US2621606A - Pump - Google Patents

Description

Dec. 16, 1952 F, E CARLSON 2,621,606

PUMP

Filed May 12, 1950 2 SHEETS-SHEET l j] j 5 ya 15a z farfzgys Patented Dec. 16, 1952 PUMP Floyd E. Carlson, Rockford, Ill., assigner to Sundstrand Machine Tool C0., a corporation of Illinois Application May 12, 1950, Serial No. 161,539

7 claims. 1

This invention relates to a pump, and more particularly to a pump having improved means for providing a seal between the inlet and outlet ports thereof.

The general object of this invention is to provide an improved pump.

Another object of this invention is to provide a pump having a non-rotatably mounted cylinder block which is bodily movable in a `generally circular path within a cylindrical chamber with an end Ywall having inlet and outlet openings, said block vhaving an end face engaging said end vwall and at least one cylinder port opening into said end face, and means for exerting variable pressure to force the end face of the block against the end'wall of the chamber.

Another object is to provide a pump of this character in which said variable pressure increases as the speed of movement of the block increases.

Another object is to provide a pump of this character in which the means for `exerting variable pressure comprise a'flyball governor device on the drive shaft of the pump and a thrust bearing between the governor and the cylinder block, said governor having a cam surface engaging a follower to increase the pressure of said bearing as the speed of rotation vof the drive shaft increases.

vAnother object is to provide a pump in which the drive means maybe started and brought upto substantially full speed before the full load is applied to reduce torque during ystarting and acceleration of the `drive means and in which the load is removed as ythe drive means decelerates.

Another object is to provide a pump of this character in which the means for exerting variable pressure comprise a spider secured to the drive shaft, a `pair of weights pivotally mounted on the spider and movable away from the drive shaft as a function of the speed of rotation of said shaft, and a lthrust bearing between the Weights and the cylinder block, said weights each having a cam surface engaging a follower to increase the pressure as the speed of rotation of the shaft increases.

Other objects will become readily apparent from the following detailed description taken in connection with the accompanying drawings in which:

Fig. 1 is a longitudinal section through a pump constructed in accordance with the invention, taken along the line I-l of Fig. .2;

Fig. 2 is :a transverse section 'through .the

(Cl. 10S-158) 2 center of thecylinder block, looking tothe right in Fig. l, underlying parts being shown in broken linesyand Fig. 3 is a fragmentary transverse sectio taken along the lines 3 3 of Fig. l.

While there in shown in the drawing and hereinafter describedin detail a preferred form of the invention, it is to be understood that the invention is not limited to the particular form and arrangement shown. t kis contemplated that various changes may be made by'those skilled in the art `without departing from the spirit and scope of the appended claims.

Referring now'to the drawings, the pump comprises a casing designated .generally at It and including a cup-shaped body having side walls I l, a base I2 and a cover member I3 which may be secured on'the cup-shaped body by a plurality of bolts I4.

Within the casing Hl is a chamber l5 having a cylindrical wall 15a and having an end wall 15b formed by the inner surface of the cover member t3. This end wall has an inner recess I6 which communicates by means of a passage l'l with an outlet port 'i8 in the cover of the casing. An annular rib I9 having an inner surface IQa'which forms part `of said end wall lEb of the chamber 15,' lseparates the inner recess I6 from va concentric annular outer recess 2B. This outer recess communicates by 4means of a passage 2| with 'an .inlet port 22 in the vcover member i3.

A .cylindrical cylinder block 25 is non-rotatably mounted within the chamber l5, the cylinder block having a smaller diameter than said ychamber. The cylinder block has one end face 25a engaging the end wall lb so that the surface 19a of the annular rib YI9 may, by engagement with the end face 25a, form a seal between the recesses 'I6 landAZl. The cylinder block 25 has a central well 26 in its other end face which does not extend through the block, as shown in Fig. 1. The cylinder block 25 has equally spaced around its periphery a plurality of cylinders 2M, 2lb and 2'lc,which are preferably angular to radii of the block in order .to increase the length of the cylinders. Each cylinder has near its inner end a port 23a, 28h and 28o respectively, which ports -open into the .end 'face A5a of the cylinder block. It iis :not lnecessary that the ports open directly vinto the face of the cylinder block, .but the ports may extend through channels defining an arc and opening into said end face 25a in positions to give properly timed valve a-ction, as will hereafter be described. Pistons 29a, "29h and 29e are mounted one in each cylinder for reciprocation therein. Each piston has a portion extending out of the cylinder and engaging the cylindrical wall Ia of the chamber I5, as shown in Fig. 2. Springs 30a, 38h and 30C are provided to urge the pistons "outwardly, although these springs are not necessary if the pump intake is under pressure.

A drive shaft 3i is rotatably mounted in sleeve bearings 32 and 33 in the casing I0, and the inner end of the shaft has an eccentric projection 3Ia forming a crank which fits movably in the well 26 of the cylinder block 25, a bushing 34 providing a rotatable mounting for the crank in the well. A flexible sleeve 35 connects the block 25 with the end wall I2 of the casing. This sleeve is connected at one end to the cylinder block by clamping bolts 36, a clamping ring 31 and a gasket 38. The other end of the sleeve is connected to the casing by means of clamping bolts 39 which extend through the casing base I2, a clamping ring 40, and a gasket 4I. The flexible sleeve 35 surrounds the shaft 3I and provides a non-rotatable seal between the cylinder ports and the shaft, and consequently no rotary seal is required for the shaft 3|. A drain 42 is provided between the chamber I5 and the inlet 22.

A spider is pinned to the drive shaft 3| and a pair of oppositely disposed weights 46a and 4Gb are pivotally mounted on the spider, these weights each having a cam surface 46a and 4Gb for engagement with an annular follower 4I forming part of a thrust bearing having an annular member 48 secured to the cylinder block 25. In the space between the members 4'! and 48 is a ball retainer 49 carrying a plurality of anti-friction balls 50.

In the operation of the pump, the drive shaft is rotated and the eccentric crank 3 la causes the cylinder block 25 to move bodily in a generally circular path in the chamber I5. The block is held against rotation by the sleeve 35, although the exibility of the sleeve permits arcuate movement of the block about its axis when necessary. As the block moves bodily within the chamber I5, the pistons 29 are reciprocated successively through compression and suction strokes and the respective ports 28 are moved across the surface I9a of the annular rib I9 alternately into communication with the recesses I6 and 20. As pointed out above, the positions at which the respective cylinder ports 28 open into the end face 25a provides proper valving action in correctly timed relationship with the reciprocal movement of the pistons.

Obviously, in order to create a pumping action the recesses I6 and 20 must be sealed one from the other, for if no seal exists no pressure in excess of the inlet pressure can be developed in the outlet, but the fluid being pumped will merely flow back to the inlet on the compression stroke of each piston. As the drive shaft 3l is rotated, the weights 46 act as a iiyball governor device and move outwardly away from the shaft 3I in an amount dependent upon the speed of rotation of said shaft. As these weights move outwardly, they cam the thrust bearing device to the right (as the parts appear in Fig. 1) to exert pressure against the cylinder block 25, this pressure varying as a function of speed of rotation of the shaft and increasing as the speed of rotation of the shaft increases.

I prefer to arrange the parts so that the force exerted by the flyball governor will create a seal sufficient to balance the pressure desired to be developed in the outlet recess I8 at a speed of rotation which is slightly below the operating speed of the pump. For example, in a pump developing pounds per square inch pressure in the pressure chamber on the outlet side, the governor weights are so Constructed and arranged that the force developed by the governor will create a seal sufficient to balance 100 pounds pressure in the recess I6 at a speed of 1700 R. P. M. of the drive shaft. During operation, the shaft rotates at 1800 R. P. M. Consequently, pumping pressure will not be developed ,until the pump reaches nearly top speed. When the drive shaft is stationary, the force exerted by the governor is zero, and there is no seal, so that the starting torque of the device will be at a minimum. The motor will, therefore, accelerate rapidly until a speed of 1700 R. P. M. is reached at which point the pump will be at effective operating condition and be developing 100 p. s. i. pressure, and at 1800 R. P. M. the pressure of the fiyball governor device will create an effective seal between the recesses I6 and 28 to maintain this pressure with little or no loss. When the pump motor is shut olf, the pressure on the outlet side will be dissipated when the speed drops below 1700 R. P. M., reducing the torque load so that the motor and pump are not rapidly braked, but may coast to a stop.

The provision of means for exerting variable pressure to force the end face of the block 25 against the end wall of the chamber I5 so that the pressure increases as the speed of movement of the block increases is considerably advantageous over means which provide a constant pressure, as for example a spring bearing against the block. With such a spring' the pump must start against the torque provided by full pumping action.

I claim:

.1.. A pump comprising in combination, a casing having a cylindrical chamber therein, means providing an end wall in the chamber having an inner recess and a concentric outer annular recess, an annular rib forming part of said wall and located intermediate the recesses to separate the same, an inlet and an outlet port in the casing; passageways connecting said recesses respectively with the inlet and outlet ports; a cylindrical cylinder block of smaller diameter than said chamber nonrotatably mounted therein, a face at each end of the block with one end face engaging said end wall and with the other end face having a central well therein extending only partially through said block, a plurality of cylinders formed in the periphery of the block; a cylinder port for each cylinder and opening into said end face; a piston reciprocably mounted in each cylinder and having a portion extending therefrom and engaging the cylindrical lwall of said chamber; a drive shaft mounted in said casing for rotation about an axis normal to the plane of the first mentioned end face; an eccentric projection on the end of said shaft and fitting movably in the well in said block for moving said block bodily in a generally circular path upon rotation of Said shaft to reciprocate said pistons and to move said cylinder ports alternately into communication with said recesses; a flexible sleeve connecting said block and casing and surrounding said shaft to provide a nonrotatable seal between said cylinder ports and said shaft; and means for exerting variable pressure to force the first mentioned end face of said block against the end wall of said chamber, lcomprising fa spider on 'saidfshaft a pair of o'ppos'itely disposed weights pivotally mounted on said `spider and movable awaylfromz-said spider as-'a function lof the speed of "rotation of said fshalft, a thrust bearing between said weights and block, and 1a cam Ssurface on .each weight and engaging the bearing to increase said pressure as the speed of rotation of :said shaft increases.

f2.' .A pump compr'isingin combination,a casing havinga cylindrical chamber therein-means providing an end wall-inthe chamber having an inner recess and arconcentr-ic outer annular recess, .an annular rib 'formingpart of saidvwall and .located intermediate the recesses to-'separate the same, an inlet and an `outlet in the casing; passageways connecting said recesses respectively with the inlet and outlet ports; a cylindrical cylinder block of smaller diameter than said chamber nonrotatably mounted therein, a face at each end of the block with one end face engaging said end wall and with the other end face having a central well therein extending only partially through said block, a plurality of cylinders formed in the periphery of the block; a cylinder port for -each cylinder opening into said end face; a piston reciprocably mounted in each cylinder and having a portion extending therefrom and engaging the cylindrical wall of said chamber; a drive shaft mounted in said casing for rotation about an'axis normal to the plane of the rst mentioned end face; an eccentric projection on the end of said shaft and fitting movably in the well in said block for moving said block bodily in a generally circular path upon rotation of said shaft to reciprocate said pistons and to move said cylinder ports alternately into communication with said recesses; and means for exerting variable pressure to force the first mentioned end face of said block against the end wall of said chamber, said pressure increasing as the speed of rotation of said shaft increases.

3. A pump comprising in combination, a casing having a cylindrical chamber therein, means providing and end wall in the chamber having an inner recess and a concentric outer annular recess, an annular rib forming part of said wall and located intermediate the recesses to separate the same, an inlet and an outlet port in the casing; means connecting said recesses respectively with the inlet and outlet ports; a cylindrical cylinder block of smaller diameter than said chamber nonrotatably mounted therein, a face at each end of the block with one end face engaging said end wall and said block having a plurality of cylinders in its periphery each with a cylinder port opening into said end face; a piston reciprocably mounted in each cylinder and having a portion extending therefrom and engaging the cylindrical Wall of said chamber; a drive shaft mounted in said casing for rotation about an axis normal to the plane of said end face; crank means movably coupling said shaft to the other end face of said block for moving said block bodily in a generally circular path upon rotation of said shaft to reciprocate said pistons and to move said cylinder ports alternately into communication with said recesses; a flexible sleeve connecting said block and casing and surrounding said shaft to provide a nonrotatable seal between said cylinder ports and said shaft; and means for exerting variable pressure to force the rst mentioned end face of said block against the end wall of said chamber, said last named means comprising a fiyball governor device on said shaft and a v'thrust `bearing between said governor and said other end face of the block, a follower connected to the bearing and a cam surface on the governor engaging the fol-- lower to increase the pressure on said bearing as the speedofrotation-of said shaft increases.

4. -A pump comprising vin combination, -a casing having a cylindrical lchamber vtherein, means defining an-end wall in the chamber vhav-ing inlet and outlet openings; a Ycylindrical cylinder .block of smaller diameter than .said chamber nonro'tatably mounted therein, a face at each end of the block with one end face vengaging said end wall, a cylinder in the lblock provided with Ya cylinder port Aopening into said v'end face; :a piston reciprocably mounted in said cylinder and having a portion engageable with 'the cylindrical wall of said chamber; a drive shaft mounted lin said casing for rotation about an axis normal to the plane of the first mentioned end face; crank means movably coupling said shaft to the other end face of said block for moving said block bodily in a generally circular path upon rotation of said shaft to reciprocate said piston and to move said port alternately into communication with said openings; and means for exerting variable pressure to force the first mentioned end face of said block against the end wall of said chamber, comprising a spider on said shaft, a pair of weights pivotally mounted on said spider and movable as a function of the speed of rotation offsaid shaft, and a thrust bearing between said Weights and block, a cam surface on the weights and engaging the bearing to increase said pressure as the speed of rotation of said shaft increases.

5. A pump comprising in combination, a casing having a cylindrical chamber therein, means defining an end Wall in the chamber having inlet and outlet openings; a cylindrical cylinder block of smaller diameter than said chamber nonrotatably mounted therein, a face at each end of the block with one end face engaging said end wall, a cylinder in the block provided with a cylinder port opening into said end face; a piston reciprocably mounted in said cylinder and having a portion engageable with the cylindrical wall of said chamber; a drive shaft mounted in said casing for rotation about an axis normal to the plane of the first mentioned end face; crank means movably coupling said shaft to the other end face of said block forrmoving said block bodily in a generally circular path upon rotation of said shaft to reciprocate said piston and to move said port alternately into communication with said openings; and means for exerting variable pressure to force the rst mentioned end face of said block against the end wall of said chamber, comprising a flyball governor device on said shaft and a thrust bearing between said governor and said other end face of the block, and a cam surface operated by the governor to increase the pressure on said bearing as the speed of rotation of said shaft increases.

6. A pump comprising in combination, a casing having a cylindrical chamber therein, means defining an end wall in the chamber having inlet and outlet openings; a cylindrical cylinder block of smaller diameter than said chamber nonrotatably mounted therein, a face at each end of the block with one end face engaging said end wall, a cylinder in the block provided with a cylinder port opening into said end face; a piston reciprocably mounted in said cylinder and having a portion engageable with the cylindrical wall of said chamber; a drive shaft mounted in said casing for rotation about an aXis normal to the plane of the first mentioned end face; crank means movably coupling said shaft to the other end face of said block for moving said block 5 bodily in a generally circular path upon rotation of said shaft to reciprocate said piston and to movesaid port alternately into communication withsaid openings; and means for exerting variable pressure to force the first mentioned end 10 face of said block against the end Wall of said chamber, said pressure increasing as the speed of rotation of said shaft increases.

7. A pump comprising in combination, a casing having a cylindrical chamber therein, means defining an end Wall in the chamber having inlet and outlet openings; a cylindrical cylinder block of smaller diameter than said chamber nonrotatably mounted therein, a face at each end of the block with one end face engaging said end wall, a cylinder in the block provided with a cylinder` port opening into said end face; a piston reciprocably mounted in said cylinder and having a portion engageable With the cylindrical Wall of said chamber; means for moving said block bodily in a generally circular path with said portion of the piston engaging the Wall of the chamber to reciprocate the piston in the cylinder and to bring said port alternately in communication With the inlet and outlet; and means for exerting variable pressure to force the end face of said block against the end Wall of said chamber, said pressure increasing as the speed of said 15 movement increases.

FLOYD E. CARLSON.

No references cited.

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