JP5318254B2 - Horizontal shaft pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontal shaft pump (a double-suction horizontal shaft pump or self-balance multistage horizontal shaft pump) which has vane wheels disposed symmetrically, makes a radial load borne by a hydrostatic bearing, and effectively suppresses a dynamic thrust load acting on a spindle shaft in a low-flow-rate area including the vicinity of a point of cut-off. <P>SOLUTION: The double-suction horizontal shaft pump 1 includes the hydrostatic bearings 8 and 9 for bearing the radial load of the spindle 2. Sheet members 41A and 41B and balancing discs 43A and 43B are disposed adjacently to both ends of the hydrostatic bearing 9. The dynamic thrust load is canceled by an urging force equivalent to a difference between an urging force directed toward an anti-driving side 2b by the balancing disc 43A and an urging force directed toward a driving side by the balancing disc 43B is canceled out. The sheet member 41B and the balancing disc 43B are disposed adjacently to a driving-side end of the hydrostatic bearing 9 on the anti-driving side. The sheet member 41A and the balancing disc 43A are disposed adjacently to an anti-driving-side end of the hydrostatic bearing 8 on the driving side. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a horizontal shaft pump in which the arrangement of impellers has left-right symmetry.

  In the multistage horizontal shaft pump disclosed in Patent Document 1, a radial load of the main shaft is supported by a hydrostatic bearing using discharged pressure water.

  Double suction horizontal shaft pumps and self-balanced multistage horizontal shaft pumps (the number and direction of the impellers are symmetrical on the left and right of the main shaft) have a symmetrical arrangement of impellers, so theoretically the thrust load on the main shaft Does not work. In fact, in the case of operation at the design point (usually at or near the maximum efficiency point), the thrust load acting on the main shaft of both suction horizontal shaft pumps is extremely small. However, in the case of a double suction horizontal shaft pump, for example, in a small flow rate region including the vicinity of the deadline, the flow rate sucked at the left and right suction ports of the impeller is not uniform in time, so that the differential pressure that varies with time is present. A thrust load (dynamic thrust load) that varies with time is generated due to this differential pressure. Similarly, in the case of a self-balanced multistage horizontal shaft pump, a dynamic thrust load acts on the main shaft in a small flow rate region.

  Existing horizontal shaft pumps having a configuration that supports the radial load of the main shaft by hydrostatic bearings, including those disclosed in Patent Document 1, have a small flow rate that is generated despite the symmetrical arrangement of the impellers. The suppression of dynamic thrust load in the region is not considered. In particular, Patent Document 1 discloses only a multi-stage horizontal shaft pump in which the suction ports of the impellers of each stage are directed in the same direction, and does not mention a self-balance type multi-stage horizontal shaft pump in the first place.

JP-A-10-89283

  The present invention relates to a horizontal shaft pump (both suction horizontal shaft pump and self-balanced multi-stage horizontal shaft pump) having a configuration in which the arrangement of the impeller has left-right symmetry and a radial load is supported by a hydrostatic bearing. It is an object to effectively suppress a dynamic thrust load acting on a main shaft in a small flow rate region including the vicinity of a point.

The present invention is a horizontal shaft pump in which the arrangement of the impeller is bilaterally symmetric, the casing housing the impeller attached to the main shaft, and the main shaft disposed on the drive side of the main shaft in the casing. A drive-side hydrostatic bearing that supports a radial load of the main shaft, a counter-drive-side hydrostatic bearing that is disposed on the counter-drive side of the main shaft in the casing and supports the radial load of the main shaft, and a discharge port of the impeller A pressure water supply passage for supplying the discharged pressure water to the drive side hydrostatic bearing and the non-drive side hydrostatic bearing; and a first seat portion fixed to the casing side, the first side on the drive side The first water gap is fixed to the main shaft so as to be spaced from the gap, and the pressure water after passing through one of the driving side hydrostatic bearing and the counter driving side hydrostatic bearing is the blade A part of the flow path returning to the car inlet side The first balancing disc and the second seat portion fixed to the casing side are fixed to the main shaft so as to be arranged on the counter drive side with a second gap therebetween. The second gap constitutes a part of a flow path in which the pressure water after passing through the other of the driving side hydrostatic bearing and the counter driving side hydrostatic bearing returns to the suction port side of the impeller. A second balancing disk , wherein the first seat part and the first balancing disk are arranged adjacent to the driving side end of the counter driving side hydrostatic bearing, the second sheet portion and the second balance disc that are positioned adjacent to an end of the non-driven side of the drive-side static pressure bearing, provides horizontal axis pump.

  Depending on the direction of the dynamic thrust load, one of the gap between the first seat portion and the first balancing disk and the gap between the second seat portion and the second balancing disk is narrowed and the other is widened. By reducing and enlarging the gap, the thrust force generated by the first balancing disk (thrust force toward the non-driving side) and the thrust force generated by the second balancing disk (the driving side is changed depending on the direction of the dynamic thrust load). One of the directed thrust forces) increases and the other decreases, and the dynamic thrust load is offset by the thrust force corresponding to these differences. As a result, the dynamic thrust load acting on the main shaft in a small flow rate region including the vicinity of the deadline can be effectively suppressed.

  The present invention can be applied not only to both suction horizontal pumps but also to a self-balanced multistage horizontal pump.

  It is preferable to further include a foreign matter removing means that is interposed in the pressure water supply path and removes the foreign matter from the pressure water. According to this configuration, even if foreign matter such as slurry is mixed in the pressure water (pump pumped liquid) discharged from the impeller, the pressure water after the foreign matter is removed by the foreign matter removing means is on the driving side and the non-driving side. Supplied to the hydrostatic bearing. As a result, wear can be prevented and dynamic thrust load can be suppressed with high reliability. Since the pressure water from which foreign matter has been removed can be supplied to the hydrostatic bearing, the bearing material of the hydrostatic bearing is not limited to ceramic, and resin or rubber can be used.

  According to the present invention, the first thrust force by the first balancing disk (thrust force toward the non-driving side) and the second thrust force by the second balancing disk according to the direction of the dynamic thrust load. (Thrust force facing the drive side) changes and the dynamic thrust load is canceled by the thrust force corresponding to these differences. Therefore, the dynamic thrust load acting on the main shaft in the small flow rate region including the vicinity of the deadline is reduced. It can be effectively suppressed.

Sectional drawing of the both suction horizontal shaft pump which concerns on the reference example of this invention. The enlarged view of the part II of FIG. The enlarged view of the part III of FIG. The enlarged view of the part IV of FIG. The enlarged view seen from the arrow V of FIG. The schematic diagram which shows the circulation path of the pressure water in the both suction horizontal shaft pump which concerns on a reference example . Sectional drawing of the both suction horizontal-axis pump which concerns on 1st Embodiment of this invention. The enlarged view of the part VIII of FIG. The enlarged view of the part IX of FIG. The enlarged view of the part X of FIG. The schematic diagram which shows the circulation path of the pressure water in the both suction horizontal shaft pump which concerns on 1st Embodiment. Sectional drawing of the multistage horizontal shaft pump which concerns on 2nd Embodiment of this invention. The enlarged view of the part XIII of FIG. The enlarged view of the part XIV of FIG.

( Reference example )
1 to 6 show a double suction horizontal shaft pump 1 according to a reference example of the present invention (hereinafter simply referred to as pump 1).

  The main shaft 2 of the pump 1 extends in the horizontal direction, and both suction type impellers 3 attached to the main shaft 2 are accommodated in a casing 4. In the drawing of the main shaft 2, the right side is a driving side 2 a connected to a prime mover (not shown), and the left side is a counter driving side 2 b in the drawing. The drive side 2 a of the main shaft 2 passes through the casing 4, but the end of the counter drive side 2 b is accommodated in the casing 4. A shaft seal device 5 is attached to a portion of the casing 4 through which the main shaft 2 passes. Specifically, the shaft seal device 5 is fixed to a cover 6 fixed to the outer surface of the casing 4. The casing 4 houses hydrostatic bearings 8 and 9 that support the radial load of the main shaft 2 as will be described in detail later.

  In the casing 4 in which the impeller 3 is accommodated, suction side spiral chambers 11A and 11B and a discharge side spiral chamber 12 are provided. Suction ports 20A and 20B, which will be described later, of the impeller 3 open to the suction-side spiral chambers 11A, 11B, and a discharge port 21, which will be described later, of the impeller 3 opens to the discharge-side spiral chamber 12. The impeller 3 rotates together with the main shaft 2 that is rotationally driven by a prime mover connected to the drive side 2a, and water (others) flows into the suction side spiral chambers 11A and 11B from a suction port (not shown) provided in the casing 4 Is sucked into the impeller 3 from the suction ports 20A and 20B, discharged from the discharge port 21 to the discharge-side spiral chamber 12, and flows out from a discharge port (not shown) provided in the casing 4.

  The impeller 3 includes a boss portion 15 attached to the main shaft 2 and substantially circular side plates 16A and 16B disposed on both sides of the boss portion 15. A plurality of blades 17 are provided between the boss portion 15 and the side plates 16A and 16B. Each of the side plates 16A and 16B includes cylindrical base portions 18A and 18B that are open at both ends. Wear rings 19 </ b> A and 19 </ b> B are attached to portions of the casing 4 surrounding the base portions 18 </ b> A and 18 </ b> B. The portion surrounded by the cap portions 18A and 18B faces the inlet of the blade 17 and functions as the suction ports 20A and 20B of the impeller 3. On the other hand, the outer peripheral sides of the side plates 16 </ b> A and 16 </ b> B where the outlets of the blades 17 are located function as the discharge ports 21 of the impeller 3.

  As shown most clearly in FIG. 3, an adjustment ring 65 having a constant width is attached to the outer periphery of the cap portion 18 </ b> B on the counter driving side 2 b of the impeller 3. Therefore, the width of the base portion 18B on the counter driving side 2b is a width obtained by adding the width t1 of the base portion 18B itself and the width Δt of the adjustment ring 65, and is larger than the width t1 of the base portion 18A on the driving side 2a. The width of the wear ring 19B on the counter drive side 2b is set smaller than the wear ring 19A on the drive side 2a by an amount corresponding to the width Δt of the adjustment ring 65.

  In the casing 4, a hydrostatic bearing 8 that supports the radial load of the main shaft 2 on the driving side 2 a from the impeller 3, and a hydrostatic bearing that supports the radial load of the main shaft 2 on the counter driving side 2 b from the impeller 3. 9 is arranged.

  The hydrostatic bearing 8 on the drive side 2 a includes a substantially cylindrical holder 24 fixed to the casing 4 at a position adjacent to the shaft seal device 5. A bearing body 26 is held by the holder 24. The bearing body 26 is generally cylindrical and is made of a material having slidability, wear resistance, corrosion resistance, and the like such as ceramics. A pressure water chamber 28A is formed by providing a partial cut on the left end side in the drawing of the holder 24 and the bearing body 26. The pressure water chamber 28 </ b> A communicates with a supply port 29 </ b> A formed in the casing 4. The pressure water chamber 28 </ b> A communicates with a minute gap between the inner peripheral surface of the bearing body 26 and the outer peripheral surface of the main shaft 2. Further, the pressure water chamber 28A communicates with the shaft seal device 5 side (however, a floating ring for reducing leakage is disposed between the pressure water chamber 28A and the shaft seal device 5).

  The hydrostatic bearing 9 on the counter driving side 2b is a bearing body made of a substantially cylindrical holder 25 fixed to the casing 4 near the end of the counter driving side 2b of the main shaft 2, and ceramics etc. held by the holder 25. 27. A space 10 is provided between the end surface 2 c of the counter driving side 2 b of the main shaft 2 exposed from the end of the hydrostatic bearing 9 and the cover 7 fixed to the casing 4. Further, by providing a partial cut on the right end side in the drawing of the holder 25 and the bearing body 27, a pressure water chamber 28B communicating with the supply port 29B of the casing 4 is formed. The pressure water chamber 28 </ b> B communicates with a minute gap between the inner peripheral surface of the bearing body 27 and the outer peripheral surface of the main shaft 2.

  The casing 4 includes a sheet member (first member) at a position between the static pressure bearing 9 and the suction port 20B of the impeller 3, more specifically at a position adjacent to the end of the driving side 2 a of the static pressure bearing 9. Sheet member) 41A is attached, and a balance disk (first balance disk) 43A is disposed on the main shaft 2 in a pair with the sheet member 41A.

Referring to FIG. 2, the sheet member 41 </ b> A has a cylindrical shape with openings at both ends as a whole, and the main shaft 2 passes therethrough. In addition, in the drawing of the sheet member 41A, a flange-shaped portion 41a having an enlarged diameter is provided at the right end portion. An annular recess 41b is formed on the end surface of the bowl-shaped portion 41a. The balancing disk 43A is fixed to the main shaft 2 so as to face the sheet member 41A. The balancing disk 43A in the present reference example includes a base member 44 that is fixed to the main shaft 2 with a key, and a disk body 45 that is fixed to a surface of the base member 44 that faces the sheet member 41A. The disk main body 45 is made of a material having slidability, wear resistance, corrosion resistance, and the like such as ceramics.

  A thin cylindrical channel 46A is formed between the inner peripheral surface of the sheet member 41A and the main shaft 2. Further, a wide ring-shaped space 47A is constituted by the disk main body 45 of the balancing disk 43A and the recess 41b of the sheet member 41A. The outer diameter of the disc body 45 is set to be smaller than the outer diameter of the recess 41b of the flange portion 41a of the first sheet member 41, and the disc body 45 can partially enter the recess 41b in the thickness direction. Therefore, a ring-shaped gap 48A is formed between the end surface of the sheet member 41A and the base member 44 of the balancing disk 43A. The pressure water chamber 28B communicates with the suction-side spiral chamber 11B (the suction port 20A side of the impeller 3) via the flow path 46A, the space 47A, and the gap 48A.

Referring to FIG. 3, the casing 4 has a position between the hydrostatic bearing 9 and the cover 7 on the counter driving side 2b, more specifically, a position adjacent to the end of the counter driving side 2b of the hydrostatic bearing 9. In addition, a sheet member 41B is arranged, and a balancing disk (second balancing disk) 43B is arranged on the main shaft 2 in a pair with the sheet member 41B. In this reference example , the sheet member 41 </ b> B has an integral structure with the holder 25 of the hydrostatic bearing 9. The arrangement and structure of the seat member 41B and the balancing disc 43B are the same as those of the seat member 41A and the balancing disc 43A described above, respectively, except that the left and right orientations (directions in which the main shaft 2 extends) are reversed in the drawing. The same reference numerals are used for the same or similar elements.

  One end of a substantially thin cylindrical flow path 46B formed between the inner peripheral surface of the sheet member 41B and the main shaft 2 is open to the end surface of the bearing body 27 of the hydrostatic bearing 9 on the counter drive side. Therefore, a minute gap between the outer peripheral surface of the bearing body 27 of the hydrostatic bearing 9 and the outer peripheral surface of the main shaft 2 is between the flow path 46B, the disk main body 45 of the balancing disk 43B, and the recess 41b of the sheet member 41B. The space 47B and the end surface of the seat member 41B and a gap 48B between the base member 44 of the balancing disc 43B communicate with the space 10 on the side of the end surface 2c of the counter drive side 2b of the main shaft 2.

Referring to FIGS. 1 and 6, a supply pipe (pressure supply path) 51 for supplying pressure water discharged from the discharge port 21 of the impeller 3 to the static pressure bearings 8 and 9 is provided. The supply pipeline 51 in this reference example includes a main pipeline 52 having one end connected to the discharge-side spiral chamber 12 in the casing 4, a drive-side pipeline 53 and a non-drive-side pipeline branched from the other end of the main pipeline 52. A path 54 is provided. The drive side pipe line 53 is connected to the supply port 29A for the hydrostatic bearing 8 on the drive side 2a. The counter drive side pipe line 54 is connected to the supply port 29B for the hydrostatic bearing 9 on the counter drive side 2b.

  A strainer 55 for removing foreign substances from the pressure water is interposed in the main pipeline 52. Instead of the strainer 55, other foreign matter removing means such as a cyclone separator may be provided in the main pipeline 52. Since the pressure water from which foreign matter has been removed by the strainer 55 or the cyclone separator can be supplied to the hydrostatic bearing, the bearing material of the hydrostatic bearings 8 and 9 is not limited to ceramic, and resin or rubber can be used.

  An adjustment valve 56 </ b> A for manually adjusting the flow rate of the pressure water supplied from the discharge-side spiral chamber 12 to the hydrostatic bearing 8 is interposed in the drive side conduit 53. Similarly, an adjustment valve 56B for manually adjusting the flow rate of the pressure water supplied from the discharge side spiral chamber 12 to the hydrostatic bearing 9 is interposed in the counter driving side conduit 54.

  Referring to FIGS. 1 and 6, a return port 30 </ b> A is formed in the cover 6 which is fixed to a portion through which the drive side 2 a of the main shaft 2 of the casing 4 passes. The return port 30A communicates with a space in the cover 6 where the shaft seal device 5 is disposed. One end of a return pipe 58 </ b> A is connected to the return port 30. The other end of the return pipe line 58 </ b> A is connected to the suction side spiral chamber 11 </ b> A in the casing 4. Similarly, a return port 30 </ b> B is formed in the cover 7 fixed to the counter driving side 2 b of the main shaft 2 of the casing 4. The return port 30 </ b> B communicates with the space 10 between the end surface 2 c of the main shaft 2 and the cover 7. One end of a return pipe 58B is connected to the return port 30. The other end of the return pipe 58 </ b> B is connected to the suction side spiral chamber 11 </ b> B in the casing 4.

  When the impeller 3 rotates together with the main shaft 2 that is driven to rotate by the prime mover, pressure water is discharged from the discharge port 21 of the impeller 3 to the discharge-side spiral chamber 12, and this pressure water is discharged from the main pipeline 52 to the drive-side pipeline 53. It is supplied to the pressure water chamber 28A through the supply port 29A. Similarly, the pressure water discharged from the discharge port 21 of the impeller 3 to the discharge side spiral chamber 12 is supplied from the main pipeline 52 to the pressure water chamber 28B via the counter drive side pipeline 54 and the supply port 29B. The Pressure water is forcibly supplied from the pressure water chambers 28 </ b> A and 28 </ b> B to the sliding surfaces between the inner periphery of the bearing bodies 24 and 26 of the hydrostatic bearing 8.9 and the outer periphery of the main shaft 2. Radial load is supported. The pressure water after being supplied between the sliding surfaces flows into the suction side spiral chambers 11A and 11B via the return pipes 58A and 48B, and returns to the suction ports 20A and 20B of the impeller 3.

  Referring to FIGS. 2 and 6, the pressure water supplied to the pressure water chamber 28B is generated by the flow path 46A between the sheet member 41A and the main shaft 2, the balance disk 43A (disk body), and the recess 41b of the sheet member 41A. The air flows into the suction side spiral chamber 11B through the space 47A and the gap 48A between the seat member 41A and the balance disk 43A (base member 44). Accordingly, the pressure water pressure (static pressure) in the pressure water chamber 28B corresponding to the discharge pressure of the impeller 3 is applied to the surface of the counter disk 2A on the counter drive side 2b (the surface facing the sheet member 41A of the disk main body 45). ) A pressure P1 between Pd and the pressure (static pressure) Ps in the suction side spiral chamber 11A acts (Pd> P1> Ps). On the other hand, the pressure Ps in the suction side vortex chamber 11B acts on the surface on the drive side 2a of the balance disc 43A (the surface opposite to the disc body 45 of the base member 44). Therefore, an urging force (rightward urging force in the figure) F1 directed to the drive side 2a corresponding to the differential pressure between the pressure P1 and the pressure Ps acts on the main shaft 2 from the balancing disk 43A.

  3 and 6, the pressurized water supplied to the pressure water chamber 28 </ b> B passes through a minute gap between the hydrostatic bearing 9 and the main shaft 2, and then the flow path 46 </ b> B between the sheet member 41 </ b> B and the main shaft 2. The space 10 (return pipe line) passes through the space 47B formed by the balance disk 43B (disk body 45) and the recess 41 of the sheet member 41B, and the gap 48B between the sheet member 41B and the balance disk 43B (base member 44). It flows into the suction side spiral chamber 11B via 58A. Accordingly, the balance disk 43B has a pressure P2 between the pressure Pd in the pressure water chamber 28B corresponding to the discharge pressure of the impeller 3 and the pressure Ps in the suction side spiral chamber 11B on the surface of the drive side 2a. (Pd> P2> Ps) On the other hand, the pressure Ps in the suction side spiral chamber 11B acts on the surface of the counter driving side 2b. Therefore, a biasing force F2 (a biasing force in the left direction in the drawing) F2 directed to the counter driving side 2b corresponding to the differential pressure between the pressure P2 and the pressure Ps acts on the main shaft 2 from the balancing disk 43B.

  In the small flow rate region including the vicinity of the deadline, the flow rate sucked at the left and right suction ports 20A and 20B in the drawing of the impeller 3 is not uniform in time, and thus a differential pressure that varies with time is generated. As a result, a dynamic thrust load whose magnitude and direction change with time is generated. However, this dynamic thrust load is offset by changes in the urging forces F1 and F2 of the balancing disks 43A and 43B, as will be described in detail below.

  First, when the dynamic thrust load is directed to the counter driving side 2b, the main shaft 2 is displaced to the counter driving side 2b (left side in the figure). When the main shaft 2 is displaced to the non-driving side 2b, the gap 48A between the balancing disk 43A and the sheet member 41A is narrowed, so that the pressure P1 in the space 47A (pressure that biases the balancing disk 43A toward the driving side 2a) increases. Therefore, when the dynamic thrust load is directed to the non-driving side 2b, the urging force F1 for urging the balance disc 43A toward the driving side 2a increases. On the other hand, when the dynamic thrust load is directed to the non-driving side 2b and the main shaft 2 is displaced to the non-driving side 2b, the gap 48B between the balancing disk 43B and the seat member 41B increases, and therefore the pressure P2 (the balancing disk 43B) in the space 47B. ) To the counter-drive side 2b). For this reason, when the dynamic thrust load is directed to the non-driving side 2b, the urging force F2 that the balancing disk 43B urges the main shaft 2 to the non-driving side 2b becomes small. That is, when the dynamic thrust load is directed to the counter driving side 2b, the urging force F1 directed to the driving side 2a by the balancing disk 43A is larger than the urging force F2 directed to the counter driving side 2b by the balancing disk 43B. The dynamic thrust load is canceled by the urging force (F1-F2) facing the drive side 2a corresponding to the difference.

  Conversely, when the dynamic thrust load is directed toward the driving side 2a, the gap 48A between the balancing disk 43A and the seat member 41A increases, and the urging force F1 directed toward the driving side 2a by the balancing disk 43A decreases, while the balancing is reduced. The gap 48B between the disk 43B and the sheet member 41B is narrowed, and the biasing force F2 directed to the drive side 2b by the balancing disk 43B is increased. Then, the dynamic thrust load is canceled by the biasing force (F2-F1) facing the counter driving side 2b corresponding to the difference.

  In this way, the biasing force F1 facing the drive side 2a by the balancing disk 43A and the biasing force F2 facing the counter-drive side 2b by the balancing disk 43B change according to the direction of the dynamic thrust load, and the difference between them. The dynamic thrust load is canceled by the urging force corresponding to. As a result, it is possible to effectively suppress the dynamic thrust load acting on the main shaft in the small flow rate region including the vicinity of the cut-off point and the vibration resulting therefrom.

  The cap portions 18A and 18B have different pressures acting on the left and right surfaces in the figure. Specifically, the pressure Ps of the suction side spiral chambers 11A and 11B acts on the outer surfaces of the cap parts 18A and 18B, while the pressure Ps and the pressure Pd of the discharge port 21 of the impeller 3 are on the inner side. The pressure Pi acts on (Pi> Ps). Accordingly, a force fa directed toward the drive side 2a (rightward in the drawing) corresponding to a value obtained by multiplying the pressure difference between the pressures Pi and Pd by the width t1 of the cap portion 18A acts on the cap portion 18A of the drive side 2a, and the counter drive is performed. The base portion 18B on the side 2b has a force fb in the direction opposite to the driving side 2b (leftward in the drawing) corresponding to the difference between the pressures Pi and Pd multiplied by the width t1 + Δt of the base portion 18B and the adjustment ring 65. The force fb is larger than the force fa, and an urging force F3 (= fb−fa) directed to the counter driving side 2b corresponding to the difference between the two acts on the main shaft 2. This urging force F3 acts on the main shaft 2 as a static thrust load directed to the counter-drive side 2b that does not vary substantially in time, and suppresses a dynamic thrust load in a small flow rate region.

  When the main shaft 2 is largely displaced toward the driving side 2a due to a dynamic thrust load or the like, the thrust load directed toward the driving side 2a is supported by pressing the balancing disk 43A against the sheet member 41A. On the other hand, when the displacement is greatly caused by the dynamic thrust load or the like to the non-driving side 2b, the balancing disk 43B is pressed against the sheet member 41B, so that the thrust load directed to the driving side 2b is supported. Thus, high thrust load support force is obtained by the balancing disks 43A and 43B being pressed against the sheet members 41A and 41B.

  When the flow rate of the pressure water is increased by increasing the opening degree of the regulating valve 56B of the counter drive side pipe 54, the pressures P1 and P2 in the spaces 47A and 47B acting on the balancing disks 43A and 43B increase. Conversely, when the opening degree of the regulating valve 56B is lowered, the pressures P1 and P2 in the spaces 47A and 47B acting on the balancing disks 43A and 43B are reduced. In this way, the urging forces F1 and F2 can be adjusted by adjusting the pressures P1 and P2 acting on the balancing disks 43A and 43B with the adjusting valve 56A. Similarly, the pressure of the pressure water supplied to the pressure water chamber 28 </ b> A can be adjusted by adjusting the opening of the adjustment valve 56 </ b> A of the drive side pipe 53. By adjusting the urging forces F1 and F2 with the adjusting valve 56B, the position of the main shaft 2 in the thrust direction with respect to the casing 4 can be adjusted. As shown in FIG. 5, a gauge 61 extending in the thrust direction of the main shaft 2 is attached to the cover 6 on the drive side 2a. By referring to this gauge 61, it becomes easy to grasp the change in the position of the main shaft 2 in the thrust direction, and the operation of adjusting the position of the main shaft 2 in the thrust direction by operating the adjusting valve 56B becomes easy.

  Even if foreign matter such as slurry is mixed in the pressure water (pump pumped liquid) discharged from the impeller 3, the pressure water after the foreign matter is removed by the strainer 55 provided in the main pipeline 52 of the supply pipeline 51. It is supplied to the hydrostatic bearings 8 and 9. As a result, wear of the bearing bodies 26 and 27 of the hydrostatic bearings 8 and 9 can be prevented. Since the pressure water from which foreign matter has been removed by the strainer 55 can be supplied to the hydrostatic bearing, the bearing material of the hydrostatic bearings 8 and 9 is not limited to ceramic, and resin or rubber can be used.

(First Embodiment)
7 to 11 show both suction horizontal shaft pumps 1 'according to the first embodiment of the present invention (hereinafter simply referred to as pump 1').

In the pump 1 of the reference example , a pair of balancing disks 43A and 43B and sheet members 41A and 41B are disposed adjacent to both sides (the driving side 2a and the counter driving side 2b) of the hydrostatic bearing 9 on the counter driving side 2b. Yes. In the pump 1 ′ of the present embodiment, one balancing disk 43A and the seat member 41A are disposed adjacent to the end of the drive side 2a (right side in the drawing) of the hydrostatic bearing 9 on the counter drive side 2b. Then, it is the same as that of a reference example . However, the other balancing disk 43B and the seat member 41B are not the end portion (the left end portion in the figure) of the anti-driving side 2b of the hydrostatic bearing 9 of the counter driving side 2b, but the hydrostatic bearing 8 of the driving side 2a. Is disposed adjacent to the end (the left end in the figure) of the non-driving side 2b.

  Referring to FIG. 10, a seat member 41 </ b> B is attached to the casing 4 at a position adjacent to the end of the hydrostatic bearing 8 on the non-driving side 2 b, and a balancing disk 43 </ b> B is disposed on the main shaft 2 in a pair with the seat member 41 </ b> B. Yes. The pressure water supplied to the pressure water chamber 28 </ b> A passes through a minute gap between the inner peripheral surface of the bearing body 26 of the hydrostatic bearing 8 and the outer peripheral surface of the main shaft 2, and then between the sheet member 41 </ b> B and the main shaft 2. The suction side vortex passes through the passage 46B, the space 47B formed by the balance disk 43B (disk body 45) and the depression 41 of the sheet member 41B, and the gap 48B between the sheet member 41B and the balance disk 43B (base member 44). It flows into the chamber 11A and returns to the suction port 20A of the impeller 3. A biasing force (left biasing force in the figure) directed to the counter driving side 2b corresponding to a differential pressure between the pressure P2 (Pd> P2> Ps) in the space 47B and the pressure Ps acting on the counter driving side 2b of the balancing disk 43B. ) F2 acts on the main shaft 2 from the balancing disk 43B.

  Depending on the direction of the dynamic thrust load, the urging force F1 facing the driving side 2a by the balancing disk 43A and the urging force F2 facing the counter driving side 2b by the balancing disk 43B change, and the urging force corresponding to the difference between them is changed. The dynamic thrust load is offset by the force. As a result, it is possible to effectively suppress the dynamic thrust load acting on the main shaft in the small flow rate region including the vicinity of the cut-off point and the vibration resulting therefrom.

  When the main shaft 2 is greatly displaced due to a dynamic thrust load or the like, one of the balancing disks 43A and 43B is pressed against the corresponding sheet member 41A and 41B according to the direction of the displacement, and a high thrust load supporting force is obtained. It is done.

As shown most clearly in FIG. 8, the adjustment ring 65 (see FIG. 4) is not attached to any of the cap portions 18 </ b> A and 18 </ b> B of the impeller 3. Therefore, the widths t1 of the cap portions 18A and 18B on the driving side 2a and the counter driving side 2b are equal, and the urging force (reference numeral F3 in FIG. 4) due to the pressure difference acting on the individual cap portions 18A and 18B is applied to the main shaft 2. Does not work. However, by attaching the adjustment ring 65 to the base portion 18B of the counter driving side 2b as in the reference example , a biasing force F3 directed to the counter driving side 2b that does not substantially change in time is applied to the main shaft 2. Also good.

  By operating the adjustment valve 56B, the pressure P1 acting on the balancing disk 43A can be changed to adjust the urging force F1 acting on the main shaft 2 from the balancing disk 43A. Further, the pressure P2 acting on the balance disk 43B can be changed by operating the adjustment valve 56A, and the biasing force F2 acting on the main shaft 2 from the balance disk 43B can be adjusted. The position of the main shaft 2 in the thrust direction with respect to the casing 4 can be adjusted by adjusting the urging forces F1 and F2 by the adjusting valves 56A and 56B. At this time, the operation is facilitated by referring to the cage 61 (FIG. 5). Further, the pressure water after the foreign matter is removed by the strainer 55 is supplied to the hydrostatic bearings 8 and 9, and wear of the bearing bodies 26 and 27 can be prevented.

Since the other configurations and operations of the first embodiment are the same as those of the reference example , the same elements are denoted by the same reference numerals and description thereof is omitted.

( Second embodiment)
12 to 14 show a self-balanced multi-stage horizontal axis pump 201 according to a second embodiment of the present invention (hereinafter simply referred to as horizontal axis pump 201).

The pump 201 is provided with two single-suction impellers 202A and 202B at the first stage, and a double suction impeller 3 similar to the reference example at the second stage. The impellers 202A and 202B are disposed symmetrically on the main shaft 2 with the impeller 3 interposed therebetween. Further, the impellers 202A and 202B have the same configuration except that the suction port of the impeller 202A faces right in the figure but the suction port of the impeller 202B faces left in the figure. A shaft seal device 205 is attached to the casing 204 at a portion through which the drive side 2a of the main shaft 2 passes. In order to support the radial load of the main shaft 2, the hydrostatic bearing 8 is accommodated in the drive side 2 a of the casing 204, and the hydrostatic bearing 9 is accommodated in the counter drive side 2 b.

As with both suction horizontal shaft pumps 1 ′ of the first embodiment, a pair of a seat member 41 </ b> A and a balancing disk 43 is disposed adjacent to the end of the drive side 2 a of the hydrostatic bearing 9 on the counter drive side 2 b ( 14), a pair of the sheet member 41B and the balancing disk 43 is disposed adjacent to the end of the hydrostatic bearing 8 on the driving side 2a on the counter driving side 2b.

  The urging forces F1 and F2 acting on the main shaft 2 are changed by the balancing disks 43A and 43B according to the direction of the dynamic thrust load, and the dynamic thrust load is canceled by the urging force corresponding to the difference therebetween. As a result, it is possible to effectively suppress the dynamic thrust load acting on the main shaft in the small flow rate region including the vicinity of the cut-off point and the vibration resulting therefrom. Moreover, a high thrust load supporting force is obtained by pressing the balancing disks 43A and 43B against the corresponding sheet members 41A and 41B. Furthermore, the position of the main shaft 2 in the thrust direction can be adjusted by changing the urging forces F1 and F2 by the adjusting valves 56B and 56A. By removing the foreign matter in the pressure water with the strainer 55, the wear of the hydrostatic bearings 8 and 9 can be prevented.

Since other configurations and operations of the second embodiment are the same as those of the reference example , the same elements are denoted by the same reference numerals, and description thereof is omitted.

1, 1 'Double suction horizontal shaft pump 2 Main shaft 2a Drive side 2b Counter drive side 2c End face 3 Impeller 4 Casing 5 Shaft seal device 6, 7 Cover 8, 9 Static pressure bearing 10 Space 11A, 11B Suction side spiral chamber 12 Discharge Side spiral chamber 13, 14
15 Boss part 16A, 16B Side plate 17 Blade 18A, 18B Base part 19A, 19B Wear ring 20A, 20B Suction port 21 Discharge port 24, 25 Holder 26, 27 Bearing body 28A, 28B Pressure chamber 29A, 29B Supply port 30A, 30B Return Port 41A, 41B Sheet member 41a Cone portion 41b Depression 43A, 43B Balance disk 44 Base member 45 Disk body 46A, 46B Channel 47A, 47B Space 48A, 48B Clearance 51 Supply pipeline 52 Main pipeline 53 Drive side pipeline 54 Non-driving side pipe 55 Strainer 56A, 56B Adjusting valve 58A, 58B Return pipe 61 Cage 65 Adjusting ring 201 Multistage horizontal shaft pump 202A, 202B Impeller 204 Casing

Claims (4)

A horizontal shaft pump in which the arrangement of the impeller has left-right symmetry,
A casing containing an impeller attached to the main shaft;
A drive-side hydrostatic bearing disposed on the drive side of the main shaft in the casing and supporting a radial load of the main shaft;
A non-drive-side hydrostatic bearing disposed on the non-drive side of the main shaft in the casing and supporting a radial load of the main shaft;
A pressure water supply path for supplying pressure water discharged from a discharge port of the impeller to the driving side hydrostatic bearing and the counter driving side hydrostatic bearing;
The first seat portion fixed to the casing side is fixed to the main shaft so as to be arranged with a first gap on the driving side, and the first gap is connected to the driving side hydrostatic bearing and the A first balancing disk that constitutes a part of a flow path in which the pressure water after passing through one of the counter driving side hydrostatic bearings returns to the suction port side of the impeller;
The second seat portion fixed to the casing side is fixed to the main shaft so as to be disposed on the counter driving side with a second gap therebetween, and the second gap is connected to the driving side hydrostatic bearing and A second balancing disk that constitutes part of a flow path in which the pressure water after passing through the other of the counter-drive-side hydrostatic bearings returns to the suction port side of the impeller; and
Equipped with a,
The first seat part and the first balancing disk are arranged adjacent to the driving side end of the counter driving side hydrostatic bearing, and the second seat part and the second balancing disk are wherein the drive side hydrostatic bearing that is disposed adjacent an end of the non-drive side, the horizontal axis pump. It is a double-suction horizontal axis pump, the horizontal axis pump according to claim 1. The horizontal axis pump according to claim 1, which is a self-balanced multistage horizontal axis pump. The horizontal axis pump according to any one of claims 1 to 3 , further comprising a foreign matter removing unit that is provided in the pressure water supply path and removes foreign matter from the pressure water.

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