JP2014152742A - Casing of pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a hole from being formed in a casing by wear of an inner wall.SOLUTION: The casing comprises: a first casing body 51 that has a bottomed cylindrical shape and can coaxially house an impeller 22; a suction hole 33 provided at the bottom center of the first casing body 51; and a protruding portion 55 protruding along the axial direction of the first casing body 51 from the bottom of the first casing body 51 and including a first upward slope 56 whose axial height from the bottom of the first casing body 51 is gradually increased along the rotation direction of the impeller 22.

Description

  The present invention relates to a casing of a pump device that houses an impeller and boosts fluid.

  Currently, a cooling device that cools a machined part of a machine tool, a heat generating portion of a manufacturing apparatus, and the like is known. Such a cooling device includes a storage tank for storing the coolant liquid, a pump device for increasing the pressure of the coolant liquid in the storage tank, and a pipe for supplying the coolant liquid to the heat generating portion and returning the supplied coolant liquid to the storage tank. Is known, and the coolant liquid is circulated (see, for example, Patent Document 1).

  The pump device used for the cooling device includes a motor unit fixed outside the storage tank and a pump unit arranged inside the storage tank. In the pump part, an impeller fixed to the rotating shaft of the motor part and a casing (housing) for housing the impeller are arranged in a plurality of stages.

  As the impeller rotates, the coolant liquid in the storage tank is sucked into the casing and is increased in pressure while being guided by the casing inner wall. The coolant is further increased in pressure by the impeller and pump casing on the downstream side, and sent to the machining site of the machine tool.

  The coolant liquid sent to the machine tool is used for cooling the processing site, and then supplied again to the storage tank via a pipe.

  Foreign materials such as chips enter the coolant liquid that has returned to the storage tank. For this reason, for example, a strainer is provided in the pump device to prevent chips and the like in the coolant from being supplied to the casing and the machine tool.

JP 2009-299596 A

  The above-described pump device casing has the following problems. In other words, the strainer cannot remove all foreign matters in the coolant liquid that has returned to the storage tank, and foreign matters such as fine chips and abrasive grains are supplied into the pump casing together with the coolant liquid by the rotation of the impeller.

  The coolant liquid in the pump casing turns in the impeller rotation direction. At this time, the foreign matter in the coolant liquid has a larger specific gravity than the coolant liquid, and thus settles on the bottom surface of the pump casing. These foreign substances swirl on the bottom surface of the pump casing in accordance with the swirling of the coolant and wear the inner wall. As this wear progresses, there is a problem that a hole is formed in the inner wall of the pump casing and the pump performance of the coolant pump is lowered.

  Therefore, an object of the present invention is to provide a casing of a pump device that prevents perforation due to wear of an inner wall.

  In order to solve the problems and achieve the object, the casing of the pump device of the present invention is configured as follows.

  A bottomed cylindrical casing main body that can accommodate the impeller coaxially, a suction hole provided in the center of the bottom of the casing main body, and protrudes from the bottom along the axial direction of the casing main body, from the bottom And a protrusion having a slope whose axial height gradually increases along the rotation direction of the impeller.

  According to the present invention, it is possible to prevent perforation of the casing due to wear of the inner wall.

Sectional drawing which shows typically the structure of the cooling device with which the casing of the pump apparatus which concerns on one embodiment of this invention was integrated. The perspective view which shows the pump apparatus partially fractured | ruptured. The perspective view which fractures | ruptures and shows the casing part of the pump apparatus partially. The top view which shows the casing part. Sectional drawing which shows the shape which cut | disconnected the protrusion part formed in the inside of the casing part by the dashed-two dotted line S1-S1 line | wire in FIG. 4A, and looked at the arrow direction. The bottom view which shows the casing part. Sectional drawing which cut | disconnected the casing part by the dashed-two dotted line S2-S2 line | wire in FIG. 5, and looked at the arrow direction. Explanatory drawing which shows typically the flow of the foreign material inside the pump apparatus. FIG. 8 is an explanatory diagram schematically showing the flow of foreign matter inside a general pump device as a comparative example of FIG. 7.

  FIG. 1 is a cross-sectional view schematically showing a configuration of a cooling device 100 in which a casing part (a casing of a pump device) 26 according to an embodiment of the present invention is incorporated, and FIG. 3 is a perspective view showing the casing portion 26 of the pump device 1 in a partially broken view, FIG. 4A is a plan view showing the second casing 60, and FIG. 4B shows the second protrusion 63 of the second casing 60. FIG. 4A is a cross-sectional view showing a shape cut along the two-dot chain line S1-S1 in FIG. 4A and viewed in the direction of the arrow, FIG. 5 is a bottom view showing the first casing 50, FIG. 6 shows the first casing 50 in FIG. Sectional drawing cut | disconnected by the dashed-two dotted line S2-S2 line, and seeing in the arrow direction, FIG. 7 is explanatory drawing which shows typically the flow of the foreign material E inside the pump apparatus 1, FIG. 8 is a comparative example of FIG. Schematic illustration of the flow of foreign matter E inside a typical pump device 2 Is an explanatory view showing the.

  As shown in FIG. 1, the cooling device 100 includes a storage tank 101 that stores the coolant W, a discharge pipe 114 that forms a flow path from the storage tank 101 to the machine tool M, and a connection from the machine tool M to the storage tank 101. A suction pipe 115 that forms a flow path and a pump device 1 that increases the pressure of the coolant liquid W in the storage tank 101 are provided.

  The storage tank 101 is disposed in the vicinity of the machine tool M. The storage tank 101 has a storage tank 110 capable of storing the coolant liquid W therein and a top plate 111 formed with an opening 112 through which a pump casing 21 described later can be inserted.

  The discharge pipe 114 is connected to the pump device 1, and an end portion thereof opens toward the machining site of the machine tool M. The suction pipe 115 is formed so that the coolant W supplied to the machine tool M can be pulled back into the storage tank 101.

  The pump device 1 includes a motor unit 11, a pump unit 12, and a shaft seal device 13. The pump device 1 is fixed to the storage tank 101 by a first flange portion 27 described later.

  The motor unit 11 includes a motor casing 15 and a rotating shaft 16 fixed to a rotor inside the motor casing 15.

  The rotating shaft 16 is provided so as to extend from the motor unit 11. The rotating shaft 16 is inserted into the pump portion 12 while being supported by the pump 12 via a bearing 19. The rotary shaft 16 has a key 17 that can fix a part of the shaft seal device 13 and a part of the pump unit 12. The end portion of the rotary shaft 16 is formed so that a fastening member B such as a bolt can be screwed together.

  The pump unit 12 is a two-stage pump. The pump unit 12 includes a pump casing 21, a plurality of impellers 22, a strainer 23, and a cover 24. In the pump unit 12, at least the first stage impeller 22 is disposed in the coolant liquid W in the storage tank 101.

  The pump casing 21 includes a casing portion 26 that houses a plurality of impellers 22, a first flange portion 27 that is fixed to the opening 112 of the storage tank 101, and a first connection that connects the casing portion 26 and the first flange portion 27. And a second connecting portion 42 that connects the motor casing 15 and the first flange portion 27.

  The casing portion 26 has a plurality of pump chambers 31 for accommodating the plurality of impellers 22 therein. These pump chambers 31 are continuous by a flow path formed by a plurality of vanes 32. The casing portion 26 includes a first casing 50 having a suction port 33 formed on the lower surface thereof, and a second casing 60 that forms a flow path communicating from the first casing 50 to the first connecting portion 41. . The first casing 50 and the second casing 60 are fixed to the first connecting portion 41 by stud bolts SB described later.

The impeller 22 is accommodated in each of the first casing 50 and the second casing 60. Each of the impellers 22 is fixed to the rotating shaft 16 by a key 17. The impeller 22 is fastened by a bolt B provided at the tip of the rotary shaft 16. The first casing 50 is manufactured by casting using ductile cast iron as a material. Ductile cast iron is a material of JIS standard material symbol FCD (Ferrum Casting Ductile) 450-500. The first casing 50 is formed in a bottomed cylindrical shape and has a first casing body 51 that can accommodate the impeller 22. A suction hole 33 is formed in the center of the bottom of the first casing body 51.

  A second flange portion 53 having a fixing hole 52 through which the stud bolt SB can be inserted in a direction parallel to the rotation axis of the impeller is formed on the outer peripheral portion of the first casing body 51. The tip end of the stud bolt SB is inserted and fixed to the third flange portion 43 of the first connecting portion 41. That is, the stud bolt SB has a function of fixing the first casing 50 and the second casing 60 to the first connecting portion 41.

  The side wall of the first casing body 51 has a sufficient thickness as long as its inner peripheral surface does not block the discharge port on the outer peripheral surface of the impeller 22 and the outer peripheral surface does not interfere with the outer peripheral surface of the stud bolt SB. doing.

  That is, as shown in FIG. 6, the gap G1 between the outer peripheral surface of the first casing body 51 and the stud bolt SB is formed to a dimension that does not interfere with the outer peripheral surface of the first casing body 51 and the stud bolt SB. Yes. A gap G2 between the inner peripheral surface of the first casing body 51 and the outer peripheral surface of the impeller 22 is set to a dimension for the pump device 1 to have sufficient pump performance. The wall thickness K of the first casing body 51 is a maximum value while satisfying the above-described conditions of the gaps G1 and G2.

  A first protrusion 55 having the same shape as a second protrusion 63 described later is formed on the bottom of the first casing body 51. That is, the first projecting portion 55 has a first uphill slope 56, a first flat surface 57, and a first downhill, which have the same shape as a second uphill slope 64, a second flat surface 65, and a second down slope 66 described later, respectively. A slope 58 is provided.

  Further, between the inner peripheral surface and the bottom surface of the first casing body 51, an arc shape having a radius R2 that is 1.2 to 1.3 times the wall thickness K is formed in a cross-sectional view passing through the rotation shaft of the impeller 22. The first bottom corner 59 is provided.

  The second casing 60 is manufactured by casting using ductile cast iron as a material. The second casing 60 is formed in a bottomed cylindrical shape and has a second casing body 61 that can accommodate the impeller 22. A guide path 62 is formed at the center of the bottom of the second casing body 61. A plurality of vanes 32 are provided on the first casing 50 side of the second casing body 61.

  The inner diameter R <b> 1 of the second casing 60 is formed to be equal to the inner diameter of the first casing 50, and the thickness thereof is formed in the same manner as the side wall thickness K of the first casing 50.

  A second protrusion 63 protruding from the bottom surface is formed on the bottom of the second casing body 61 along the inner peripheral surface of the second casing body 61. As shown in FIGS. 4A and 4B, the second protrusion 63 is formed in a trapezoidal shape when viewed from the front in the radial direction of the second casing body 61 from the rotation shaft of the impeller. The second protrusion 63 is formed such that the radial thickness S of the second casing body 61 is 0.85 to 0.9 times the inner diameter R <b> 1 of the second casing body 61. The second protrusion 63 has a second uphill slope 64, a second flat surface 65, and a second downward slope 66 parallel to the radial direction of the second casing body 61.

  The second uphill slope 64 has a height from the bottom surface in the rotation axis direction of the impeller 22 that gradually increases along the rotation direction of the impeller 22, and is continuous with the second flat surface 65. The second flat surface 65 is formed at a height H that is 0.03 to 0.05 times the inner diameter R1 of the second casing body 61, and the second descending slope 66 at the end opposite to the second uphill slope 64. It is continuous. The height of the second descending slope 66 from the bottom surface in the rotation axis direction of the impeller 22 gradually decreases along the rotation direction of the impeller 22.

  The range of the rotation direction of the impeller 22 of the second uphill slope 64, the second flat surface 65, and the second descending slope 66 is an angle D1, D2, D3 about the rotation axis of the impeller 22, as shown in FIG. 4A. It is prescribed by. In the present embodiment, the angles D1, D2, and D3 are in the ranges of 10 degrees, 20 degrees, and 10 degrees, respectively.

  Further, between the inner peripheral surface and the bottom surface of the second casing main body 61, similarly to the first bottom surface corner portion 59, a second bottom surface formed in an arc shape having a radius R2 in a sectional view passing through the rotation axis of the impeller 22. A corner 67 is provided.

  The first flange portion 27 has a disc shape through which the rotary shaft 16 can be inserted, and is formed on the surface around the opening 112 of the top plate 111 so as to be fixed by a fastening member B.

  The rotating shaft 16 can be inserted through the first connecting portion 41 and the second connecting portion 42. Further, the first connecting portion 41 and the second connecting portion 42 are formed therein with a discharge passage 34 communicating with the pump casing 21 and communicating with the discharge port 36.

  The 1st connection part 41 is formed so that the pump casing 21 can be fixed. A cover 24 extending from the opening 112 of the top plate 111 toward the storage tank 110 is fixed to the outside of the first connecting portion 41. The first connecting portion 41 is formed with an insertion hole 35 through which the rotation shaft 16 can be inserted, and the shaft seal device 13 is provided between the first connection portion 41 and the rotation shaft 16.

  The second connecting part 42 is provided in the upper part of the first flange part 27 and is formed in a cylindrical shape in which the discharge flow path part 34 is disposed in a part thereof. The 2nd connection part 42 connects and supports the motor casing 15, is formed so that the rotating shaft 16 can be inserted into the interior and the bearing 19 can be fixed.

  The shaft seal device 13 includes a fixed body 71 fixed to the insertion hole 35 of the casing portion 26, a rotary body 72 fixed to the rotary shaft 16, and a flange portion 73 fixed to the rotary shaft 16. The shaft sealing device 13 is formed so as to be capable of shaft sealing between the rotary shaft 16 and the casing portion 26.

  In the cooling device 100 configured as described above, when the electric power is supplied to the motor unit 11 of the pump device 1, the rotating shaft 16 rotates and the impeller 22 fixed to the rotating shaft 16 rotates. As the impeller 22 rotates, as shown by an arrow F in FIG. 1, the coolant liquid W stored in the storage tank 101 is sucked into the uppermost pump chamber 31 through the strainer 23 and the pressure is increased. And pumped to the secondary side. The coolant liquid W is further increased in pressure in the pump chamber 31 on the secondary side, moves from the discharge port 36 to the discharge pipe 114 via the discharge flow path 34, and is supplied to the machine tool M.

  The coolant liquid W supplied to the machine tool M is returned to the storage tank 101 through the suction pipe 115 from the coolant liquid W receiving part of the machine tool M after cooling the machining site. The coolant liquid W returned to the storage tank 101 is supplied with increased pressure by the pump unit 12 and supplied to the machine tool M. As indicated by the arrow F of the coolant liquid W shown in FIG. 1, the coolant liquid W is circulated and used in the cooling device 100.

  The coolant liquid W drawn back from the machine tool M includes foreign matter E such as chips and abrasive grains that have fallen off from the processing site. Among these foreign substances E, fine ones are sucked into the most upstream pump chamber 31 through the strainer 23 together with the coolant W by the rotation of the impeller 22. The sucked foreign matter E has a specific gravity larger than that of the coolant liquid W, and thus settles at the bottom of the first casing 50.

  The foreign matter E settled on the bottom of the first casing 50 turns around the first bottom corner 59 by the rotation of the impeller 22, and, as shown by the arrow Y 1 in FIG. It is diffused into the pump chamber 31.

  The foreign matter E diffused into the pump chamber 31 inside the first casing 50 is guided to the second casing 60 together with the coolant liquid W. The foreign matter E is diffused into the pump chamber 31 by the second protrusion 63 in the second casing 60 as well as in the first casing 50.

  The foreign matter E is diffused into the pump chamber 31 in the second casing 60 and then guided to the machine tool M through the discharge pipe 114 together with the coolant W.

  The foreign substance E sent to the machine tool M flows into the storage tank 110 from the suction pipe 115 again. That is, the foreign matter E circulates with the coolant W without being precipitated in the first casing 50 and the second casing 60.

  As shown in FIG. 8, in the case of the casing 2 in which no protrusions or arc-shaped corners are formed, foreign matter concentrates on the bottom corners as shown by the arrow Y2, the casing inner wall wears out, and the performance as a pump is reduced. descend. On the other hand, in the present embodiment, foreign substances can be diffused by the first protrusion 59, the second protrusion 61, the first bottom corner 59, and the second bottom corner 67.

  In addition, by forming the first bottom surface corner angle 59 and the second bottom surface corner angle 66 having an arc-shaped cross section, no cutting process is required during manufacturing. For this reason, it is possible to use a material that has sufficient wear resistance while being unsuitable for cutting, such as ductile cast iron.

  As described above, according to the casing portion 26 according to the present invention, the first protrusion 55 and the second protrusion 61 are provided in the first casing 50 and the second casing 60, so that the foreign matter E is introduced into the pump chamber 31. It can be diffused and circulated. As a result, it is possible to suppress wear of the inner wall due to the foreign matter E, and to prevent a decrease in pump performance.

  In addition, by providing the first bottom corner 59 and the second bottom corner 67 having a circular cross section at the bottom corner, the foreign matter E is not concentrated locally, and the inner wall is prevented from being worn by the foreign matter E. It becomes possible. Furthermore, the first casing 50 and the second casing 60 can be formed by casting by forming the first bottom corner 59 and the second bottom corner 62 in an arc shape. For this reason, while not suitable for cutting, ductile cast iron having high strength can be used, and the first casing 50 and the second casing 60 can obtain sufficient strength.

  As described above, according to the casing of the pump device according to the present invention, it is possible to prevent perforation due to wear of the inner wall by diffusing foreign matter into the coolant liquid.

  The present invention is not limited to the above embodiment. For example, in the above-described example, the two-stage pump device has been described. However, the present invention can be similarly applied even when the pump device is formed in three or more stages or only one stage. is there. Of course, various modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 100 ... Cooling device, 101 ... Storage tank, 1 ... Pump device, 11 ... Motor part, 26 ... Casing part, 50 ... 1st casing, 60 ... 2nd casing.

Claims (4)

A bottomed cylindrical casing body that can accommodate the impeller coaxially;
A suction hole provided in the center of the bottom of the casing body;
A pump that protrudes from the bottom along the axial direction of the casing body and has a slope having a slope in which the axial height from the bottom gradually increases along the rotation direction of the impeller. Equipment casing. The casing body includes a flange portion provided on an outer periphery of the casing body;
A fixing hole provided in the flange portion and formed so that a bolt can be inserted and removed in the direction of the rotation axis of the impeller;
The distance in the radial direction of the casing body between the portion of the bolt facing the outer peripheral surface of the casing body and the outer peripheral surface of the casing main body when inserted into the fixing hole, and the outer peripheral surface of the impeller and the 2. The casing of the pump device according to claim 1, further comprising a thick side wall that minimizes a distance in a radial direction of the casing body between the inner circumferential surface of the casing body.   The casing body is located between the inner peripheral surface and the bottom portion, and a cross-sectional shape passing through the rotation shaft of the impeller is continuous with the inner peripheral surface and the bottom portion. The casing of the pump device according to claim 1, further comprising a bottom corner that has an arc shape having a radius of 2 to 1.3 times.   The casing of the pump device according to claim 1, wherein the casing body is made of ductile cast iron.

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