Abstract:
A rotary device has a housing with an elliptical inside surface surrounding an elliptical rotor. Vane and seal assemblies on the rotor and housing are controlled with cam and linkages to provide positive effective gas seals between the housing and rotor. A slack adjuster maintains lateral sealing relationships between the housing vale and seal assemblies and opposite side walls of the housing.

Description:
FIELD OF THE INVENTION 
     The invention is directed to the field of rotary air compressors and rotary fluid motors of the type having a housing with a chamber accommodating a rotor. 
     BACKGROUND OF INVENTION 
     Rotary air compressors and rotary engines have housings that include chambers accommodating rotating rotors. A plurality of vanes movably mounted on the rotors function to move and compress air in the chambers in response to rotation of the rotors. It is conventional practice to utilize springs to continuously bias the vanes into engagement with surfaces, such as the inside walls of housings forming chambers accommodating the rotors. Examples of rotary air compressors having spring-biased vanes associated with the rotors are shown in U.S. Pat. Nos. 1,242,692 and 1,424,977. Rotary compressors and engines having spring-biased vanes movably mounted on the rotors have limited operating speeds. Centrifugal forces cause the vanes to move into frictional contact with the inside walls of the housings providing the chambers for the rotors. This frictional contact causes heat and wear of the vanes and inside walls of the housings. 
     Rotary vane-type devices have been designed to positively position the vanes during the rotation of the rotors relative to the housings of the devices. The positive positioning of the vanes is achieved through rollers located within continuous cam tracks. Shank et al. shows, in U.S. Pat. No. 4,299,097, a vane-type air compressor having a rotor with a plurality of vanes. Rollers located in tracks positively control the location of the vanes during the rotation of the rotor. 
     SUMMARY OF INVENTION 
     The invention relates to a rotary device having a housing with an elliptical inside surface surrounding a space accommodating a rotor. The rotor is rotatably mounted on the housing and divides the space into a plurality of chambers. The rotor has a plurality of vane and seal assemblies located in sliding sealing engagement with the housing. First cam means operably associated with the rotor vane and seal assemblies control the positions thereof and the sealing action during rotation of the rotor. A plurality of housing vane and seal assemblies movably mounted on the housing are retained in operative sealing relation with the outer surface of the rotor with a second cam means. The second cam means reciprocates the housing vane and seal assemblies in response to rotation of the rotor to maintain an effective gas sliding seal between the rotor and the housing vane and seal assemblies. The rotary device has positive control of both the rotor and housing vane and seal assemblies to provide effective sliding gas seals between the stationary housing and the rotating rotor. The positive control of the sealing relation of the rotor and housing vane and seal assemblies results in a minimum of wear in the structural parts and a minimum of generation of heat. The elliptical shapes of the housing and the rotor are relatively easy to machine and fabricate, and provide efficient pumping and compression of a fluid, such as air. 
     According to the invention, there is provided a housing means having an inside surface surrounding a space. The housing means has fluid intake port means and fluid exhaust port means allowing fluid to flow into and discharge from chambers formed with rotor means. The rotor means rotatably mounted on the housing means is located in the space surrounded by the inside surface of the housing means. A plurality of first vane means movably mounted on the rotor means provides a fluid seal with the inside surface of the housing means. The first cam means operates to move the first vane means to sealing contiguous relation with the inside surface of the housing means during rotation of the rotor means. Second vane means movably mounted on the housing means engage the rotor means and separate the intake port means from the exhaust port means. Second cam means are operable to move the second vane means to gas sealing relation with said rotor means whereby, on rotation of the rotor means, fluid, such as air, is drawn into the chambers through the intake port means and is discharged under pressure from the compression chambers through the exhaust port means. 
     A particular embodiment of the rotary device comprises a gas compressor having a housing means provided with an elliptical inside surface surrounding an elliptical volume separated into four chambers. The housing means has gas intake port means open to opposite chambers adjacent the minor axis thereof and gas exhaust port means open to the other opposite chambers adjacent the minor axis thereof. The exhaust port means is separated from the gas intake port means. An elliptical rotor means is located in the chambers. The elliptical rotor means has a major axis extended along the mid-sections of opposite ends of the rotor means. Shaft means rotatably mounted on the housing means locate the rotor means in chambers. First vane means are movably mounted on the major axis opposite ends of the rotor means. The first vane means have seal means located in gas sealing relation relative to the inside elliptical surface of the housing means. A first cam means is operably connected to the first vane means for moving the first vane means relative to the rotor means during rotation of the rotor means in a manner to maintain the seal means of the first vane means in gas sealing relation relative to the inside surface of the housing means. Second vane means are movably mounted on the housing means between the intake port means and exhaust port means and extend into the chamber. The first and second vane means separate the chambers into gas intake chambers and gas compression and exhaust chambers. The second vane means have seal means locatable in gas sealing relation relative to the outer elliptical surface of the rotor means. A second cam means connected to the second vane means operates to move the second vane means in response to rotation of the rotor means to provide an effective sliding seal between the second vane means and the outer elliptical surface of the rotor means. 
     The first cam means includes means having generally oval-shaped track means mounted on the housing means. Cam follower means located in the track means is connected to the first vane means so that movement of the first vane means relative to the rotor means is determined by the shape of the track means. The oval-shaped track means has major and minor axes the coincide with the major and minor axes of the elliptical inside surface of the housing. The second cam means includes means mounted on the shaft means having general oval second track means and second cam follower means cooperating with the second track means. Motion transmitting means connect the second cam follower means to the movable second vane means so that, on rotation of the shaft means, the second track means rotates thereby moving the second cam follower means and motion transmitting means to effect the movement of the second vane means. The motion transmitting means includes a rocker arm and link means for transmitting the oscillating movement of the second cam means caused by the rotating second track means to reciprocate movement of the second vane means. The motion transmitting means has adjustment means for adjusting the contiguous relationship between the seal means of the second vane means and the elliptical surface of the rotor means to maintain an effective gas seal during rotation of the rotor means. 
     The first and second vane means comprise first and second vane segments that cooperate with each other to provide sliding sealing contact with adjacent side walls of the housing. The outer vane segment has a transverse seal member located in sealing engagement with an elliptical surface of the housing or rotor. The seal member can be a ceramic member that is biased with the pressure of the compressed gas into sealing relation with its adjacent elliptical surface. Slack adjusting means is incorporated into the motion transmitting means connecting the second vane means to the second track means. The slack adjusting means includes a rod that is linearly adjustable to maintain the vane segments in sealing relation with respect to the side walls of the housing and the transverse seal in sealing relation with its adjacent elliptical surface. 
    
    
     IN THE DRAWINGS 
     FIG. 1 is a perspective view of the rotary device of the invention; 
     FIG. 2 is an enlarged top view of the rotary device of FIG. 1; 
     FIG. 3 is an enlarged sectional view taken along the line 3--3 of FIG. 2; 
     FIG. 4 is an enlarged sectional view taken along the line 4--4 of FIG. 2; 
     FIG. 5 is an enlarged sectional view of the vane and seal assembly shown in FIG. 3; 
     FIG. 6 is an enlarged fragmentary sectional view taken along the line 6--6 of FIG. 5; 
     FIG. 7 is an enlarged sectional view taken along the line 7--7 of FIG. 4; 
     FIG. 8 is an enlarged sectional view taken along the line 8--8 of FIG. 5; 
     FIG. 9 is an enlarged sectional view taken along the line 9--9 of FIG. 3; 
     FIG. 10 is a sectional view taken along the line 10--10 of FIG. 3; 
     FIG. 11 is a sectional view taken along the line 11--11 of FIG. 4; 
     FIG. 12 is an enlarged sectional view of the housing vane and seal assembly and power transmitting linkage therefor, as shown in FIG. 11; 
     FIG. 13 is an enlarged sectional view taken along the line 13--13 of FIG. 12; 
     FIG. 14 is a sectional view taken along the line 14--14 of FIG. 12; 
     FIG. 15 is an enlarged sectional view taken along the line 15--15 of FIG. 12; 
     FIG. 16 is an enlarged sectional view taken along the line 16--16 of FIG. 12; 
     FIG. 17 is an enlarged sectional view taken along the line 17--17 of FIG. 11; 
     FIG. 18 is an enlarged sectional view taken along the line 18--18 of FIG. 11; 
     FIG. 19 is a diagrammatic view of the rotary device with the major axis of the elliptical rotor located along the major axis of the elliptical chamber; and 
     FIG. 20 is a diagrammatic view of the rotary device with the major axis of the elliptical rotor located along the minor axis of the elliptical chamber. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, there is shown the rotary device of the invention indicated generally at 20. Rotary device 20 is a gas compressor operated by a motor 21, such as an internal combustion engine or an electric motor. Device 20 can operate as a fluid pump or as a rotary fluid motor. The term fluid includes gas and liquids. Device 20 herein described is an air compressor. Other gases can be compressed with device 20. 
     Rotary device 20 has a cylindrical housing 22 rotatably supporting a shaft 23. Housing 22 is located on a base 24 attached to a support 26. Housing 22 has a cylindrical body 27 secured to a first end plate 28 and a second end plate 29 with a plurality of nut and bolt assemblies 32. The inside surfaces of end plates 28 and 29 are covered with layers or coatings of ceramic material 30 and 31. The ceramic material has a low coefficient of expansion, is wear-resistant, and requires a minimum of lubrication to maintain a fluid seal with the adjacent rotary structure. Examples of suitable ceramic materials are silicon nitride, silicon carbide, and other ceramic compositions including silicon, aluminum, oxygen, nitrogen, and other materials. The layers of ceramic material 30 and 31 are applied to the metal of the end plates by any suitable process. The material of plates 28 and 29 can be ceramic materials. 
     As shown in FIG. 3, shaft 23 is rotatably supported on bearings 33 and 37. A bearing cap 34 accommodates bearing 33 and is secured to end plate 28 with a plurality of bolts 36. A bearing cap 38 accommodates bearing 37. A plurality of bolts 39 secures bearing cap 38 to end plate 31. 
     Body 27 has an elliptical inside wall 41 surrounding an elliptical volume divided into the four chambers 42A, 42B, 42C, and 42D. Wall 41 has uniform width, a vertical major axis and a horizontal minor axis, as shown in FIG. 4. The orientation of body 27 can be changed to alter the orientation of the major and minor axes of elliptical inside wall 41. Body 27 has a pair of gas inlet ports 43 and 44 in opposite portions thereof near the mid-section of the minor axis of chamber 42. Ports 43 and 44 are open to the atmosphere and chamber 42, whereby air can flow into opposite portions of chamber 42, as shown by the arrows. Air filters and cleaners can be used to reduce the amount of foreign matter carried by air flowing into ports 43 and 44. 
     Body 27 has a pair of air outlet ports 46 and 47 located in opposite portions of body 27 adjacent inlet ports 43 and 44. Ports 46 and 47 are open to a portion of the minor axis of chamber 42 and lead to check valves 48 and 49 mounted on body 27. Check valves 48 and 49 allow air to flow from chamber 42 to pipes 51 and 52 leading to a manifold, tank, or receiver for accumulating air under pressure. Check valves 48 and 49 can be conventional reed valves for controlling one-way flow of a compressible fluid, such as air. Other types of one-way valves can be used to control the flow of air from chamber 42 into manifold pipes 51 and 52. 
     As shown in FIG. 4, a rotor indicated generally at 53 located within chamber 42 is drivably mounted on shaft 23 and secured thereto with a key 54. Rotor 53 has an elliptical rotor member 56 having a center hole accommodating shaft 23 and key 54. Member 56 has an elliptical outer surface 57 having a major axis equal to the minor axis of chamber 42 and a minor horizontal axis equal to or less than the minor diameter of elliptical chamber 42. The outer surface 57 of rotor member 56 has an elliptical outline that has the same general elliptical shape or the elliptical outline of inside wall 41. The major axis of elliptical inside wall 41 is substantially greater than the major diameter of the elliptical outer surface 57 of rotor member 56. As shown in FIG. 11, member 56 has opposite generally flat side walls 58 and 59. Side wall 58 is located in sliding sealing engagement with the inside surface of ceramic coating 30 on end plate 28. Side wall 59 is located in sliding sealing engagement with the inside surface of ceramic coating 31 on end plate 29. As shown in FIGS. 4 and 11, perimeter seals 55 mounted on the outer arcuate sections of the sides of rotor member 56 prevent gas from flowing around the sides of the rotor member. Seals 55 engage ceramic coatings 30 and 31. 
     Elliptical member 56 has a major apex 61 with a radial slot 62. A flat vane and seal assembly 63 is slidably disposed in slot 62 and located in sliding sealing engagement with the side wall surfaces of ceramic coatings 30 and 31 and the elliptical surface 41 of ceramic coating 27A. As shown in FIGS. 3, 5, and 6, rotor vane and seal assembly 63 has a pair of generally triangular vane segments 164 and 166 slidably mounted on each other along a diagonal line. Vane segment 164 has a generally flat side 167 located in sliding engagement with ceramic coating 30 and a transverse top edge 168 spaced a short distance below elliptical surface 41 of body 27. As shown in FIG. 6, vane segment 164 has a diagonal tongue 169 located in a groove 171 in vane segment 166. The tongue and groove structure allow vane segments 164 and 166 to move in opposite directions to retain the side walls 167 and 172 in sliding engagement with the adjacent ceramic coatings 30 and 31 and perimeter seals 55 in sealing engagement with coatings 30 and 31. 
     A generally flat blade-like seal member 173 of ceramic material or other materials is located in a slot 182 in the upper or top edge of vane segment 164. As shown in FIG. 8, seal member 173 has a convex-shaped outer edge 174 located in sliding sealing engagement with the inside elliptical surface 41 of ceramic coating 27A. A sine curved spring 175 biases member 173 into engagement with coating 27A. Seal member 173 has a pair of circumferentially directed holes 176 and 177 accommodating pins 178 and 179 for holding seal member 173 in moving assembled relation with vane segment 164. As shown in FIG. 8, hole 176 is slightly larger than pin 178 allowing seal member 173 to have limited radial movement relative to vane segment 164. Seal member 173 has a width slightly smaller than the width of slot 182. This allows seal member 173 to have limited circumferential movement in slot 182. As shown in FIG. 8, seal member 173 has been moved to the left in slot 182. A passage 183 between seal member 173 and segment 164 allows compressed gas in compression chamber 42B to flow through passage 183 into a base chamber 184 under seal member 173. The pressure of the gas in chamber 184 forces seal member 173 to move radially and retains outer edge 174 in sliding sealing engagement with the elliptical surface 41. As shown in FIG. 8, a pin 178 is located generally normal to the radial line of vane segment 164. Pin 178 is located within a hole 181 in the upper end of vane segment 164. The outlet end of hole 181 has a smaller diameter than the inelt end to prevent pin 178 from moving through hole 181. 
     As shown in FIGS. 5 and 7, a radial rod 186 has an inner end connected to cam follower rod 77 with a pin and set screw assembly 187. Assembly 187 is threaded into the right end of rod 77 and engages rod 186. Rod 186 extends through tubular member 78 into holes 188 and 189 in vane segments 166 and 164. A pin and screw assembly 191 located in a threaded bore in vane segment 164 has a forward rod end located in a hole in the upper end of rod 186 to secure rod 186 to vane segment 164. Radial holes 188 and 189 are larger than rods 186 in diameter to allow the vane segments 164 and 166 to move relative to each other along the diagonal tongue and groove structure 169, 171 to allow for expansion of the overall width of vane 63. 
     As shown in FIG. 5, the lower end of tubular member 78 extends through a hole 193 in rotor body 56 and engages a biasing means shown as a plurality of Bellville washers 194. The upper end of tubular member 78 is in engagement with the bottom of vane segment 166. Biasing means 194 establishes a biasing force on the vane segments 164 and 166 to retain them in sliding sealing engagement with the inside surfaces of the ceramic coatings 30 and 31. Member 56 has a second major apex 66 located diametrically opposite apex 61. Apex 66 has a radial slot 67 accommodating a generally flat vane and vane and seal assembly 68. Vane and seal assembly 68 has a seal member 69 located in sliding sealing relation with elliptical inside surface 41. Vane and seal assembly 68 is identical in structure and function as vane and seal assembly 63. 
     Vane and seal assemblies 63 and 68 reciprocate in slots 62 and 67, respectively, in response to rotation of member 56, as shown by the arrow 157 in FIG. 4. Vane and seal assemblies 63 and 68 are positively controlled by a first cam assembly indicated generally at 71 in FIGS. 3, 9, and 10. Cam assembly 71 comprises a first generally flat ring 72 located within a circular recess inside of end plate 28. A plurality of bolts 82 secure ring 72 to end plate 28. Ring 72 has a non-circular oval track 73 having a major axis and a minor axis that are aligned with the major and minor axes of inside wall 41. A second generally flat ring 74 is mounted on an inside recess in end plate 29. A plurality of bolts 83 secure ring 74 to end plate 29. Ring 74 has a non-circular oval track 76 having a size and shape that duplicates track 73. As shown in FIG. 3, tracks 73 and 76 face each other and accommodate opposite ends or followers of a cam follower rod 77. The mid-portion of rod 77 is secured to a radial stem 186 operatively connected to the inner end of vane segment 166. A second rod 79 has opposite ends or followers located in tracks 73 and 76 and an intermediate portion secured to a radial stem 81. Stem 81 is connected to the inner end of vane and seal assembly 68. As shown in FIGS. 9 and 10, the follower ends of rods 77 and 79 are located in diametrically opposite portions of cam tracks 73 and 76. The opposite ends of rods 77 and 79 can accommodate rotatable sleeves or roller bearings located in tracks 73 and 76. On rotation of rotor 53, the ends of rods 77 and 79 move along tracks 73 and 76 in the direction of the arrows 84 and 86, as shown in FIGS. 9 and 10. Since cam tracks 73 and 76 are oval in shape and rotor 53 rotates about an axis, the vane and seal assemblies 63 and 68 move radially with respect to rotor member 56 and thereby maintain the outer ends 174 of seal member 173 in contiguous sliding sealing relation with the elliptical inside wall 41 of body 27. The sides of vane segments 164 and 166 are generally flat and located in surface engagement with the inside ceramic coatings 30 and 31 of end plates 28 and 29 whereby vane and seal assemblies 63 and 68 and rotor member 57 move and compress air during rotation of rotor 53. 
     As shown in FIGS. 4, 11, 12, and 15, a pair of housing vane and seal assemblies 87 and 91 are located along the minor axis of inside wall 41. Vane and seal assemblies 87 and 91 are aligned with each other and located in the minor axis of the elliptical inside wall 41 between the intake and exhaust ports 43, 47, and 44, 46. Vane and seal assembly 87 is located in a generally rectangular slot 89 in body 27 and moves in slot 89 in response to rotation of rotor member. The second vane and seal assembly 91 is located in a generally rectangular slot 93 in body 27. Vane and assemblies 87 and 91 are identical in structure and function to maintain the sealing relation with the outside elliptical surface 57 of rotor 56 and form barriers between the intake and exhaust ports. 
     The following description is limited to the vane and seal assembly 87 and the motion transmitting structure, including slack adjuster, for controlling the radial movement of the vane and seal assembly relative to housing 27. Referring to FIGS. 11, 12, and 15, vane and seal assembly 87 has a pair of triangular vane segments 200 and 201 slidably associated with engagement with each other along a bias line 202. Vane segment 200 has a generally flat side 203 located in sliding sealing engagement with the ceramic coating 30. The vane segments 200 and 201 are slidably joined together with a tongue and groove structure 204, as shown in FIG. 13. Returning to FIG. 15, vane segment 200 has a transverse slot 206. A generally flat seal member 207 is retained in slot 206 with a pair of pins 211. Pins 211 extend through hole 208 and hole 209 in seal member 207. As shown in FIG. 15, pin 211 is located in a hole 212 in inside edge 205. The outlet end of hole 212 has a smaller diameter than the inlet end to prevent pin 212 from moving through hole 212. Holes 208 and 209 are slightly larger than pins 207 to allow seal member 207 to be moved radially inwardly into engagement with the elliptical outer surface 57 of rotor 56 with a spring 215. As shown in FIG. 15, seal member 207 has a width smaller than the thickness of slot 206, thereby providing a passage 213 leading to a base chamber 214. In use, gas under pressure flows through passage 213 into chamber 214 and biases seal member 207 radially inwardly into engagement with rotor surface 57. The seal member 207 has a convex curve transverse face 216 that is spring biased with a leaf spring 215 into sliding sealing relation with elliptical rotor surface 57. 
     Returning to FIG. 12, vane segment 201 has a generally flat side 217 located in sliding sealing engagement with the ceramic coating 31. In use, vane segments 200 and 201 slide along the bias line 202 to hold the surfaces 203 and 217 in engagement with the ceramic coatings 30 and 31. 
     A second can assembly indicated generally at 94 in FIGS. 11 and 18 functions to control the movement of the housing vane and seal assemblies 87 and 91, shown in FIGS. 4 and 11, in slots 89 and 93, respectively, and maintain the vane and seal assemblies 87 and 91 in sliding sealing relation with respect to the elliptical outer surface 57 of rotor body 56 and ceramic coatings 30 and 31 during rotation thereof. Second cam assembly 94 comprises a ring 96 secured to shaft 23 with a key 98. Ring 96 can be secured to a flange integral with shaft 23. Ring 96 has an outwardly directed oval cam follower track 97. As shown in FIGS. 17 and 18, track 97 has a generally horizontal major axis and a vertical minor axis. The major and minor axes of track 97 are aligned with the major and minor axes of rotor 56. A pair of cam followers 99 and 101 are located in opposite portions of track 97. A first lever and link assembly indicated generally at 102 is operatively connected to cam follower 99 and vane and seal assembly 87. Assembly 102 comprises a bell crank 103 pivotally connected with a pivot member 104 to end plate 29. A fastener 106, such as a bolt, connects an end of bell crank 102, to cam follower 99. As shown in FIGS. 11 and 12, the opposite end of bell crank 102 is connected to an upwardly directed link or rod 107 with a pivot pin 108. Returning to FIG. 11, rod 107 extends upwardly through a passage 109 in end plate 29 and is pivotally connected to a rocker arm 111 with a connector block 112. Connector block 112 has a slot accommodating the mid-portion of lever 111, as shown in FIG. 12. A pin 113 pivotally connects lever 111 to block 112. The lower end of block 112 extends through a hole 115 in a frame 117 and is pivotally connected to the upper end of rod 107 with a pin 114. Block 112 is a cylinder that reciprocates in an upright passage in frame 117. One end of lever 111 is pivotally connected to a fulcrum block 116 with a pin 118. Block 116 has a slot 121 accommodating the fulcrum end of lever 111. As shown in FIG. 14, block 116 is slidably located within an upright cylindrical bore 122 in frame 117 allowing for the course adjustment of the cam follower control linkage. The upper end of block 16 is attached to a threaded bolt 123. Bolt 123 is threaded through a passage in frame 117 and accommodates a locking nut 124. Adjustment of bolt 123 will selectively raise and lower fulcrum pivot pin 118 thereby adjusting the clearance or gap of seal member 207 with respect to the elliptical outside surface 57 of rotor member 56. Referring to FIG. 12, an upright cylindrical rod 126 extends upwardly through a hole 127 in body 27 and terminates in a bifurcated upper end 128. A pin 129 pivotally connects link 111 to bifurcated end 128. An upwardly projected cylindrical projection 130 is slidably accommodated in a cylindrical bore 131 and controls the movement of rod 126. The inner end of rod 126 extends through a pair of holes 221 and 222 in vane segments 201 and 200. Vane segment 200 has a lateral threaded bore 223 accommodating a pin set and screw assembly 224. The forward end of assembly 224 extends through a hole in the lower inner end of rod 126 to secure the rod to the vane segment 200. Holes 221 and 222 are slightly larger than the diameter of the rod 126 to allow vane segments 200 and 201 to move in lateral opposite directions into sealing engagement with the ceramic coatings 30 and 31. 
     An automatic vane adjusting mechanism or slack adjuster indicated generally at 226 is used to maintain the seal surfaces 203 and 217 in sliding sealing engagement with the ceramic coatings 30 and 31 during operation of the rotary device. The slack adjuster 226 has a sleeve 227 located about rod 126. The lower end of sleeve 227 engages vane segment 201. The upper end of sleeve 227 has an upwardly diverging funnel-shaped head 228 surrounding a pocket 229. A cylindrical lock ring 231 located in pocket 229 is positioned in tight frictional engagement with the rod 126. 
     As shown in FIG. 16, lock ring 231 is a split circular ring having an inside diameter located in tight frictional engagement with the outside cylindrical surface of rod 126. A cylindrical collar 232 is located above lock ring 231. Collar 232 is slidably positioned on rod 126 and has a lower end in engagement with lock ring 231. The upper end of collar 232 located in engagement with biasing means 233 spaces collar 232 from the head 128. Biasing means 233 comprises a plurality of Bellville washers that function to bias collar 232 into engagement with locking ring 231. 
     In use, slack adjuster 226 functions to maintain the vane segments 200 and 201 in sliding sealing engagement with ceramic coatings 30 and 31. As the vane segments and seal member wear, slack adjuster 226 spreads the vane and seal assembly 87 toward the end plates 28 and 29 to compensate for the wear. Biasing means 223 forces lock ring 231 into engagement with funnel-shaped head 228. Sleeve 227, being in engagement with vane segment 201, forces segment 201 in a downward direction. The tongue and groove arrangement between segments 200 and 201 cause segments 200 and 201 to move laterally in opposite directions. Split lock ring 231 prevents sleeve 227 from moving upwardly away from vane segment 202 so that vane segments 200 and 201 are retained in their adjusted positions. 
     Vane and seal assembly 91 is identical in structure and function to the vane and seal assembly 87. The power transmitting linkage 132 connecting vane and seal assembly 91 to cam plate 96 is identical to the power transmitting linkage, including slack adjuster 226, as shown in FIG. 12. The structure of lever and link assembly 132 that corresponds to linkage 102 has the same reference numbers with the suffix A. The slack adjuster is operable to automatically adjust the sliding sealing relationship between the vane segments of vane and seal assembly 91 and ceramic coatings 30 and 31. 
     In use, on rotation of shaft 23 in the direction of arrow 156, shown in FIG. 17 and 18, shaft 23 rotates ring 96. Cam followers 99 and 101 follow the moving track 97 and pivot the bell cranks 103 and 133, as shown in broken lines in FIG. 18. This causes links 107 and 137 to reciprocate. The reciprocating motion of links 103 and 133 is transferred via levers 111 and 111A to stems 126 and 126A, thereby reciprocating vane and seal assemblies 87 and 91 in a manner to maintain their seal members in close sealing relation with the outer elliptical surface 57 of rotor member 56. 
     Referring to FIGS. 4, 19, and 20, in operation, motor 21 drives shaft 23 rotating rotor member 56, as indicated by arrow 157. Vanes 63 and 68 are maintained in sealing engagement with the elliptical inside wall 41 of body 27 and force air from the opposite chambes 42B and 42D through outlet ports 46 and 47 and check valves 48 and 49 to a gas receiver, such as a tank. The housing vane and seal assemblies 87 and 91 are maintained in sealing relation with the outer elliptical surface 57 of rotor member 56 by operation of second cam assembly 94 to separate intake ports 43 and 44 from the exhaust ports 46 and 47. As shown in FIG. 20, vane and seal assemblies 63 and 68 are in their in or retracted positions and vane and seal assemblies 87 and 91 are in their in positions, so that they clear each other when the major axis of rotor member 56 coincides with the minor axis of the elliptical surface 41. 
     While there has been shown and described the preferred embodiment of the rotary device of the invention, it is understood that changes in the structures, materials, arrangements of structures, and size of the structures can be made by those skilled in the art without departing from the invention. The invention is defined in the following Claims.