Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
  • F04D15/0055—Rotors with adjustable blades

Definitions

• Adjustment device for adjusting propeller blades of a propeller pump and a propeller pump including such a device
• the present invention relates to propeller pumps or axial pumps and, in particular, to a device for adjusting the propeller blades of the pump.
• frequency control By using so called frequency control to adjust the flow of a pump it is possible to achieve this flow variation during the operation of the pump by increasing/ decreasing the number of revolutions of the propeller in order to achieve a corresponding increase/ decrease of the flow in accordance with the requirements or desires.
• the frequency control allows an adjustment of the flow of about 30 %, which, in many applications, is a too narrow range. This applies in particular in applications where considerably flow variations are desired or required as, for example, in adventure baths, artificial waterfalls for paddling and other waterfall activities such as rafting. Therefore, a number of approaches have been proposed that address the above mentioned problems.
• US 2,357,229 discloses a pump rotor provided with swivelling blades angularly adjustable automatically while the rotor is in motion.
• Each swivelling blade is formed integrally with its spindle and with an operating crank depending therefrom.
• Pivotally mounted on the lower end of each crank is a block slidably fitting in a groove in one face of a hollow prismatic member disposed around the axis of the hub.
• the prismatic member is hollow with a cylinder interior serving as the cylinder of the axial servo-motor and slidable on the fixed piston carried at the lower end of a hollow part of the hub depending from the inner bearings.
• EP 0 541 046 discloses a propeller pump with blade pitch adjustment in which an adjustment apparatus by a threaded spindle, an adjustment nut axially adjustable thereon which is provided with a slide bar and, via a guide bar bracket arranged in the propeller hub, determines the position of the blades and thereby allows a variation of the flow.
• JP 60162073 A discloses a runner-vane operating mechanism for mixed-flow water wheel.
• a slidable guide directly connected to a piston of a vertically movable servo-motor and an inclined groove is formed in each opposed position on an operating lever fixed onto a runner vane stem.
• a pair of opposed slider blocks are arranged in slidable ways in the longitudinal direction of the groove.
• Each blade is fixedly connected to a respective operating lever. By sliding each block in respective groove, the pitch angle of each corresponding blade can be adjusted.
• DE 1 101 154 discloses an adjustment device for adjusting the blades of a pump or a turbine comprising a hub, bearings incorporated therein, a plurality of propeller blades mounted in said bearings and projecting from said hub, each blade being connected with a corresponding block through a slot, which in turn is connected to a slot block arranged in the slot. By an axial displacement of the slot an adjustment of the pitch angle of blades can be obtained.
• AU of the above described pumps with adjustable propellers blades or adjustments devices disclose an unsymmetrical distribution of forces at the hub or, in fact, at respective attachment point of the cranks or arms.
• the pump rotor with adjustable propeller blades according to US 2,357,229 and the adjustment device of JP 60162073 A both discloses long cranks or arms carrying the blades, which gives a long arm of lever between the blade and respective attachment point at the hub.
• This may cause problems because, in many applications, the flow may periodically be very strong, in particular in certain applications such as in adventure baths, artificial waterfalls for paddling and other waterfall activities such as rafting, which entail that considerable forces will act on the pumps and especially on parts of the pumps such as the propeller blades, the cranks or arms carrying the blades, and the attachment points of the cranks or arms. Accordingly, the durability of the pumps can be severely shorten.
• the wear of certain parts such as the attachments point of the cranks or arms at the hub may be significant, shutdowns due to maintenance may be frequent.
• one object of the present invention is to provide an adjustment device for adjusting the propeller blades of a pump and a pump including such a device which, in comparison with prior art, have a high endurance against wear and a high ability of withstanding large forces. This, in turn, provides for a long durability and a good reliability.
• Yet another object of the present invention is to provide a propeller pump comprising an adjustment device for adjusting the propeller blades of the pump during operation of the pump and an adjustment device for adjusting the propeller blades of the pump during operation of the pump.
• pitch angle refers to the angle between the outer periphery of the pressure side of the propeller blade and the neutral line.
• a propeller pump comprising a hub, bearings incorporated therein, a plurality of propeller blades mounted in the bearings and projecting from the hub, comprising an adjustment device for adjusting the pitch angle of the propeller blades about an axis perpendicular to a drive shaft of the propeller.
• the adjustment device comprises adjustment means mounted within the hub arranged to be axially movable in a direction along the drive shaft, the adjustment means being provided with a plurality of guide slots arranged at circumferential spacings around the surface; a plurality of attachment means rotationally mounted in the hub, each being fixedly attached to a propeller blade and supported by at least one guide slot, wherein each attachment means and the corresponding at least one guide slot are arranged to interact such that a force applied on the attachment means is distributed symmetrically about an axis perpendicular to the drive shaft and parallel with a rotational axis of the attachment means; and wherein the guide slots are arranged to, at an axial movement of the adjustment means, cause the attachment means to rotate about its own rotational axis, whereby the propeller blade in turn is rotated.
• an adjustment device for a propeller pump comprising a hub, bearings incorporated therein, a plurality of propeller blades mounted in said bearings and projecting from said hub, for adjusting the pitch angle of said propeller blades about an axis perpendicular to a drive shaft of the propeller in accordance with the first aspect of the present invention.
• the present invention is based on the idea of arranging each one of the guide slots, which are formed so as to, at an axial movement of the adjustment means, cause the attachment means on which the propeller blades are mounted to rotate about its own rotational axis such that the propeller blades in turn are rotated, to interact with a corresponding attachment means such that a force exerted on the corresponding propeller blade or the attachment means is distributed symmetrically about an axis perpendicular to the drive shaft and parallel with a rotational axis of the attachment means.
• Another advantage is that, due to the symmetrical distribution of the forces, the pitch angle of the propeller blades can be adjusted during operating conditions with large flows applying large forces on the propeller blades, which, in turn, impart large forces to the attachment means. Accordingly, the applicability of the propeller pump according to the present invention is increased.
• a further advantage is that the flow can be varied or changed within a broad range of possible flows at a maintained high efficiency. According to a preferred embodiment, the flow can be varied within a range of 100-50 % at a efficiency of about 85-80 %•
• An additional advantage is that the construction of the adjustment device according to the present invention is less complex in comparison with the prior art solutions discussed above. Thereby, the manufacturing costs can be lowered.
• each attachment means is supported by two inclined guide slots. Thereby, the ability to withstand forces can be improved even further.
• the two inclined guide slots consist of one upper guide slot, in a direction along the drive shaft, and one lower guide slot, in a direction along the drive shaft, the upper and the lower guide slot being symmetrically arranged about a centre, in a direction along the drive shaft, perimeter line of the adjustment means such that an angle is formed between each guide slot and the perimeter line.
• Fig. 1 schematically shows a propeller pump including an adjustment device according to the present invention
• Fig. 2 schematically shows in more detail the propeller pump in Fig. 1 including an adjustment device according to the present invention
• Fig. 3 shows the adjustment means according to the present invention of
• the propeller pump or the axial pump 1 comprises a hub 2, in which bearings 3 (see Fig. 2) are incorporated.
• a propeller blade 4 is mounted in each bearing 3 and projects from the hub 2.
• the direction of the flow is indicated with an arrow denoted with A, i.e. in the y-direction as indicated with the two- dimensional coordinate system of Fig.1.
• the pump 1 is mounted in a pump house 9.
• Adjustment means 5 is slidably arranged within the hub 2 so that it can be moved reciprocally in the y-direction, i.e. in a direction along a drive shaft 7 of the pump 1 connected to a motor (not shown) for driving the pump.
• the adjustment means 5 is a cylindrical sleeve arranged concentrically with the drive shaft 7.
• An outer envelope surface 8 of the adjustment cylinder 5 is provided with a number of inclined guide slots 6, formed in pairs, see Fig. 2.
• the pairs of guide slots 6 are arranged at circumferential spacings at diametrically opposed positions around the surface 8 and symmetrically about a centre, in the x-direction, perimeter line of the adjustment cylinder 5 such that an angle is formed between each guide slot 6 and the perimeter line.
• the angle between each guide slot and the centre perimeter line may be varied.
• the pairs of guide slots are replaced by a single guide slot.
• a pair of yokes 12 is fixedly attached to the adjustment cylinder 5, for example, by means of bolts (not shown).
• an attachment rod 14 is fixedly mounted between the yokes 12, for example, by means of mounting screws (not shown), which attachment rod 14, in turn, is connected to actuator means (not shown) arranged in a housing 16 powered by drive unit 17.
• the drive unit 17 may be electrical, pneumatic, or hydraulic.
• the drive unit 17 is, in turn powered via a drive cable 18 arranged within the drive shaft 7. If the drive unit 17 is electrical the drive cable 18 is an electrical lead, if the drive unit 17 is hydraulic the drive cable is an oil line, and if the drive unit 17 pneumatic the drive cable 18 is a line conducting, for example, pressurized air.
• the attachment rod 14 is mounted on a worm drive arranged in the housing 16, which worm drive, in turn, is connected to the drive unit, which, in this case, is electrical.
• Each propeller blade 4 is mounted on an attachment plate 20, which in this embodiment is formed as a circular plate.
• a pair of guide means 22 are, in turn, mounted on the attachment plate 20.
• the guide means 22 are guide pins or protrusions, each being slidably supported in a respective inclined guide slot 6.
• the guide means 22 are needle bearings arranged in pulleys or rolls.
• the adjustment means 5 is a cylindrical sleeve and the outer envelope surface 8 of the adjustment cylinder 5 is provided with a number of inclined guide slots 6, formed in pairs.
• the slots are through openings, which not however is a necessary feature.
• the slots can be formed as recesses in the outer envelope surface 8.
• the pairs of guide slots 6 are arranged at circumferential spacings at diametrically opposed positions around the outer surface 8 and symmetrically about a centre, in the x-direction (i.e. a direction perpendicular to the drive shaft), perimeter line of the adjustment cylinder 5 such that an angle is formed between each guide slot 6 and the perimeter line.
• the adjustment means 25 is a sleeve having a square-formed outer envelope surface 28a-28d, i.e. in a cross section, in a plane perpendicular to the y-direction, the outer perimeter of the sleeve is quadratic, and a circular inner envelope surface 29, i.e. in a cross section, in a plane perpendicular to the y-direction, the inner perimeter of the sleeve is circular. Furthermore, each lateral surface 28a-28d (where only the sides 28a, 28b are shown in Fig.
• the slots are through openings, which however is not a necessary feature.
• the slots can be formed as recesses in the outer envelope surface 8.
• the pairs of guide slots 26a and 26b are arranged at circumferential spacings at diametrically opposed positions around the outer surface 28 and symmetrically about a centre, in the x-direction (i.e. a direction perpendicular to the drive shaft), perimeter line of the adjustment sleeve 25 such that an angle is formed between an upper guide slot 26a and a lower guide slot 26b, in the x-direction, of each pair and the perimeter line.
• the adjustment means 35 is a circular sleeve.
• An outer envelope surface 38 of the adjustment sleeve 35 is provided with a number of V-shaped guide slots 36.
• the slots are through openings, which however is not a necessary feature.
• the slots can be formed as recesses in the outer envelope surface 38 of the sleeve.
• the guide slots 36 are arranged at circumferential spacings at diametrically opposed positions around the outer surface 38 and symmetrically about a centre, in the x- direction (i.e. a direction perpendicular to the drive shaft), perimeter line of the adjustment sleeve 35 such that an angle is formed between each arm of respective guide slot 36 and the perimeter line.
• the adjustment means can be provided with groups of four inclined guide slots.
• the slots are through openings, which however is not a necessary feature.
• the slots can be formed as recesses in a outer envelope surface of the sleeve.
• the guide slots are arranged at circumferential spacings around the outer surface and symmetrically about a centre, in the x- direction (i.e.
• this embodiment of the adjustment means is used with an attachment plate provided with four guide pins, wherein each guide pin is slidably supported in one inclined guide slot.
• the adjustment means can be designed as an octagonal sleeve or a hexagonal sleeve.
• the different designs of the adjustments sleeve and the guide slots can be combined in other ways and the above mentioned, for example, the V-shaped guide slots can be provided on the sleeve have a quadratic outer perimeter.
• the adjustment device work as follows.
• the drive unit 17 receives an instruction or command that the flow should be increased or decreased by a control unit.
• This instruction can be created either manually by an operator via an operator unit or automatically by, for example, the control unit.
• the drive unit 17 activates the actuator means, which, in turn, moves the attachment rod 14 axially in the y-direction (i.e. along the axis of the drive shaft 7), either in forward direction or a rearward direction depending of whether the flow is to be increased or decreased.
• the adjustment means 5 is moved in a direction such that the pitch angle of the propeller blades increases, the flow is, in turn, increased.
• the guide pins 22 will slide in respective inclined guide slots 6 causing the attachment plates 20 to rotate in a counter clock- wise direction, as viewed in the fig. 1.
• each propeller blade 4 mounted on a respective attachment plate 20 is rotated in the same direction and the pitch angle of the propeller blades is increased.
• the pitch angle is defined as the angle between the outer periphery 40 of the propeller blade 42 and the neutral line 44.
• each propeller blade 4 mounted on a respective attachment plate 20 is rotated in the same direction and the pitch angle of the propeller blades is decreased and, thus, the flow of the pump is decreased.
• the pitch angle can be changed within a range of approximately 28 degrees to 5 degrees, and more preferably, within a range of approximately 25 degrees to 6 degrees.
• a preferred angle adjustment is approximately +/- 1 degree.
• the flow change resulting from an adjustment of the angel with 1 degree depends of the absolute angle position.
• An adjustment from a large angle, for example, from 24 to 23 degrees, corresponds to a reduction of the flow of about 3 %.
• the flow reduction is about 5 %.
• a range of about 25 degrees to about 8 degrees corresponds to a regulating range of the flow about 50 % to 100 % of the flow at an approximately constant efficiency, i.e. at an efficiency of about 85-80 %.
• the pump and in particular parts such as, for example, the propeller blades, the attachment means including the attachment plates and guide pins as well as the adjustment sleeve are subjected to forces of a considerable magnitude resulting from the flow. Due to the construction of the adjustment device in accordance with the present invention, in which the adjustment device is provided with guide slots formed symmetrically with respect to a centre line, along a x-direction and perpendicular to the y- direction (see Fig.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)
• Rotary Pumps (AREA)

Applications Claiming Priority (2)

Publications (1)

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Citations (2)

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• 2006
  • 2006-06-05 CN CN2006800221686A patent/CN101228356B/zh not_active Expired - Fee Related
  • 2006-06-05 BR BRPI0612494-1A patent/BRPI0612494A2/pt not_active IP Right Cessation
  • 2006-06-05 US US11/993,931 patent/US20080199318A1/en not_active Abandoned
  • 2006-06-05 WO PCT/SE2006/000658 patent/WO2006137765A1/en active Application Filing
  • 2006-06-05 MX MX2007013538A patent/MX2007013538A/es not_active Application Discontinuation
  • 2006-06-05 EP EP06747852A patent/EP1893873A1/en not_active Withdrawn
  • 2006-06-05 RU RU2008102237/06A patent/RU2008102237A/ru unknown
  • 2006-06-21 AR ARP060102664A patent/AR054490A1/es unknown
• 2007
  • 2007-11-09 NI NI200700288A patent/NI200700288A/es unknown

Patent Citations (2)

Non-Patent Citations (1)

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