Title PUMP ASSEMBLY

The present invention concerns an improved pump assembly for pumping fluid from one location to another.

The invention has been designed chiefly to pump ground water from bore holes and will therefore be described in this context. It is to be appreciated, however, that the invention may have other uses. The pump assembly may, for instance, be used to pump other fluids, such as oil or sludge, other than from bore holes. Background of the Invention

The pumping of ground water from bore holes has traditionally entailed feeding a pipe of sorts down a bore hole until partially submerged in water and then drawing the water up through the pipe by means of an above-ground pump attached to an upper end of the pipe. Various types of engines, as well as wind-power, have been used to drive such pumps.

Another method of pumping ground water entails feeding a submersible pump down the bore hole itself. It appears that most known submersible pumps are driven by electric motors. Although electric submersible pumps have advantages over traditional pumps in that they are generally easier to install and more economical to operate, a disadvantage is that they require a source of electricity. In remote areas when a mains supply is not available, such pumps may need to be powered by batteries. Disadvantages with using batteries include that batteries are usually short lived, requiring frequent replacement and/or maintenance, and are expensive to purchase.

Summary of the Invention A first aspect of the present invention is directed towards an improved hydraulic pump assembly that overcomes a disadvantage referred to above.

According to a first aspect of the present invention, there is provided a hydraulic pump assembly for pumping fluid from a first location to a second location, said assembly comprising: a chamber having an inlet and an outlet; a hydraulic motor housed within the chamber; a progressing cavity pump connected to the motor and extending outwardly

from the chamber outlet; and a discharge conduit extendible from a discharge outlet of the progressing cavity pump to the second location, with the construction and arrangement being such that when the hydraulic motor is driven, fluid is pumped from the first location via the chamber inlet to the second location.

The chamber may be of any suitable shape and volume. Preferably the chamber is provided by a housing having a cylindrical side wall and upper and lower end walls connected to the side wall. The end walls may be detachable from the side wall. Preferably, the inlet is located at the lower end wall and the outlet is located at the upper end wall. The chamber inlet and outlet can be of any suitable size, shape and construction. Preferably, the chamber inlet is a collar extending from the lower end wall and the chamber outlet is a collar extending from the upper end wall. The collars may be threaded.

Any suitable type of progressing cavity pump may be used. The progressing cavity pump preferably has a rotor and a stator, the stator extends from the outlet of the chamber and the rotor is coupled to a drive shaft of the motor for rotation within the stator. The progressing cavity pump can be connected to the chamber outlet in any suitable way. Preferably, a suction inlet of the stator is threaded and is connected to the chamber inlet. The rotor preferably turns on a left-hand rotation. The assembly preferably includes a flexible coupling interconnecting the drive shaft of the hydraulic motor and the rotor. Any suitable type of flexible coupling may be used.

Any suitable type of hydraulic motor may be used. Preferably, the hydraulic motor is a variable speed, side port motor. The hydraulic fluid driving the pump may be, for instance, oil or water.

The assembly may include a porting block, hydraulic fittings and hydraulic lines for circulating hydraulic fluid between the hydraulic motor and a hydraulic pump. Preferably, the hydraulic fittings extend through openings in the upper end wall, one end of each fitting is connected to a said hydraulic line, the other end of each fitting is connected to the porting block, and the porting block is connected to the hydraulic motor.

Any suitable types of hydraulic fittings may be used. The porting block may be of any suitable size; shape and construction. Preferably, the porting block has a pair of end ports, a pair of side ports and respective passages extending there between. The end ports

may be connected to the hydraulic fittings and the side ports may be connected to the side ports of the hydraulic motor. The hydraulic lines may be of any suitable size, shape and construction.

The discharge conduit may be of any suitable size, shape and construction. The discharge conduit may comprise two or more attachable pieces. Preferably, the discharge conduit is flexible. The discharge conduit may consist of plastics material, such as polypipe®. The discharge conduit may be connected to the discharge outlet in any suitable way.

The assembly may include a filter extending from the chamber inlet for filtering out particulate matter when drawing fluid from the first location into the chamber inlet. The filter may be of any suitable size, shape and construction. Preferably, the filter includes a collar and a closed-end cylindrical mesh screen extends from the collar. The collar may be threaded.

The assembly may include a connector conduit extending between the filter and the chamber inlet. The connector may be of any suitable size, shape and construction. The connector may have threaded ends for connection to the threaded collars of the filter and the chamber inlet.

Preferably, the pump assembly is submersible. If the assembly is used, for instance, to pump bore water, the pump assembly is preferably sized to fit within an about 4i4 to 6 inch bore hole.

Some pump assemblies, such as the one described above, include a rotary positive displacement pump which has an eccentrically rotating rotor that is turned by a drive shaft of a motor. Such rotation will inevitably damage the motor, by way of lateral forces and thrust, even if a flexible coupling is used to interconnect the drive shaft and the rotor. A second aspect of the present invention is directed towards an improved pump assembly having a shaft aligning assembly that minimizes the damage caused to a motor by an eccentrically rotating rotor.

According to a second aspect of the present invention, there is provided a pump assembly for pumping fluid from one location to another, said assembly comprising: a motor having a body and a drive shaft rotatable relative to the body; a rotary positive displacement pump having a stator, a rotor that rotates eccentrically within the stator, an inlet for fluid at an end of the stator, and an outlet for

fluid from the displacement pump; a shaft assembly comprising at least one shaft and a flexible coupling, wherein a first end of the shaft is connected to the rotor and a second end of the shaft is connected to the drive shaft by way of the flexible coupling; a support body mounted to the stator and to the body of the motor and extending alongside the shaft assembly, wherein said support body enables the drive shaft to rotate the shaft assembly relative to the body of the motor and the stator; and a shaft aligning assembly comprising at least one bearing block situated adjacent the flexible coupling and at least one shaft aligner situated between the bearing block and the stator, wherein the shaft aligning assembly is supported by the support body, and the shaft of the shaft assembly extends substantially co-axially with the drive shaft through the bearing block and the shaft aligner.

The motor may be of any suitable size, shape and construction. The motor may be, for instance, hydraulically or electrically driven. Preferably, the motor is a variable speed hydraulic motor. The hydraulic fluid driving the pump may be, for instance, oil or water.

The rotary positive displacement pump may be of any suitable size, shape and construction. Preferably, the pump is a progressing cavity pump such as the type described in the specification of Australian Patent No. 784082, the entire contents of which are herein incorporated by cross reference. The inlet end of the stator may be threaded.

The support body may be of any suitable size, shape and construction. The support body made be made of any suitable material or materials such as metal or plastics material. Preferably, the support body houses the shaft assembly, the shaft aligning assembly and/or the motor. The support body may be mounted to the stator and the body of the motor in any suitable way, but preferably by way of threaded connections.

Preferably, the support body comprises a first housing for the motor, and a second housing for the shaft aligning assembly. The first and second housings may be of unitary construction or may be detachable from one another. The first and second housings may comprise a framework, a mesh and/or solid walls.

The first housing for the motor may have a cylindrical side wall and upper and lower end walls connected to the side wall. The end walls may be detachable from the side wall. The first housing may have one or more inlets for fluid. The first housing

may have one or more outlets for fluid. Preferably, an inlet for fluid is located in the lower end wall and an outlet for fluid is located in the upper end wall. A threaded collar of the first housing extending from the lower end wall may provide the fluid inlet. A threaded collar of the first housing extending from the upper end wall may provide the fluid outlet. Preferably, an opening in the upper end wall provides access for an electrical cable or hydraulic lines to the body of the motor, depending on whether the motor is electrically or hydraulically driven.

The first housing may include a mount for mounting the body of the motor to a wall of the first housing. Any suitable mount may be used. Preferably, a mounting plate is bolted to the body of the motor and further connected to the upper end wall.

The second housing may comprise an open-ended tube. The tube may of any suitable shape when viewed in cross section, including round, rectangular or triangular. The second housing preferably comprises a cylindrical tube having threaded ends. One of the ends may be screwed to the threaded collar of the first housing providing the fluid outlet. The other end may be screwed to the threaded inlet end of the stator.

The pump assembly may include a filter extending from the inlet of the first housing for filtering out particulate matter when drawing fluid therein The filter may be of any suitable size, shape and construction. Preferably, the filter includes a collar and a closed-end cylindrical mesh screen extends from the collar. The collar may be threaded and may be connected to the threaded collar providing the first housing fluid inlet. The filter may be made of any suitable material or materials, such as plastics material or metal.

The bearing block of the shaft aligning assembly may be of any suitable size, shape and construction. The bearing block may be made of any suitable material or materials, such as metal. The bearing block may include a body, a centrally located bore for the shaft of the shaft assembly, ball or roller bearings situated between the body and the bore, and seals for excluding fluid from the ball or roller bearings. The bearing bock may be cylindrical. The bearing block may have plurality of flow passages allowing the general flow of fluid from the motor to the stator. Preferably, the body has a plurality of circumferentially spaced flow passages extending parallel with the central bore. The bearing block may be supported by the support body in any suitable way. Preferably, the body of the bearing block has a laterally extending flange or shoulder that is too large for the tube of the second housing and is retained within the threaded collar providing the

fluid outlet when the end of the tube is screwed into engagement with that threaded collar.

The shaft aligner of the shaft aligning assembly may be of any suitable size, shape and construction. The shaft aligner may be made of any suitable material or materials, such as plastics material or metal. The shaft aligner may include a body and a centrally located bore for the shaft of the shaft assembly. The body may be cylindrical.

The shaft aligner may have plurality of flow passages allowing the general flow of fluid from the motor to the stator. Preferably, the body of the shaft aligner has a plurality of circumferentially spaced flow passages extending parallel with the central bore. The bore may have longitudinally extending lobes that serve to lubricate the part of the shaft extending through the bore such that the shaft may freely rotate within the bore. The shaft aligner may be supported by the second housing in any suitable way.

The shaft assembly may be of any suitable size, shape and construction. The shaft assembly may be made of any suitable material or materials, such as metal. The shaft assembly may include two or more shaft pieces that are connectable to one another, and such shaft pieces may be connected in any suitable way. Such shafts pieces may have male or female threads or may be connected by a threaded connector. The shaft pieces may be of differing diameter. Preferably, the shaft of the shaft assembly has a length of about 500 mm to about 3000 mm. The first end of the shaft of the shaft assembly may be connected to the rotor in any suitable way. Preferably, the first end of the shaft is threaded, an end of the rotor is threaded, and the ends of the shaft and the rotor are screwed together.

The shaft aligning assembly may include at least one spacer for spacing the shaft aligner at a fixed distance from the bearing block. The spacer may be made of any suitable material or materials, such as plastics material or metal. Any suitable type of spacer may be used. The spacer may be a shaft connector abutting the bearing block and the shaft aligner. The spacer may be a shoulder of the shaft of the shaft assembly which abuts the shaft aligner.

Any suitable type of flexible coupling may be used. Such coupling are well known in the art and typically comprise a pair of hubs, a flexible insert located between the hubs, and a pair of shaft locking bushes and screws for connecting the drive shaft and the shaft of the shaft assembly to a respective hub.

The pump assembly may be part of a pump system which comprises a

hydraulic pump, a hydraulic fluid reservoir and hydraulic lines for circulating hydraulic fluid between the hydraulic motor and the hydraulic pump. This may be achieved in any suitable way. Any suitable hydraulic pump may be used, such as a rotary piston pump. The hydraulic pump may be powered in any suitable way, but preferably is powered by way of a windshaft of a windmill, or an output shaft of an electric motor or combustion engine. Quick-release couplings may enable the hydraulic lines to be readily reconnected to an alternative power source. For instance, should there be inadequate wind for driving the pump by way of a windmill, the hydraulic lines may be readily coupled to pump that is driven by a diesel engine. The pump assembly may include a discharge conduit extending from the outlet of the displacement pump. The discharge conduit may be of any suitable size, shape and construction. The discharge conduit may comprise two or more attachable pieces. Preferably, the discharge conduit is flexible. The discharge conduit may consist of plastics material, such as polypipe®. The discharge conduit may be connected to the outlet in any suitable way.

The pump assembly may be used to pump any suitable type of fluid. If the pump assembly is used, for instance, to pump bore water, the pump assembly may be sized to fit within an about 4 ¹ A to 6 inch bore hole.

Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 is a partly detailed schematic of a preferred hydraulic pump assembly according to the first aspect of the invention;

Figure 2 is an exploded view of part of the hydraulic pump assembly shown in Figure 1;

Figure 3 is an exploded view of parts of a preferred pump assembly according to the second aspect of the invention;

Figure 4 is an exploded view of other parts of the pump assembly shown in Figure 3; Figure 5 is a schematic of a preferred hydraulic pump system comprising the hydraulic pump assembly shown in Figure 1 or Figure 3; and

Figure 6 is a cross sectional view of a hydraulic rotary coupling of the hydraulic pump system shown in Figure 5.

Description of the Preferred Embodiments

In the figures, like reference numerals refer to like features.

Figures 1, 2 and 5 show a submersible hydraulic pump assembly 1 that is part of a pump system for pumping ground water from a bore hole 203 to an above ground reservoir 204, according to the first aspect of the invention.

The pump assembly 1 includes a hydraulic motor 2, a housing 3, a progressing cavity pump 4 (see Figure 1), a flexible coupling 5, a porting block 6, hydraulic fittings 7, 8, a connector conduit 9, a filter 10, a pair of hydraulic lines 40, 41 (see Figure 1) and a discharge conduit 42 (see Figures 1 and 5). The housing 3 has a cylindrical side wall 11, an upper end wall 12 and a lower end wall 13. The housing 3 provides a chamber 14 (see Figure 1) within which is housed the hydraulic motor 2. A threaded collar inlet 16 to the chamber 14 extends from the lower end wall 13 and a threaded collar outlet 17 from the chamber 14 extends from the upper end wall 12. As can be gleaned from Figure 1, four bolts 18 connect the upper end wall 12 to the side wall 11. Openings 19 in the upper end wall 12 for the bolts 18 are shown in Figure 2. Four bolts 20 connect the lower end wall 13 to the side wall 11. Openings 21 in the lower end wall 13 for the bolts 20 are shown in Figure 2. As seen in Figure 2, the upper end wall 12 has two additional openings 22, 23.

The hydraulic motor 2 has two side ports 25, 26 and a straight keyed drive shaft 27. The hydraulic motor 2 is a variable speed motor.

The porting block 6 has a pair of end ports 30, 31, a pair of side ports 32, 33 and respective passages extending there between. The side ports 32, 33 coincide with the side ports 25, 26 of the hydraulic motor 2. The porting block 6 circulates hydraulic fluid to the hydraulic motor 2 as well as mounts the hydraulic motor 2 relative to the upper end wall 2.

The hydraulic fittings 7, 8 extend through the openings 22, 23 in the upper end wall 12. A first end 44, 45 of each hydraulic fitting 7, 8 is connected to an end of a hydraulic line 40, 41, and a second end 46, 47 is connected to an end port 30, 31 of the porting block 6. The other end of each hydraulic line 40, 41 is in fluid communication with a hydraulic pump 200, a hydraulic rotary coupling 217 and a hydraulic fluid reservoir 208, as shown in Figure 5. The hydraulic pump 200 is a wind-driven rotary piston pump 200 and circulates hydraulic fluid to the hydraulic motor 2 by way of the hydraulic lines 40, 41, the hydraulic rotary coupling 217, hydraulic fittings 7, 8 and

porting block 6. Further details of windmill driven hydraulic pumps may be found in the specification of Australian Patent No. 784082.

As seen in Figure 6, the rotary hydraulic coupling 217 comprises a central shaft 230 having and outer face 233 as well as an inlet passage 231 and an outlet passage 232 for hydraulic fluid that extend to the outer face 233. The coupling 217 further comprises a collar 240 having an inner face 241 that rotates around the outer face 233. A pair of spaced annular grooves 242, 243 extend along the inner face 241. Groove 242 is in fluid communication with the inlet passage 231 and groove 243 is in fluid communication with the outlet passage 232. The collar 240 has an inlet passage 250 that extends to groove 243 and an outlet passage 251 that extends to groove 242. A pair of grooves 262, 263 and circlips locatable within those grooves 262, 263 lock the shaft 230 and collar 240 together. Three O-rings 265, 266, 267 sealingly extend between the outer 233 and inner faces 241. The collar 240 may be mounted to the windmill such that the shaft 230 may rotate relative thereto. This enables the lines 40, 41 above the coupling 217 to freely rotate through 360 degrees (with the windshaft) relative to the lines 40, 41 below the coupling 217 without impeding the flow of hydraulic fluid through the lines 40, 41.

The progressing cavity pump 4 has a stator 99, a rotor 50, a suction inlet 52 and a discharge outlet 51 (see Figure 1). The suction inlet 52 of the stator 11 is threaded and is connected to the threaded collar outlet 17. The flexible coupling 5 interconnects the drive shaft 27 and the rotor 50. The rotor 50 turns on a left-hand rotation.

The filter 10 has a threaded collar 60 and a closed-end cylindrical mesh screen 61 extending from the threaded collar 60. The connector conduit 9 has threaded ends 62, 63 (see Figure 2). End 62 is connected to the threaded collar 60 and end 63 is connected to the threaded collar inlet 16.

In use, the pump assembly 1 is lowered through an about A ¹ A to 6 inch bore hole 203 until the filter 10 is fully submerged in underground water. A free end of the discharge conduit 42 is placed in, for example, a water collection reservoir 204. The hydraulic motor 2 is then driven using the hydraulic pump 200. The hydraulic motor 2 turns the rotor 50 and water is pumped, in turn, through the mesh screen 61, through the connector conduit 9, through the chamber inlet 16, through the chamber 14, through the chamber outlet 12, through the stator 44, through the discharge outlet 51 and through the discharge conduit 42. The mesh screen 61 ensures that the assembly 1 will not become

clogged with particulate matter present in the underground water.

The pump assembly according to the first aspect has the following advantages:

• it can be used within narrow bore holes • having a hydraulic motor beneath the progressing cavity pump minimises corrosion of the progressing cavity pump

Figures 3, 4 and 5 show part of a submersible hydraulic pump assembly 100 that is part of a pump system for pumping ground water through a bore hole 203 to an above ground reservoir 204, according to the second aspect of the invention. The pump assembly 100 includes a hydraulic motor 101, a progressing cavity pump, a shaft assembly, a support body and a shaft aligning assembly.

The hydraulic motor 101 has a body 102 having two side ports 103 and a straight keyed drive shaft 104. The hydraulic motor 101 is a variable speed motor.

The progressing cavity pump (shown in part) includes a stator 107 having a threaded inlet 108 and a rotor 109 (shown in Figure 4) that rotates eccentrically within the stator 107. The rotor 109 has a threaded end 110, as seen in Figure 4. An outlet 219 of the pump and its connection to a discharge conduit 220 are shown in Figure 5.

The shaft assembly includes a whip shaft 112 having a shoulder 119 and threaded ends 113, 114, a threaded connector 115, a stub shaft 116 having a threaded end 117 and another end 118 having a key and a key way, and a flexible coupling 120 (shown in part). Threaded end 113 of the whip shaft 112 is screwed into the threaded end 110 of the rotor 109. Connector 115 connects together the threaded ends 114, 116 of the whip shaft 112 and the stub shaft 116.

The flexible coupling 120 connects the end 118 of the stub shaft 116 to the drive shaft 104 of the motor 101. The flexible coupling 120 has two hubs 121, 122 and a rubber spider 123 that is located between the hubs 121, 122. Two taper lock bushes and screws (not shown) connect the shafts 104, 118 to a respective hub 121, 122.

The support body includes a first housing 130 for the motor 101. The first housing 130 has a cylindrical side wall 131, an upper end wall 132 and a lower end wall 133. A threaded collar inlet 135 of the first housing 130 extends from the lower end wall 133 and a threaded collar outlet 136 of the first housing 130 extends from the upper end wall 132. Four bolts (not shown) connect the end walls 132, 133 to the side wall 131. Openings 138 for those bolts in the end walls 132, 133 are shown in Figure 3. The upper

end wall 132 has an additional opening 140 which serves as an inlet for water and provides access for hydraulic lines 215, 216 of the pump assembly (see Figure 5) to the two side ports 103 of the motor 101.

The first housing 130 includes an oval plate 142 for mounting the body 102 of the motor 101 to the upper end wall 132. As seen in Figure 3, five bolts 145 extend through openings in the oval plate 142 and fasten the oval plate 142 to a face 146 of the motor 101. Moreover, two bolts 148 extend through openings in a pair of lobes of the oval plate 142 and are fastened to the plate 142 by way of a pair of nuts 149. A head of each bolt 148 is welded to an underside of the upper end wall 132. The flexible coupling 120 is located between the oval plate 142 and the upper end wall 132.

The support body includes a second housing 160 for the shaft aligning assembly and for most of the shaft assembly. The second housing 160 is a tube 160 having threaded ends 161, 162. Threaded end 161 may be screwed to the threaded inlet 108 of the stator 107. Threaded end 162 may be screwed to the threaded collar outlet 136 of the first housing 130.

As seen in Figure 4, the shaft aligning assembly includes a bearing block 170 and a shaft aligner 180.

The bearing block 170 includes a cylindrical body 171, a centrally located bore 172 through which the stub shaft 116 extends, a plurality of circumferentially spaced flow passages 175 extending parallel with the central bore 172, two roller bearings (not shown) situated between the body 171 and the bore 172, and various felt and rubber seals 173 at each end of the body 171 for maintaining grease within the roller bearings and for excluding water from the roller bearings. The body 171 has a laterally extending flange 177 that is too large for the tube 160 and is retained within the threaded collar outlet 136 when the threaded end 162 is screwed thereto. The passages 175 allow the flow of water from the first housing 130 to the stator 107. The body 171 abuts the connector 115.

The shaft aligner 180 includes a plastic cylindrical body 181, a centrally located bore 182 through which extends the whip shaft 112, and a plurality of circumferentially spaced flow passages 184 extending parallel with the central bore 182. The passages 184 allow the flow of water from the first housing 130 to the stator 107. The bore 182 has three longitudinally extending lobes 186 that serve to lubricate the whip shaft 112 within the bore 182 such that the shaft 112 may freely rotate within the bore 182. The body 181 abuts the connector 115 as well as the shoulder 119 of the whip shaft

112.

The pump assembly 100 includes a filter 190 comprising a closed-end cylindrical mesh screen that extends from the threaded collar inlet 135.

In use, the pump assembly 100 is lowered through an about 454 to 6 inch bore hole 203 until at least part of the rotor 109 is submerged in underground water. A free end of the discharge conduit 220 is placed in, for example, a water collection reservoir

204. The hydraulic motor 101 is then driven using a hydraulic pump 200. The hydraulic motor 101 turns the rotor 109 and water is pumped, in turn, through the filter 190 and through the opening 140, through the tube 160 and passages 175 and 184, through the stator 107, through the discharge outlet 219 and through the discharge conduit 220.

The shaft aligner 180 removes most of the eccentric wobble from the rotating whip shaft 112. The bearing block 170 brings or almost brings the stub shaft 116 into perfect co-axial alignment with the drive shaft 104 of the motor 101 and absorbs any thrust that is imparted by the rotor 109. The flexible coupling 120 allows for misalignment of the stub shaft 116 with the drive shaft 104 due to lateral movement of the motor relative to other parts of the pump assembly 100.

The pump assembly according to the second aspect has the following advantages:

• it can be used within narrow bore holes • having a hydraulic motor beneath the progressing cavity pump minimises corrosion of the progressing cavity pump

• there is minimal wear on the motor as the shaft is brought into substantial axial alignment with the drive shaft of the motor

• it may also pump fluid when the motor and progressing cavity pump are situated horizontally

Whilst the above has been given by way of illustrative example of the invention, many modifications and variations may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth. The term "comprise" and variants of the term such as "comprises" or

"comprising" are used herein to denote the inclusion of a stated integer or stated integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.