US2825307A - Hydraulic control system - Google Patents

Description

' March 4, 1958 '0. B. ENYEART ET AL 2,825,307

HYDRAULIC CONTROL SYSTEM Filed Jan. 19', 1956 FIG. 2

.l 84 as 52 62 70 v 12 l2 J 64 48 '4 FIG. 4

ENTORS no NAGLE v. GUYSCHING DUANE B. ENYEART AGENT therein.

Un ted Ps sn Sidney, Ohio, a corporation of Ohio Application January 19, 1956, Serial No. 560,183 2' Claims. '61. in -41 This invention relates to means for controlling hydraulic motors which, due to the particular construction, have a definite limit of motion. In this class of motors principally fall piston and cylinder motors, and paddle motors wherein one or more paddles move between one or more abutment vanes. In accordance with thisinvention this class of motors is improved by providing means by which they may move to definite positions intermediate the end positions created by their inherent structure.

Therefore it is an object of this invention to provide means whereby motors which have discontinuous motion may be stopped intermediate their end positions.

It is another object to provide means whereby such motors may be stopped accurately and positively intermediate their end positions.

It is another object ,to provide means whereby such motors may bestopped at any one selected position of a plurality of different positions.

It is another object to provide means to provide such stopping control in an, economical manner.

Other objects and advantages will become apparent on consideration of the following specification and the attached drawings in which Figure 1 is a partial sectional elevation. of a rotary motor taken generally along the line. 11 ,of Figure 2,

Figure 2 is a sectional view of across the axis of the motor of Figure 1 taken along the line 2--2 of Figure 1,

Figure 3 is a partial elevation of the embodiment of Figure 1 taken along the line 3-3 of Figure l, and

Figure 4 is a partial cross sectional view of a difierent embodiment wherein the motor with which the invention is employed is of the linear motion type.

Referring now to Figure 1, a rotary motor is shown This motor has a frame mounting member carrying a generally circular motor frame 12 and within the motor frame 12 is a rotary member 14 which carries an output gear 16. Embracing the motor frame 12 is a cylindrical valving member '18 which may be manually moved by means of a plate .20 which is secured to the member 18 by means of screws 22 and is keyed to a shaft 24 by means of a key 26. On the other end of the shaft 24 is'a knob 28 which is keyed thereto for manually rotating the shaft 24 .and the cylindrical mem ber 18 which rotates therewith.

As is best seen in Figure 2 the output member 14 carries a vane 30 which rotates within the confines of the stationary member 12 in an almost annular space therein. Member 12 carries thereon an abutment member 32 which provides walls to limit the motion of the vane 30 and through the means of the vane 30 and abutment 32 two spaces 34 and 36 are defiend. It can be readily seen that if fluid under pressure is permitted to flow into one of the spaces, for example 34, and space 36 is permitted to be connected to a drain, the vane 30 will have a pressure dilferential thereacross and the output member 14 will move in a clockwise 2,825,307 Patented Man 4, i958 2 direction as viewed in Figure 2. Motion of the output member 14 will turn gear 16 which is secured thereto by appropriate means such as screws 38. Clearance between the motor frame 12 and the vane 30 as well as between the output member or rotor 14 and the abutment 32 is kept at a minimum to minimize leakage.

According to applicants invention, motor frame 12 has a plurality of holes or ports 40, 42 44, 46, 48, 50, 52, 54, 56, 58', and 60 communicating between its interior and it s exterior. These holes are spaced apart and are related to the width of the vane 30 so that the vane 30 substantially closes at'least two of the holes. The'cylindrical member 18 acts as a valving member and contains two holes 62 and 64 which are adapted to line up with two of the holes in the member 12, which holes are spaced apart approximately the width of the, vane 39 as is mentioned above. The holes 62 and 64 are permitted to drain fluid to the sump. It can be seen that manual motion of knob 28 causes cylindrical valving member. 18 to rotate and valve different pairs of holes 40 to 60 to drain.

, The abutment 32 contains interdrilling which provides fluid inlets 66 and 68. Inlet 66 is connected to line 70 (see Figure 3) and inlet 68 is connected to line 72. A pump 74draws fluid from a sump 76 through line 78 and discharges it under pressure to lines 80 and 82. Lines 80 and 82 are respectively connected to lines 70 and 72 through fluid resistances 84 and 86. Hydraulic oil is preferably used as an operating fluid for it acts as a lubricant as well as a power medium. However, gas, 'water, or other liquid could be used by providing suitable clearances so no rubbing occurs or by the provision of carbon or special metal in the wearing areas to prevent galling. I

In the illustration of Figures 1 through 3 the motor is shown as having one vane and one abutment. As is well known in the art, two diametrically opposed vanes and two diametrically opposed abutments may be used .to

double the torque with the same fluid pressure at the,

expense of total motion. In this case the cylindrical valving member 13 would be provided with two diametrically opposed pairs of holes to provide openings to drain adjacent both sides of both vanes when the rotor is in its desired position. Fluid would be supplied through resistances to both sides of both abutments. I

The pump 74 supplies the operating fluid under pressure to lines 80 and 82, and the pressure may be limited to a safe value by means of a relief valve or by'using a pressure compensated variable delivery pump. The resistances 84 and 86 are. provided to act as flow dividers so that when one or the other of lines 70 or 72 is open to drain the pump pressure does not fall off appreciably but fluid under pressure is supplied to the other side of movable vane member 30 to cause motion. Of course separate pumps could be used to supply lines .70 and 72 or other known flow dividing means could be. used.

It can be seen from the description of the device of Figures 1 through 3-that as the pump 74 discharges fluid under pressure into lines 80 and 82 it is conveyed through resistances 84 and 86 into spaces .36 and34 through ports 66 and 68. If the knob 28 is turned to cause the ports 62 and 64 to lie over the ports 54 and 56 it can be seen that the space 36 will be opened to drain through port 56 and port 64. At the same time the fluid entering through port 68 will be under pressure to cause a force to act on the face of vane 30 and this force will turn the output member 14 in a clockwise direction as seen in Figure 2 until the vane 36 covers both ports 54 and 56. In this position the pressure in space 36 will rise for it is no longer open to drain and the vane 30 will stop. Preferably, the vane 30 does not ber 14 is very accurate. If the angular position of vane 30 is incorrect to the slightest extent, one drain will be at least slightly opened and the pressure on that side of the vane 36 will fall due to flow through and consequent pressure drop in resistance 84 or 86. A correcting force results to restore the vane 30 to the correct position. If the knob 28 is turned the other way so that ports 42 and 44 communicate todrain through ports 62 and 6 1, it can be seen that the space 34 is open to drain and fluid under pressure entering through port 66 will move the vane 30 until it covers both ports 42 and 44. By moving the cylindrical valving member 18 over any pair of ports in the motor frame 12 the' vane 30 is moved by power to cover that pair of ports. Of course,-if the vane 30 is made the same width as one of the ports in motor frame 12, only one of the ports need be opened to "drain. Thus the vane 38, output member 14, and gear 16, seek their new position. Gear 16 can be used to drive any device such as a selector valve where accurate positioning in a plurality of different positions is desired.

The embodiment of Figure t is a reciprocating fluid motor having a cylinder 88 and a piston 90 therein. The piston divides the cylinder into spaces 92 and 94 in cooperation with the end walls of cylinder 88 and connected to the piston'90 is a piston rod 96. A pump 98 draws fluid from a sump 1th) through a suction line 162 and the pump 93 delivers it under pressure through two fluid resistances 194 and 106. Resistance 164 is connected by means of line 198 to a port in the end of the cylinder to discharge into space 92 and resistance 106 discharges into a line 110 which in turn is connected into space 94 in the other end of the cylinder 88. The cylinder is securely mounted in a stationary fashion by means of the lines 108 and 110 or by any other suitable structural means. The cylinder 88 has a plurality of holes 112 therein and the holes are spaced apart such a distance that at least two of them are substantially cov ered by the piston 90 at the same time. The holes 112 serve as ports for porting to drain. Embracing the cylinder 88 is a cylindrical valving member or sleeve 114 which contains ports 116 and 118 for porting pairs of the holes 112 to drain. The ports 116 and 118 are spaced in such a manner that they open selected pairs of ports 112 to drain.

It can be seen that if the sleeve 114 is moved to port the leftmost pair of ports 112 to drain through ports 116 and 118, that the space 92 will be open to drain but fluid under pressure will flow through resistance 1% and line 110 to the space 94 thereby causing the piston 9 and its rod 96 to move leftward until the piston covers the pair of drained ports. Similarly, the cylindrical valving member 114 can be moved to align with ports 116 and 118 with any pair of ports 112 to open them to drain. Fluid pressure on the other side of piston 90 causes the piston to move to cover both of the drained ports 112.. Thus it can be seen that this motor can move to any one of a plurality of selected positions for accurate positioning of the piston rod 96 and the appropriate mechanism attached thereto. Again, if the piston is of such width as to cover only one port 112, then only one port need be opened to drain to cause positioning.

While valving has been described as being done by ported valving members 18 and 114, it is clear that valving could also be done by any appropriately op erating valves. For example, if an electrical positioning signal is available, it might be desirable to use solenoid operated valves. These motors have been described in particularity with respect to input and output members, but it can be seen that the members described as output members herein can be secured to the frame and the other member be used as an output member.

This invention is capable of a number of embodiments and thus it is desired that the scope of the invention be defined by the appended claims.

What we claim 18? 1. In a unitary fluid pressure, actuated motor and motor control valve structure, a frame, walls defining an annular space in said frame, an abutment on said frame extending into said annular space, a driven member arranged to oscillate around a given axis, a vane on said driven member extending into said annular space, fluid pressure supply means for supplying fluid to said space on each side of said abutment, a plurality of ports in said frame, at least one of said ports being away from said abutment, a valving member embracing said frame and covering said ports and having valving ports therein, said valving member being actuatable coaxiaily with said driven member to open at least one of said ports from said space, whereby upon supplying fluid to said space on each side of said abutment said vane moves to cover said open port.

2. In a unitary fluid pressure actuated motor and control valve structure, a main frame .for supporting the motor and control valve, said frame having cylindrical walls arranged around a centerline defining an annular space in said frame, an abutment in said frame extending into said annular space, a driven member arranged to rotate around a given axis which corresponds to the center line of said cylindrical walls, a vane on said driven member extending into said annular space, said vane and said abutment dividing said annular space into first and second spaces, fluid pressure supply means for supplying fluid under pressure into each of said spaces, a plurality of substantially radial ports in said frame extending from said annular space to the outside of said frame, at least one of said ports being away from said abutment, a valving member embracing said frame and arranged to cover said ports and having at least one valving port therein, said valving member being rotatable, in the same plane and on the same axis as said driven member to correspond to the desired position of said driven memher to open at least one of said substantially radial ports, whereby upon supplying fluid to said first and second space on the sides of said abutment said driven member is caused to rotate to cover said open port so that it seeks the same angular position as a valving member.

References Cited in the file of this patent UNITED STATES PATENTS 1,484,030 Kitchen Feb. 19, 1924 2,219,955 Smitt Oct. 29, 1940 2,398,997 Berry et a1. Apr. 23, 1946 2,481,426 Hull Sept. 6, 1949 2,703,149 Nelson Mar. 1, 1955

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