US2951470A

US2951470A - Oscillating actuator

Info

Publication number: US2951470A
Application number: US690336A
Authority: US
Inventors: Richard E Self
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-10-15
Filing date: 1957-10-15
Publication date: 1960-09-06
Anticipated expiration: 1977-09-06
Also published as: FR1214956A

Description

Sept. 6, 1960 R. E. SELF oscILLATING AcTUAToR 2 Sheets-Sheet 1 Filed Oct. l5, 1957 @n E Q vm. .mn

mm mm. UWM. Nm'

Sept. 6, 1960 R. E. SELF 2,951,470

OSCILLATINGMACTUATOR l Filed oct. 15, 1957 2 sheets-sheet 2 INVENTOR. R/CHHRD E. `'SELF ATTORNEY-5 United States Patent OSCILLATING ACTUATOR Richard E. Self, Sherman Oaks, Calif. (8354 Wilcox Ave., Bell, Calif.)

Filed Oct. 15, 1957, Ser. No. 690,336

Claims. (Cl. 121-99) This invention relates to oscilating devices of the pressure fluid type, including such devices known as actuators, which are prime movers or motors, and dampeners or shock absorbers where rotary or vibrating-motion is dampened by restricting or metering the iiow of fluid pressure through the device, and has as its general object to provide an improved uid sealing mechanism in such a device.

A further object of the invention is to provide an improved oscillating device embodying a rotor having one or more (eg. a pair of) radial vanes projecting (e.g. in diametrically opposite directions) from a generally cylindrical hub, and having a pair of circular end members to which the axial extremities of said vanes are united, together with improved means for sealing the rotor to the mating internal surfaces of a housing embodying a generally cylindrical lateral wall portion and a pair of diametrically opposed reentrant partitions extending radially inwardly, in diametrically opposed relation, to the diameter of the rotor hub, and defining the circumferential extremities of arcuate cavities in which the vanes of the rotor are areuately movable between limit positions established by the radial sides of such partitions, the circular end members of the rotor being oscillatable in circular spaces between theaxial extremities of the partitions and the ends of the housing.

A further object is to provide, in an oscillating actuator or similar device having the construction outlined in the preceding paragraph, an improved seal mechanism for effectively sealing the vanes of the rotor to the walls of the arcuate cavities so as to provide non-leaking fluid pressure chambers upon respective sides of each vane Within its respective cavity, whereby to increase the eiiiciency and the accuracy of response of the rotor to the flows .of iiuid into and out of the respective chambers, and especially to avoid bypassing of Huid from one chamber to another of a pair of adjacent iiuid pressure chambers.

In particular, the invention aims to provide a sealing mechanism wherein each of the respective fluid pressure chambers is provided with a respective seal which extends unbrokenly around the complete perimeter of the respective chamber in a. manner to seal off all crevices between the rotor and the housing entirely around such perimeter. In this respect the invention provides a novel and important improvement over conventional sealing arrangements arranged in broken array Awith reference to the perimeters of the various fluid pressure chambers. For example, one common sealing Aarrangement wherein a seriesof straight sealing strips extending parallel to the rotor axis along the radially outer extremities of the rotor vanes, are terminated at the ends of the rotor, and wheref in`a pair of circular O-rings extend unbrokenly around and coaxial with the rotor axis between the respective ends of the rotor and housing, has proven to be quite unsatisfactory for completely preventing leakage between adjoining fluid pressure chambers despite all attempts to attain uid tight joints between the ends of the straight sealing strips and the ends of the housing.

ICC

Other objects and advantages will become apparent in the ensuing specifications and appended drawings in which:

Fig. 1 is an end View of an actuator embodying the invention;

Fig. 2 is a transverse sectional view of the same;

Figure 3 is an axial sectional view of the same taken on the line 3-3 of Fig. 2 with a portion thereof shown in elevation;

Fig. 4 is an enlarged detail sectional view of a fragmentary part of the rotor hub;

Fig. S is an exploded perspective view showing the assembled rotor as it would appear without the housing and showing the housing fragmentarily and with a portion thereof broken away and shown in section;

Fig. 6 is a fragmentary detail sectional view of an end portion of the rotor taken on the line 6 6 of Fig. 5;

Fig. 7 is a fragmentary detail sectional View of the outer marginal portion of a rotor vane; and

Fig. 8 is a fragmentary sectional View of a modified form of the seal.

Referring now to the drawings in detail, I have shown v therein, as one form in which the invention may be embodied, an oscillating actuator embodying, in general, a rotor A (Fig. 3) and a housing B in which the rotor A is mounted on an actuator shaft C (Fig. 2).

Rotor A is formed in two sections a and a' respectively7 joined end to end at a radial parting plane 10, and secured together by cap screws 11 extended through bores in the section a and threaded into the section a. An O-ring 10', seated in an annular end-face groove in one of the rotor sections, maintains a hermetic seal between the rotor sections at parting plane 10. This sectional construction makes it possible to assemble the rotor within the housing B, the respective sections of the rotor being inserted through respective ends of the housing Iwhich are open during assembly, and the rotor sections being securedA to one another after being thus inserted into the housing.

In its assembled form, the rotor A includes a generally cylindrical hub portion 12, a pair of radial vanes 13, and a pair of

circular end members

14, 14. The end

mem# bers

14, 14 are formed integrally in the respective sec` tions a, a' and the hub 12 and vanes 13 are formed sec# tionally in the respective sections a, a', the hub and vane sections being joined integrally to the inner sides ofthe respective end members 14, 14'. The vanes 13 are rectangular, extend full length between the end members 14, 14', and have radially outward faces 15, parallel Ato the rotor axis, disposed at the same diameter as the generally cylindrical peripheral faces of rim portions 16 of the end members 14, 14', and merging with said periph eral faces. The rim portions 16 are joined to the hub portions 12 of the respective rotor sections by frustoconical end web members 17 which terminate in cylindrical hub collars 18 (Fig. 3) defining annular recesses the bottoms of which are defined by end shouldersV 19 of the hub sections. Y l

Extending through the hub 12, which is tubular, is a peripherally splined central body portion 20 of the shaft C, the hub 12 having internal splines meshing with the splines of the body 20. At one end of the body 20, shaft C has an end bearing flange 21 -which seats against one of the shoulders 19. A retainer nut 22 is threaded upon a threaded section 23 of the other end of shaft body 20, and is tightened against the other shoulder 19 to maintain the rotor sections a and a and the shaft C in tight assembly.

Beyond the flange 21 and threaded section 23, shaft C has reduced, splined

end studs

24, 25 respectively for torque-transmitting coupling to mechanism with which the actuator may be associated. n

` The rotor A is provided with grooves to receive four seal rings D of irregular perimeter. Such grooves include a pair of circular groove portions 26 in the peripheral faces of the end member rims 16, radial groove-portions 27 in the inner faces of the fusto conical webs 17 of the respective end members 14, 14', joined to the respective circular grooves 26 by short axially extending groove portions Z8 in those portions of the rim members 16 which lie inwardly of the grooves 26, bottom groove portions 29 extending axially in the outer faces of hub 12 and joined to the inner extremities of the radial groove portions 27, and straight outer groove portions 30 in the marginal faces 15 of vanes 13, extending be'- tween and joining the respective circular ,groove portions 26. Groove portions 2 7, 28 and 29 have a common width substantially twice the cross sectional diameter of the seal rings D, and accommodate

stretches

31, 32 and 33 of two adjoining seal rings lying side by side as shown in Fig. 5. The

groove portions

27, 28 and 29 are duplicated on both sides of the rotor in diametrically opposed relation, the

adjoining streches

31, 32 and 33 of the seal rings D in these groove portions being in contact with one another on a common` diametral plane of the rotor axis. Groove portions 3i) (Fig. 7) likewise are of substantially twice the width of theseal ring cross section and accommodate contacting outer straight stretches 34 of adjacent seal rings extending, at the periphery of the rotor, between the 90 quadrant Vend stretches 35 of respective seal rings, which end stretches 35 in each seal ring join the ends of outer straight stretch 34 thereof to the short axial portions 32.

The housing B comprises a cylindrical lateral portion 36 having therein a pair of diarnetrically

opposed housing portions

37 and 37. The housing portions 37 and 37' comprise respective pairs of radial wall portions 38, 38', pairs of end wall portions 39 and respective quartercylindrical bottom wall portions 4t), v10. The

radial portions

38, 38 have radial inner walls which define the limits of arcuate swinging movement of rotor vanes 13, and cooperate with the vane 13, the hub 12, the lateral housing wall 36 and the rotor end members 14, 14' to define fluid pressure chambers 41 (Fig. 2). The

bottom wall members 40, 40' have quarter-cylindrical inner faces which are fitted to the hub` 12 so as to be swept by and constantly sealed to the straight bottom stretches 33 of the seal rings D. The quarter cylindrical portions of lateral wall member 36 bridging between the

radial wall members

38, 38 have quarter-cyclindrical inner walls 36 which are fitted to the straight outer margins 15 of the vanes 13 so as to be swept by and in constant sealing contact with the outer straight stretches 34 of the seal rings D. The

radial portions

31 and 32 of the seal rings are in sealing engagement with the end wall members 39 of the housing housing portions 37, 37', and with end portions 36a of the lateral walls 36 which are continuously cylindrical throughout the circumference of the housing. The arcuate end portions 35 of the seal rings seal against the cylindrical inner walls of the end housing portions 36a.

It will now be apparent that each of the -four fluid pressure chambers `41 is completely circumscribed by a respective seal ring D which provides a continuous huid seal between the adjoining parts of the rotor and the housing around the complete perimeter of the respective chamber 41, regarded as being extended at its bottom in the narrow arcuate clearance space between the hub '12 and the bottom wall 40 (or 40') to the bottom stretch 33 of the respective seal ring. Since the fluid pressure chamber is thus circumscribed completely by a continuous seal ring, there is no point Where any leakage of fluid from one chamber to an adjacent chamber can occur and there is no point where leakage from the end of the housing can occur.

The housing B is provided with respective end caps 4Z tted into the annular recesses defined in the respective ends of rotor A and each is provided with a cylindrical rim 43 having an annular shoulder which bears against a gasket ring 44 sealing the cap in a counterbore 45 in the cylindrical end portions 36a of the housing, each cap 142, being threaded into a respective counterbore 45, and each having a radial inner end collar provided with an annular internal groove receiving an O-ring 46 by means of which it is sealed to the hub collar 18 of rotor A.

In one of the end caps 42. there is provided a fluid pressure port 47 (preferably a single port as shown in Fig. 3) which conveys pressure uid from a pressure line of the system to the end space between that end cap and the adjacent end of the rotor. Such pressure fluid, bleeding through the annular crevice 16 between rotor rim 16 and the housing end 36a, will travel in the crevices between the adjoining seal stretches 33 and 34 (forcing them apart, amplifying their cross-sectional distortion, and increasing their sealing efliciency) and will reach the annular end space between the opposite end of the rotor and its adjacent end cap, thus endloading the sections of the rotor at both ends to maintain tight contact at the parting plane 10, As shown in Fig. 1, several pressure ports 47 may be optionally provided in respective end bosses 43 which may be drilled and tapped as indicatedl in Fig. 1 for attachment of respective connections to a fluid pressure line. The

end studs

24 and 25 are adapted for driving connection with instruments or other parts of apparatus in either driving or driven connection with the actuator.

In the housing portion 37 of the housing B, there are provided fluid inlet and outlet ports 49 the outer end of which may be counterbored and tapped as indicated, for attachment of iluid line fittings through which uid may be directed into one of the chambers 41 and drained from an alternate chamber. Transfer ports 50 extend diagonally through the rotor A to provide intercommunication between diametrically opposite, paired chambers 41 so that uidv pressure applied to one chamber of a pair is simultaneously transmitted to the other chamber of the pair while the fluid in the alternate pair of chambers is drained from the remote chamber of that pair to the near chamber directly connected with a uid port 49 and thence from the near chamber through such port 49.

The housing, on the sides adjacent the ported reentrant section 37', may be provided with lips 51 for purposes of side mounting the actuator against a flat wall through which the tduid lines may extend.

As shown in Fig. 8, the seal rings, instead of being of 0ring cross section and of soft, compressible material, retained in a groove as in Figs. 1-7, may be of thin ribbon metal of spring metal characteristic, welded, brazed or otherwise secured and sealed to the various surfaces of rotor A along the same contours as in Figs. 1-7, and in fluid pressure energized and yielding spring pressure contact with the opposed surfaces of casing B,

for high-temperature operation.

As shown, the seal rings D' are preferably seated in grooves in the various rotor surfaces as in the preferred form of the invention previously described, including groove portions 30' extending axially in the marginal outer extremity faces 15 of vanes 13', leaving bearing lands on both sides of the groove portions, for'positive positioning of the rotor within the housing, with all torque reaction loads, radial loads, etc., being taken between such bearing lands and the mating su-rfaces of the housing.

While a device embodying a two-vane rotor and a housing which correspondingly has vane chambers and separating partitions each of quadrant extent, it will be understood that the invention can be embodied in a single-vane device having a vane chamber and a partition member both of greater than 90 extent, or in a device having three or more vanes and corresponding vane chambers and partitions of less than 90 arcuate extent.

I claim:

1. A device of the type described that comprises a rotor including a rotor shaft, a housing enclosing said rotor and supporting said rotor and shaft for oscillation therein, said rotor having a center portion of generally cylindrical shape and end portions of generally circular shape and of larger diameter than said center portion, and at least one vane extending radially and axially from said center portion and between said end portions to aA radius substantially equal to that of said end portions, said housing having at -least one housing portion extending axially and radially of said rotor into the space provided between said end portions of said rotor and the wall of said housing and said center portions of the rotor, thus, dividing the space between the center portion of the rotor and the housing into at least two pressure chambers, said housing having pressure openings into each of said chambers, a continuous gasket extending along the outer surface of the aforementioned vane to the circular end portions of the rotor, thence, peripherally around the circular end portions of the rotor to a position that will be opposite to the aforementioned housing portion in any position of oscillation of the rotor, and from there down the inner faces of the said end portions and across the center portion to complete the continuity.

2. A device of the type defined in claim l further characterized in that at least two continuous gaskets are provided which extend along the outer surface of the vane to the circular end portions of the rotor, and thence peripherally in opposite directions around the circular end portions of the rotor to positions that will be opposite to said housing portion in any position of oscillation of the rotor, and from there down the inner faces of the end portions and across the center portion to complete the continuity of each of the two continuous gaskets.

3. A device as defined in claim 2 in which the gaskets are held in continuous grooves in the rotor surface.

4. A device as dened in claim l further characterized in that the rotor has at least two vanes and the housing has at least two portions thus forming at least four pressure chambers, two of which are connected through openings in the housing and the other two of which are connected to the first two through openings in the rotor, the rotor in this instance carrying at least four gaskets, each gasket being continuous and extending longitudinally along the outer surface of a vane and then along the outer surface of the two end members to a position that will be opposite to one of said housing portions in any position of oscillation of the rotor and from there down the inner face of the end portion and across the hub to complete the continuity.

5. A device as deined in claim 4 in which the gaskets are held in continuous grooves in the rotor surface.

References Cited in the le of this patent UNITED STATES PATENTS 540,492 Humes June 4, 1895 2,164,876 Horlacher Iuly 4, 1939' 2,569,640 Mercier et a1. Oct. 2, 1951