US2982224A - Rotary pump - Google Patents

Description

May 2, 1961 J. G. WILLIAMS 2,982,224

ROTARY PUMP Filed Sept. 26, 1958 2 Sheets-Sheet l JOHN G. WILLIAMS May 2, 1961 J. G. WILLIAMS ROTARY PUMP 2 Sheets-Sheet 2 Filed Sept. 26, 1958 JOHN G. W! LLIAMS INVENTOR. M/dM BY ROTARY PUMP John G. Williams, Springfield, N.J., assignor to Worthington Corporation, Harrison, N.J., a corporation of Delaware Filed Sept. 26, 1958, Ser. No. 763,673

2 Claims. (Cl. 103-136) the rotor rotates counterclockwise the fluid entering the center suction inlet is passed'into the center core through a port and is then propelled by the vanes to the outlet opening to discharge therethrough into the outlet port which communicates with the system in which the pump is applied.

Inherent defects in the construction of the foregoing type pump have created serious operational difliculties.

Specifically, these difficulties occur because the fluid entet ing the center suction inlet is passed into the pumping chamber. is a direction that is normalto the direction of rotation of the vanes. ltis evident then that the fluid entering the pumping chamber is suddenly accelerated to rotor speed; as a consequence shock occurs and the pump is prone to the serious defects resulting from cavitation.

The rotary pump contemplated by this invention meets the problem of substantially precluding the operational difficulties encountered in the above described pump by providing a rotor with a pressure developing passage means which receives fluid in a portion thereof so as to provide for substantially shockless entrance of the fluid thereto to thereby minimize the difficulties caused by cavitation; and in the other portion which communicates with the first portion of the pressure developing passage converts the velocity head of the fluid to pressure head to thereby provide a more efficient pump.

Accordingly, it is one object of this inventionto provide a rotary pump with pressure developing passage means which obviates the operational difficulties present in prior type rotary pumps.

It is another object to provide an improved rotary vane type pump unit which is compact in construction and economically manufactured.

A further object of the invention is to provide a rotary vane type pump with an axially and radially balanced rotor in order to produce optimum dynamic balancing of the rotating parts.

It is another object of this invention to provide the rotor with blades of such configuration whereby a hydrodynamic film is formed between the blades and the liner wall to thereby preclude damaging contact therebetween.

With these and other objects in view, as may appear vane type rotary pump, and the features forming the invention will be specifically pointed out in the claims.

In the drawings Figure 1 is a longitudinal section taken on line 11 of the vane type rotary pump shown in Fig. 2.

Figure 2. is a cross-section of the vane type rotary pump contemplated by this invention.

Figure 3 is a fragmentary perspective view of the rotor including the pressure developing pocket means.

Figure 4 is an exploded fragmentary view showing the blade configuration preferably used in the rotary pump contemplated by this invention.

Referring more particularly to the accompanying drawings, the improved rotary pump, generally designated 1 comprises a casing 2 having a center suction inlet 3 formed in the rotor 4 and a discharge outlet 5 in communication therewith.

The rotor, to be described in detail hereinafter, comprises a body portion 6 at one end, the outer periphery thereof forming pumping chambers 7 and 8 with the inner periphery of a liner 9 fixedly mounted in the casing 2 in the usual manner. at the other end of the rotor 4 and is journaled in the stufling box 11 and operatively connected to the shaft 12 by lock means 13 for rotation therewith.

The shaft 12 rides in the usual bearings (not shown) mounted in the bearing housing 14 and is coupled to the usual motor in any well known fashion to cause the rotor to flow fluid from the central suction inlet to the discharge outlet 5'.

The pump casing 2 is supported in operative position by the bearing housing 14 and is connected to an adapter 15- Which is in turn do-welled to the bearing housing.

Members taking the form of outboard and inboard side plates 16 and 17 are connected to the liner and adapted to form opposite end closures for the pumping chambers formed by the rotor and the liner.

The outboard side plate 16 is provided with an opening 18 to receive a tube means 19 which is accommodated in the central suction inlet 3 and fixed to the side plate 16 and adapted to direct fluid into pressure developing passage means 20 formed in the rotor 4 in substantially shockless fashion as is discussed hereinafter.

A suction nozzle 21 is mounted on the tube means 19 to pass system fluid thereto and connected to the casing by the usual bolts 22.

As is customary, packing 23 and O-rings generally designated 24 are positioned at joints wherein a fluid-tight relationship is desired.

As was mentioned hereinabove, means taking the-form of pressure developing fluid passages 20 are formed in the rotor 4 to provide for fluid passage thereto that is substantially shockless and as a consequence provides a pump that is not confronted with the effects of cavitation. Preferably,-the pockets 20 are formed between a pair of oppositely disposed spaced walls 25 and 26 of the rotor vane 27 which include the blades 28 formed as hereinafter described to provide a hydrodynamic film between the T-shaped portion 51 thereof and the liner 9' to preclude damaging contact therebetween.

Both walls 25 and 26 are constructed whereby provisions are made for smooth fluid inlet flow along the surface thereof, and particularly on a portion of wall 26 for convenience referred to as the leading face 30 and a portion of wall 25 called. the trailing face 31 during the period when the fluid is subject to cavitation, i.e. before the fluid gains sufiicient energy from the centrifugal field (at point wherein fluid enters the pressure developing passageways) to permit it to be turned without caus- 0 ing the drop in pressure that causes portions of the fluid to vaporize or release dissolved gases.

From the foregoing paragraph it will be evident to one A neck portion 10 is formed skilled in the art that substantially shockless flow is provided for in the rotary pump contemplated herein by fashioning the walls 25 and 26 of the rotor at the inlet portions thereof to conform to the direction of inlet fiuid flow relative the rotor at the point of inlet fluid entry to the rotor.

In addition, provisions may be made in the portion 50 of the pressure developing passage means 20 whereby the velocity head of the fluid passing thereto is converted to pressure head to thereby increase the efficiency of the pump during operation thereof. The foregoing provision takes the form of a greater area in the outer portion of the passageways than for the inner portions which receive inlet fluid from the tube means 19. Further reduction in shock loads on the rotating portions of the pump is accomplished with the provision of the tube means 19, fixed in the suction inlet 3 to prevent rotation thereof relative rotor 4 as described hereinabove, which includes an outlet chamber 32 having tongues 33 and 34 formed thereon to direct the fluid into the pressure developing passages 20 in substantially shockless fashion. Preferably the configuration of the tongues is adapted to coact with the configuration of the leading and trailing faces in providing for the reduction of cavitation. As will be evident to one skilled in the art there is a predetermined relation between the guiding portions of the tongues 38 and 34 serving to pass fluid into the rotor and the walls of the rotor. That is, the tongues guide the inlet fluid into the rotor at a predetermined direction and the walls of the rotor receive or are fashioned to conform to the direction of the inlet fluid to receive this fluid so that it flows smoothly along the surface of the wall of the rotor during the period when the fluid is subject to cavitation.

As will be evident to those skilled in the art, optimum dynamic balancing is accomplished with the provision of plural pumping chambers 7 and 8 which open into the discharge outlet through openings 35 and 36in the liner 9.

Tube means 19 is easily adapted to function in the form having plural chambers with the provision of an S-shaped dividing member 37 which provides segregated plural outlet chambers 32 and 32' fashioned to accomplish the function of the tube means described hereinabove, i.e. pass fluid in shockless fashion through the pockets 20 to a respective pumping chamber 7 or 8.

Means are usually provided for introducing a lubricant to the rotating elements of the pump 1. In the particular embodiment shown in the drawings the means take the form of slots 38*and 38 in the outboard side plate 16 which communicate through passage means 39 with the suction inlet 3 at one end and the base 40 of the keyhole slot 29 in the -vane 27 at the other end. Fluid is received by the keyhole slots 29, passed therethrough and rotated therewith until the slots '29 communicate with the slots 41 and 41 which communicate with the discharge outlet 5 to discharge therethrough.

As was mentioned hereinabove and to further enhance the operative qualities of the rotary pump contemplated herein, the blades 28 preferably are formed with a T-shaped head 51 to provide a predetermined surface area which permits the formation of a hydrodynamic film between the head 51 and the liner 9 which provides a slight clearance 52 to thereby preclude any damaging abutment therebetween.

In operation of the preferred form fluid enters the inlet 3, is divided by members 37 in tube means 19 and passed through the pressure developing means 20 to each of the pumping chambers 7 and 8 and out the openings 42 and 43 to the discharge outlet 5.

As many embodiments may be made in the above invention and as many changes may be made in the embodiment above described, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative only and not'in a limiting sense.

What is claimed is:

1. A positive displacement pump of the rotary type comprising an outer casing, an outlet in said outer casing, an inner casing disposed within said outer casing and including a first and second pumping chamber, outlets for each of said first and second pumping chambers and communicating with the outlet of said outer casing, a rotor including a plurality of vanes rotatably disposed in the inner casing to provide pumping action for each of said first and second pumping chambers, said vanes having slots including blades slidably disposed therein and said blades including T-shaped heads of a predetermined surface area whereby a hydro-dynamic film is formed between the T-shaped heads and the inner casing to preclude damaging contact therebetween, a suction inlet disposed centrally in the rotor, said rotor including pressure developing passage means comprising opposite and adjacent leading and trailing faces of said vanes and said leading and trailing faces having backward slopes with respect to the direction of rotation of the rotor, said pressure developing passage means having an inlet and outlet portion for communicating the suction inlet to the outlets of said first and second pumping chambers, an S-shaped tube means having an inlet and a first and second outlet fixedly mounted in the suction inlet of said rotor, the first and second outlets of said S-shaped tube means both provided with tongue means and said tongue means sloped relative the leading face of each of said pressure developing passage means to provide a fluid inlet velocity direction that forms an acute angle with the slope of the leading face of each of said pressure developing passage means whereby the fluid inlet velocity relative said pressure developing passage means during operation lies substantially along the leading face thereof to permit pumping without the effects of cavitation.

2. The positive displacement pump claimed in claim 1 wherein the inlet of said pressure developing passage means is of lesser dimension than the outlet thereof.

References Cited in the file of this patent UNITED STATES PATENTS 730,052 Sharpneck June 2, 1903 929,018 Ripberger July 27, 1909 1,075,300 Moss Oct. 7, 1913 1,287,920 Duda Dec. 17, 1918 2,387,761 Kendrick Oct. 30, 1945 2,416,987 Fleischer Mar. 4, 1947 2,684,035 Kemp July 20, 1954 2,751,849 Sherwood June 26, 1956 FOREIGN PATENTS 132,994 Switzerland July 16, 1929 179,684 Great Britain May 17, 1922 341,874 Great Britain Jan. 21, 1931 821,156 Germany Nov. 15, 1951

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