US2706969A - Fluid-actuated motor assembly - Google Patents

Description

April 26, 1955 Q BANMSTER ETAL 2,706,969

. FLUID-ACTUATED MOTOR ASSEMBLY Filed Sept. 8, 1950 s Shets-$heet 1 ,4: FIG. I FIG 2 w I I FIG 3 I 37 36 3 45' I 45 I 39 l I 30 3/ fi :5 i L; I l /4 INVENTOR.

CLYDE E. BANNISTER a By WILLARD 0. EAKIN v ATTORNEY April 26, 1955 c. EQ' BAP lNISTER T L 2,706,969

FLUID-AQTUATED MOTOR ASSEMBLY Filed'Sept. 8, 1950 s Sheets-Sheet 2 INVENTOR. CLYDE E. BANNISTER a BY WILLARD o. EAKIN ATTORNEY April 26, 1955 Q N T ETAL 2,706,969

Q FLUID-ACTUATED MOTOR ASSEMBLY Filed Sept. 8, 1950 3 Sheets-Sheet '3 INVENTOR. CLYDE E'. BANNISTER a By WILLARD 0. EAKIN ATTORNEY United States Patent 2,706,969 FLUID-ACTUATED MOTOR ASSEMBLY Clyde E. Bannister, Houston, Tex., and Willard D. Eakin, Akron, Ohio; said Eakin assignor to said Bannister Application September 8, 1950, Serial No. 183,806 3 Claims. (Cl. 121-154) This invention relates to fluid-actuated motors and especially to the valve control of such motors, and is an improvement upon the motor described and claimed in Bannister U. S. Patent No. 2,254,641.

The chief objects of the eliminate atron of the auxiliary motor in reverse then further shiftthe latters ports.

More broadly stated, my chief objects are to provide an improved fluid-actuated motor having no dead center an requiring no reliance upon friction, inertia or an over-center spring for valve reversal.

its utility to the field of well drilling.

Of the accompanying drawings:

Fig. l is an axial section on line 11 of Figs. 7 and 9, with parts in elevation, of a well drilling assembly showing a motor assembly embodying the invention in its preferred form, with the parts at positions as in Figs. 5, 6 and 9.

ig. 2 is an elevation of the inlet valve of the auxiliary, valve-controlling motor.

is an elevation of the main-motor valve member, WhlCh is also a part of the auxiliary motor.

Fig. 4 is a fragmentary elevation of the shaft of the main motor, formed with an impeller vane, and showing a part of the main-motor valve member.

Fig. 5 is a fragmentary axial section with parts shown in elevation other than those so shown in Fig. l, and with the parts in positions as in Figs. 1, 6 and 9,

Fig. 6 is a section on line 66 of Figs. 1 and 5, showing the inlet valve of the auxiliary motor in the same position as in Figs. 1, 5, and 9.

Fig. 7 is a section on line 77 of Fig. 1.

Fig. 8 is a section at the same height as the sections shown in Figs. 9 to 11, but with the parts shown symmetrically positioned, as they are Fig. 9 is a section on line 9-9 of Figs. 1 and 5, with in the same positions as in those figures, with ports of the auxiliary motor closed, certain parts being stopped while others continue to rotate clockwlse.

Fig. 10 a section corresponding to that of Fig. 9, but showlng a later stage, with one of the exhaust during assembly only.

a reverse, counterclockwise, movement of all of the rotatable parts.

Referring first to Fig. 1 of the drawings, the assembly ground.

The assembly comprises a hollow, oscillating, mainmotor shaft 14 on the lower end of which is secured a drilling bit 15.

Formed integrally with the main-motor shaft 14 is a vane-type impeller or wing piston 16 which is driven back and forth in a pressure chamber defined by a fluid-abutment member 17 (Figs. 1 and 7), of which the upper end portion is so shaped as to serve as a bulkhead 18 in the motor casing, the floor of said prespresent in drilling fluid.

The main-motor shaft 14 is journaled in the two bulkheads, 18, 19, and a two-way thrust bearing 14a is interposed between the main motor shaft 14 and the easing 10.

in, is rotatably fitted in the hollow main-motor shaft 14 and at its open upper end is journaled in and extends through a central hole in an uppermost bulkhead 27. The bulkhead 27 defines, with the casing 10 and the inertia member 11, a chamber 28 in communication with the hole 12 in the inertia member, the valve member thus being adapted to receive the motive fluid at its open upper end.

For suitable coaction with the ports 21 to 24 in the wall of the hollow main-motor shaft 14 the main-valve member is formed with a main-motor inlet port 29 (Figs. 1, 3 and 7), above the partition 26 and registerable in alternation with the shafts motor- inlet ports 21, 22, and, below the partition 26, with a pair of mainmotor outlet ports 30, 31 so spaced that when the mainvalves motor-inlet port 29 is registered with the shafts motor-inlet port 22, as in Fig. 7, the main-valves exhaust port 30 will be with the shafts exhaust port 23 (directly below the port 21 in Fig. 7), and when the main-valves motor-inlet port 29 is registered with the shafts motor- inlet port 21, 31 will be registered (directly below the port 22 in Fig. 7)

e spacings of these ports are such (Fig. 7) that when the valve is in middle i and exhaust ports (22 and 23) being fully closed, and preferably with slight overlap, before the other pair (21 and 24) are opened, so that there is not at any time free flow of motive fluid through the motor, and this avoids lowering of the working pressure of the fluid, for actuating the auxiliary, valve-shifting motor about to be described. The entrapping of the motive fluid on the two sides of the impeller vane is of such infinitesimal duration, or is to such extent relieved by even a slight leakage, that it does not stop the impeller vane too abruptly.

The oscillating movement of the main valve 25 in relation to the main shaft 14 is limited by abutment of the valves impeller 36 against stop pins 46, 47 projecting upward from the fioor of the auxiliary-motor-casing cup 32. This relative movement is of course of such amplitude as to shift the valve 25 back and forth between the position in which it is shown in Fig. 7 and a fully reversed position.

The auxiliary, valve-shifting motor comprises the cupshaped casing 32 secured upon the upper end of the mainmotor shaft 14 as by a set-screw 33 (Fig. 1). This casing is integrally formed with a fluid-abutment 34 and is provided with a lid 35 (Figs. 1 and In the casing 32 is the impeller vane or wing piston 36 of the auxiliary motor, formed integrally with a hub portion 37 of the main valve 25. This hub portion seats upon the upper end of the main shaft 14 (Fig. l) to sustain the differential of fluid pressures upon the upper and lower faces of the valves partition 26.

The auxiliary motor casing 32 is in an exhaust chamber 32a defined by the casing and bulkheads 18 and 27, and this chamber is vented by a groove 32b in the inner wall of the casing 10 and extending from the chamber to the lower end of the casing.

The hub portion 37 of the main-valve 25 is formed with two arcuately large motor- inlet ports 38, 39 at opposite sides of its impeller vane 36, each at a considerable distance from the base of the vane. The auxiliary casing 32 is formed with two arcuately large exhaust ports 40, 41, preferably at opposite sides of the casing.

For opening and closing the motor-inlet ports 38, 39 a tubular pilot valve 42 is rotatably fitted in the upper end of the main valve 25 and at its upper end is formed with a laterally projecting stop-wing 43, adapted to be stopped in each half-cycle of oscillation by one or the other of stop pins 43a, 43b (Figs. 1, 5 and 6) projecting upward from the stationary bulkhead 27.

For opening and closing the exhaust ports 40, 41, a sleeve valve 44 is rotatably fitted on the casing and is formed with an outwardly projecting stop-wing 45, adapted to be stopped in each half-cycle of oscillation by one or the other of stop pins 45a, 45b projecting upward from the stationary bulkhead 18.

In the present embodiment the size and spacing of the set of valve ports and the stop wings are in accord with the positioning of the stop pins 45a and 43a in radial alignment with the center of the motor, as shown, and likewise the stop pins 45b and 43b, and this seems desirable for simplicity of layout, but is not essential.

For opening into one and then the other, in alternation, of the main valves motor- inlet ports 38, 39, while keeping the other one closed, the pilot valve 42 is forward with a port 48 the arcuate length of which not necessarily but preferably is substantially less than the arcuate distance between the ports 38, 39 in the hub 37 of the main valve, for reasons hereinafter stated.

For opening one and then the other, in alternation, of the auxiliary- motor exhaust ports 40, 41, while keeping the other one closed, the sleeve valve 44 is formed with two arcuately large ports 49, 50, preferably but not necessarily so spaced in relation to the ports 46, 41 of the auxiliary-motor-casing cup 32 that when the cup and the sleeve valve are in the relative positions in which they are shown in Figs. 8 and 9 both of the cups ports 44), 41 will be closed.

The mode of operation of the main motor, with appropriate shifting of the main valve 2S-37, is well understood in the art and will be clear from the foregoing description and inspection of Figs. 1, 3, 4 and 7.

The operation of the auxiliary motor to provide such shifting of the main valve 25-37 (Fig. 3) is as follows:

In the original assembling of the parts, it is necessary only that the parts of the auxiliary motor be left in in a relationship other than their non-flow, symmetrical, relationship of Fig. 8.

Assuming that this is done by moving the valve-impeller pin 46, this will put the main motor ports in the positions represented by Fig. 7 and passing of motive fluid into the assembly through the hose 13 will drive clockwise the main impeller 16, main shaft 14, the auxiliary-casing cup secured to the main shaft, the main-valve impeller 36, by positive drive of its stop pin 46, the main valve 2537 and, with it, by friction, the pilot valve 42.

This positive clockwise drive of the cup 32 and the valve impeller 36 will bring the stop- wings 43, 45 into contact with the respective stop pins 43b, 45b and at a certain stage of clockwise rotation the parts will be in the relationship in which they are shown in Fig. 9 (and in Figs. 1, 5 and 6), with all ports of the auxiliary motor closed.

The main-motor ports still being in full-drive relationship, the main shaft 14, cup 32, pin 46, impeller 36, and main valve 25-37 will continue to rotate clockwise, while the pilot valve 42 and valve sleeve 44 are held by their stop pins 43b, 45b, the parts thus being rought into the relationship in which they are shown in Fig. 10, with the auxiliary-motor exhaust port 48 well opened to the sleeve valves port 49 but with the auxiliary-motor inlet port 38 well past its fully closed position and with the other inlet port, 39, just ready to open to the pilotvalve port 48.

Further driving of the main shaft and positive driving of the main-valve impeller 36 by the pin 46 opens the said port 39 to the said port 43, admitting motive fluid to the exhaust-closed chamber behind the valve impeller 36 and, with only a frictional load to be overcome (friction of the main valve in the main shaft) quickly jumps the valveimpeller vane 36 forward, in the direction of general rotation, from its stop pin 46 to its stop pin 47, which quickly and fully reverses the main-motor ports, the auxiliary motor parts then being as shown in Fig. ll.

When the opening of the port 39 to the port 43 is once begun, as it is sure to be by the positive drive of the pin 46, it is positively continued until the port 39 is so far opened that the vane 36 starts its forward jump, leaving the pin 46, and when its forward jump is started it is sure to be continued and completed, and at increasing speed, because its forward movement, of itself, further overlaps the port 39 upon the port 48.

If the main shaft 14, cup 32, main-valve vane 36 and main valve 25-37 are not stopped by contact of the main-shaft impeller vane with the ends of its chamber, which are the faces of the fluid-abutment 34, Figs. 8 to 11, or adjustable stops (not shown) that may be mounted upon it, such parts continue to rotate until reversed by the fluid pressure of main-valve reversal, at or near the positions in which they are shown in Fig. 11. In that figure, representing such fluid-pressure reversal of the main shaft, etc., a re-closing of the auxiliary- motor inlet ports 39, 48 is shown as having begun, but this is made permissible by the long arcuate length of all of the auxiliary-motor ports, by reason of which the ports 39, 48, in their positions of Fig. 11, still have ample flow capacity.

The amplitude of oscillation of the main shaft 14 can be changed by simply changing the positions of the stops 43a, 43b, 45a, 45b

Upon reversal of the main-motor ports the reverse half-cycle of oscillation is of course begun and it, ending with the next reversal, of course corresponds to the clockwise movement and reversal just described.

As friction between the main shaft and the main valve within it is overcome by the dominant pressure of the motive fluid, which, with the stop pins 46, 47, positively controls the main-motor ports at all times, the main valve can be snugly fitted in the main shaft for avoidance of leakage, and the only reliance upon friction for driving is for rotation of the pilot-valve 42 with the main valve 25-37 in which it is fitted, and as the pilot valve is light, has no load other than its own inertia opposed to its frictional drive, and it and the main valve start together from non-rotating condition, and only at the speed of the main shaft, with no rebound from a stop, this frictional drive of the light pilot valve can be safely relied upon, especially as the pilot valve can be snugly fitted in the main valve, with the additional advantage of avoidance of leakage, since the friction is sure to be positively overcome at the end of each half-cycle, or 43b.

Having by the stop pin 43a the port 48 of the pilot valve shorter than the distance between the of the several possibleexpedients for assuring positive full the port 48 is closed.

Similarly overlap security against leakage is provided by the relative dimensions of ports and intervening lands shown in Fig. 7, but this is not indispensible. It is permitted by the quickness of the forward jump of the main valve.

acting with the pressure differential, valve reversed until the beginning of the next half-cycle.

A large number of different sets of relative dimensions of parts, and size and positioning of ports and of stopwings and stops is possible without departure from the scope of the invention as defined in the appended claims and without sacrifice of all of the advantages set out in the above statement of objects.

In the appended claims the expression positive-drive means is used as meaning driving means throughout which the driving force is transmitted wholly through solid memof the auxiliary-motor ports, and thereafter, throughout the following half-cycle.

I claim: 1. A motor assembly comprising a fluid-actuated main motor and a fluid-actuated auxiliary motor for reversing the mam motor, each of said motors comprising a fluidoperation, a first slide-valve element formed with a port and carried by the fluid-impelled member of the auxiliary motor, a second slide-valve element, by the said first slide-valve element and formed with a ports, a fluid-actuated auxiliary motor fluid-impelled the settings of References Cited in the file of this patent UNITED STATES PATENTS 309,610 Dow Dec, 23, 1884 967,560 Rizer Aug. 16, 1910 1,037,865 Chambers Sept. 10, 1912 1,125,639 Bergesen Jan. 19, 1915 2,254,641 Bannister Sept. 2, 1941

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