Pump device

Abstract

To provide a pump device capable of reducing burden of maintenance management and capable of shortening an installation length into a storage tank.SOLUTION: A pump device 1 has a pump 13 immersed in liquid in a storage tank 110, and comprises: a rotational shaft 12; a pump 13 driven by the rotational shaft 12; a housing 14 provided on an upper part of the pump 13, and fixed to the storage tank 110; and a shaft seal member 15 that has a fixed body 51 fixed to the housing 14 above the storage tank 110 and into which the rotational shaft 12 is rotatably inserted, and a water-cutting flange 52 covering an upper end of the fixed body 51.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a submerged pump device provided with a shaft seal member. [Background technology]

[0002] Currently, pump devices using shaft sealing members such as mechanical seals to prevent leakage from pumps are known. Also, a technology is known in which a pump device is used in a cooling device that supplies cutting fluid as a coolant to cool a machining part of a machine tool. Such a pump device is provided in a storage tank that stores cutting fluid, and the pump is immersed in the cutting fluid and increases the pressure of the cutting fluid in the storage tank. The cutting fluid pressurized by the pump device is supplied to the machining part via piping or the like, and the cutting fluid supplied to the machining part is returned to the storage tank via piping or the like.

[0003] The mechanical seal used in the shaft seal member is subject to wear and therefore requires periodic replacement, which increases the maintenance burden of the pump device. In addition, when the pump device is used in a cooling device for cooling the machining parts of a machine tool, cutting chips and powder are contained in the cutting fluid, which increases the risk of damage to the mechanical seal, and the mechanical seal needs to be replaced more frequently than when the pump device is used for clean water.

[0004] For this reason, a technology is known that has a shaft seal member that includes a shaft seal section with a small gap between the main shaft and the fixed section, and a housing that forms a drain space to return liquid leaking from the gap to a tank (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-202129 A Summary of the Invention [Problem to be solved by the invention]

[0006] Unlike mechanical seals, shaft seal members that are configured to return liquid leaking from a gap to a tank are designed to have a drain space disposed within the storage tank, since liquid leakage is assumed. This causes a problem in that the installation length of the pump disposed within the storage tank becomes large. This results in a difference in the installation length of a pump device that uses a mechanical seal as a shaft seal member and a pump device that is designed to leak liquid, which may result in incompatibility with respect to components such as the storage tank of the cooling device, and may make it impossible to replace the pump device.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a pump device that can be installed in a storage tank in a short length. [Means for solving the problem]

[0008] According to one aspect of the present invention, a pump device is a pump device in which a pump is immersed in a storage tank, and includes a rotating shaft, the pump driven by the rotating shaft, a housing provided on an upper part of the pump and fixed to the storage tank, a fixed body fixed to the housing above the storage tank and into which the rotating shaft is rotatably inserted, and a shaft seal member having a water-cutting flange covering the upper end of the fixed body. Effect of the Invention

[0009] According to the present invention, it is possible to provide a pump device that can be installed in a storage tank in a short length. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a configuration of a pump device and a cooling device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view showing a configuration of a main part of the pump device. [Diagram 3] FIG. 11 is a cross-sectional view showing a configuration of a main part of a pump device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a pump device 1 according to one embodiment of the present invention and a cooling device 100 having the pump device 1 will be described with reference to FIGS.

[0012] Fig. 1 is a cross-sectional view partially illustrating the configuration of a pump device 1 according to one embodiment and the configuration of a cooling device 100. Fig. 2 is a cross-sectional view illustrating the configuration of a main part of a housing 14 and a shaft seal member 15 of the pump device 1.

[0013] The cooling device 100 is configured to be capable of supplying, as a liquid, a cutting fluid L used in machine tools such as NC lathes, milling machines, and machining centers to a machining section of the machine tools.

[0014] As shown in FIG. 1, the cooling device 100 includes a storage tank 110 capable of storing cutting fluid L, a pump device 1 capable of increasing the pressure of the cutting fluid L, a supply pipe 120 that forms a flow path for the cutting fluid L from the pump device 1 to a machine tool, and a recovery pipe 130 that forms a flow path for recovering the cutting fluid L from the machine tool to the storage tank 110.

[0015] The storage tank 110 includes a tank body 111 with an open top capable of storing cutting fluid L therein, and a top plate 112 that closes the opening of the tank body 111. The tank body 111 is formed, for example, on a side wall so that the recovery pipe 130 can be fixed thereto. For example, the top plate 112 is formed with an opening 112a through which a part of the housing 42 of the pump device 1 and the pump casing 21 can be inserted. Note that the recovery pipe 130 may be provided on the top plate 112 rather than on the tank body 111, as long as the recovery pipe 130 can supply the cutting fluid L recovered in the tank body 111.

[0016] The pump device 1 is a vertical pump device fixed to a top plate 112 of a storage tank 110 and increases the pressure of the cutting fluid L in a tank body 111. The pump device 1 may be a single-stage pump having a single impeller 22, or may be a multi-stage pump having a plurality of impellers 22. In this embodiment, an example of the pump device 1 will be described as a multi-stage pump. The pump device 1 includes a motor 11, a rotating shaft 12 driven by the motor 11, a pump 13 having an impeller 22 fixed to the rotating shaft 12, a housing 14 to which the motor 11 and the pump 13 are fixed and which is fixed to the top plate 112, and a shaft seal member 15.

[0017] The motor 11 is connected to an external power source and configured to rotate the rotating shaft 12 by receiving power from the external power source. The motor 11 includes a motor casing 11a, a stator 11b fixed inside the motor casing 11a, a rotor 11c rotated by the stator 11b, and a motor shaft 11d fixed to the rotor 11c and extending outside the motor casing 11a. The motor 11 also includes a cooling fan 11e provided at one end, for example the upper end, of the motor shaft 11d, and a plurality of bearings 11f provided in the motor casing 11a and supporting the motor shaft 11d.

[0018] The motor casing 11a is fixed to the housing 14. The motor shaft 11d is fixed to the rotor 11c, and rotates integrally with the rotor 11c as the rotor 11c rotates. The lower end of the motor shaft 11d extends outside the motor casing 11a. The motor shaft 11d is disposed within the housing 14 when the motor 11 is fixed to the housing 14.

[0019] The rotating shaft 12 includes a motor shaft 11d, a pump shaft 12a, and a shaft coupling 12b that connects the motor shaft 11d and the pump shaft 12a. The rotating shaft 12 is configured by connecting the motor shaft 11d and the pump shaft 12a via the shaft coupling 12b, but for example, the rotating shaft 12 may be configured such that the motor shaft 11d extends into the pump 13 so that the impeller 22 can be directly fixed thereto.

[0020] The pump 13 includes a pump shaft 12a, a pump casing 21 formed so as to be able to be placed in the storage tank 110, and a plurality of impellers 22 fixed to the rotating shaft 12 and formed so as to be able to be placed in the pump casing 21. The pump 13 is fixed to the housing 14, and the cutting fluid L discharged from the uppermost impeller 22 which is the most secondary side in the flow direction of the cutting fluid L is connected to a discharge casing part 41 provided in the housing 14. At least a portion of the pump 13 is immersed in the cutting fluid L in the storage tank 110.

[0021] The pump casing 21 includes casing sections 31 in which the impellers 22 can be arranged in the same number as the impellers 22, and a suction cover 32 connected to the casing section 31 which is the most primary side in the flow direction of the cutting fluid L.

[0022] The casing portion 31 forms a pump chamber that accommodates the impeller 22. The casing portion 31 also has a plurality of guide vanes 31a that guide the cutting fluid L discharged from the impeller 22 on the primary side to the impeller 22 on the secondary side.

[0023] The suction cover 32 covers the lowest casing part 31. For example, the suction cover 32 includes a strainer or a filter at least in part, and prevents contamination such as cutting chips of a predetermined size contained in the cutting fluid L to be sucked in from being sucked in.

[0024] The impeller 22 is disposed within the casing portion 31 and fixed to the rotating shaft 12. The impeller 22 has a pair of shrouds disposed along the axis of the rotating shaft 12, and a plurality of blades disposed between the shrouds. A suction port is formed in the center of the shroud disposed on the primary side of the pair of shrouds. When the impeller 22 rotates, it sucks in cutting fluid L from the suction port, increases the pressure of the sucked cutting fluid L with the plurality of blades, and discharges it into the pump chamber from between the pair of shrouds.

[0025] The housing 14 includes a discharge casing portion 41, a housing portion 42 that accommodates the shaft seal member 15, a flange 43 fixed to the top plate 112, and a frame 44 in which the shaft coupling 12b is disposed. The discharge casing portion 41, the housing portion 42 that accommodates the shaft seal member 15, the flange 43 fixed to the top plate 112, and the frame 44 in which the shaft coupling 12b is disposed are integrally formed by, for example, casting.

[0026] The discharge casing part 41 is fixed to the uppermost casing part 31. The discharge casing part 41 has a cover part 41a that covers the uppermost casing part 31, and a discharge pipe part 41b that connects the internal space of the cover part 41a and the supply pipe 120.

[0027] The cover portion 41a is provided with an opening 41c into which the pump shaft 12a can be inserted and in which the shaft sealing member 15 is disposed. The discharge pipe portion 41b is disposed above the top plate 112.

[0028] The housing part 42 covers the upper surface of the cover part 41a and faces a part of the circumferential side surface of the cover part 41a at a distance, thereby forming a flow path that opens from above the cover part 41a through a part of the side of the cover part 41a into the tank body 111. In other words, the housing part 42 forms an internal space 42a in the upper part of the cover part 41a for accommodating a part of the pump shaft 12a and the shaft sealing member 15, and forms a discharge path 42b for discharging the cutting fluid L leaking from the shaft sealing member 15 from the internal space 42a to the tank body 111.

[0029] The internal space 42a and the discharge path 42b form a drain space communicating with the inside of the storage tank 110 for discharging the cutting fluid L leaking from the shaft seal member 15 and cutting powder and cutting chips contained in the cutting fluid L to the tank body 111. Here, a specific example of the cover part 41a and the housing part 42 which form the internal space 42a and the discharge path 42b will be described.

[0030] The cover portion 41a includes a top plate portion 41a1 in which the opening 41c is formed, a body portion 41a2 to which the casing portion 31 is fixed, and a corner portion 41a3 formed between the top plate portion 41a1 and the body portion 41a2. The top plate portion 41a1 is formed, for example, in a linear shape extending in a direction perpendicular to the pump shaft 12a, or in a plate shape inclined downward from the center side (the opening 41c side) toward the radially outward side (the corner portion 41a3). The body portion 41a2 is formed in a cylindrical shape extending along the pump shaft 12a. The corner portion 41a3 is formed, for example, in a curved surface. The corner portion 41a3 may be an inclined surface. The corner portion 41a3 guides the cutting fluid L on the top plate portion 41a1 toward the body portion 41a2.

[0031] The housing part 42 is disposed with a predetermined gap between the top plate part 41a1 of the cover part 41a and the shaft seal member 15 so that the shaft seal member 15 can be disposed therebetween, thereby forming an internal space 42a between the top plate part 41a1 and the top plate part 41a1. The housing part 42 is also disposed with a predetermined gap between the corner part 41a3 and the body part 41a2 so that a drainage path 42b for the cutting fluid L can be formed between the corner part 41a3 and the body part 41a2. The housing part 42 is also formed with a window part 44a through which the internal space 42a can be viewed from the frame 44.

[0032] The flange 43 is provided on the discharge casing portion 41 and the housing portion 42, and is fixed to the top plate 112 with fastening members such as bolts and nuts. That is, the flange 43 is provided along the outer circumferential surfaces of the integrally formed discharge casing portion 41 and housing portion 42. The surface of the flange 43 that is fixed to the top plate 112 (flange surface) is located below the upper surface of the top plate portion 41a1 of the cover portion 41a. As a specific example, the flange surface of the flange 43 is located below the shaft seal member 15.

[0033] The frame 44 is formed integrally with the upper surface of the housing portion 42, and is formed to be able to fix the motor casing 11a. The frame 44 is formed hollow so that, for example, a part of the rotating shaft 12 can be arranged therein, and is formed with one or more openings in a circumferential direction so that the interior can be seen and fingers can be inserted. As a specific example, the frame 44 is formed so that a part of the motor shaft 11d, a part of the pump shaft 12a, and the shaft coupling 12b can be arranged therein. The frame 44 is also formed so that the window portion 44a can be seen from the opening and fingers can be inserted.

[0034] The window 44a formed in the housing 42 is formed with an opening area large enough to allow insertion of a finger inserted through the frame 44. The window 44a is closed by, for example, a lid 44b.

[0035] The lid 44b has an opening so that the pump shaft 12a can be inserted therethrough. The lid 44b is fixed to the upper surface of the housing part 42 in a liquid-tight and detachable manner, for example, via a packing 44c. The lid 44b covers the window part 44a. For example, the lid 44b is formed of a material having translucency, such as a transparent or semitransparent resin material or glass, so that the inside of the housing part 42 can be seen when the window part 44a is covered with the lid 44b. The lid 44b may be formed of a material that does not have translucency, and even with such a lid 44b, the inside of the housing part 42 can be seen by removing it from the window part 44a. Moreover, such a lid 44b forms the bottom surface of the internal space of the frame 44, and is formed so that the inside of the housing part 42 can be seen from the opening of the frame 44.

[0036] The shaft seal member 15 comprises a fixed body 51 which is fixed to an opening 41c formed in the top plate portion 41a1 of the cover portion 41a and into which the pump shaft 12a is rotatably inserted, and a water cutter flange 52 which is fixed to the pump shaft 12a and arranged opposite the fixed body 51.

[0037] The inner diameter of the fixed body 51 is set to an inner diameter that forms a predetermined gap with the pump shaft 12a. In other words, the inner diameter of the fixed body 51 is set to be larger than the outer diameter of the pump shaft 12a to be inserted and disposed. The fixed body 51 includes a disk-shaped flange 51a that is open at the center, and a cylindrical body portion 51b that is integrally formed with the flange 51a. The flange 51a is fixed to the top plate portion 41a1 of the cover portion 41a by fastening members 53 such as screws or bolts.

[0038] The water cut flange 52 faces the upper end of the body 51b of the fixed body 51 with a predetermined gap therebetween. The water cut flange 52 is fixed to the pump shaft 12a with fastening members 54 such as set screws or bolts. The water cut flange 52 is formed, for example, such that the surface facing the fixed body 51 is cylindrically recessed and the body 51b can be placed in this recess with a predetermined gap therebetween. In other words, the water cut flange 52 is formed in a cylindrical shape with an inner diameter larger than the outer diameter of the body 51b on the body 51b side, and is formed so that the tip of the body 51b can be placed therein.

[0039] The pump device 1 thus formed is configured such that the pump shaft 12a rotates with a predetermined gap relative to the fixed body 51 of the shaft seal member 15, and the water cutter flange 52, which faces the fixed body 51 with a predetermined gap, is fixed to the pump shaft 12a. With this configuration, the shaft seal member 15 is configured such that the cutting fluid L leaks out from between the pump shaft 12a and the fixed body 51, but since the water cutter flange 52 facing the fixed body 51 rotates with the rotation of the pump shaft 12a, the cutting fluid L attached to the water cutter flange 52 can be scattered in the radial direction. Therefore, the shaft seal member 15 can prevent the cutting fluid L from moving toward the motor 11 side from the water cutter flange 52.

[0040] Moreover, the top plate portion 41a1 of the cover portion 41a forming the bottom surface of the internal space 42a in which the shaft seal member 15 is disposed extends horizontally or is inclined toward the corner portion 41a3, and since the corner portion 41a3 is curved, the scattered cutting fluid L can be collected in the tank body 111 through the internal space 42a as a drain space and the discharge path 42b. Furthermore, since the corner portion 41a3 is curved and inclined downward in the direction of gravity, the cutting fluid L flows from the internal space 42a to the discharge path 42b at the corner portion 41a3, and therefore, the cutting fluid L can be prevented from accumulating in the internal space 42a (on the top plate portion 41a1).

[0041] Since the flange surface of the flange 43, which is fixed to the top plate portion 41a1 of the cover portion 41a, is located lower than the shaft sealing member 15, the shaft sealing member 15 is disposed outside the storage tank 110. By disposing the shaft sealing member 15 outside the storage tank 110, the installation length of the pump device 1 disposed inside the storage tank 110 can be shortened.

[0042] The frame 44 has a circumferential opening, and the bottom surface of the frame 44 (in other words, the ceiling surface of the housing part 42 that forms the internal space 42a) is formed by a lid 44b provided on the window part 44a. The lid 44b is made of a transparent or semi-transparent material, or can be removed from the window part 44a to visually check the internal space 42a from the outside of the frame 44 through the window part 44a. This allows the shaft seal member 15 and the top plate part 41a1 of the cover part 41a to be visually checked, so that damage to the shaft seal member 15 and metal powder accumulated on the top plate part 41a1 can be easily checked. The frame 44 and the window part 44a have an opening shape that allows fingers to be inserted, so that by removing the lid 44b, the pump device 1 can be inserted into the internal space 42a to perform work without removing the pump device 1 from the top plate 112. Therefore, the housing 14 allows easy inspection and maintenance work around the shaft seal member 15.

[0043] Furthermore, the flange 43 of the housing 14 is fixed to the top plate 112 of the storage tank 110, and the surface of the flange 43 fixed to the top plate 112 is located below the upper surface of the top plate portion 41a1 of the cover portion 41a, and further, below the shaft seal member 15. This prevents the shaft seal member 15 from being immersed in the cutting fluid L, thereby preventing the cutting fluid L from moving toward the motor 11 and preventing the visibility of the shaft seal member 15 from being reduced by the cutting fluid L during inspection.

[0044] In addition, the water cut flange 52 is configured to be recessed so that the tip of the fixed body 51 can be positioned, and thus the upper end surface and the outer circumferential surface of the upper end side of the body 51b are covered by the water cut flange 52 with a predetermined gap. Therefore, even if the cutting fluid L leaking from the gap between the pump shaft 12a and the body 51b is scattered in the radial direction due to the rotation of the pump shaft 12a, the inner circumferential surface of the water cut flange 52 can prevent the cutting fluid L from scattering outward from the water cut flange 52. Since the cutting fluid L and cutting chips tend to collect below the water cut flange 52, the cutting fluid L tends to flow from the drain space into the tank body 111, and therefore the pump device 1 can efficiently discharge the cutting fluid L and cutting chips from the drain space into the tank body 111.

[0045] As described above, in the pump device 1 of one embodiment, the shaft seal member 15 is disposed above the storage tank 110, and the window portion 44a and the lid 44b make the shaft seal member 15 visible from outside the housing 14, thereby shortening the installation length within the storage tank 110 and reducing the burden of maintaining the shaft seal member 15.

[0046] In the above example, the water cut flange 52 has a cylindrical recess so that the upper end of the fixed body 51 can be disposed and the upper end surface and the outer peripheral surface of the upper end side of the body 51b can be covered with a predetermined gap, but the present invention is not limited to this. For example, the water cut flange 52 may have a conical or truncated conical recessed shape instead of a cylindrical shape, or may have a cylindrical recessed shape having a plurality of inner diameters. In addition, for example, as in the modified example shown in FIG. 3, the water cut flange 52A may have a plate-shaped main surface without a recess and cover only the upper end surface of the body 51b in the axial direction. In this case, the outer diameter of the water cut flange 52A is preferably equal to or larger than the outer diameter of the body 51b.

[0047] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0048] 1...pump device, 11...motor, 11a...motor casing, 11b...stator, 11c...rotor, 11d...motor shaft, 11e...cooling fan, 11f...bearing, 12...rotating shaft, 12a...pump shaft, 12b...shaft coupling, 13...pump, 14...housing, 15...shaft seal member, 21...pump casing, 22...impeller, 31...casing portion, 31a...guide vane, 32...suction cover, 41...discharge casing portion, 41a...cover portion, 41a1...top plate portion, 41a2...body portion, 41a3 ...corner portion, 41b...discharge pipe portion, 41c...opening, 42...housing portion, 42a...internal space, 42b...discharge path, 43...flange, 44...frame, 44a...window portion, 44b...lid, 44c...gasket, 51...fixed body, 51a...flange, 51b...body portion, 52...water cut flange, 52A...water cut flange, 53...fastening member, 54...fastening member, 100...cooling device, 110...storage tank, 111...tank body, 112...top plate, 112a...opening, 120...supply piping, 130...recovery piping, L...cutting fluid.

Claims

1. A pump device in which a pump is immersed in a storage tank, A rotation axis; The pump is driven by the rotating shaft; and a housing provided on an upper portion of the pump and fixed to the storage tank; a fixed body provided in the housing above the storage tank, into which the rotating shaft is rotatably inserted, and a shaft seal member having a water-repellent flange covering an upper end of the fixed body; A pump device comprising:

2. the housing accommodates the shaft seal member and defines a drain space communicating with the storage tank; The pump device according to claim 1 , wherein the fixed body and the water cutting flange face each other within the drain space.

3. The pump device according to claim 1 , wherein the water cutting flange is formed with a recess that covers an upper end surface and an outer circumferential surface of the upper end of the fixed body.

4. The housing is formed with a window through which the drain space can be viewed from the outside, The pump device according to claim 2 , further comprising a removable lid that covers the window portion.

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