US2329386A

US2329386A - Rotary pump

Info

Publication number: US2329386A
Application number: US429941A
Authority: US
Inventors: Brennan Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-11-08
Filing date: 1942-02-07
Publication date: 1943-09-14
Anticipated expiration: 1960-09-14

Description

Sept. 14, 1943. R, BRENNAN 2,329,386

ROTARY PUMP Filed Feb. 77, 1942 2 .3 3p 4 cf 1 I 2 I I /0 35 W I E/ INVENTOR ROBERT B RENNAN v QTILW? L ATTYS,

Patented Sept. 14, 1943 2,329,386 ROTARY PUMP Robert Brennan, Auckland, New Zcaland Application February 7, 1942, Serial No. 429,941 In New Zealand November 8, 1940 1 Claim.

This invention relates to a pump construction of known type in which the pumping elements comprise the combination of a cylindrical stator member and a rotor member arranged axially within the stator, shaped with co-operating surfaces of helical formation, and one of which surfaces is made of a flexible nature. The rotation of the rotor member within 'the stator, while such rotor member is restrained from longitudinal movement, causes a displacement of fluid from one end of the stator to the other and performs the pumping action.

The rotor is driven by axial longitudinal connection through universal or flexible joints, with a driving shaft to which rotation is imparted. In the operations of the rotor therefore, a longitudinal re-action upon the rotor takes place and this re-action tends to displace the rotor axially within the stator. Consequently in the general construction of the pump, means must be provided to counteract this tendency to displacement which is in effect a thrust upon the rotor driving connections and upon their bearings. In the restricted space available and also because of the difiiculty of lubrication, this thrust load is a very undesirable factor in respect of this class of pump. Any means for relieving the joints from this load would greatly increase the efficiency of the pump and help to eliminate excessive wear.

The present invention has been devised with the object of providing for the balancing of the end thrust upon the rotor and its associated parts and also for the doubling of the capacity of the pump as concerned with the diameter of the rotor.

The invention comprises, therefore, a construction of pump of this class in which the stator and rotor members are duplicated in longitudinal end to end association. and in which each unit combination of rotor and stator has its helical formation formed or arranged in opposition to that of the other. Thus one unit combination is made with a left hand helix and the other with a right hand helix. This duplicated arrangement is combined with a cylinder construction under which the adjacent and inner ends of the two units open from an inlet chamber, and the remote and outer ends, open to a common outlet, to provide for each unit acting to convey or pump the fluid from the inlet to the outlet. The respective relative positions of the inlet and outlet may, however, be reversed.

The invention also comprises means for the conveyance of rotation to. the said duplicated rotor.

In fully describing the invention, reference will be made to the accompanying sheet of drawings, in which- Figure l is a sectional plan of the complete pump, the rotor, however, being shown in plan.

Figures 2, 3 and 4 are cross sections upon the respective lines 2-2, 3-3 and 44 of Figure 1, in all cases looking to the right of the said lines.

Figure 5 is a side elevation of the complete pump.

Figure 6 is a longitudinal section on an enlarged scale, of the'double r two ended rotor and showing means for the connection of the driving spindle thereto.

In giving effect to the invention a compound or duplicated rotor member is provided having a medial portion I0 and ends I I and I! each formed of the helical nature common to this known type of rotary pump, but so made that the helix of one is of right hand nature while that of the other end is of left hand, or opposed nature. In

the form shown, this rotor member is made (as shown in Figure 6) hollow throughout its length and its driving spindle I3 is caused to pass in through one end of the hollow and has its end connected with the medial portion III by means of a suitable universal joint l4, so formed as to ensure of the joint being kept liquid tight as by surrounding the joint by the sleeve I5. Into the other end of the hollow a plunger I6 is fitted and outside this a spring I! is arranged in compression between the plunger and a plug I 8 screwed into the hollow end. The space within the plunger is packed with a suitable lubricant and-such lubricant is forced by the plunger and spring, in around the universal joint H to keep it lubricated. A washer l9 of leather or other suitable material is arranged around the spindle I3 upon the other side of the joint I4 to keep the lubricant from passing out through the other end of the hollow.

This duplicate rotor member has each helical end enclosed within a stator member 20-2l respectively. Such stator is of the usual flexible nature, generally being formed of rubber, characteristic of these pumps and the stator for each end has its helical groove made in correspondence with the rotor end associated therewith to effect the pumping action by which liquid may be passed, or forced, through the stator from one end to the other. As the two ends and their stators are formed with opposing helices the course of the liquid in each instance is in an opposite direction to that of the other. Consequently by mounting the rotor and its stators within a suitable arrangement of chambers, provision may be made for liquid led into the space between the two stators being pumped out through both stators and delivered through their outer ends, or reversely, liquid may be pumped from the outer ends and delivered at their inner ends.

It will be apparent that in such an arrangement of rotor and stators, the two ends being opposition one to the other in respect of the longitudinal thrust on the members in the pumping, there is an absence of any resultant lengthwise thrust on the rotor as a whole. Consequently there is also an absence of thrust upon the driving spindle and its bearings. The power required to drive the rotor is therefore lessened in relation to the pumps capacity, while with a given diameter of rotor, the pumps capacity is doubled as compared with that of a pump having the usual single rotor.

The construction and arrangement of cylinder and chambers for the mounting of the said rotor and stators. as shown in the drawing, comprise a block 22 formed with an open ended inlet chamber 23 in its centre and into which chamber an inlet port 24 opens from one side of the block, and also formed with an outlet chamber 25, divided from the inlet chamber by a partition member 26, and which chamber 25 also opens-to both ends of the block and has an outlet port 21 leading out through the block side opposite that on which the inlet port is situated. On each end of the block a cylinder 28 is fitted to extend outward, such cylinder having a bore 29 which coincides with and opens to the end of the inlet chamber 23 and also being formed with a separate passage 30 in its wall extending longitudinally throughout the same length as that of the bore and which passage at its inner end coincides with and opens to the corresponding end of the outlet chamber 25. Each cylinder at its outer end extends beyond the outer ends of the bore 29 and passage 30 to provide a connection between such ends. One cylinder has its outer end closed while the other cylinder is formed at its outer end with a gland bearing 3| through which the driving spindle 13 of the rotor is designed to be passed.

The compound or duplicated rotor is disposed to extend across the inlet chamber 23 of the block 2| so that its medial portion I is positioned in such chamber and its two helical ends H and i2 extend into the respective bores 29 of the two cylinders. Into the inner end of each cylinder bore the corresponding stator member --2l is fitted to surround its associated portion of the rotor. Such stator is secured in position by forming it with a flange 32 on its inner end which engages with a shoulder 33 surrounding the bore end and which flange is then clamped by the fastening of the cylinder end to the block 22, to thereby effect a composite and firm assembly of the whole.

This assembly is supported upon any suitable base plate 34 and such base plate may have combined therewith at one end a standard bearing 35 to receive the end of the power shaft 36 which also passes in through the gland 3|. This power shaft is connected by any approved form of universal joint 31 with the outer end of the driving spindle l3 to effect the driving of the pump rotor in the manner characteristic of pumps of this nature.

The rotation of the rotor in the required direction will cause liquid to be drawn in through the inlet port 24 into the chamber 23, and then forced out by both rotor ends to the outer ends of the respective cylinders and then to pass through the passages 30 to the outlet chamber 25 and out through the port 21.

In order to provide for the continuous lubrication of the rotor and statorsby the passage'of liquid through them should the inlet supply fail for any cause, provision is made for the re-circulation of the liquid remaining in the pump in such a circumstance. For this purpose a hole 38 is formed in the partition member 26 dividing the inlet chamber 23 from the outlet chamber 25. The operations of the rotor will thus cause the liquid to be circulated from the inlet chamber through the cylinders and back from the outlet chamber again to the inlet chamber.

Other ways of connecting the rotor with the I power shaft through the driving spindle l3 may be employed without departing from the spirit of the invention. The manner of connection shown in the drawing by which the driving spindle is connected to the rotor at about midway in its length is preferred as providing for the rotative power being distributed evenly to both rotor ends.

I claim:

A rotary pump comprising a pair of cylindrical stator members each having an internal helical surface, a rotor member extending axially through the stator members, said motor having a helical surface at each end thereof co-operating with and corresponding to the helical surfaces of the stator members and being hollow throughout its length, an inlet for one open end of each stator, an outlet for the other open end of each stator, a chamber communicating with the outer ends of the two stators, a drive shaft, a universal joint in the hollow portion of the rotor member at the approximate intermediate point of the length thereof connecting said shaft to the rotor member to rotate the latter, and means in the hollow portion of the rotor to lubricate the universal joint.

' ROBERT BRENNAN.