US3206109A

US3206109A - Fluid cooling means for rotors of rotary mechanisms

Info

Publication number: US3206109A
Application number: US344396A
Authority: US
Inventors: Paschke Hanns-Dieter
Original assignee: Wankel GmbH; NSU Motorenwerke AG
Current assignee: Wankel GmbH; Audi AG
Priority date: 1963-03-07
Filing date: 1964-02-12
Publication date: 1965-09-14
Anticipated expiration: 1982-09-14
Also published as: GB1027983A; DE1224982B

Description

Sept. 14, 1965 HANNS-DIETER PASCHKE 3,206,109

FLUID COOLING MEANS FOR ROTOR-S OF ROTARY MECHANISMS Filed Feb. 12, 1964 s Sheets-Sheet 1 INVENTOR HANNEI-DIETER F'AEIEHKE ATT E1 Sept. 14, 1965 HANNS-DIETER PASCHKE 3,205,109

FLUID COOLING MEANS FOR ROTORS 0F ROTARY MECHANISMS Filed Feb. 12, 1964 5 Sheets-Sheet 2 INVENTOR HANNEl-DIETER F'AEEHKE BY I S Q ATTDRNEY p 1955 HANNS-DIETER PASCHKE 3,206,109

FLUID COOLING MEANS FOR ROTORS OF ROTARY MECHANISMS Filed Feb. 12, 1964 5 SheetsSheet 3 INVENTOR HANNE-DIETER PAEEHKE ATTDRNEY Se t. 14, 1965 HANNS-DIETER PASCHKE 3, 06,

FLUID COOLING MEANS FOR ROTORS OF ROTARY MECHANISMS Filed Feb. 12, 1964 5 Sheets-Sheet 4 INVENTOR HANNEl-D lliTElFi F'AEIEHKE BY l g ATTURNEY Sept. 14, 1965 HANNS-DIETER PASCHKE 3,

FLUID COOLING MEANS FOR ROTORS OF ROTARY MECHANISMS Filed Feb. 12, 1964 5 Sheets-Sheet 5 INVENTOR HANN'Ex-DIETER F'AEJEHKE ATTORNEY United States Patent 3,206,109 FLUID COOLING MEANS FOR ROTORS 0F ROTARY MECHANISMS Harms-Dieter Paschke, Neckarsulm, Wurttemberg, Germany, assignor to NSU Motorenwerke Alrtiengesellschaft, Neclrarsulm, Germany, and Wankel G.m.b.H., Lindau (Bodensee), Germany Filed Feb. 12, 1964, Ser. No. 344,396 Claims priority, application Germany, Mar. 7, 1963, N 22,853 Claims. (CL 230-410) This invention relates to rotary mechanisms having fluid cooling means for the rotors of said mechanisms and in particular to an improved means for circulating the cooling fluid through said rotor.

The present invention is directed to improvement in the fluid cooling means described in US. Patent 3,102,682, issued on September 3, 1963 and assigned to the same assignee as the present invention. As explained in said patent, the rotor of the rotary mechanism is mounted so as to rotate on a rotating eccentric and makes a planetary circulating movement relative to the external housing or outer body. By this arrangement the rotor is acted upon by acceleration forces which periodically reverse in direction and therefore any cooling liquid within the rotor and movable therewith is subject to the same periodic reversal of the acceleration forces. The rotor of the present invention is provided with a plurality of separate circumferentially-spaced internal compartments with openings for supplying and draining the cooling fluid from said compartments. When the acceleration forces on a particular rotor compartment are directed radially outwardly the cooling liquid is thrown into said compartments through an inlet opening and upon reversal of the acceleration forces the cooling liquid is thrown radially inwardly and out of the outlet opening of said compartment. As the coolant flows out of the outlet opening it can be collected for recirculation through the interior of the rotor after suitable removal of the heat from the cooling fluid.

It has been found in a construction of the type illustrated by the aforementioned patent, that a considerable amount of cooling fluid is required for maintaining the circulation of the cooling fluid through the rotor. Due to the relatively rapid circulation of the cooling fluid through the rotor in the above described construction, the effective use of the fluid for cooling during a single pass through a cooling compartment is not completely utilized and therefore it will be apparent that the amount of cooling fluid circulated through the rotor is greater than necessary.

The present invention has for its prime object providing means for reducing the amount of cooling medium circulated through the interior of the rotor while maintaining maximum cooling effectiveness of the rotor interior walls. The invention is generally carried out by providing a plurality of circumferentially spaced cooling compartments in the interior of the rotor and providing openings thereto for supplying and draining the cooling fluid with said openings being so located with respect to the direction of the circulating fluid, when the acceleration forces acting on a particular rotor compartment are directed radially inwardly, the cooling fluid within the rotor compartment will not be completely drained from 3,206,109 Patent-ed Sept. 14, 1965 said compartment but some of said cooling fluid will be mixed with incoming cooling fluid so as to increase the volume of cooling fluid available for cooling the rotor Walls. By this means the total volume of oil within each rotor compartment will be maintained without requiring a total increase in the volume of oil required for circulation through the entire rotor interior.

Accordingly, it is an object of the invention to provide a novel and improved cooling means for the interior of the rotor in a rotary mechanism.

It is another object of the invention to provide a novel and improved fluid cooling means for the interior of a rotor in a rotary mechanism wherein the amount of cooling fluid required for cooling said rotor interior is substantially reduced over previous constructions having cooling means for r-otor interiors.

It is an additional object of the invention to provide a novel and improved means for supplying and draining cooling fluid from the interior of the rotor in a rotary mechanism.

Other objects and advantages of the invention will become apparent upon reading the following detailed description of the invention with the accompanying drawings wherein;

FIG. 1 is an axial sectional view of a rotary mechanism embodying the invention,

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1 and diagrammatically illustrating the cooling fluid in the cooling compartments,

FIGS. 3-8 are views similar to FIG. 2 and diagrammatically illustrating the oil circulation in portions of the interior rotor at different states of rotor rotation, and

FIG. 9 is an axial sectional view of the rotary mechanism illustrating another embodiment of the invention.

Referring now to FIGS. 1 and 2, there is shown therein a rotary mechanism being preferably in the form of a rotary combustion engine although the invention may be embodied in other types of rotary mechanisms such as fluid pumps, fluid motors or the like. The rotary mechanism 10 is composed of an outer body including a pair of

end walls

12 and 14 interconnected by a peripheral wall 16 to form a cavity therein. The profile of the inner surface 18 of the outer body peripheral Wall 16 is preferably basically a two-lobed epitrochoid (FIG. 2). A shaft 20 is mounted coaxially with the cavity formed by the outer body and is rotatable relative to said outer body. The shaft 20 has an eccentric portion 22 formed thereon upon which is rotatably mounted a rotor 24 having a multilobed profile and whose outer peripheral wall 26 forms a plurality of circumferentially-spaced apex portions for sealing engagement with the inner surface 18 of the outer body peripheral wall 16. Preferably, as illustrated, the rotor has three apex portions and the multilobed cavity of the outer body has two-lobed portions although other combinations are possible. Seal strips 28 are provided in each of the apex portions of the rotor 24 and extend from one end face of the rotor to the other end face and are in continuous sealing engagement with the inner surface 18 of the outer body peripheral wall 16 to form a plurality of working chambers 30 which during relative rotation vary in volume. The apex seals 28 mate with intermediate seal bodies 32 also provided in each of the apex portions of the rotor and with side seals 34 provided in each of the

end walls

36 and 38, re-

spectively, to provide a continuous seal adjacent the periphery of the rotor and on each side thereof.

As further illustrated, the rotor 26 is supported on the eccentric portion 22 by a sleeve-type bearing 40. Suitable bearings 42 are also provided for supporting the rotating shaft 20 in the outer body housing and surrounding bearings 42 on one side of the mechanism is an externally toothed gear 44 which meshes with an internally toothed gear 46 either supported by the rotor end wall 36 or made integral with a portion of said end wall 36. The

gears

42 and 44 serve to help rotatably position the rotor with respect to the epitrochoidal surface of the peripheral wall 16 but do not drive or impart torque to the shaft 20. In the embodiment illustrated having a two-lobed epitrochoid and a three-lobed rotor, the ratio of rotation of the shaft with respect to the rotor is 3:1 wherein for each rotation of the rotor about is axis the shaft rotates three times about its axis with the axes of the shaft and rotor being designated as M M in FIG. 2, respectively. An intake port 48 is provided for admitting air and/or a fuel-air mixture, an ignition means 50 may be provided for igniting the mixture and an exhaust port 52 is provided for expelling the burnt gases so that the stages of intake, compression, expansion and exhaust may be carried out.

In order to supply a cooling fluid for cooling the interior walls of the rotor, an inlet passageway 54 may be provided in the end wall 12 of the outer body and may be suitably connected to a pump and fluid reservoir (not shown) for pumping the fluid through a passageway 54 and into an annular cavity 56 between the rotor and the housing end wall 12. As further illustrated in the drawings, particularly with reference to FIG. 2, the rotor 24 is made hollow and is provided with a plurality of axially-extending interior walls or partitions 60 with said partitions 69 being circumferentially-spaced around the rotor 24 to divide the rotor interior into a plurality of cirumferentially-spaced cooling compartments 58. The partitions 69 extend in an avial direction from one end wall 36 of the rotor to the opposite end wall 38 and in a radial direction from the rotor peripheral wall 26 radially inward to the rotor hub or the radially interior wall 62 of the rotor. In order to supply the cooling fluid to the interior of the rotor or to the rotor compartment 58 an inlet passageway 64 is provided in the wall 36 of the rotor and has an inlet opening 66 to each of the compartments 58. An oulet passageway 68 for each compartment is provided in the end wall 38 of the rotor and has an outlet opening '79 communicating with the interior of each compartment 58. As will be explained in greater detail below, the relationship between the inlet opening 66 and the outlet openings 70 for each rotor compartment 58 with respect to the

rotor end walls

36 and 38 is significant to the operation of the invention.

During relative rotation of the rotor 24 and the eccentric portion 22, acceleration forces are generated which act substantially in the direction of maximum eccentricity of the eccentric portion 22. As will be apparent from FIG. 2, with the acceleration forces acting radially outwardly with respect to some of the rotor compartments, 'or upwardly in said FIG. 2, any fluid present in the annular cavity 56 or in the rotor compartment will be thrown radially outwardly in response to the acceleration forces and the fluid on the opposite side of the mechanism or the downward side will be thrown radially inwardly with respect to the rotor compartments 58. As the rotor rotates relative to the outer body, the acceleration forces will periodically change direction with respect to said rotor. Therefore, with respect to the rotor compartments 58 it will be seen that the acceleration forces successively change direction and that at one instant the fluid will be acted upon by radially outwardly directed forces and that at another instant the fluid will be acted upon by the radially inwardly directed forces. During operation of the mechanism, the fluid present in the cavity 56 will therefore be thrown radially outward into the inlet passageway 64 and out of the inlet passageway opening 66 to the compartments 58 and during a reversal of the direction of the acceleration forces the fluid in the compartments 58 will then be thrown radially inwardly and into the outlet opening 70 and out of the outlet passageway 68 and will drain into an annular collection scoop member 72 to which is connected an outlet passageway 74 in the outer body end wall 14 for draining the fluid out of the rotary mechanism and to a suitable cooling means. The cooling fluid may then be recirculated through the rotor so that the same cooling fluid may be used over again. Annular seals 76 are provided between each of the

rotor end walls

36 and 38 and the

housing end walls

12 and 14, respectively, to prevent leakage of the cooling fluid radially outwardly into the working chambers 30 of the rotary mechanism.

In the prior embodiments of cooling fluid mechanisms for the interior of rotors in rotary mechanisms the relationship between the inlet and outlet openings for the rotor compartments was such that when the cooling fluid was acted upon by radially inwardly directed acceleration forces substantially all of the cooling fluid in a rotor compartment was drained out of said compartment. During the filling portion of the cycle therefore a relatively large amount of cooling fluid was then required to refill the compartment in order to provide maximum effective cooling. It will be apparent that in these systems a relatively large total amount of cooling fluid is required in order to provide for the substantially complete exchange of the cooling fluid in each of the compartments. The present invention, however, overcomes this disadvantage by providing a relationship between the inlet and outlet openings for each compartment wherein the cooling fluid is not completely drained from each compartment so that a lesser amount is required during the filling cycle portion which therefore results in a lesser total amount of cooling fluid being required to maintain maximum cooling of the rotor interior. With reference to FIG. 1, it will be seen that the inlet opening 66 and the outlet opening 70 are disposed so that they are spaced radially outwardly a substantial distance from the radially innermost portion of their respective rotor compartment 58. By this means, when the acceleration forces are directed radially inwardly for draining the cooling fluid from the compartments 58, some of the cooling fluid will drain through the inlet opening 66 into the passageway 64 where it will mix with supply fluid from the annular cavity 56 which is at a slightly higher pressure due to the pump supply through the passageway 54 and therefore at least a portion of the cooling fluid will be prevented from draining from the compartments 58. During the draining portion of the cycle, as a result of the location of the inlet opening 66 and the outlet opening 70, a residual amount of cooling fluid will be left in each of the rotor compartments 58 below the level of said inlet opening 66 and said outlet opening 70. Therefore, there will always be some cooling fluid remaining in the rotor compartments for circulation over the walls thereof and a lesser amount of cooling fluid will be required to fill each of said rotor compartments during the filling portion of the cycle.

Referring now to FIGS. 2-8, as seen therein, theoutlet openings 70 are disposed so that they are spaced from the partitions 60 in a circumferential direction and spaced from the rotor peripheral wall 26 and the rotor inner wall 62 in a radial direction. Although not shown in said figures, the openings 66 for supplying cooling fluid to the compartments 58 are similarly disposed with respect to the compartment walls of said compartments'SS. As described above, this arrangement results in a residual amount of cooling fluid remaining behind in each chamher during the drainage portion of the cycle. This occurs because some of the cooling fluid will be thrown radially inwardly beyond the openings 66 and 70 and will not drain from the compartments since at this time the out let and inlet opening will be radially outward from this portion of the cooling fluid. It will be apparent that this would not be the case if the inlet and outlet openings 66 and 70 were disposed so that they were adjacent the most radially inward portion of the compartment. Again referring to FIGS. 2-8, the circulation of the cooling fluid in the rotary compartments 58 is diagrammatically illustrated for different stages of rotor rotation. In FIG. 2 two

compartments

58a and 58b are shown at a stage of rotation wherein such compartments are substantially at the position of maximum eccentricity of the shaft rotation and the cooling fluid therein is shown during the supply phase. The cooling fluid at this time is thrown into said compartments and collects adjacent the inner surface the rotor peripheral Wall 26. In FIGS. 3 and 4 the cooling fluid will be seen as rotating around the inner surfaces of the walls of the compartment 58 in the direction of rotor rotation until when the rotor has reached the position shown in FIG. 5 wherein the point of maximum eccentricity of the shaft is opposite to the

compartments

58a and 58b, the cooling fluid will then be thrown radially inwardly at which time a major portion of the cooling fluid will be drained out through the opening 70 and a portion through the opening 66. However, it will be noted that a residual amount of cooling fluid will remain in the

compartments

58a and 58b even when the acceleration forces are directed radially inward, as illustrated. While FIG. 2 shows the supply phase of the

compartments

58a and 58b, FIG. 5 shows the drainage phase of such compartments. As previously stated the cooling fluid circulates around the interior walls of the compartments in the direction of rotor rotation so that the surfaces will be cooled by the contact with the cooling fluid. The residual quantity of fluid remaining in the compartments 58a and 5812 will, during further rotation of the rotor, wash over the surfaces of the

compartments

58a and 58b and thereby cool the surfaces until a new supply of cooling fluid is supplied as shown in FIGS. 7 and 8. It will also be apparent that these surfaces would not be cooled during this portion of rotation of the rotor if the compartments were completely emptied during this phase of rotor rotation illustrated in FIG. 5. It will be understood that each of the compartments of the rotor operates in the same manner as the compartments 58a and 5811 which are used only as examples.

FIG. 9 shows a second embodiment of the invention which is substantially identical to the embodiment illustrated in FIG. 1 and bears similar numeral designations. However, in the embodiment of FIG. 9 at least some of the compartments 58' have no outlet passageway 68 and outlet openings 70' so that during the drainage phase of the cycle, any drainage from these compartments will have to flow back through the inlet opening 66'. Therefore, a greater amount of residual cooling fluid will remain in these compartments and that which drains out of these compartments will mix with the incoming supply of cooling fluid from the cooling supply cavity 56'. It should be understood however, that some of the compartments must be provided with outflow openings 70 as in the embodiment of FIG. 1, to provide for a complete exchange of the cooling fluid during operation of the mechanism.

From the above description it will be seen that a novel and improved cooling mechanism is provided for the interior of the rotor in a rotary mechanism. By use of the mechanism of the invention a substantially smaller amount of cooling fluid is required to cool the rotor in terior while still maintaining maximum cooling effectiveness. Further, through the present invention, it is possible not only to use a smaller quantity of cooling fluid but the invention also has the advantage that a smaller supply reservoir, cooling recirculating mechanism and oil pump may be used which reduces the weight of the entire cooling unit.

While the invention has been specifically set forth in its preferred embodiments in the above description, it will be obvious to those skilled in the art, after understanding the invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. It is intended in the appended claims to cover all such modifications.

What is claimed is:

1. A rotary mechanism having an outer body comprising a peripheral wall interconnected with a pair of parallel end walls defining a cavity; a rotatable shaft mounted in said outer body coaxial with the axis of said outer body peripheral wall and having an eccentric portion; a rotor rotatably supported on said eccentric portion for rotation about its axis while describing a planetary motion relative to the axis of said outer body peripheral wall whereby acceleration forces are generated in said rotor which successively change direction relative to said rotor, said rotor having a hub portion and a peripheral wall interconnected with a pair of parallel end walls defining a cavity therein with said cavity having a plurality of circumferentially-spaced, axially-extending partitions dividing said cavity into a plurality of compartments over the entire circumference thereof; an inlet opening for each of said compartments in one of said rotor end walls for supplying a cooling liquid to each said compartment when the acceleration forces are directed substantially radially outwardly relative to each said compartment, said inlet opening being disposed in the region of the radially inner portion of its associated compartment but spaced radially outwardly a substantial distance from the radially innermost portion of said compartment; and a single outlet opening for at least some of said compartments in the other of said rotor end walls for draining cooling liquid from said compartments when the acceleration forces are directed substantially radially inwardly relative to said compartments, and said outlet opening being disposed closer to the radially innermost portion of its compartment than its radially outer portion but spaced radially outwardly a substantial distance from the radially innermost portion of its compartment such that at least some of said cooling liquid will drain through said inlet opening for mixture with a fresh supply of cooling liquid for said rotor compartment.

2. A rotary mechanism as recited in claim 1 wherein said inlet opening and said outlet opening are circumferentially-spaced from the partitions forming each said com partment so that due to the spacing of said openings relative to the walls of said compartments a residual amount of cooling liquid will remain in each said compartment after the remainder of said cooling liquid is drained through said openings.

3. A rotary mechanism as recited in claim 1 wherein each of said rotor compartments is provided with an inlet and an outlet opening.

4. A rotary mechanism as recited in claim 1 wherein said inlet and outlet openings are disposed substantially at the same level with respect to said rotor end walls.

5. A rotary mechanism having an outer body comprising a peripheral wall interconnected with a pair of parallel end walls defining a cavity; a rotatable shaft mounted in said outer body coaxial with the axis of said outer body peripheral wall and having an eccentric portion; a rotor rotatably supported on said eccentric portion for rotation about its axis while describing a planetary motion relative to the axis of said outer body peripheral wall whereby acceleration forces are generated in said rotor which successively change direction relative to said rotor, said rotor having a hub portion and a peripheral wall interconnected with a pair of parallel end Walls defining a cavity therein with said cavity having a plurality of circumferentially-spaced, axially-extending partitions dividing said cavity into a plurality of compartments over the entire circumference thereof; an inlet opening for each of said compartments in one of said rotor end walls for supplying a cooling liquid to each said compartment when the acceleration forces are directed substantially radially outwardly relative to each said compartment, and a single outlet opening for at least some of said compartments in the other of said rotor end Walls for draining cooling liquid from said compartments when the acceleration forces are directed substantially radially inwardly relative to said compartments, said inlet opening and said outlet opening being disposed closer to the radially innermost portion of its compartment than its radially outer portion but spaced radially outwardly from the radially innermost portion of their compartment and being spaced from the partitions forming said compartment such that a resid- References Cited by the Examiner UNITED STATES PATENTS 9/63 Paschke 2302l0 X 12/63 Bentele 230-210 10 LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner.

Claims

1. A ROTARY MECHANISM HAVING AN OUTER BODY COMPRISING A PERIPHERAL WALL INTERCONNECTED WITH A PAIR OF PARALLEL END WALLS DEFINING A CAVITY; A ROTATABLE SHAFT MOUNTED IN SAID OUTER BODY COAXIAL WITH THE AXIS OF SAID OUTER BODY PERIPHERAL WALL AND HAVING AN ECCENTRIC PORTION; A ROTOR ROTATABLY SUPPORTED ON SAID ECCENTRIC PORTION FOR ROTATION ABOUT ITS AXIS WHILE DESCRIBING A PLANETARY MOTION RELATIVE TO THE AXIS OF SAID OUTER BODY PERIPHERAL WALL WHEREBY ACCELERATION FORCES ARE GENERATED IN SAID ROTOR WHICH SUCCESSIVELY CHANGE DIRECTION RELATIVE TO SAID ROTOR, SAID ROTOR HAVING A HUB PORTION AND A PERIPHERAL WALL INTERCONNECTED WITH A PAIR OF PARALLEL END WALLS DEFINING A CAVITY THEREIN WITH SAID CAVITY HAVING A PLURALITY OF CIRCUMFERENTIALLY-SPACED, AXIALLY-EXTENDING PARTITIONS DIVIDING SAID CAVITY INTO A PLURALITY OF COMPARTMENTS OVER THE ENTIRE CIRCUMFERENCE THEREOF; AN INLET OPENING FOR EACH OF SAID COMPARTMENTS IN ONE OF SAID ROTOR END WALLS FOR SUPPLYING A COOLING LIQUID TO EACH SAID COMPARTMENT WHEN THE ACCELERATION FORCES ARE DIRECTED SUBSTANTIALLY RADIALLY OUTWARDLY RELATIVE TO EACH SAID COMPARTMENT, SAID INLET OPENING BEING DISPOSED IN THE REGION OF THE RADIALLY INNER PORTION OF ITS ASSOCIATED COMPARTMENT BUT SPACED RADIALLY OUTWARDLY A SUBSTANTIAL DISTANCE FROM THE RADIALLY INNERMOST PORTION OF SAID COMPARTMENT; AND A SINGLE OUTLET OPENING FOR AT LEAST SOME OF SAID COMPARTMENTS IN THE OTHER OF SAID ROTOR END WALLS FOR DRAINING COOLING LIQUID FROM SAID COMPARTMENTS WHEN THE ACCELERATION FORCES ARE DIRECTED SUBSTANTIALLY RADIALLY INWARDLY RELATIVE TO SAID COMPARTMENTS, AND SAID OUTLET OPENING BEING DISPOSED CLOSER TO THE RADIALLY INNERMOST PORTION OF ITS COMPARTMENT THAN ITS RADIALLY OUTER PORTION BUT SPACED RADIALLY OUTWARDLY A SUBSTANTIAL DISTANCE FROM THE RADIALLY INNERMOST PORTION OF ITS COMPARTMENT SUCH THAT AT LEAST SOME OF SAID COOLING LIQUID WILL DRAIN THROUGH SAID INLET OPENING FOR MIXTURE WITH A FRESH SUPPLY FOR COOLING LIQUID FOR SAID ROTOR COMPARTMENT.