaft, connecting apertures being provided between the axially adjoining tubular slide members.

In this connection it should be observed that the resulting free spaces on the working rear side of the tubular slide members may also be shaped as working chambers. An annular chamber formed in this manner is subdivided by mutually offset partitions.

Machines of this type could hitherto be constructed only for limited pressures of the operating or working medium. The utilization of high, and very high, pressures entails various problems. On the one hand the slide members must be very sturdy in order to have sufiicient strength to withstand the forces present at high pressures. If, however, the slide members are made of solid construction it has been found that after passing below the partitions separating the working chambers the slide member-s arein each case moved into the working chamber subjected to the pressure of the working medium. Thus, a solid slide member displaces working medium and at the same time is subjected to a force corresponding to its cross-section and to the pressure of the working medium, this force acting against its movement. In the case of the application of high and very high pressures these forces become very great, which circumstance has a particularly disadvantageous effect precisely because the application of high and very high pressures leads to small dimensions of the machine, which thus permits only limited dimensions for the parts necessary for moving the slide members. When high and very high pressures are applied, moreover, particularly stringent requirements are imposed on the seal between the pressure side and the unloaded side of the slide members.

A principal object of the invention is to provide a construction of a rotary piston machine (e.g., pump, or motor) of the above described type which complies with all recited requirements.

The invention achieves this object through the fact that the side parts are joined fast to the piston, and the slide members are guided in the side parts, and that the slide members are tubular and have open ends. Through this tubular construction the slide members are given.

serted into the working chamber the medium displaced by the slide member can flow off through the slide member and penetrate into the space freed by the slide member through its sliding movement. At both ends of the tube the pressure is, therefore, the same during the movement of the slide members, so that the moving forces are extremely small. The working medium is also not displaced into the working chamber by the slide member, but can flow off towards the rear end of the latter The tubular construction of the slide members provides the additional advantage that, despite their great power of resistance, they need have only a relatively small weight. Moreover, at the point of contact between the slide members and the side parts a relatively great sealing length is achieved, which circumstance provides a considerable advantage particularly at the high and very high pressures applied.

A parallel axis rotary piston machine is already known in which the side parts are joined fast to the piston and the slide members are guided in the side parts. In this known machine, however, the recesses formed in the side wall ares extended beyond the working chamber, so that fillers mounted at the sides of the slide members are necessary. In addition, the slide members in this known machine are constructed as simple solid discs and not as open tubes.

It is advantageous for the number of pistons in the motor or pump to amount to twice or a multiple of the number of partitions, because at high and very high pressures of the working medium this ensures that the forces occurring during the rotation of the rotor of the working machine, acting on the axis of rotation, and originating from the pressure of the working medium, cancel one another. In an asymmetrically constructed machine, on the other hand, very high rotating or even jumping radial forces would act on the axis or mounting of the rotor of the machine, and would jeopardize the practicability of a machine of this type.

The control cam used in accordance with the invention in the present machine ensures that the slide members are moved out of the region of the working chambers in the area of the running surface zones situated near the axis, in order to prevent the slide members from running onto said zones situated near the axis. In order to make full use of the available volume of the Working chambers, the radial movement of the slide members is effected in a relatively small angular region at the end of the working chambers.

Where in a known rotary piston engine slide members are joined to push-rods which are provided with running rollers at the end facing the axis, these lie against a central stationary cam under the action of compression springs. Corresponding to the path of the running surface the cam also has Zones situated near the axis and Zones remote from the axis. The smaller the angular region selected for the transition from a zone near the axis to a zone remote from the axis, or vice versa, the steeper is the rise of the control cam in this transition region and, in dependence thereon, the radial acceleration of the control slide member. The permissible acceleration of the slide members, and also the necessary transition curves in the path of the control cam, impose a lower limit on the angular region of the transition movement and an upper limit on the speed of the rotating piston. If a rotary piston machine of this type is used at high and very high pressures, the dimensions of such machines can be kept very small. However, the smaller the dimensions of the machine, the greater will be the slopes of the control curve if the displacing movement of the slide members is to be effected within a determined sector. Through the special construction of the control cam according to the invention it has now been made possible for the machine as a whole to be given very small dimensions without exceeding the permissible acceleration of the slide members.

In those cases where in the machines according to the invention the annular chamber which is formed by the successive working chambers is cut to its full depth in the constructional body carrying the pistons, and if at the same time use is made of pistons which are constructed as tubes open at both ends, then during the rotation said pistons will be constrained to move rhythmically in the direction of their axis out of a respective chamber, which is closed at the rear, into the annular chamber and out of the latter again. This is particularly when the axis of the tubes extends parallel to the axis of rotation of the machine, because if in such a case the constructional body carrying the partitions were to be connected at its end face to the constructional body carrying the pistons the pressure of the working medium would drive the two constructional bodies apart in the axial direction. Through the arrangement according to the invention, in which the constructional body carrying the partitions closes the annular chamber cylindrically, this is avoided.

Further features of the invention will be seen from the following description of exemplified embodiments, in conjunction with the drawings, and the claims.

In the accompanying diagrammatical drawings:

FIGURE 1 is a radial section through the center of the annular working chamber of the machine;

FIGURE 2 is an axial section through the machine illustrated in FIGURE 1;

FIGURE 3 is a cross-section through the embedding of a circular slide member in the side parts of the piston;

FIGURE 4 is a cross-section through a circular slide member which is reinforced by an internal rib;

FIGURE 5 is a cross-section of a slide member c0nsisting of two tubes disposed side by side;

FIGURE 6 is an axial section through a machine in which the axes of the tubes extend parallel to the axis of rotation of the machine;

FIGURE 7 is an axial section through a machine in which the working chambers forming an annular space are cut in the rotating part;

FIGURE 8 is a portion of the radial section on the line AA in FIGURE 7; and

FIGURE 9 illustrates an example of the assembly of two individual machines which are disposed in mirror image symmetry (i.e., allochirally) to one another and are combined to form a constructional unit.

FIGURES 1 to 3 illustrate a hydraulic motor in which a stator 1 is mounted fast or prevented from rotating by means of the stops or cams 2. Together with the piston hub 3, the stator 1 forms the annular space 4 which is subdivided by the partitions 5 mounted on the stator 1 and by the vane or slide members 6 carried by the piston hub 3. Two partitions 5 are provided, with each of which there are associated one inlet 7 and one outlet 8 for the working medium of the machine. The annular space accordingly has two working chambers. A total of four slide members are provided, whereby the effect is achieved that two working chambers are always acting. The number of pistons also amounts to twice the number of partitions, whereby the effect is achieved that the radial stresses are always mutually cancelled by the pressure of the working medium in the two working chambers. The slide members 6 are constituted by round tubes which are open at both ends.

The invention is, however, not restricted to the use of round tubes but it is also possible to use tubes having a square or rectangular cross-section.

The axis of the slide members 6 extends in the radial direction, and on the rotation of the piston 3 the slide members 6 are moved in the same direction out of the chambers '9 into the annular space 4 and out of the latter again.

The chamber 9 is closed at its rear, but it is also conceivable for two chambers of the machine which always work similarly to be connected together in each case; that is to say, in the exemplified embodiment illustrated in FIGURE 1 two chambers 9 lying opposite one another in each case. It can be seen from FIGURES 2 and 3 that the diameter of the slide members 6 is greater than the width 25 of the annular space 4. The increased sealing length corresponding to the dimension of the arc 2424 is thereby obtained for the seal between the spaces on both sides of the slide members 6. With the same width 25 of the annular space 4 and the diameter of the slide members, there would be only linear contact between the latter and the side walls of the annular space; that is to say, there would be only very short sealing length.

A greater length is also provided in the peripheral direction by the slide members for the seal between their front end face and the inner peripheral surface of the stator 1 than in the case of flat slide members of conventional construction.

The minimum sealing length existing here corresponds to twice the wall thickness of the slide member. The concept of providing the slide members with thick walls because of stressing by the high pressures of the working medium accordingly has at the same time the effect of improving the seal.

It is possibleand is, moreover, in accordance with the sense of the inventionto provide on the end face of the slide member, which cooperates with the inner peripheral wall surface of the stator 1 special material assisting the sealing action and/or sliding properties, such as for example oil-proof rubber, bearing metals, or the like, which material may also be inserted-into the slide member as a concentric ring.

From FIGURE 1, moreover, it can be seen that the length of the partitions 5, measured in the direction of movement, is greater at their point adjoining the bottom of the annular space than the diameter of the slide members. The effect thereby is achieved that when the slide members 6 .pass beneath the .partitions 5, as is shown by the slide members having horizontally directed axes, the inwardly directed end face of the partition 5 cooperates with the bottom peripheral surface of the annular space so as to provide a seal during the entire process of passing therebeneath. i

On the rotation of the piston hub the slide members 6 are moved out of the chambers 9 into the annular space 4 and out of the chambers 9 into the annular space 4 and out of the latter again. As the example illustrated shows, this is effected mechanically by means of the roller 11 joined by the member to the piston slide valve 6 and of the running surface 12. The movement could also be effected hydraulically or the' mechanical moving device could also be provided with hydraulic assistance.

In this arrapgementthe part 13 of the running surface 12, as illustrated for example for the upper half of the running surface in FIGURE 1, may be constructed elastically by meanspfi the underlayer 14 "of rubber or the like or be sprungby means of the springs 15. The effect is thereby achieved that thepiston slide valves 6 lie against the annular space peripheral surface of the stator 1 with pressure corresponding to the springing. 1 The movement of advance of the piston slide valves 6 into the annular space-4'may be limited by stops. The tips 16 of the slide and sealin-g'rings 17 disposed on the stator 1 and illustrated in FIGURE 2, or the boundary 18 of the recess 19 in the piston hub 3 may serve as stops for the driver bolt 20. Y Both stops may also be effective at the same time. This 1s of particular importance in the present case because, as already mentioned, very considerable forces may act on she stops through the high pressures of the working merum.

Whereas on the left-hand side of FIGURE 2 sealing rings 17, which at the same time also serve to mount the piston hub 3, are illustrated for the seals between the stator 1 and the piston hub 3, this sealing may also be ef fected in any other conceivable manner. On the right-hand side of FIGURE 2, annular bead seals 21 are accordingly illustrated. The piston hub 3 may likewise be mounted on the stator 1 in any other conceivable manner. From FIG- URES 1 and 2 it can be seen that the running surface 12 is disposed as far to the outside as possible, so that there are relatively gentle gradients for the curves.

In FIGURE 2 the running surface 12 is disposed at the top and the drive flange 22 for the piston hub 3 at the bottom. The running surface accordingly extends on the opposite side of the annular space 4 to the drive side, which results in particularly simple constructional dimensions. It would also be conceivable to provide running surfaces 12 one on each side of the annular space 4.

FIGURE 4 shows a cross-section through a circular slide member which is reinforced by a bridge extending in the direction of the main force axis.

This may be of importance because of the high pressures expected, particularly when the slide members are constructed with thin walls in order to reduce their weight, which is advantageous in high speed machines. The end faces of the slide members will in this case also be made with thick walls in order to obtain adequate sealing lengths.

. FIGURE 5 shows a cross-section through a slide member which is composed of two tubes disposed side by side in the direction of the width of the working chamber. The dimensions of the slide member in the peripheral direction are thereby shortened, which circumstance is important when it is required to subdivide the annular space into the largest possible number of Working chambers. The construction of the slide member from two tubes provides the advantage that in this case also, as in the case of the slide member consisting of a circular tube, the spaces in which the slide members move radially in the piston hub 3 can be produced by simply boring out the piston hub 3. It can likewise be seen in FIGURE 5 that the slide member composed of two tubes also engages on both sides in the side walls of the annular space, whereby the greatest possible sealing length is obtained. -As compared with the slide member consisting of only one tube, the respective arc length is naturally shorter. It is, however, conceivable to improve the sealing by means of additional sealing devices 23. Such measures could also be taken in the case of the slide member consisting of one tube.

FIGURE 6 illustrates an example of construction of a machine according to the invention, in which the axes of the piston tubes extend parallel to the axis of rotation of the machine. At the same timeit constitutes an example of the case where two ormore individual machines are structurally combined to form a machine unit. In this case also the chambers 9 of the two pistons 6, which work similarly to one another, are joined together, which is,

achieved by means of the bore 26.

Another form of construction is illustrated URES 7 and 8, wherein the stationary stator 27 is providedwith partitions 28. On both sides of the partitions 28 there are disposed the inlets 29 and outlets 30 for'the working medium. An annular chamber 32 is entirely out out. of the rotating part 31 of the machine. It is closed cylindrically by the stator 27. Axially movable tubular pistons 33 are inserted in the rotating part 31. On the rotation of the rotor 31 the pistons'33 are moved rhythmi-' cally out of the chamber 37 into the annular space 32 and out of the latter again by means of bolts 34 and rollers 35 through slotted links 36. In this way the path for the partitions 28 is rhythmically freed by constraint for the passage of the annular space 32.

According to one aspect of the invention, the width 40 of the piston tubes 33, measured in a plane passed through the axis of the machine and the axis of the piston, is greater than the respective dimension of the annular space, in this case the radial height 41. The effect is thereby achieved that between the tubular piston and the respective walls of the annular space there is not only linear guidance but also a great sealing length, viewed in the peripheral direction.

' As can be seen from FIGURE 8, the partitions 28 are made so thick that by the diameter 42 they. cover the passage apertures 38 which are provided in the wall of the annular space and through which the piston tube is moved into and out of the annular space. The recess 39 provided in the rotor 31 for the movement of the piston tube is' also covered, since its length 43 in the peripheral direction is substantially smaller than the thickness of the partition 28 measured in the peripheral direction.

FIGURE 9 illustrates an embodiment in which two single machines are disposed in an allochiral arrangement in relation to one another and are grouped together to form a structural unit in such a manner that they form a in FIG-.

common annular space. The annular space 32 is in this case disposed in the center of the machine. From both sides the pistons 33 are moved in opposite directions into and out of the annular space 32 after the style of a boxer engine. The pistons 33 encounter one another in the center of the annular space 32, and suitable means are adopted to provide a seal at the point of contact of the two pistons during the time in which they are in contact. As compared with the arrangement illustrated in FIGURE 6 the solution illustrated in FIGURE 9 provides the particular advantage that the distance which the pistons have t travel rhythmically is only half as great.

I claim:

1. A fluid displacement device, comprising a stator;

a rotor coaxially mounted within the stator and forming at least two working chambers between stator and rotor;

vane members associated with said working chambers and mounted in said rotor for movement into and out of said Working chambers;

the stator having radially or axially staggered peripheral running surfaces engageable by said vane members;

each vane member having the form of an open-ended tube one end of which engages said running surfaces;

the working chambers having side walls which are formed by integral flanges on the rotor between which flanges said tubular vane members are guided.

2. A device as defined in claim 1 in which the vane members are disposed in the rotor with their axes parallel to the axis of the rotor.

3. A device as defined in claim 1 in which the vane members are disposed in the rotor with their axes at an angle to the axis of the rotor.

4. A device as defined in claim 1 in which the running surfaces extend at any inclination to theaxis of the rotor.

5. A device as defined in claim 1 in which the tubular vane member is internally reinforced by a Web or rib.

6. A device as defined in claim 1 in which the vane member comprises at least two tubes disposed in juxtaposed relationship.

7. A device as defined in claim 1 in which the tubular vane member has a seal at that end thereof facing said running surfaces.

8. A device as defined in claim 1 in which the working chambers in succession form an annular space which is subdivided by partitions, while the cross-sectional dimension of the tubular vane members is greater than the respective dimension of the annular space, measured in a plane extending through the axis of the device and the axis of the vane member, whereby the vane members are adapted in a form-locking manner to the peripheral wall carrying the partitions in the region in which they cooperate with said peripheral wall.

9. A device as defined in claim 1 in which each tubular vane member is slidable in accordance with a self-contained control cam, adapted to the path of the running surface by means of guide elements joined to it and cooperating with the control cam, the control cam and the guide elements being situated outside the working chambers.

10. A device as defined in claim 9 in which said control cam is of elastic construction in individual regions on the running surfaces.

11. A device as defined in claim 1 in which the path of the tubular vane members is limited by stops in the case of guide elements not cooperating in a form-locking manner.

12. A device as defined in claim 7 in which at least two individual devices are allochirally disposed and are combined to form a common annular chamber and are operated with oppositely acting tubular vane members in the manner of a boxer engine.

13. A device as defined in claim 1 in which a plurality of the devices are disposed on a common shaft, connecting apertures being provided between the axially adjoining tubular vane members.

References Cited UNITED STATES PATENTS 1,051,360 1/1913 Wisdom 103136 1,603,437 10/1926 Wingquist 103136 1,974,122 9/1934 Phillips 103--136 2,125,988 8/1938 Broman 103136 2,356,916 8/1944 Brewster 103136 2,394,120 2/1946 Tucker 103136 2,957,429 10/ 1960 Fisk 103139 2,977,889 4/1961 Fisk 103139 2,980,030 4/ 1961 Couturier 91-126 3,154,293 10/1964 Matson 103136 DONLEY I. STOCKING, Primary Examiner.

WILBUR I. GOODLIN, Examiner.

Claims

1. A FLUID DISPLACEMENT DEVICE, COMPRISING A STATOR; A ROTOR COAXIALLY MOUNTED WITHIN THE STATOR AND FORMING AT LEAST TWO WORKING CHAMBERS BETWEEN STATOR AND ROTOR; VANE MEMBERS ASSOCIATED WITH SAID WORKING CHAMBERS AND MOUNTED IN SAID ROTOR FOR MOVEMENT INTO AND OUT OF SAID WORKING CHAMBERS; THE STATOR HAVING RADIALLY OR AXIALLY STAGGERED PERIPHERAL RUNNING SURFACES ENGAGEABLE BY SAID VANE MEMBERS; EACH VANE MEMBER HAVING THE FORM OF AN OPEN-ENDED TUBE ONE END OF WHICH ENGAGES SAID RUNNING SURFACES; THE WORKING CHAMBERS HAVING SIDE WALLS WHICH ARE FORMED BY INTEGRAL FLANGES ON THE ROTOR BETWEEN WHICH FLANGES SAID TUBULAR VANE MEMBERS ARE GUIDED.