US3322335A

US3322335A - Vane seal and bearing for rotary compressors

Info

Publication number: US3322335A
Application number: US484812A
Authority: US
Inventors: Donald W Partain
Original assignee: TRW Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1965-09-03
Filing date: 1965-09-03
Publication date: 1967-05-30
Anticipated expiration: 1984-05-30

Description

May 30, 1967 D. w. PARTAIN 3,322,335

VANE SEAL AND BEARING FOR ROTARY COMPRESSORS 2 Sheets-Sheet 1 Filed Sept. 5, 1965 INVENTOR. 0oA/4L0 Vl/ Pier/WV HW% ATTORNEYS May 30, 1967 D. w. PARTAIN 3,322,335 VANE SEAL AND BEARING FOR ROTARY COMPRBSSORS 2 Sheets-$heet 23 Filed Sept. 3, 1965 g m/ 31 s \Z\\\ x a INVENTOR. DOA/440 W EI/QTA/N ATTORNEYS United States Patent 3,322,335 VANE SEAL AND BEARING FOR RDTARY CUMPRESSURS Donald W. Partain, Rocky River, @hio, assignor to 111W Inc, Cleveland, Ulric, a corporation of Ghio Filed Sept. 3, 1965, 501'. No. 484,312 7 Claims. (Cl. Mil-15?) This invention relates to improvements in compressors and more particularly relates to improvements in the vane seals for compressors of the rotary vane type.

In rotary compressors or pumps of the vane type, the vanes are mounted for rotatable movement along the pumping chamber about an axis coaxial with the axis of the chamber and are rotatably driven by a rotor, rotatable about an axis eccentric of the axis of rotation of the vanes. Vane bearings and seals having guide slots extending therethrough and having generally cylindrical outer surfaces provide slidable guides for the vanes in the slots of the bearings and are mounted in facing concave recesses in the rotor for pivotal movement with respect thereto in accordance with angular movement of the vanes. The vane bearings form sealing glands as well as hearings, and are usually made from a suitable plastic material and are subjected to considerable wear during operation of the pump particularly along the flat surfaces of the guide slots for the vanes, with a resultant leakage past the vanes.

A principal object of the invention, therefore, is to provide an improved motor vane bearing seal so arranged as to continually take up the vane and compensate for wear on the seal.

A still further object of the invention is to provide a wear take up means for the vane slots for the cylindrical vane bearing seals of the rotary vane air compressor, in the form of a wear take-up bar recessed in the vane seal bearing, and yieldably biased into intimate contact with the leading side of the vane.

A still further object of the invention is to provide an improved form of vane bearing seal for a rotary compressor and the like having a spring loaded wear take-up bar incorporated as part of the vane bearing seal on the leading side of the seal and positively pushed into contact with the vane by wear take-up springs having yieldable engagement with opposite ends of the bar.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings Wherein:

FIGURE 1 is a fragmentary longitudinal sectional view taken through a rotary compressor constructed in accordance with the principles of the present invention looking at the vane and bearing seal towards the leading side of the compressor;

FIGURE 2 is a fragmentary vertical sectional view of the compressor taken substantially along line 11-11 of FIGURE 1;

FIGURE 3 is an exploded View of the vane bearing seal;

FIGURE 4 is a longitudinal sectional view taken through the vane bearing seal, showing the vane slidably guided therein; and

FIGURE 5 is a fragmentary transverse sectional view taken through the vane seal bearing shown in FIGURES 3 and 4.

In the embodiment of the invention illustrated in FIG- URES 1 and 2 of the drawings, a rotary vane pump is shown as including a pump housing 11 having an interior cylindrical wall 12. The interior cylindrical wall 12 extends between an integrally formed end wall 13 of the pump and an opposite end wall 14, formed by the inner end face of a removable end cap 15. Within the com- 3 ,322,335 Patented May 30, 1967 pressor chamber formed by the cylindrical wall 12 and the

end Walls

13 and 14 is an annular rotor 16, mounted for rotation about an axis eccentric of the axis about which the cylindrical wall 12 is struck. The rotor 16 has an end disk 17 recessed within the end wall 13 and has an integrally formed shaft 18 extending outwardly through the wall 13 and journalled in the end wall of the housing on an anti-friction bearing 11'. The shaft 18 is shown as having a pulley 20 on its outer end, which may be driven from a suitable motor (not shown) in a conventional manner.

Mounted in the end cap 15 of the pump housing is a stationary shaft 21 extending inwardly of said housing concentric with the axis of rotation of the shaft 18 and forming a bearing mounting for the opposite end of the rotor from the shaft 18. Needle bearings 22 form a sup port for the rotor on the shaft 21.

The stationary shaft 21 is shown as having an integrally formed shaft 23 extending therefrom across the pumping chamber and eccentric of the axis of rotation of the shaft 18 and the rotor 16. The stationary shaft 23 forms a pivotal mounting for three circumferentially spaced

vanes

25, 25 rotatably mounted in the shaft 23 on

needle bearings

26, 26.

The rotor 16 is shown as having three facing generally semi-cylindrical arcuate recesses 27 therein, spaced apart. The recesses 27 may be formed by drilling to form bores open to opposite sides of the rotor. Cylin drical vane seal bearings 29 are mounted in the

arcuate recesses

27, 27 and have slots 31 extending diametrically therethrough forming guide slots for the vanes 25 and effecting rotatable movement of the vanes 25 about the wall 12 of the pumping chamber by rotation of the rotor 16. The vane seal bearings not only serve to seal and form guides for the

vanes

25, 25, but also seal the pumping chamber extending between the exterior of the rotor 16 and the internal cylindrical wall 12 between an intake port 33 and an outlet port '32.

The intake port 33, is shown in FIGURE 2 as being angularly spaced from the region of lap of the rotor 16 with the cylindrical wall 12 of the pumping chamber. The outlet port 32 leads from the pumping chamber on the incoming side of the region of lap of the rotor 16 with the cylindrical wall of the pumping chamber. The rotor 16 acts as a seal in the lap space between the intake and outlet ports.

Referring now in particular to the novel vane seal bearing of the invention, each vane seal bearing 29 may be made from a suitable plastic sealing and bearing mate rial, a suitable material being a phenolic resin, such as Bakelite. Other suitable materials may be a graphite and Teflon impregnated phenolic material; a sintered nylon and graphite oil impregnated material; a sintered Teflon and molybdenum disulfide; and a sintered epoxy resin and molybdenum disulfide. The foregoing materials are all commercial materials and have proved to be suitable bearing and sealing materials and any material may be used, although a preferred material is Bakelite.

Each vane seal hearing has reduced diameter opposite

ends

35, 35 rotatably carried in opposite end plates of the rotor. A slot 36 extends generally radially through the vane bearing seal 29 on the leading side thereof and perpendicular to and opening into the slot 30. The slot 36 forms a guide slot for a wear take-up bar 37.

The wear take-up bar 37 may be made from the same material as the vane seal bearing 29 and is shown as being generally rectangular in cross-section having an outer face 33 conforming to the contour of the preriphery of the seal bearing 2% and having an inner sealing face 39 engageable with the vane 25, slidably guided in the slot 30. The take-up bar 37 extends for substantially the length of the slot 36 and has right angled recessed end portions 40, on the opposite side thereof from the bearing face 39 and adapted to be engaged by engaging end portions 41 of springs 43, pressing the wear take-up bar 37 into sealing contact with the vane to maintain a bearing and seal in engagement with the vane as the surface of the slot wears, regardless of wear on the wear take-up bar.

Each spring 43 is shown as being a leaf spring of a generally C or U-shaped formation. As shown in FIGURE 3 of the drawings the reduced diameter portions 35, of the vane seal bearings 29 have

slots

44 and 45, extending along opposite sides thereof in alignment with the slot 36 and connected together by a slot 46 extending along the end of the reduced diameter portion. The

slots

44, 45 and 46 form a recess to recess the base and legs of the leaf spring 43 inwardly of the outer surfaces of the reduced diameter portions 35 of the vane seal hearing. The slots 45 are inwardly stepped adjacent the wear take-up bar 37 to accommodate freedom of movement of outer ends of legs 47 of the springs to maintain the engaging end portions 41 of the springs into engagement with the recessed end portions 40, 4-0 of the take-up bar 37, to take up for wear on the bar and slot for the full extent of travel of the springs.

The wear take-up bar 37 is thus positively biased into contact with the vane by the

engaging end portions

41, 41 of the

springs

43, 43 to take up for wear on the fiat vane seal bearing surfaces extending along opposite sides of the vane and thereby maintain the vane seal hearing assembly tight throughout the life of the compressor, and materially reduce leakage through the vane slot.

While I have herein shown and described one form in which the invention may be embodied, it may readily be understood that various variations and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts thereof.

I claim as my invention:

1. In a rotary vane compressor,

a housing having an interior cylindrical wall and parallel spaced end walls,

an annular rotor journalled within said housing for rotation about an axis eccentric of the axial center thereof,

a plurality of vanes extending radially of the axial center of said housing and mounted for pivotal movement about said axis,

vane seal bearings pivotally mounted in said rotor and each having a vane guide slot extending therethrough forming a guide and seal for an associated vane,

said vane seal bearings each having reduced diameter opposite end portions pivotally mounted in said rotor and each having a radial slot on the leading side thereof opening to said vane guide slot,

said reduced diameter end portions having recessed portions extending diametrically along the ends thereof and inwardly along opposite sides thereof,

one of said recessed portions opening to said radial slot,

a wear take-up bar slidably mounted in said radial slot and U-shaped springs recessed within said recessed portions of said reduced diameter ends of said vane seal bearings,

and having engaging end portions extending into said radial slot and having bearing engagement with opposite ends of said wear take-up bar for yieldably biasing said wear take-up bar into sealing engagement with said vane.

2. A rotary vane compressor in accordance with claim ll,

wherein the recessed portions opening to the radial slot form outer continuations of the radial slot and are radially inwardly stepped adjacent the slot, to accommodate the engaging end portions of said leaf springs to take up for wear on said take-up bar and slot for the full extent of travel thereof.

3. A rotary vane compressor in accordance with claim 1,

wherein the wear take-up bar has inwardly stepped opposite outer end portions engaged by the engaging end portions of the leaf spring wherein the engaging end portions of the leaf springs extend inwardly of the planes of the legs of the springs, and wherein the recessed portions of the reduced diameter ends of the vane bearing seal form outer continuations of the slot and have radially inwardly stepped portions adjacent the slot and opening to the slot, to accommodate full travel of said engaging end portions of said springs. 4. In a vane bearing and sealing means particularly adapted to guide and seal the vane of a rotary air compressor and in combination with a vane,

a generally cylindrical pivotal seal bearing having a vane guide slot extending diametrically therethrough,

said seal bearing having reduced diameter opposite end portions forming pivotal mountings therefor and having a radial slot on the leading side thereof opening to said vane guide slot and to the periphery of said seal bearing,

said reduced diameter end portions having recessed portions extending diametrically along the ends thereof and inwardly along opposite sides there of, and opening to said radial slot,

a wear take-up bar slidably mounted in said radial slot and having inwardly stepped outer end portions,

U-shaped springs recessed within said recessed portions of said reduced diameter ends of said vane seal bearing and having engaging end portions extending into said radial slot and having engagement with said recessed end portions of said wear take-up bar and yieldably biasing said wear take-up bar into sealing engagement with an associated vane.

5. A vane bearing and sealing means in accordance with claim 4,

wherein the recessed portions in said reduced diameter end portions opening to said radial slot are inwardly stepped adjacent said radial slot, and the engaging end portions of the leaf springs extend along said recessed portions inwardly of the planes of the legs of the springs and beyond said inwardly stepped portions of said slots into bearing engagement with the inwardly stepped end portions of said wear takeup bar.

6. In a vane sealing means and in combination with a rotary vane air compressor having a compression chamher having an inner cylindrical wall and having an annular rotor mounted eccentrieally of the axis about which said wall is struck,

vanes extending through said rotor and pivotally and slidably moved thereby about an axis concentric of the axis about which said interior cylindrical wall is struck,

one piece bearing and vane seals mounted in said rotor and having slots extending diametrically therethrough forming guides for said vanes and maintaining said vanes in radial relation with respect to said inner cylindrical wall for the full extent of rotation thereof,

each bearing and vane seal having a right angled slot on the leading side thereof extending perpendicular to said vane guide slot and opening to said vane guide slot,

a take-up bar slidably mounted in said right angled slot and made from a bearing and sealing material, and leaf spring means recessed in the ends of said bearing and vane seals and having engaging end portions extending into said right angled slot into engagement with the ends of said take-up bar to bias said take-up bar into sealing engagement with said vane.

7. In a sealing means and in combination With a rotary vane air compressor having a compression chamber having an inner cylindrical Wall and having an annular rotor mounted eccentrically of the axis about which said wall is struck,

a Wear take-up bar slidably mounted in said right angled slot and made from the same material as said bearing and vane seal,

and generally U-shaped leaf springs extending along the ends and opposite sides of the bearing and vane seal and recessed therein and having legs having inwardly extending engaging end portions having engagement with opposite ends of said wear take-up bar and pressing said Wear take-up bar into sealing engagement with an associated wane.

References Cited UNITED STATES PATENTS 570,643 11/1896 Keller 103144 680,479 8/1901 English et a1 91-124 687,170 11/1901 Stilson 103144 756,646 4/1904 Jollifife et a1. 91-124 1,036,032 8/1912 Tree 91-124 1,354,281 9/1920 Carroll 91-124 1,980,726 11/1934 Higbee 230-157 DONLEY J. STOCKING, Primary Examiner. WILBUR J. GOODLIN, Examiner.

Claims

1. IN A ROTARY COMPRESSOR, A HOUSING HAVING AN INTERIOR CYLINDRICAL WALL AND PARALLEL SPACED END WALLS, AN ANNULAR ROTOR JOURNALLED WITHIN SAID HOUSING FOR ROTATION ABOUT AN AXIS ECCENTRIC OF THE AXIAL CENTER THEREOF, A PLURALITY OF VANES EXTENDING RADIALLY OF THE AXIAL CENTER OF SAID HOUSING AND MOUNTED FOR PIVOTAL MOVEMENT ABOUT SAID AXIS, VANE SEAL BEARINGS PIVOTALLY MOUNTED IN SAID ROTOR AND EACH HAVING A VANE GUIDE SLOT EXTENDING THERETHROUGH FORMING A GUDIE AND SEAL FOR AN ASSOSIATED VANE, SAID VANE SEAL BEARINGS EACH HAVING REDUCED DIAMETER OPPOSITE END PORTIONS PIVOTALLY MOUNTED IN SAID ROTOR AND EACH HAVING A RADIAL SLOT ON THE LEADING SIDE THEREOF OPENING TO SAID VANE GUIDE SLOT, SAID REDUCED DIAMETER END PORTIONS HAVING RECESSED PORTIONS EXTENDING DIAMETRICALLY ALONG THE ENDS THEREOF AND INWARDLY ALONG OPPOSITE SIDES THEREOF, ONE OF SAID RECESSED PORTIONS OPENING TO SAID RADIAL SLOT, A WEAR TAKE-UP BAR SLIDABLY MOUNTED IN SAID RADIAL SLOT AND U-SHAPED SPRINGS RECESSED WITHIN SAID RECESSED PORTIONS OF SAID REDUCED DIAMETER ENDS OF SAID VANE SEAL BEARINGS, AND HAVING ENGAGING END PORTIONS EXTENDING INTO SAID RADIAL SLOT AND HAVING BEARING ENGAGEMENT WITH OPPOSITE ENDS OF SAID WEAR TAKE-UP BAR FOR YEILDABLY BIASING SAID WEAR TAKE-UP BAR INTO SEALING ENGAGEMENT WITH SAID VANE.