US2149645A - Governor for fluid motors - Google Patents

Description

March 7, '1939. P. VAN srrTERT A GOVERNOR FOR FLUIDMoToRs 'Filed April 28, '1937 PAUL VA/v /rrf/Pr INVENTQR ATTORNEY s a speed governor for portable fluid actuated mo` Patented` Mar. 7, 1939 PATENT OFFICE GovEnNoa son num Mo'ronsA Paul Van Sittert, Cleveland Heights, Ohio, alsignor to The (llevelandV Pneumatic Tool Company, Cleveland. Ohio, a corporation of Ohio Application April 28. 1987, Serial No. 139,687

5Claims.

'I'his invention relates broadly to uid actuated motors, but more particularly to a speed-governor for fluid actuated rotary motors.

The main object .of this invention is to provide tor such as grinders and the like, with means adinstable for selectively controlling the free speed oi the motor.

Another object of this invention is to produce a speed governor of simple construction forming a compact assembly which is strong. durable and eiilcient.

Another object of this invention is to produce in similar characters of reference designate coi'-,

responding parts and wherein:

Fig. 1 is a longitudinal sectional view of a fluid actuated motor embodying the invention.

Fig. 2 is an enlarged sectional View illustrating the governor.

Referring to the drawing, I0 represents a main housing having a stationary cylinder II disposed therein and formed with a rotor-chamber` I2, which chamber accommodates. the usual rotor I3 carrying blades I4. Keyed to the rotor I8 by a lkey I3a, there is a rotor shaft I6 depending from the housing I0 to receive a cutting tool such as agrinding wheel I6, which is secured thereon in the usual way between a washer I1 and a nut I8. Within the lower part of the housing I0, the shaft I6 is Journaled within a ball bearing I9,

which is secured in position by a nut 20.

Extending through the upper end of the housing I0, there is the shafted end portion 2i of the rotor I3, which end is also journaled within a ball bearing 22 secured in position by a nut 28. The shafted end portion 2| is internally threaded to receive an extension 24, which is mounted co- `axially with the rotor I3 for rotation therewith. This extension protrudes into a chamber 26 formed within the motor cover 26, which is secured to the housing I0 by one or more bolts 21.

Rigidly secured to the housing Ill =and extend- 1ing laterally therefrom in opposite direction, there are two vhandles 28 and 28. The handle 29 is preferably made of a casting having different passages cored therein and including an inlet passage III terminated at its outer end by a threaded connection 3i. This passage is controlled'by a throttle valve 32 slidably mounted' within a bushing 33, which bushing is held-in position by a screw threaded plug 34. The interior oi' the bushing 33 is in communication with the passage I0 through ports 36, while the throttle vI,

valve is always urged in closed position by a compression spring 36. To actuate the throttle valve, there is provided the usu'al mechanism including a rotatable handle 31 carrying, in ,eccentric relation with the rotary axis thereof, a/roller 38 which lo engages one end of a slidable pin 39 havingy its other end resting on the throttle valve 32.

Referring now more particularly to the present invention, it will be seen that within the cover 26 there is a speed governor including the exten- 15 sion 24 whichis formed with integral arms 40 extending laterally therefrom, and each carrying albell-crank weight 4I pivotally mounted thereon by a pin 42. These weights have their inner end resting on an annular shoulder 43 formed on a 20 governor-controlled valve 44 which has one endy slidably guided within a counterbore 24a formed in the extension 24, while the other end thereof 'forms a head or a metering portion 46. Screwed within thecover 26 and disposed coaxially with l the valve 44, there is a bushing 46 having a head 41 extending outside of the cover and formed withtwo holes 48 adapted to receive a wrench through which the bushing may be rotated. Below the head 41, within a counterbore provided within the cover 26, there is a locking spring 46 for holding the bushing against accidental rotation. The bushing extends through an annular groove 60 cored within the cover 26, and has its inner end turned smooth for fluid tight engagement with the inner wall of a bore 6I extending from the chamber 25 to the groove 50. Internally, the bushing is provided with a counterbore 62 opening into the chamber 25 through a relatively short bore 63, and in constant communication with the annular groove 60 through 4 radial ports 64. The short bore 63 is of adiameter substantially equal to that of the head 45 of the valve 44, which head is constantly urged away from the bore 63 by a compression spring 66 located within the extension 24 and acting on the valve 44. Extending through the valve 44, there is a small port 66.

Leading from the throttle valve 32 into the annular groove 60, there is an inlet passage 61, and from the chamber 26 into the cylinder I I, there is another passage 66. From this last passage, the motive fluid may be admitted into the rotor chamber I2 through a plurality of inlet In the handle 29 there isalso provided a 1ubricant reservoir 50, from which lubricant is admittd into the passageway through a lubricant-regulator generally designated by 8l.

. In the operation of the motor. motive :duid is admitted into the passageway 5B from a motive iluid conveying conduit (not shown) secured to the handle 29 through the connection 3l. .The throttle valve is then opened by manualb rotating its component :handle 3l, thereby Yadmit-V ting motive iluid into the annular groove 55 viathe passage 51. Inthis instance, that iswhen the motive Auid is rst admitted into the groove 50, the governor-valve 44, due to the eifort of the compression spring 55, will assume the position shown in Fig. 1.. In 'this extreme open posi- Y tion of the .governor-valve, the weights 4| are. engaging the outer wall of theeextemlon24 to prevent further opening movement of the valve.

'I'he motive uid admittedinto the groove 5 0 isv vnow fr ee to ow therefrom 4finto the chamber 25 jvia the bore 53, from where itis admitted into the rotor-chamber i2v through the passage 58 and portsv 5S. Once in they rotor-chamber I2, the motive uid will-act onthe blades I4 Vfor imparting rotation to the rotor 1n the usual manner Y, ment, thus resulting in motors having a maxi' mum freespeed well below that prescribed. In

Y the present construction, as the speed of the rotorV increases, the lower portion oi the weights v4I swingsiroutwardly causing the inner end of the bell-crank-weights to swing inwardly for movingV the valve 44 against the compression spring 5 5. until the lower end of the valve engages the bottoml of the counterbore 24a` formed within the extension 24. -In this instance, the motive uid conveying bore 53 between the groove 55 and the chamber 25', that is, `the annular clearance between the inner edge of the bore 53 and the corresponding edgeof the valve-head 45, has an eiective conveying capacity calculated to result in a free speed of the' motor well below to that prescribed. However, by turning, or morespeciilcally screwing the bushing 46, the annular Spacelbetween the inner edge of the bore 53 and the head 45 of .the valve 44 may be increased until the motor reaches the prescribed free speed.

When the cutting tool l5 is applied to thework,

it will transmit a torque resistance to the rotor Y tending toretard the speed of the motor. In this instancethe spring 55 acting on the valve 44 will gradually open the latter relative to the bore 53 for maintaining the speed of the motor substantially constant.

Due to the port 55 provided through the valve t4,A the motive uid admitted into the bushingcounterbore 52 and'acting on the upper end-of the valve, will owthrough the port 5l to act on the other side of the valve to nullify the action of the motive fluid on the valve.

. valve 44 and the `adiacent edge of the bore 53 will 'create a suction tending to move Athe valve against .the spring et, thus cooperating with the centrifugal force of the weights 4| for effecting the closing movement of the valve relative to the bore 53. Y

From the foregoing explanation, it will be understood thatthe invention providesa fluid actuated rotary motor Aequipped with a simple device through which the free speed of the motor may be controlled or adjusted from thev exterior of 'the/motor, and that through this device the free Y speed prescribed for a motor of a given size may readily' be vobtained withoutnecessitating undue accuracy' in thev manufacture of the controlling parts. Y 1 Y f Itwill also be understood that due to the novel design of the'speed governor and its component valve, the action of the governor is`not affected by wear of its moving parts. In the present construction, the head or metering portion 45 ofthe valve 44 is moved toward or from the boren for controlling the motive iluid conveying capacity of the passageway admitting motive fluid into the rotor-chamber l2. This passageway includes the space between the head 45 of the valve 44 and the inner edge of the bore 53, and since the head `45 does not engage the bushing 48, the head 45 is not subjected to wear aifecting the control of the motive fluid conveying passageway.

Although the foregoing description is necessarily 'of a detailed character, inorder to completelyl 'set forth the invention, it is to be underl stood that the specic terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit4 of the invention as herein claimed.

- I claim: 1. A iluid actuated rotary tool including a housing, a rotor rotatable within said housing, a passage conveying motive :duid to said rotor, a duality of movable spaced elements cooperating with each otherforV controlling said passage, means A responsive to the speed of thel rotor and acting on one of said elements for partially closing said passage, and means associated with the other of said elements .for opening said passage irrespective of the position of said first -mentioned element. l I

2. A rotary motor including va housing having a ilid actuated rotor rotatable therein, a dualityof longitudinally spaced elements within said housing, the longitudinal space between said elements constituting a. passage conveying. motive uid to the 'rotor for actuating the same, one of said Velements beingmovablerelative to theother for controlling'the motive iluid conveying capacity -of said passage, and means responsive to the rotary speed of said rotor for automatically eflecting the movement vof saidelement.

3. A rotary'motor including a housing having al uid actuated' rotor rotatable therein, means` within said housing conveying motive uid to the rotor for actuating -the same including a passage,

a valve, ahead on said valve constantly spaced vaxially from one end of said passage cooperating therewith and axially movable relative thereto for controlling the motive fluid conveying capacity of said passage, and means responsive to the A rotary speed of said 'rotor for automatically eifectthe axial movement of said valve and head. However, the iiow of the motivev fluid between the head 45 of the tending into said passage, and a governor-controlled valve spaced from said bushing and co'- opera'ti'ng therewith for automatically controlling said.- passage, said bushing being adjustable from the exterior of said housing for increasing the motive uid conveying capacity of said passage irrespective of said valve.

5. A rotary motor including a housing having a uid actuated rotor rotatable therein, a valvew t bushing within said housing, a passage through said bushing conveying motive fluid 'to said rotor for actuating the same, a governor-controlled' valve having a head spaced from said bushing and movable toward and from said passage for controlling the motive uid conveying capacity thereof, said bushing being adjustable from the extesaid valve.

PAUL VAN SITTERT.

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