US2393204A - Fluid operated motor - Google Patents

Description

Jan. is, 1946; R, F TAYLOR 2,393,204.

FLUID OPERATED MOTOR Filed Jan. 10, 1944 INVENToR.

, RHODE/wc E TA /L of? ATTORNEY Patented Jan. 15, 1946 2,393,204 FLUID orEnA'rEn Moron Rhoderio F. Taylor, East Cleveland, Ohio, assignor to The Marquette Metal Products Company, Cleveland, Ohio, a corporation of Ohio Application `lanuary 10, 1944, Serial No. 517,635

Claims.

This invention relates to fluid operated motors and more particularly to a, hydraulically operated motor of the moving vane type suitable for use as the prime mover of a windshield wiping mechanism but having many other applications.

A vane contained within a closed chamber and reversibly swingable about a fixed axis through a portion of a circular path in response to fluid pressure changes on opposite sides of the vane forms an emcient and simple means for driving a power take-off shaft with alternate rotary motion. However, the fluid flow controlling mechanisms of prior motors of the vane type are complicated and inefficient and therefore substantially nullify the advantages provided by the power producing means. l

In the motor of the present invention, the iiuid fiow controlling mechanism and the power producing mechanism cooperate with each other and with the motor housing in a novel and improved manner which not only greatly reduces the initial cost of the motor but also renders the motor. more eicient and reliable than prior prime movers of a similar type. This cooperative relationship permits the use of an unique and greatly simplified -valve actuating means. Furthermore, an improved and very rugged vane construction in accordance with this invention reduces uid leakage around the vane to a minimum without increasing the frictional loss or otherwise impairing the operation of the motor.

The improved motor hereof produces a large torque in relation to its size and weight making it ideally suitable for installation in aircraft or other vehicles wherein special consideration must be given to the torque-weight ratio. In l addition, the fluid consumption of the motor is low, and the few moving parts render the motor reliable and capable of operating for long periods without attention. The motor also meets other exacting requirements of aircraft installations, for example, such as ease of repair, capability of operating in any position, and flexibility of design to permit pre-selection of the extent of angular movement of the power take off shaft.

An object of this invention is to provide a fluid operated motor of the vane type which overcomes the aforementioned disadvantages and which meets the foregoing requirements.

Another object is to provide a vane type fluid operated motor in which the motor housing, uid controlling mechanism and power producing mechanism cooperate in an improved manner to produce a simple and inexpensive yet rugged and eflicient machine.

Further objects are to provide a fluid operated motor of `the vane type having a simplified and improved valve operating means, having an eicient uid ow controlling mechanism, and having a vane of laminated construction.

Other objects and advantages will become apparent from the following description wherein reference is made to the drawing, in which Fig. 1 is a sectional view of the motor taken along the line I- I of Fig. 2;

Figs. 2, 3 and 4 are sectional views taken along the lines 2 2, 3-3 and li-Il, respectively, of Fig. 1, and

Figs. 5 and 6 are fragmentary sectional views taken along the lines 5-5 and 6 6, respectively, of Fig. 1.

Referring further to the drawing, a housing for the motor comprises a pair of generally cupshaped body members I0 and l I having end walls I2 and It, respectively, and having their open ends disposed toward each other on opposite sides of a plate l5 which forms a dividing wall between chambers I6 and I8 defined within the members lll and II, respectively. The members Il! and II and the plate I5 may be held in assembled relation by a plurality of cap screws l9'whlch extend through aligned openings in side walls of the member I0 and in the plate I5 intol threaded sockets in side walls of themember ll.- Suitable gaskets 20 may be interposed between the abutting surfaces of the plate l5 and the members I0 and II, respectively.

The body members l0 and ll are preferably of generally segmental, circular shape in planes parallel to the planes of the open faces of the body members; and the contour of the plate I conforms to that of the adjacent outer surfaces of said members. The chamber I6 is also of segmental circular shape in planes parallel to the principal .plane of the plate I5 and has a wall surface 2| constituting part of a cylinder and generally radial, planar side wall surfaces 22 and 2t joined at their convergent edges or margins by a partially cylindrical or cylindric wall surface 25 which is concentric with the cylindric surface 2|. The chamber I8 is preferably similar in shape to the chamber I6, and the end wall It has a thickened portion 26 extending into the chamber I8 at the end of the member Il through which the axis of the surfaces 2| and 25 passes.

A power take-off shaft 28 of the motor may have an elongated exterior portion adapted to pass freely through an opening in a window or windshield frame (not shown) and terminating in a splined portion 29 and a threaded portion 3Q ward end portion vslot in the shaft portion 35.

for attachment of a windshield wiper blade drive arm (not shown) or other device to be oscillated by the motor. The shaft 28 is rotatably supported in an opening in the end wall AI2 which is co-axial with the cylindric surfaces 2| and 25 and which is counterbored from its inner end to define an annular shoulder 22. The radius of the counterbore is slightly less than the radius of the surface 25.

An enlarged portion 34.0f the shaft 28 defines an annular shoulder which abuts the shoulder 32 to prevent outward axial movement of the shaft, and the outer surface of `a further enlarged portion 85 of the shaft fits closely but rotatably against the surface 25. The shaft portion 35 is axially spaced from a further reduced inner rear- 25 of the shaft by opposed transverse radial slots which define a central diametral shaft section 38:

The outer end of the opening in the Wall I2 is counterbored to receive a threaded annular sealing plug 38 which surrounds the shaft 28 and holds an elastic annular sealing ring 4B in fluid sealing engagement against both the bottom of the counterbore and the peripheral surface of the shaft.

An axial and radialslot in the portion 35 of the shaft 28 lies in a plane substantially parallel to the plane of the shaft section 38 and receives an offset narrowed end portion of a power displace- -ment member in the form of a vane 4I which is made substantially rigid with the shaft as by suitable cross pins or rivets connecting the vane and shaft.

The vane 4I comprises a generally rectangular, planular elastic member 44 of synthetic rubber or the like interposed between a pair of rigid plates 45 preferably of metal, the member 44 and plates 45 being held in assembled relation by the rivets 42 and the pressure of the side walls of the Preferably the free portions of the plates 45 are pre-stressed toward each other slightly as by bowing the sheet metal. The member 44 is slightly longer and wider than the plates 45 and has its side edges bearing against the inner surface of the wall I2 and the opposing wail surface defined by plate I5, respectively, and its outer lateral edge bearing against the wall surface 2|, whereas the edges of the plates 45 are disposed a slight distance from the adjacent wall surfaces, respectively. The vane 4I in conjunction with the shaft 28 thus divides the chamber I6 into two fluid tight portions and the vane is free to swing about the axis of the shaft 28 to drive the shaft with alternate rotary motion in a manner to be described later herein.

The inner end portion36 of the shaft 28 is rotatably supported in a valve sleeve 45 which is pressed into a, complementary socket formed in the thickened portion 25 of the wall I4 and fitting snugly into an opening in the plate I aligned with the socket. A valve cylinder 48 constituted by a cylindrical body of metal of the same diameter as the shaft portion 36 and aligner' therewith is also rotatably received within the sleeve 45 and is disposed between the inner end of the shaft 28 and the bottom of the socket formed by the sleeve and endwise adjacent body wall, thereby limiting or preventing inward axial movement of the shaft.

A substantially rigid crank arm 49 pressed into a radial opening` in the valve cylinder 48 extends into the chamber I8, and a similar crankarm 50 is pressed into a radial opening in the shaft portion 36. Both crank arms extend into the chamber Il, the sleeve 4l having an axial slot 8| providing clearance for limited movement of the crank arms. As shown moet clearly in Fig. 3, the portion of the slot 5I through which the crank arm 4l passes is slightly narrower than the portion through which the arm 50 passes and defines spaced stopping surfaces 5Ia and 5Ib for the crank arm 48. The outer ends of the crank arms 48 and 58 are normally biased by a helical compression spring 52 to one of two spaced apart positions causing the valve cylinder 48 and the shaft 28 to have two normal relatively turned positions.

One end of the spring 52 is secured to the arm 48 in a suitable manner to permit the spring to swing about the end of the arm 48 as a center. As shown, a straightened end portion of the spring 52 passes through an opening in the end of the arm 48 and is bent over to hold the spring securely while permitting limited free rotary movement of the arm. The other end of the spring 52 is secured to the end of the arm 50 as by means of a single coil loop within a circumferential groove on a bent over portion 54 of the arm 50.

The valve cylinder 48 is provided with diametrally opposed transverse radial slots which define, with the sleeve 45. a pair of valve chambers 55 and 55; and diametrically opposed radial ports 58 and 58 are formed in the sleeve 46 in the plane of the valve chambers.

A pipe threaded inlet port 58 and a pipe threaded outlet port 5l are formed in the body member Il on opposite sides of the valve cylinder G5 for receiving suitable duid conduits or couplings 52 and 64, respectively. Passages 55 and 35 extend from the ports 5I and 58, respectively, through the thickened portions 28 of the member II and intersect the sleeve 45 (Fig. 2) adjacent to the ports 58 and 58 with which the passages communicate, respectively. Displaced ninety degrees from the ports 55 and 55 are diametrically opposed longitudinal grooves 55 and 59 formed as half drill bores in the interior wall surface of the sleeve 48 and opening, at their innermost ends, into the chamber I5. As shown most clearly in Figs. 5 and 6, the openings from the chamber I5 into the grooves 55 and 58 are continuously on opposite sides of the diametral shaft section 35.

Further structural features of the motor will become apparent from the following description of operation of the mechanism.

With the moving parts of the motor in the solid line position shown in the drawing, fluid entering the inlet port 50 from a suitable source of fluid pressure (not shown) flows through the passage 55, the port 59, the valve chamber 55, and the groove 58 into the chamber I6. The pressure of this fluid in the chamber I5 against the vane 4I swings the vane clockwise (Fig. 5) to effect rotary motion of the shaft 28. While the vane is swinging in this direction, iiuid already in the chamber I5 on theopposite side of the vane 4| is forced by the vane through the groove 58, the valve chamber 55, the port 58, and the passage to the outlet port 5 I.

Rotation of the shaft 28 clockwise (Fig. 5) causes counterclockwise movement of the arm 50 (Figs. 2 and 3) toward the arm 48 which movement effects compression of the spring 52 and rotates the spring counter-clockwise about its pivot point on the arm 48. At a predetermined point in the rotation of the shaft 25 determined by the position of the surface 5Ia, the arm 50 becomes aligned with the arm 49 and the spring 52 is compressed toits greatest extent. Continued movement of the arm 50 a few degrees beyond the aligned position (shown by broken lines in Fig. 3) causes the spring'52 to rotate the arm 49 clockwise (Figs. 2 and 3) away from the surface Ela with a snap action. The rotary movement of the arm 49 rapidly turns the valve cylinder 48 until the arm 49 engages the surface 5Ib.

As soon as the cylinder 48 reaches its turned position, fluid flows from the inlet passage 56 through the port 59, the valve chamber 55, and the groove 89 into the chamber I6. Due to the pressure of the fluid thus introduced into the chamber i8, the vane 4I swings counterclockwise (Fig. 5) and rotates the shaft 28 back to its initial position. During return movement of the shaft 28, the arm 50 again causes concurrent rotation and compression of the spring 52 until the arms 49 and 50 are in alignment. Slight movementpf the arm 4u beyond the aligned position, which is determined by the location of the surface Bib, permits the spring to expand and move the arm 49 from the surface Elb to the surface Bla with a snap action. The cylinder 48 is thus returned quickly to its initial position to permit repeated oscillatory movement of the shaft 28.

Fluid is discharged from the chamber I8 during return movement of the vane 4I through the groove 68, the chamber 56, the port 58, and the passage 55 to the outlet port 5I. Alternate rotary movement of the shaft 28 continues until iiuid under pressure is no longer supplied to the motor. I

It is obvious from the foregoing description of operation that by preselecting the width of the slot 5l between the'surfaces lila and 5Ib during manufacture, the extent of rotary movement of the shaft 28 and consequently of the sweep of a 'windshield wiper blade driven thereby can be varied to suit varied operating conditions. Furthermore, by altering the turned position of the sleeve 48 with respect to the normal positions of the arm 50, the wiper blade sweep can be made different on opposite sidesof the center line of the unit.

I claim: n

1. In a vane type fiuid motor, a casing comprising two segmental cup-shaped members with their open sides facing each other, an intermediate ,wall member generally closing communication between the cups, a shaft and piston vane assembly in one of the cup-shaped members in sealing contact with the innerwalls thereof and with said intermediate wall member, valve mechanism for thevmotor in the other vcup-shaped member and comprising a valve sleeve supported by the latter member and intermediate wall in alignment with the shaft and receiving and supporting one end of the shaft, a valve cylinder rotatably supported within the sleeve, said sleeve v being open at one side and spring connected arms projecting laterally from the valve cylinder and shaft through said open side of the sleeve and constituting a snap action mechanism for the valve mechanism.

2. In a fluid operated motor having a rotatable power take-off shaft driven by a vane swingable in a pressure chamber, passage means for conducting operating fluid to and from said chamber, fluid flow controlling means associated with said passage means and including a rotatable valve member at one end of the shaft in alignment therewith, crank arms extending outwardly laterally from said shaft and said valvel member respectively, a valve sleeve for said valve member surrounding the same and receiving said end of the shaft as a support therefor, and a spring interconnecting said arms andl normally biasing said arms apart. l

3. In a uid operated motor having a rotatable power take-off shaft driven by a vane swingable in a pressure chamber, passage means for conducting operating fluid to and from said chamber, fluid flow controlling means associated with said passage means and including a valve rotatable on the axis of the shaft, crank arms extending outwardly from said shaft and said Valve respectively, a compression spring interconnecting said arms and normally biasing said arms apart, the arm associated with said shaft being movable by said shaft toward said other arm to compress said spring, and said spring being operable at a predetermined point in the movement of said shaft to force said arms apart with a snap action.

4. In a fluid operated motor having a power take-off shaft driven with alternate rotary motion by a vane secured to said shaft within a pressure chamber, passage means for conducting operating fluid to and from said chamber, a valve cylinder for controlling the flow of fluid in said passages, a non-rotatable sleeve rotatably supporting said valve and having a longitudinal slot, crank arms secured to said shaft and said cylinder, respectively, the crank arm associated with said cylinder being disposed within said slot to determine the extreme turned positions of said cylinder, and means constituting a driving connection between said crank arms.

5. In a fluid operated motor having a power take-off shaft driven with alternate rotary motion by a vane secured to said shaft within a pressure chamber, passage means for conducting operating fluid to and from said chamber, fluid flow controlling means associated with said passage means for controlling the flow of fluid to said chamber and including a valve cylinder. means rotatably supporting said valve cylinder and said shaft concentrically, crank arms extending outwardly from said valve cylinder and said shaft, respectively. a compression spring interconnecting the outer ends of said crank arms and operable to drive the crank arm associated with said valve means upon rotation of said shaft to rotate the crank arm associated with said shaft.

RHODERIC F. TAYLOR.

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