US3195412A

US3195412A - Apparatus for shaping a pump rotor

Info

Publication number: US3195412A
Application number: US76702A
Authority: US
Inventors: Delbert L Phillips
Original assignee: Whittaker Corp
Current assignee: Whittaker Corp
Priority date: 1955-07-28
Filing date: 1960-12-19
Publication date: 1965-07-20
Anticipated expiration: 1982-07-20

Description

July 20, 1965 D. PHILLIPS 3,195,412

APPARATUS FOR SHAPING A PUMP ROTQR Original Filed July 28, 1955 s Sheets-Sheet 1 PW W 5 DELBERT 1.. PHILLIPS,

IN VEN TOR.

I BY

ATTORNE Y5 July 20, 1965 D. L. PHILLIPS 3, Q

APPARATUS FOR SHAPING A PUMP ROTOR Original Filed July 28, 1955 6 sheets-Sheet 2 DELBERT L. PHILLIPS,

INVEN TOR.

ATTORNEKfi y 20, 1965 D. PHILLIPS 3,195,412

APPARATUS FOR SHAPING A PUMP ROTOR Original Filed July 28, 1955 6 Sheets-Sheet 3 H DELBERT L. PHILLIPS,

' INVENTOR.

A TTORNEY! y 1955 D. L. PHILLIPS 3,195,412

APPARATUS FOR SHAPING A PUMP ROTOR Original Filed July 28, 1955 6 Sheets'-Sheet 4 05-1. BERT L. PHILLIPS,

IN V EN TOR.

A TTORNE Y5 July 20, 1965 D. L. PHILLIPS 3,195,412

APPARATUS FOR SHAPING A PUMP ROTOR Original Filed July 28, 1955 e Sheets-Sheet 5 DELBERT L. PHILLIPS;

INVENTOR.

ATTORNEY5 July 20, 1965 D. PHILLIPS APPARATUS FOR swarms A PUMP ROTOR Original Filed July 28, 1955 6 Sheets-Sheet 6 17a 4a m;

DELBERT 1.. PHILLIPS,

INVENTOR.

' ATTORNEY! United States. Patent APPARATUS FUR SHAPENG A PUMP RUTGR Delbert L. Phillips, Los Angeles, Caiifi, assignor to Whittaker Corporation, a corporation of California Original appiication .Iuly 28, 1955, Ser. No. 525,003, new

Patent No. 2,990,782, dated July 4-, 1961. Divided and this application Dec. 19, 1960, Ser. No. 76,7432

This invention relates to an apparatus for shaping a rotor of a particular type of pump. This application is a division of my co-pending application Serial No. 525,- 003, filed July 28, 1955, now Patent No. 2,990,782, and entitled Pump Device which, in turn, is a continuationin-part of application Serial No. 391,104 filed November 9, 1953, and now abandoned.

As disclosed in the parent application, the pump, which may also be used as a fluid motor, has a casing with input and output ports, a rotor cooperating with the casing to form an annular or ring shaped chamber having two spaced walls, a blade unitary with the rotor and of undulating configuration for wiping contact with the two spaced walls, and a reciprocative abutment in sealing engagement with the undulating blade from opposite sides thereof to divide the annular chamber into expanding input compartments and contacting output compartments.

The problem arises of sealing the juncture of the reciprocative abutment with the two faces of the undulating rotor blade. This problem presents diiliculties because the angle of the blade relative to the reciprocative abutment varies widely. The angle is 90 at one position of theblade relative to the abutment and varies to a maximum departure in both directions from this central angle. It is desirable that these maximum departures from the 90 angle be of relatively large magnitude because the volumetric displacement of the rotary device depends on these magnitudes. Sealing arrangements heretofore used in the art are effective only if the departures from the intermediate 90 angle is limited to a few degrees and consequently prior art rotary devices of this type have provided limited volumetric displacement per unit of rotation.

The limiting effect may be appreciated when it is considered that the circumferential pitch or helical inclination of a radially extending undulating blade relative to its plane of rotation varies radially of the blade, the pitch being greatest at the hub or root or" the blade and least at the outer circumference or periphery of the blade. The pitch also varies, of course, circumferentially, being substantially zero where the blade undulations wipe the end wall of the chamber and being greatest in the region midway of the two end walls of the chamber. It is apparent, then, that the point of maximum pitch of such an undulating blade is at the hub or root of the blade in the mid-region of the annular chamber.

The desired sealing action throughout a Wide range of angles is afforded by providing a reciprocative abutment with spaced edges of rounded cross-sectional configuration and by varying the thickness of the rotor blade in accord with its changes in pitch to maintain constant contact with both of the rounded edges. The present invention is directed to the problem of fabricating such a rotor with the blade of the rotor appropriately varying in thickness.

In general, the method of shaping the rotor blade is charcterized by the use of a material-removing element such as an end mill to remove material from a rotor blank, the material-removing element having the same rounded configuration as the rounded slot edges of the abutment member in the rotary device. The materialremoviug element is advanced laterally against the rotor 3,l95,4l2 Patented July 20, 1965 blank with the blank rotating about its axis and with the material-removing element shifting relative to the rotating blank in the same manner that a rounded edge of the reciprocative abutment shifts relative to the rotor blade in the operation of the intended device. In this manner, each face of the rotor blade is accurately shaped for maintaining constant contact with the corresponding rounded sealing edge of the reciprocative abutment.

The preferred practice of the invention is further characterized by the provision of a relatively simple apparatus to carry out this process for accurately shaping the rotor blank. Such an apparatus that provides for rotation of a rotor blank and for synchronous advancement of a material-removing element may be designed for flexible use to shape rotors of various dimensions with various numbers of peripheral undulations.

The various features and advantages of the invention may be understood from the following detailed descrip tion considered with the accompanying drawings.

In the drawings, which are to be regarded as merely illustrative:

FIGURE 1 is a perspective view of a selected embodiment of the invention that may be used either as a pump or as a fluid motor,

FIGURE 2 is a longitudinal sectional view taken as indicated by the line 2-2 of FIGURE 1;

FIGURE 3 is a transverse sectional view taken as indicated by the line 33 of FIGURE 2;

FIGURE 4 is a view of the device with a cover removed, the view being takcn as indicated by the line 4-4 of FIGURE 2;

FIGURE 5 is an exploded perspective View showing basic workin parts of the device;

FIGURE 6 is a diagrammatic view on a large scale showing how the reciprocative abutment cooperates with the undulating rotor blade; I

FIGURE 7 is a similar but fragmentary view showing two different positions of the reciprocative abutment relative to the undulating blade;

FIGURE 8 is a fragmentary section taken as indicated by the line 8-8 of FIGURE 6 and showing how a sealing shoe cooperates with the reciprocative abutment;

FIGURE 9 is a fragmentary sectional view on an enlarged scale taken as indicated by the line 9-9 of FI URE 6 and showing how rotary sealing elements carried by the reciprocative abutment cooperate with the undulating rotary blade;

FIGURE 10a is a diagram showing the relation of the reciprocative abutment with the peripheral or outer circumferential portion of the undulating blade at various circumferential stations;

FIGURE 10b is a similar diagram showing the relation of the reciprocative abutment with the root portion of the undulating rotary blade;

FIGURES 11, 12 and 13 show the cross-sectional configuration of the undulating rotary blade at different circumferential stations;

FIGURE 14 is a simplified diagrammatic perspective View of an apparatus that may be employed to shape the undulating rotor blade;

FIG. 14a is a section taken as indicated by the line 14a14a of FIGURE 14 showing one end of a Scotch yoke member;

FIGURE 15 is an enlarged transverse section taken as indicated by the line l5.l5 of FIGURE 14 and showing how the apapratus of FIGURE 14 may be adjusted to compensate for the thickness of the rotor blade; and

FIGURES 16a and 16b are diagrams indicating the paths of movement of the rotary cutting element of FIG- URE 14 as required for shaping the opposite faces of the undulating rotor blade.

To appreciate the apparatus taught by the present invenconstruction and operation of a pump of the type to which FIGS. l-9 illustrate such a pump.

theinvention relates.

The pump has anannular or ring shaped pump cham ber, generally designated by numeral 30, which is defined by a cylindrical wall 32, two spaced

end walls

34 and 35,

and the hub 36 of a rotor that is generally designated by numeral 38. The rotor 38 has a radially extending blade 40 and is mounted on a suitable shaft 42. 1 p

The blade 40 is of undulating circumferential configuration, shaped and dimensioned to wipe the two

end Walls

34 and 35 and, may be termed a single-undulation blade since only one portionof the blade makes wiping contact with each of the two endwalls, these-two wiping portions being spaced circumerentially 180 apart. tive abutment, generally designated by numeral 44, spans a radial portion of the annular chamber 30 in a generally axial direction in sealing contact with the'two-faceS of the undulating blade 40 and thus cooperates with the rotating blade to divide the annular chamber into expanding input compartments and contracting output compartments. Throughout most of the range of rotation of' the rotor, one side of the reciprocative abutment cooperates with'the undulating rotor blade 40' to form two expanding compartments: and the other side cooperates to form two contracting compartments. When either of the two wiping portions of the blade 40 is at the reciproca- A reciproca- I The main casing section 65 is formed with four bosses 72 (FIGS. 1 and 2) to serve as legs and is also formed with four bosses 74 to receive cap screws 75 for the re taining plate 70. The-main casing section 65 provides the previously mentioned cylindrical wall 32 and the pre-v viously mentioned end wall 34 of theannular chamber and provides an oval opening 76 to theannular chamber.

The cup-shaped end section 68 of the casing telescopes into the cylindrical wall 32 of the main casing section 65 as best shown in FIG. 2, and is sealed by an O-ring 78. This end section of the casing provides the second end wall 35 of the annular chamber. A stud 80 threaded into the cylindrical wall 32 extends into a blind bore 82 of the end section 68 of the casing as shown in FIG. 2'to maintainthe end sectionat a desired rotary position rela-, tive to the main casing section 65. The retaining'plate 70 which has a central opening 84 to clear the shaft 42 abuts the outer end of the end casing section 68 to hold the end casing section in position in opposition to fluid tive abutment 44, however, there is momentarily only one expanding compartment on one side of the abutment and only one contracting compartment on theother side of the abutment. With the rotor rotating at a constant rate, the various compartments expand and'contract ata constant rate for substantially non-pulsating fluid flow through the device.

r The reciprocative abutment 44 is of curved configuration to reciprocate along a curved path and preferably the portions of the abutment member that engage the opposite faces of the rotor blade 40 are integral with each other, the abutment member being formed with a slot to receive the rotor blade.

As best shown in FIG. 5, the

pressure.

As shown in FIG. 2, the rotor 38 has a trunnion '85 that extends through an aperture 86 in the end wall and has a second trunnion 88 that is journaled in a bear ing sleeve 90 in a blind bore 92 in the end wall 34. The

' cup-shaped end section 68 of the. casing has an axial tubular portion 94 in which is mounted a suitable ball bearing 95 for the shaft 42. The outer race of the ball bearing abuts a split retainer ring 96 and also abuts a sealing collar 98 which confines an O-ring 100 in a circumferential groove 102 in the shaft 42.

The arcuate wall 45 of the reciprocative abutment 44 oscillates longitudinally in an arcuate space or way 104, the opposite ends of which are interconnected by an ane gular fluid passage 105 to keep fluid from beingtrapped thereinr The arcuate way 104 and the angular fluid passage 105 are formed in part by the main casing section 65 and in part by the end. section 68 of the casing. For this pur-' pose, as may be seen in FIG. 5, the end section 68 of the abutment member 44 has an arcuate abutment wall grally united with the arcuate abutment wall by a pair of radial arms 50. The tubular bearing portion 48 which is concentric to the axis of curvature of the abutment wall 45 is rotatable on a suitable pivot pin-52 that is mounted in a blind bore 54 of the casing, a counter-bore being provided to accommodate the tubular, bearing portion. Preferably the tubular bearing portion 48 of the reciprocative abutment 44 is provided with a pair of bearing sleeves 56 (FIG. 3) of suitable material to minimize frictional resistance of the reciprocative abutment on the bearing pin 52. These bearing sleeves 56 may, for example, be made of nylon.

As best shown in FIG. 9, each side of the slot of the reciprocative abutment member 44 is provided with four cylindrical sealing elements 58 mounted in'longitudinal alignment on a retaining pin carried by the abutment." The cylindrical sealing elements 58 are floating'ly mounted on the reciprocative abutment 44 in the sense that they fit sufficiently loosely on the two pins 60 for freedom for lateral movement relative to the pin and the abutment member is cut away or recessed to permit such freedom.

The reciprocative abutmentis formed with cylindrically" curved recesses 62 as shown in FIGS. 6 and 7 which par-;

tially enclose the sealing elements 58 and these recesses are slightly oversized with respect to the outside diameter cover member 66, and a cup-shaped casing end section 68 together with a retaining plate that is best shown in FIGS. 1 and 2.. I

tween the cover member 66 and a fiat surface casing has a slot 106 in the end-wall 35 thereof and additionally has a partition wall 108 defining a space in communication with the slot. The two .radial arms 50 of the reciprocative abutment move in a shallow space be- 7 (FIG. 5) provided by the main casing section 65.

The cover member 66, which is sealed by an O-ring 109, is held in place by screws 112 threaded into bosses 114 of the main casing section 65 and provides two

ports

115 and 116 separated by a dividing wall 118. As best shown in FIG. 2, an adapter 120 may be mounted on the cover member 66 by means of cap screws 122 to adapt the device for connection to threaded pipe. The adapter 120 has threaded

ports

124 and 125 to register with the

ports

115 and 116, the two threaded ports being separated by a dividing wall 126. Suitable O-rings 128; seal the juncture between the adapter 120 and the cover members 66 around the two threaded ports.

To keep fluid from passing over the reciprocative abutment 44, a sealing element 130 of suitable material such as nylon is seated ina groove 132 in sliding contact with the upper edge of the arcuate abutment wall 45. To keep the fluid from moving from one face of the abutment blade 44 to the other face around the opposite ends of the abutment blade, suitable sealing elements 134 may be mounted in recesses 135 in the casing adjacent the arcuate way 104, there being one such sealing element in a recess on each side of the oval chamber opening 76. As best shown inFIGS. 6, 7 and 8, each of the sealing elements 134 may be of half-round cross-sectional configuration elements 134. It is important to note that since the reciprocation oi the abutment 44 is pivotally guided by the pivot pin 52, none of the sealing elements associated With the reciprocative abutment is burdened with a guiding function and none is subject to guiding pressure in addition to fluid pressure.

While the rotor 33 may be made of various materials for withstanding high temperature and pressures, preferably the rotor as constructed for use at moderate te peratures and pressures is at least partly made of a suitable plastic that will afford a low coefficient of friction. For example, the rotor may be made entirely of a plastic such as nylon.

in the present embodiment of the invention, the rotor 3e and its undulating blade 40 are of combined plastic and metal construction, as best shown in FIG. 2, the rotor and blade being in the form of an investment casting with a steel core 138. The steel core 13:; is undersized with respect to the outside dimensions desired for the rotor and preferably is formed with numerous apertures M in its blade portion. This steel core is covered with a plastic sheath 142 of nylon or other suitable plastic material with the opposite faces of the plastic sheath interconnected through the apertures E40, as indicated in FIG. 2. The plastic sheath 142 may extend over the hub 36 of the rotor and may additionally extend over the circumferential surfaces of the rotor trunnions 05 and 83. It is apparent that the plastic sheath 142 materially reduces the frictional resistance of rotation of the rotor and the metal core 138 lends rigidity and thermal stability to the rotor.

The pump has plastic liners 144 for the two

end walls

34 and 35 of the annular chamber. These liners may be made of nylon. The plastic liners 144 are formed with circumferential lips 145 as shown in FIG. 2 and the circumferential edge of the rotor blade 40 is shaped with bevels M6 to conform to the circumferential lips. Nylon is advantageous both for the sheath 142. of the rotor and for the end liners 14.4 of the annular chamber. Nylon is especially advantageous because it has been found that nylon tends to recover from indentations made therein by hard foreign particles.

For handling fluids with solid particles entrained therein, the invention provides recesses into which such particles may be swept by the rotor blade instead of being trapped by the blade. For this purpose, the two end walls of the chamber may be cut away adj cent the reciprocative abutment on the output side thereof. Thus, if the rotor rotates counterclockwise as viewed in the drawings to make port 116 the output port, the two end walls may be cut away to provide particle receiving recesses 147, as shown in FIGS. 5 and 6. These recesses communicate directly with the output port and are continually flushed by the outgoing fluid.

Since the rotor blade 40 is of generally helical configuration, the blade may be described as having pitch angle relative to its plane of rotation. in this instance, however, the pitch of the blade varies around the circumference of the blade and also varies radially of the blade. These variations in pitch may be understood by reference to the diagrammatical representation of the rotor blade in FIGS. 6, 10a and 101).

As shown in FIG. 6, the blade 40 has two diametrically opposite portions 148 shaped and positioned for wiping contact with the two end walls 54 and or the annular chamber 30, these two opposite portions being in generally tangential relation to the two end walls 34 211K. 35. The two opposite portions 14-8 of the rotor blade are of substantially Zero pitch since they are in planes substantially perpendicular to the axis of the rotor 38, i.e., are aligned with the plane of rotation of the rotor. The pitch angle of the rotor blade varies around the circumference between the opposite portions 148 sinusoidally or approximately in the manner of a sine curve, the pitch angle progressively increasing from each of the end walls of the chamber to the middle of the chamber. Thus, in

FIG. 6 the sealing elements 58 of the reciprocative abutment 4 are shown in contact with the rotor blade 40 in the central region of maximum blade pitch, there being two such regions spaced 180 apart circumferem tially. The fact that the root portion of inner diameter of the rotor blade 40 varies through a greater pitch angle than the peripheral portion may be seen in FIG. 6 where the two curved broken lines represent the thickness or" the root portion of the rotor blade. Here, again, the pitch angle is maximum in the region midway between the two diametrically opposite wiping portions 148 and since the pitch angle of the root portion of the blade exceeds the pitch angle of the peripheral portion, the point of maximum pitch angle for the whole blade is in this root region, there being two such root regions 180 apart.

These facts regarding pitch angle are shown diagrammatically in FIG. 10a representing the peripheral portion of the blade and in FIG. 10b representing the root portion of the blade. The two opposite wiping portions 148 are shown at the 0 station and at the 180 station, and the intermediate portions of the blade at maximum pitch angle are shown at the 90 and 270 stations.

As heretofore stated, an important feature of the invention is the concept of so varying the thickness of the rotor blade 40 as to cause the two opposite faces of the rotor blade to maintain constant contact with the curved edges of the slot 46 of the reciprocative abutment 44. Since the curved edges of the slot provided by the two rows of rotary sealing elements 58 are fixed in spacing relative to each other, the thickness of the blade must, in general, vary inversely as the pitch angle of the blade, being relatively thick at Zero pitch angle and relatively thin at maximum pitch angle. While this relationship holds true for FEGURE 10a which represents the periphery of the rotor blade, it is more readily apparent in FIG. 10]; which represents the root of the blade. Thus, in l IS. 1012 the blade is of maximum thickness where the rotor blade is of minimum pitch angle at the 0 and 180 stations and is or" minimum thickness in the region of the 90 and 270 stations.

It is to be noted, however, that the controlling factor is the angle of the rotor blade 40 relative to the reciprocative abutment at the abutment slot. Since the reciprocative abutment is curved and moves in a curved path, the points of maximum blade thickness are slightly displaced from the 0 and 180 stations and the points of minimum blade thickness are, in like manner, slightly displaced from the 90 and 270 stations, as may be seen in FIG. 10b.

These facts with regard to the varying thickness of the blade for maintaining constant contact with the slot edges of the reciprocative abutment member mean that the blade is thinner at its root portions than at its peripheral portions, as may be seen in FIGS. ll, 12 and 13, which show the radial cross-sectional configuration of the blade 40 at the four stations. It will be noted in FIG. 12 that the rotor blade narrows markedly towards the hub 36 at the 90 and 270 stations.

It is also to be noted in FIGS. 11 to 13 that the radially inward taper of the rotor blade is of slightly curved configuration and that this inward curvature occurs also at the 0 and 180 stations as may be seen at 152 in F168. 11 and 13. This inward curvature is required because the slot of the reciprocative abutment moves in an arcuate path. This arcuate path is represented by the curved line 154 in FIG. 6. It will be noted that the midpoint of the curved line 154 lies on one side of the radial plane 155 through the axis of the rotor and that the two opposite ends of the curved line lie on the other side of this axial plane. It is this departure of the curved path 154 from the plane 155 that requires the curvular tapering cross sectional configuration of the rotor blade shown in FIGS. 11, 12 and 13. For the same rea on, at the points on the curved path 154 of maximum departure from the plane 155, i.e., at the 0 and stations and again at the 90 and 270 stations, the two series of rotary cylindrical sealing elements 58 of the reciprocative abutment make contact with the rotor blade 40 along lines that that curve slightly around the circumferences of the sealing elements rather than along straight lines parallel to the axes of the elements.

It is apparent from the foregoing discussion that since the thickness of the rotor blade 40 variescontinuously circumferentially as well asra-dially and has surfaces that are curved radially as well as circumferentially, the rotor blade is of a complicated configuration, the configuration being especially complicated s-ince allowance must be made for the arcuate path of movement of the reciprocative abutment 44. .In this regard a feature of the invention is a highly accurate method of arriving at a precise configuration for a rotor blade 40 as well as for arriving at the configuration of a metal core 138 for a rotor blade.

Broadly described, this method comprises removing material from a rotor blank by means of a material-removing element that is of the same rounded configuration as the rounded edges of the slot 46 of the reciprocative abutment. The method includes the steps of rotating the rotor blank about its axis and of advancing the material-removing element against the blank along a .path relative to the rotating blank that corresponds to the path of a curved slot edge relative to the rotor as intended in the operating device. While such a method may be carried out by hand, it may be practiced in a highly advantageous manner by means of an apparatussuch as shown in FIGS. -14, 14a and The apparatus which is shown in a simplified and dia grammatic manner in FIG. 14 includes a headstock 156 and a tailstock 158 to hold a blank or workpiece 160 in the usual rotarymanner for the removal of material therefrom. The headstock and tailstock are mounted on a common bed plate 162 that slides in'a way 164 in a fixed base 165 and is controlled by a screw 166. The screw 166 is threaded into an upward projection 168 of the base and is manually operable by a hand crank '170. -F or rota-' tion of the workpiece or blank 160 in a well known manne-r, the headstock 156 has an axial drive shaft 172. The shaft 172 may be provided with a drive sheave 174 that is actuated by a V-belt 175 from a suitable power source.

The apparatus holds and operates a material-removing element 176 which preferably is a rotary tool in the form of an end mill. described embodiment of the invention, the end mill 176 is of the same diameter as the previously described rotary For shaping the rotor 38 of the above sealing element 58. Any suitable arrangement may be provided to actuate the end mill 176 and to advance the end mill against the blank 160 in the required synchronization with the rotation of the blank by the headstock through a fixed member 184 and is manually rotatable by a hand crank 185.

Journaled in the outer ends of the two yoke arms 180 is a driven shaft 186 which is provided with a driven sheave 188 and a gear 190. The driven sheave 188 is connected by a V-belt 192 to a drive sheave 194 on a. vertical drive shaft 195. The drive sheave 194 is slidable along the drive shaft 195 in engagement with extensive splines 196 so that it may be adjusted on the drive shaft in accord with various levels of adjustment of the support 'yoke 178.

Hingedly mounted on the driven shaft 186 is a spindle housing 198 in which is journaled an upright shaft 200 for rotating the end mill 176, the end mill being releasably connected with this upright shaft in a well known manner. A gear 202 on the upright shaft 200 is in mesh with the previously mentioned gear 190 for actuation of the upright shaft. By virture of this arrangement the gear;

surrounded by a larger ring 205 which is integral with and extends upward from an arm 206 in the form of aheavy plate, this arm being-rotatably mounted on the previously mentioned driven shaft 186. .Thus the ring 205 and the neck 20,4 of the spindle housing both pivot about the axis of the upright shaft 200 with the. axis of the ring and the axis of the neck atthe same radial distance from the axis of the driven shaft. .The purpose of this arrangement is to perrnit the neck 204' of the spindle housing 198 tov be shifted between two alternate positions inside the ring 205 to allow for the thickness of therotor blade. For the purpose of positioning the spindle housing 198 at the two alternate positions relative to'the ring 205, the ring has two threaded bores 208 and 210 in'which a suitable set screw 212 may be threaded alternately to crowd the spindle housing neck 204 against one or the other side of the ring. Thus, in FIG. 15 the set screw 212 is threaded into the-bore 208 to. hold the spindle housing neck 204 firmly against the opposite side of the ring. g

In the present embodiment of the apparatus, the spindle housing 198 is moved along its arcuate path by an actuator in the form of a Scotch yoke member 214 that operatively engages the ring 205. As shown in FIG. 14a, the Scotch, yoke member has an elongated opening or slot'215 with parallel edges in snug sliding'engagernent with the periphery of the ring 205. j

The 'Scotch .yoke member 214'is mounted for longitudinal sliding movementin a suitably supported guide sleeve 216 and is shaped at its second end to provide a second slot 218 that is parallel to thefirst slot 215. The

second slot 218 is in snug sliding fit with acrank pin 220 that extends upward froma disk 222 on a vertical driven shaft 224. The vertical driven shaft 224 is actuated in any suitable manner in synchronism with the axial shaft 172 of the headstock'156, so that a single rotation of the disk 222 occurs simultaneously with a single rotation of the rotor blank 160. For this purpose a gear 225 on the headstock shaft 172 may mesh with an idler gcar'226 which meshes in'turn with a third gear 228. The third gear 228 is on a counter-shaft 230 that carries a bevel gear 232 in mesh with a bevel gear 234 on the vertical driven shaft 224.

The manner in which the described apparatus serves its purpose-is apparent from the fact that the arcuate path of the end mill 176 corresponds in position and curvature to the arcuate path of a rounded edge of the slot of the previously described reciprocative abutment 44 of the rotary device. The movement of the end mill along its path is synchronized Withthe rotation of the headstock shaft 156 in the same manner as the movement of the reciprocatlve abutment is synchronized with the rotation of the rotor 38in the previously described rotary device.

' Thus, in the course ofa half of a revolution of' the. rotor blank in FIGr14, the end mill 176 advancesalong an arcuate path 1n one direction generally longitudinally of the axis ofrotation of the blank and in the nexthalf revolution returns in the opposite direction in the same synchronized manner-along the same path.

By virtue'of the Scotch yoke arrangement, the move arcuate path, the lower end of the end mill is of sufficient diameter to be tangential at all times to the desired cylindrical curvature of the rotor hub 36 and thus shapes the hub as well as the rotor blade 46.

FIG. 16a shows three positions of the end mill 176 along its path of movement when the apparatus is adjusted as indicated in FIGS. 14, 14a and 15. The spindle housing 198 is at its right limit position with the housing neck 204 at the right position in the ring 2555 for shaping the right face of the rotor blade 40, as the rotor blank 16% is viewed in FIG. 14. It is the acceleration of the end mill to maximum speed of lateral movement at the midpoint of its range of lateral movement that causes corresponding maximum pitch of the rotor blade 40 at the point midway between the two end Walls of the chamber.

When the rightward face of the rotor blade and the rightward portion of the rotor hub have been shaped by the arcuate movement of the end mill 176 along the path Shown in FIG. 16a, the apparatus is adjusted to advance the end mill against the rotor blank from the opposite side of the blank in the manner indicated diagrammatically in FIG. 16]). For this purpose, the setscrew 212 is withdrawn from the position shown in FIG. and is threaded into the second threaded bore 216 to force the neck 204 of the spindle housing 198 against the opposite side of the ring 205. The end mill 176 is then advanced against the rotor blank in the same synchronized manner to form the second face of the rotor blade 40.

Since the hand crank 170 may be rotated to shift the position of the rotor blank 160 along its axis, it is apparent that the thickness to which the rotor blade 40 is cut may be adjusted. Such adjustment may be made, for example, to oversize the thickness of the rotor blade to compensate for shrinkage when the rotor shaped by the apparatus is to be used as a pattern for casting a rotor. It is further apparent that the thickness of the rotor blade shaped by the apparatus may be undersized to form the previously described steel core 138 or a pattern for the steel core. Thus, in preparing for the fabrication of a rotor having a steel core and a plastic sheath, the described apparatus is used to make a pattern for the steel core of the rotor and is used again to make a second pattern for the investment casting.

Although the now preferred practice of the invention has been shown and described herein, it is to be understood that the invention is not to be limited thereto, for it is susceptible to changes in form and detail within the scope of the appended claims.

I claim:

1. An apparatus for shaping a rotor with a blade of undulating configuration and having a radially variable thickness for sealing cooperation of the two faces of the blade with two corresponding spaced rounded edges of a reciprocative abutment in a rotary device of the character described, said apparatus comprising: means to mount a rotor blank for rotation about an axis therethrough; a material-removing element of rounded con figuration corresponding to the rounded configuration of said edges; a holder for said material-removing element, said holder being pivoted to advance said element in an arcuate path conforming to the arcuate path of a curved 'reciproc'ative abutment; means to actuate said element for removal of material from said blank; means to rotate said blank about said axis in accord with the intended rotation of the rotor in the device; and means operatively connected with said holder to advance said element laterally against said blank in accord with the intended path of the corresponding one of said edges relative to the rotor in the device and with the same synchronism relative to the rotation of the blank as the intended synchronism of said one edge relative to the rotation of the rotor,

thereby to remove material from the blank to shape one face of the undulating blade.

2. A combination as set forth in claim 1 in which said advancing means includes a Scotch yoke mechanism operatively connecting said pivoted holder with said blankrotating means.

3. An apparatus for shaping a rotor with a blade of undulating configuration and having a radially variable thickness for sealing cooperation of the two faces of the blade with two coresponding spaced rounded edges of a reciprocative abutment in a rotary device of the character described, said apparatus comprising: means to mount a rotor blank for rotation about an axis therethrough; power means to rotate said mounting means for rotation of the blank on said axis; a rotary cutter of a cylindrical configuration corresponding to the rounded configuration of said edges, said rotary cutter being positioned with its axis substantially perpendicular to the axis of said mounting means; a holder for said material-removing element, said holder being pivoted to swing about a third axis parallel with the axis of the material-removing element whereby the holder may be swung laterally to advance the material-removing element against a rotor blank on said mounting means; and means operatively connected to said mounting means for rotation thereby synchronously therewith to accelerate said holding means sinusoidally in synchronism with the rotation of the blank.

4. A combination as set forth in claim 3 in which said means for accelerating said holder sinusoidally comprises a. crank operated by the blank-rotating means and a Scotch yoke operated by the crank and connected to said holding means.

5. Apparatus for shaping a rotor With a blade of undulating configuration which has a variable circumferential and radial thickness comprising:

means to rotate a rotor blank about a first axis of rotation,

a material removing element adapted to rotate about a second axis of rotation,

said second axis of rotation being perpendicular to the said first axis of rotation,

a pivoted holder for said material removing element,

a connecting rod pivoted at one end thereof about a third axis of rotation which is parallel to the said second axis of rotation,

said holder being attached to the second end of said connecting rod,

synchronous means connected between said holder and the means to rotate the rotor blank, whereby rotation of said rotor blank will be accompanied by a rotation of hold about said third axis.

6. Apparatus as set forth in claim 5 whereby the plane of the first axis of rotation which extends perpendicular to the plane of the arcuate path of said holder bisects said arcuate path at two discrete points.

UNITED STATES PATENTS References Cited by the Examiner 564,800 7/96 Price 15 2,853,766 9/58 Wellington 29-1564 2,921,505 1/60 Hoglund 90-15 2,925,648 2/60 Aspelin 29-156.4 2,949,065 8/60 Kulusic 90-15 FOREIGN PATENTS 133,583 10/19 Great Britain.

WILLIAM W. DYER, JR., Primary Examiner. I. SPENCER OVERHOLSER, Examiner.

Claims

1. AN APPARATUS FOR SHAPING A ROTOR WITH A BLADE OF UNDULATING CONFIGURATION AND HAVINGA RADIALLY VARIABLE THICKNESS FOR SEALING COOPERATION OF THE TWO FACES OF THE BLADE WITH TWO CORRESPONDING SPACED ROUNDED EDGES OF A RECIPROCATIVE ABUTMENT IN A ROTARY DEVICE OF THE CHARACTER DESCRIBED, SAID APPARATUS COMPRISING; MEANS TO MOUNT A ROTOR BLANK FOR ROTATION ABOUT AN AXIS THERETHROUGH; A MATERIAL-REMOVING ELEMENT OF ROUNDED CONFIGURATION CORRESPONDING TO THE ROUNDED CONFIGURATION OF SAID EDGES; A HOLDER FOR SAID MATERIAL-REMOVING ELEMENT, SAID HOLDER BEING PIVOTED TO ADVANCE SAID ELEMENT IN AN ARCUATE PATH CONFORMING TO THE ARCUATE PATH OF A CURVED RECIPROCATIVE ABUTMENT; MEANS TO ACTUATE SAID ELEMENT FOR REMOVAL OF MATERIAL FROM SAID BLANK; MEANS TO ROTATE SAID BLANK ABOUT SAID AXIS IN ACCORD WITH THE INTENDED ROTATION OF THE ROTOR IN THE DEVICE; AND MEANS OPERATIVELY CONNECTED WITH SAID HOLDER TO ADVANCE SAID ELEMENT LATERALLY AGAINST SAID BLANK IN ACCORD WITH THE INTENDED PATH OF THE CORRESPONDING ONE OF SAID EDGES RELATIVE TO THE ROTOR IN THE DEVICE AND WITH THE SAME SYNCHRONISM RELATIVE TO THE ROTATION OF THE BLANK AS THE INTENDED SYNCHRONISM OF SAID ONE EDGE RELATIVE TO THE ROTATION OF THE ROTOR, THEREBY TO REMOVE MATERIAL FROMTHE BLANK TO SHAPE ONE FACE OF THE UNDULATING BLADE.