Pump motor mount

Abstract

To provide a prime mover frame of a pump which enables easy adjustment of a natural frequency in a discharge direction and a direction intersecting with the discharge direction.SOLUTION: A prime mover frame 30 of a pump 10 includes: a frame body 32 having an outer peripheral wall 33 attached to an upper part 13 of a pump casing 11, an opening 33a provided at the outer peripheral wall 33, and a placement plate 34 on which a prime mover 20 is placed; multiple beam members 38 each of which is fastened at one end side to the placement plate 34 and may deflect; one mass body 42 attached to the multiple beam members 38; and adjustment parts 44 each of which is provided at the beam member 38 or the mass body 42 to adjust a natural frequency of the mass body 42.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pump motor mount. [Background technology]

[0002] A drainage pump comprises a pump casing that penetrates the installation floor, a motor stand (motor stand) attached to the upper side of the pump casing, and a motor (motor) attached to the motor stand. When the operation of the motor causes the natural frequency of the motor stand to resonate in sync with the pump rotation speed, excessive vibration occurs. To avoid such resonance, the motor stand is designed so that its natural frequency is detuned from the excitation frequency, such as the motor rotation speed. However, if the rigidity of the installation floor is not as designed or if it changes over time, the natural frequency may change, causing resonance.

[0003] Patent Document 1 discloses a motor frame designed to suppress pump resonance. This motor frame includes multiple fixed columns fixed in fixed positions between a foundation member secured to the base plate of the pump casing and a mounting member on which the motor is mounted, and an adjustable column that can be attached to any position. The adjustable column includes a jack that can be extended or retracted to change the dynamic rigidity of the motor frame and eliminate resonance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-180133 Summary of the Invention [Problem to be solved by the invention]

[0005] The motor frame has an opening that exposes the discharge port of the pump casing. Therefore, the rigidity of the motor frame differs between the discharge direction of pumped water and the direction perpendicular to the discharge direction, and the natural frequency also differs. However, Patent Document 1 does not take into consideration the natural frequency in the discharge direction of pumped water or the direction perpendicular to the discharge direction. Furthermore, the motor frame in Patent Document 1 requires extensive work, such as changing the installation position of and adding adjustment columns, to adjust the natural frequency.

[0006] An object of the present invention is to provide a motor mount for a pump that can easily adjust the natural frequencies in the discharge direction and in a direction intersecting the discharge direction. [Means for solving the problem]

[0007] One aspect of the present invention provides a pump motor mount comprising: a mount body having an outer peripheral wall attached to an upper portion of a pump casing and surrounding a portion of the upper portion; an opening provided in the outer peripheral wall to expose the discharge port of the pump casing; and a mounting plate provided at the upper end of the outer peripheral wall on which a motor is placed; a plurality of flexible beam members having one end fixed to the mounting plate and extending in a first direction intersecting the mounting plate; a mass body attached to the plurality of beam members; and an adjustment unit provided on the beam members or the mass body for adjusting the natural frequency of the mass body in a second direction intersecting the first direction and in which liquid is discharged from the discharge port, and in a third direction intersecting both the first direction and the second direction.

[0008] The motor stand includes multiple beam members each having one end fixed to the mounting plate, and a mass body attached to these beam members. This suppresses vibration of the motor stand caused by the motor. This prevents the natural frequency of the motor stand from resonating in synchronization with the pump rotation speed, thereby suppressing excessive vibration in the pump.

[0009] The beam member or mass body is also provided with an adjustment unit for adjusting the natural frequency of the mass body in the liquid discharge direction (second direction) and in the direction intersecting the discharge direction (third direction). This allows the adjustment unit to easily adjust the natural frequency of the mass body in the discharge direction and the direction intersecting the discharge direction without requiring extensive work, even if the rigidity of the installation floor is not as designed or has changed over time. This allows the natural frequency and rigidity of the motor frame to be adjusted in the orthogonal direction and in the discharge direction, preventing excessive pump vibration even if an unintended problem occurs with the installation floor. [Effects of the Invention]

[0010] In the present invention, the natural frequencies in the ejection direction and in the direction intersecting the ejection direction can be easily adjusted. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic front view of a pump using a motor mount according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a right side view of the pump in FIG. 1. [Figure 3] FIG. [Figure 4] FIG. 2 is a cross-sectional view of the dynamic vibration absorption mechanism of the motor mount of FIG. 1. [Figure 5] FIG. 2 is a diagram showing an outline of a dynamic vibration absorbing mechanism. [Figure 6] Graph showing vibration change due to critical damping ratio. [Figure 7] FIG. 10 is a cross-sectional view of a dynamic vibration absorbing mechanism of a motor mount according to a second embodiment. [Figure 8] FIG. 11 is a plan view of a dynamic vibration absorbing mechanism of a motor mount according to a third embodiment. [Figure 9] FIG. 9 is a side view of the dynamic vibration absorbing mechanism of FIG. 8 . [Figure 10] FIG. 10 is a plan view of a dynamic vibration absorbing mechanism of a motor mount according to a fourth embodiment. [Figure 11] FIG. 11 is a plan view showing an adjustment state of the natural frequency of the motor mount of FIG. 10. [Figure 12] FIG. 10 is a view similar to FIG. 4 of the motor mount of the fifth embodiment. [Figure 13] FIG. 13 is an exploded perspective view of the mass body of FIG. 12; DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] (First embodiment) 1 and 2, a motor stand 30 according to a first embodiment of the present invention is provided for mounting a motor 20 that drives a vertical pump (pump) 10.

[0014] The vertical pump 10 comprises a pump casing 11, a main shaft 16, and an impeller 17. The pump casing 11 comprises a lifting pipe (lower portion) 12 arranged in the suction tank 2 below the installation floor 1, and a discharge elbow (upper portion) 13 arranged on the installation floor 1. The discharge elbow 13 comprises a base plate 14 for fixing it to the installation floor 1. The portion of the discharge elbow 13 located on the rightmost side in FIG. 1 is a discharge port 15 for discharging pumped water. The main shaft 16 passes through the discharge elbow 13 and extends coaxially along the axis A of the lifting pipe 12. The impeller 17 is attached to the lower end of the main shaft 16 so as to be located at a lower portion within the lifting pipe 12.

[0015] Prime mover 20 is an electric motor equipped with output shaft 21. Output shaft 21 is connected via coupling 25 to a portion of main shaft 16 that protrudes outward from pump casing 11. Prime mover 20 is operated by a control unit (not shown) to rotate impeller 17 integrally with main shaft 16, thereby discharging water (liquid) from suction tank 2 through pump casing 11. Prime mover 20 may be an internal combustion engine as long as it can rotate impeller 17 integrally with main shaft 16.

[0016] In the accompanying drawings, the Z direction is the vertical direction (first direction) in which the main shaft 16 extends. The Y direction is the direction perpendicular to the vertical direction Z, and the direction indicated by the arrow is the discharge direction of pumped water (second direction). The X direction is the direction (first direction) perpendicular to both the vertical direction Z and the discharge direction Y, and this direction will be referred to as the orthogonal direction in the following explanation. The installation floor 1 described above extends horizontally along the XY plane.

[0017] 1 and 2, the motor pedestal 30 is composed of a pedestal body 32 and a dynamic vibration absorbing mechanism 36 attached to the pedestal body 32. The dynamic vibration absorbing mechanism 36 makes it possible to adjust the natural frequency of the pedestal body 32 in the discharge direction Y and the perpendicular direction X.

[0018] The frame body 32 includes an outer peripheral wall 33 that generally surrounds the discharge elbow 13, and a mounting plate 34 on which the prime mover 20 is placed. The frame body 32 is designed so that its natural frequency is detuned from the excitation frequency, such as the rotation speed, of the mounted prime mover 20.

[0019] The outer peripheral wall 33 is cylindrical with a diameter larger than the outer diameter of the discharge elbow 13 and smaller than the outer diameter of the base plate 14, and is bolted to the base plate 14. However, the outer peripheral wall 33 may be in a tubular shape other than a cylinder, or may be formed of multiple supports, as long as it is configured to surround a portion of the discharge elbow. The outer peripheral wall 33 is provided with an opening 33a through which a portion of the discharge elbow 13 passes to expose the discharge port 15. The opening 33a is semi-elliptical and extends in the vertical direction Z, and the lower end of the outer peripheral wall 33 is open.

[0020] The mounting plate 34 is a disk-shaped plate having a size and thickness that allows the prime mover 20 to be mounted thereon, closes the upper end of the outer peripheral wall 33, and extends horizontally along the XY plane. The mounting plate 34 has an insertion hole 34a centered at the intersection with the axis A of the water pumping pipe 12, and the output shaft 21 of the prime mover 20 protrudes into the frame body 32 through this insertion hole 34a.

[0021] The dynamic vibration absorbing mechanism 36 includes a plurality of beam members 38, one mass body 42, and an adjustment unit 44 provided for each beam member 38. In the dynamic vibration absorbing mechanism 36 of the first embodiment, the adjustment unit 44 adjusts the tilt angle θ of the mass body 42 relative to the beam members 38 and the mounting plate 34, making it possible to adjust the natural frequency of the mass body 42 in the discharge direction Y and the orthogonal direction X, thereby preventing the natural frequency of the frame main body 32 and the prime mover 20 from resonating in synchronization with the pump rotation speed.

[0022] 4, the beam member 38 is made of, for example, steel and has a cantilever structure extending downward in the vertical direction Z from the mounting plate 34. The beam member 38 includes a beam main body 38a with a uniform diameter and a fixing portion 38b at one end for fixing to the mounting plate 34. The beam main body 38a is flexible and deformable in any direction intersecting the vertical direction Z, and its upper end is supported by abutting against the mounting plate 34. The fixing portion 38b is a screw shaft with a smaller diameter than the beam main body 38a and is threaded into a screw hole formed in the mounting plate 34. However, the fixing portion 38b may be configured to pass through the mounting plate 34 and be tightened by a nut, and may be modified as needed as long as it can be fixed to the mounting plate 34.

[0023] Referring to FIG. 3 , the beam members 38 are arranged at equal intervals in the circumferential direction around the axis A of the riser pipe 12. In this embodiment, four beam members 38 are used. Two of the four beam members 38 are arranged on a line VLy that passes through the axis A and extends in the discharge direction Y, and two are arranged on a line VLx that passes through the axis A and extends in the perpendicular direction X. However, the four beam members 38 may be arranged such that two are arranged on each side of the line VLy that extends in the discharge direction Y and two are arranged on each side of the line VLx that extends in the perpendicular direction X. In other words, the four beam members 38 are arranged symmetrically with respect to the line VLy that extends in the discharge direction Y and the line VLx that extends in the perpendicular direction X, respectively, as long as the mass body 42 can be tilted in the discharge direction Y or the perpendicular direction X. The same applies when three or five or more beam members 38 are used.

[0024] Referring to FIG. 4, the beam member 38 is a hollow pipe. The lower end of the beam member 38 is closed by a plug 39, and the upper end of the beam member 38 is open. However, the upper end of the beam member 38 may also be closed by a plug. The internal space of the beam member 38 contains a large number of granular members 40, each of which is made of ceramic balls with a base particle size of 30 μm to 150 μm, a median diameter of approximately 100 μm, and a weight of 3 μg. The large number of granular members 40 are contained to enable the beam member 38 to function as a powder damper, absorbing and damping vibrations as they move within the beam member 38. However, a liquid such as oil (not shown) may be contained within the beam member 38 together with the granular members 40 to improve vibration damping function.

[0025] Mass body 42 is attached to any position on the multiple beam members 38 via adjustment units 44 and is disposed inside frame body 32. Mass body 42 is made of an annular ring and has an outer diameter that does not interfere with the interior of outer peripheral wall 33 even when beam members 38 are flexed and deformed, and has through-hole 42a with a diameter that surrounds coupling 25 shown in FIG. 1. Mass body 42 can be formed from any material as long as its weight is a set ratio (for example, 3% to 5%) of the weight of motor 20.

[0026] The mass body 42 has insertion holes 42b formed therein, each corresponding to one of the beam members 38. The diameter of the insertion holes 42b is larger than the diameter of the beam main bodies 38a, and the beam members 38 are inserted through the insertion holes 42b, allowing the mass body 42 to tilt relative to the beam members 38.

[0027] Continuing to refer to FIG. 4, the adjustment unit 44 is provided to adjust the natural frequency of the mass body 42 in the discharge direction Y and the orthogonal direction X. The adjustment unit 44 can hold the mass body 42 in either a state in which it extends in the orthogonal direction or a state in which it is tilted relative to the beam member 38. Specifically, the adjustment unit 44 includes a thread groove 38c provided on the outer peripheral surface of the beam body 38a of the beam member 38, a nut 45 that can be threaded into the thread groove 38c, and a washer 46 that is arranged between the nut 45 and the mass body 42. The nut 45 and the washer 46 are arranged above and below the mass body 42, respectively.

[0028] Washer 46 is a spherical washer having an outer diameter larger than the diameter of insertion hole 42b of mass body 42. This washer 46 includes a first washer (first member) 47 arranged in surface contact with mass body 42 and a second washer (second member) 48 arranged in surface contact with nut 45. First washer 47 includes a spherical recess 47a recessed in the axial direction to form a spherical surface. Second washer 48 includes a spherical protrusion 48a protruding in the axial direction to form a spherical surface with a curvature complementary to that of spherical recess 47a and fitted into spherical recess 47a. First washer 47 includes an insertion hole 47b having approximately the same diameter as insertion hole 42b. When nut 45 is tightened, spherical recess 47a and spherical protrusion 48a are pressed against each other in this washer 46, allowing mass body 42 to be clamped tightly even when tilted relative to beam member 38. However, the first washer 47 may have a spherical convex portion, and the second washer 48 may have a spherical concave portion. Also, the first washer 47 may be provided integrally with the mass body 42, and the second washer 48 may be provided integrally with the nut 45.

[0029] In the beam member 38 provided with such an adjustment unit 44, the range in which it can be flexibly deformed by vibration or the like is from the lower surface of the mounting plate 34 to the upper end of the upper nut 42. In this embodiment, the length L of the beam member 38, which is the range in which it can be flexibly deformed, can be adjusted as desired by the adjustment unit 44.

[0030] Here, the principle of vibration suppression of the pump casing 11 including the main shaft 16 and the impeller 17 by the dynamic vibration absorbing mechanism 36 will be described with reference to FIGS.

[0031] m1 of the main vibration system shown in Fig. 5 corresponds to the motor frame 30 shown in Fig. 1. Furthermore, the secondary vibration system shown in Fig. 5 corresponds to the dynamic vibration absorbing mechanism 36 shown in Fig. 4. More specifically, m2 shown in Fig. 5 corresponds to the mass body 42 shown in Fig. 4, k2 shown in Fig. 5 corresponds to the beam member 38 shown in Fig. 4, and c shown in Fig. 5 corresponds to the granular member 40 shown in Fig. 4.

[0032] 1 and 2, since the prime mover 20 is attached to the gantry body 32, the natural frequency ω2 of the gantry body 32 may resonate in synchronization with the rotation speed of the pump main shaft 16 or the prime mover 20 (main vibration system). However, since the prime mover gantry 30 of this embodiment is equipped with a dynamic vibration absorbing mechanism 36 (secondary vibration system) with the natural frequency ω2 shown in FIG. 4, the dynamic vibration absorbing mechanism 36 absorbs the vibration energy of the gantry body 32 and the prime mover 20, and the vibration of the gantry body 32 can be quickly reduced.

[0033] Figure 6 is a graph showing vibration changes due to critical damping ratios. In Figure 6, the horizontal axis is frequency and the vertical axis is amplitude. The two-dot chain line in Figure 6 shows the response of the frame body 32, and the one-dot chain line in Figure 6 shows the response of a non-damping type dynamic vibration absorbing mechanism 36 that does not have granular members 40 (damping function). Two dashed lines and a solid line with different pitches in Figure 6 show the response of a damping type dynamic vibration absorbing mechanism 36 that is equipped with granular members 40.

[0034] Referring to Figure 6, when a motor mount 30 equipped with a dynamic vibration absorbing mechanism 36 is used for the mount body 32, two resonance peaks appear, with their intersections at P and Q. These points P and Q do not change (are fixed points) regardless of how the damping is changed. By appropriately setting the spring constant K and damping constant of the beam member 38, the two resonance peaks passing through points P and Q can be kept low, achieving low vibration over a wide range.

[0035] In the case of the non-damping dynamic vibration absorber 36 shown by the dashed line in Fig. 6, the natural frequency of the secondary vibration system (mass body 42) can be matched to the frequency of the external force, thereby balancing the restoring force of the spring (beam member 38) with the external force. This makes the response of the primary vibration system (frame body 32 and prime mover 20) completely zero.

[0036] In the case of a damping-type dynamic vibration absorber 36, the dynamic vibration absorber 36 is adjusted so that it resonates with the rotational speed of the main vibration system (frame body 32 and prime mover 20). Because it is tuned to the main vibration system rather than an external force, it is effective over a wide frequency range and also suppresses free vibration. However, there is an optimum value for damping by the dynamic vibration absorber 36; if the damping is too small, it will be as shown by the dashed line with a wide pitch in Figure 6, and if the damping is too large, it will be as shown by the dashed line with a narrow pitch in Figure 6. If the dynamic vibration absorber 36 has appropriate damping, it can exert a vibration-damping effect over a wide range of natural frequencies, as shown by the solid line in Figure 6. Furthermore, it can exert a vibration-damping effect even if the natural frequency changes due to aging.

[0037] Next, the operation of adjusting (changing) the natural frequency of the mass body 42 in the discharge direction Y and the orthogonal direction X by the dynamic vibration absorbing mechanism 36 of the first embodiment will be described with reference to FIGS.

[0038] To change the holding position of the mass body 42 relative to the four beam members 38, for example, each of the two nuts 45 threaded onto each beam member 38 is loosened. Next, the mass body 42 is positioned relative to the beam members 38 at a desired holding position and tilt angle θ, and the lower nut 45 is rotated to hold the underside of the mass body 42 via the washer 46. After that, the upper nut 45 is rotated and pressed against the upper surface of the mass body 42 via the washer 46. As a result, the mass body 42 is sandwiched between the pair of nuts 45 via the washer 46, and is held at a desired holding position and tilt angle θ in the vertical direction Z.

[0039] When the natural frequency of the motor pedestal 30 in the orthogonal direction X is to be increased above the natural frequency in the discharge direction Y, the state shown in Fig. 4 is used. Specifically, the holding position of the mass body 42 relative to the beam member 38 on one side (the right side in Fig. 4) located on the line VLx extending in the orthogonal direction X in Fig. 3 is made lowest, and the holding position of the mass body 42 relative to the beam member 38 on the other side (the left side in Fig. 4) located on the line VLx is made highest.

[0040] This allows the length L of the flexible beam member 38, i.e., the distance of the beam member 38 from the point of application to the point of force, to be adjusted for each beam member 38. As a result, the spring constant Kx of the beam member 38 in the orthogonal direction X becomes larger than the spring constant Ky in the ejection direction Y, and the natural frequency of the mass body 42 in the orthogonal direction X becomes higher than the natural frequency in the ejection direction Y. Specifically, this is as follows.

[0041] When the length of the flexible beam member 38 is L, the moment of inertia is I, and the Young's modulus is E, the spring constant K of the beam member 38 satisfies the following formula 1.

[0042]

number

[0043] In FIG. 3, there are two beam members 38 on a line VLy extending in the discharge direction Y, each having the same deflectable length L, and therefore the spring constant Ky of the beam member 38 in the discharge direction Y satisfies the following formula 2.

[0044]

number

[0045] 3, on a line VLx extending in the orthogonal direction X, there are beam members 38 with flexible deformation lengths of L1 and L2. If the radius from the center of the mass body 42 to the beam member 38 with length L2 is R and the inclination angle of the mass body 42 with respect to the line VLx extending in the orthogonal direction X is θ, then the spring constant Kx of the beam member 38 in the orthogonal direction X satisfies the following formula 3.

[0046]

number

[0047] Let b be the difference between the length L of the beam member 38 located on the line VLy extending in the discharge direction Y and the length L2 of the beam member 38 located on the line VLx extending in the orthogonal direction X. Then, by substituting b for Rθ in Equation 3, the spring constant Kx of the beam member 38 in the orthogonal direction X satisfies the following Equation 4.

[0048]

number

[0049] As shown in Equation 4, when mass body 42 is tilted with respect to line VLx extending in orthogonal direction X, the spring constant Kx of beam member 38 in orthogonal direction X becomes larger than the spring constant Ky of beam member 38 in ejection direction Y. This makes the rigidity of beam member 38 higher in orthogonal direction X than in ejection direction Y, and the natural frequency ωx of mass body 42 in orthogonal direction X can be made higher than the natural frequency ωy of mass body 42 in ejection direction Y. In this way, tilting mass body 42 can impart directionality to the natural frequency of mass body 42.

[0050] On the other hand, when the natural frequency ωy of the motor pedestal 30 in the discharge direction Y is to be increased above the natural frequency ωx in the orthogonal direction X, the mass body 42 is held at the lowest position relative to one beam member 38 located on a line VLy extending in the discharge direction Y in FIG. 3 , and the mass body 42 is held at the highest position relative to the other beam member 38 located on the line VLy. This makes the spring constant Ky of the beam member 38 in the discharge direction Y greater than the spring constant Kx in the orthogonal direction X. As a result, the rigidity of the beam member 38 is higher in the discharge direction Y than in the orthogonal direction X, and the natural frequency ωy of the mass body 42 in the discharge direction Y can be increased above the natural frequency ωx in the orthogonal direction X.

[0051] Furthermore, if it is desired to increase the spring constant K of the four beam members 38 overall, the mass body 42 is held above the beam members 38 so that the flexible length L is shortened. Conversely, if it is desired to decrease the spring constant K of the four beam members 38 overall, the mass body 42 is held below the beam members 38 so that the flexible length L is lengthened. In this way, by adjusting the overall length L of the flexible beam members 38, it is possible to adjust the spring constant K of the four beam members 38 overall. As a result, it is possible to adjust the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y.

[0052] As described above, in the motor pedestal 30 of this embodiment, the natural frequencies ωx, ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be adjusted by adjusting the holding position of the mass body 42 with the adjustment unit 44 without performing any major work. Therefore, if the rigidity of the installation floor 1 is not as designed or has changed over time, the natural frequencies ωx, ωy of the mass body 42 can be adjusted with the adjustment unit 44 in accordance with the actual state of the installation floor 1, thereby adjusting the natural frequencies of the mass body 42 in the discharge direction Y and the orthogonal direction X, and thereby preventing the natural frequencies of the pedestal main body 32 and the motor 20 from resonating in synchronization with the pump rotation speed.

[0053] The motor stand 30 configured in this manner has the following features.

[0054] The motor frame 30 includes a plurality of beam members 38 each having one end fixed to the mounting plate 34, and a mass body 42 attached to these beam members 38. This makes it possible to suppress vibration of the motor frame 30 caused by the motor 20. As a result, the natural frequency of the motor frame 30 resonates in synchronization with the pump rotation speed, and excessive vibration of the vertical shaft pump 10 can be suppressed.

[0055] The beam member 38 is provided with an adjustment unit 44 for adjusting the natural frequencies ωy, ωx of the mass body 42 in the discharge direction Y and the orthogonal direction X. As a result, if the rigidity of the installation floor 1 is not as designed or has changed over time, the natural frequencies ωy, ωx of the mass body 42 in the discharge direction Y and the orthogonal direction X can be easily adjusted by operating the adjustment unit 44 without performing any major work. Therefore, the natural frequency and rigidity of the motor pedestal 30 in the orthogonal direction X and the discharge direction Y can be adjusted, which prevents the natural frequency of the pedestal body 32 from resonating in synchronization with the pump rotation speed.

[0056] The mass body 42 has an insertion hole 42b that allows it to tilt relative to the beam member 38. The adjustment unit 44 also has a thread groove 38c formed in the beam member 38, a nut 45 threaded into the thread groove 38c, and a washer 46 that is larger than the insertion hole 42b of the mass body 42. The washer 46 includes a first washer 47 having a spherical recess 47a and a second washer 48 having a spherical protrusion 48a. This allows the holding position of the mass body 42 to be adjusted for each beam member 38 so that the mass body 42 tilts relative to the beam member 38 and the mounting plate 34. This allows the distance from the mounting plate 34 to the adjustment unit 44, which is the range within which the beam member 38 can flexibly deform, i.e., the length of the beam member 38 from the point of application to the point of force, to be adjusted for each beam member 38. This allows the spring constant K to be adjusted for each beam member 38, thereby reliably adjusting the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y. As a result, vibration of the motor stand 30 can be suppressed in accordance with the actual installation floor 1, and the natural frequency of the motor stand 30 can be prevented from resonating in synchronization with the pump rotation speed.

[0057] The beam members 38 are hollow and can accommodate a large number of granular members 40 inside. This allows the beam members 38 to also have a damping function. Therefore, vibrations of the motor pedestal 30 can be efficiently suppressed.

[0058] Other embodiments and various modifications of the present invention will be described below, but in these descriptions, points that are not particularly mentioned are the same as those in the first embodiment. In the drawings referred to below, the same elements as those in the first embodiment are given the same reference numerals.

[0059] (Second embodiment) Referring to Figure 7, in the second embodiment of the motor stand 30, mass bodies 42 are fixed to fixed positions of multiple beam members 38, and the length L of the flexibly deformable beam members 38 can be adjusted by adjustment parts 44 provided on the mass bodies 42.

[0060] In the beam member 38 of the second embodiment, no thread groove 38c (see FIG. 4) is provided on the outer peripheral surface of the beam main body 38a. The end of the beam main body 38a opposite to the fixing portion 38b is provided with a fixing portion 38d consisting of a screw shaft. One end of the beam main body 38a abuts against the mounting plate 34, and the other end of the beam main body 38a abuts against and is supported by the mass body 42.

[0061] Mass body 42 is formed with insertion holes 42b having a diameter large enough to insert fastening portions 38d of beam members 38. By tightening nuts 50 onto fastening portions 38d that protrude downward from insertion holes 42b, mass body 42 is fixed to the beam members 38 so as to extend horizontally at a constant distance (spacing) H from the mounting plate 34. However, fastening portions 38d can be changed as needed as long as the configuration allows mass body 42 to be fixed in a fixed position.

[0062] The adjustment unit 44 is disposed on the mass body 42 and adjusts the natural frequency of the mass body 42 in the discharge direction Y and the orthogonal direction X by changing the length L of the flexible beam members 38. Specifically, the adjustment unit 44 of the second embodiment includes a base member 52 and a slide member 53 provided for each beam member 38.

[0063] The base member 52 is a cylindrical body with a diameter that surrounds the beam member 38 at a distance, and is fixed to the upper surface of the mass body 42, which faces the mounting plate 34. A screw groove 52a is formed on the inner peripheral surface of the base member 52.

[0064] The slide member 53 is a cylindrical body that is disposed between the beam member 38 and the base member 52 and is movable along the beam member 38 relative to the base member 52. A threaded portion 53a that can be threaded into the thread groove 52a of the base member 52 is provided on the outer circumferential surface of the slide member 53. The slide member 53 also has an insertion hole 53b with the smallest possible diameter within the range that allows the beam member 38 to be inserted therethrough.

[0065] In this way, in beam member 38 having adjustment portion 44 disposed at its base, the range in which it can be flexibly deformed by vibration or the like is from the underside of mounting plate 34 to the upper end of slide member 53. The length L of beam member 38, which is the range in which it can be flexibly deformed, can be adjusted for each beam member 38 by changing the amount of screwing of slide member 53 into base member 52.

[0066] When the natural frequency ωx of the motor pedestal 30 in the orthogonal direction X is to be increased above the natural frequency ωy in the discharge direction Y, as in the adjustment unit 44 located on the rightmost side in Fig. 7, the slide member 53 of the beam member 38 located on the line VLx (see Fig. 3) extending in the orthogonal direction X is rotated to move out from the base member 52, and the length L2 of the deformable beam member 38 is made shorter than the length L of the beam member 38 on the line VLy (see Fig. 3) extending in the discharge direction Y. As a result, the spring constant K of the beam member 38 on the line VLx (see Fig. 3) extending in the orthogonal direction X becomes larger than the spring constant K of the beam member 38 on the line VLy (see Fig. 3) extending in the discharge direction Y, and the rigidity of the beam member 38 on the line VLx (see Fig. 3) extending in the orthogonal direction X becomes larger than the rigidity of the beam member 38 on the line VLy (see Fig. 3) extending in the discharge direction Y. As a result, the natural frequency ωx of the mass body 42 in the orthogonal direction X can be made higher than the natural frequency ωy in the discharge direction Y. Of course, the adjustment portion 44 of the beam member 38 located on the leftmost side in Fig. 7 may also be adjusted in a similar manner. Furthermore, the slide member 53 of the beam member 38 located on the line VLy (see Fig. 3) extending in the discharge direction Y may be retracted to make the length L of the flexibly deformable beam member 38 longer than the lengths L1, L2 of the beam member 38 located on the line VLx (see Fig. 3) extending in the orthogonal direction Y.

[0067] On the other hand, when the natural frequency ωy in the discharge direction Y of the motor pedestal 30 is to be increased above the natural frequency ωx in the orthogonal direction X, as in the adjustment unit 44 located on the leftmost side in Fig. 7, the slide member 53 of the beam member 38 located on the line VLx (see Fig. 3) extending in the orthogonal direction X is rotated and retracted into the base member 52, so that the length L1 of the flexibly deformable beam member 38 is made longer than the length L of the beam member 38 on the line VLy (see Fig. 3) extending in the discharge direction Y. As a result, the spring constant K of the beam member 38 on the line VLx (see Fig. 3) extending in the orthogonal direction X becomes smaller than the spring constant K of the beam member 38 on the line VLy (see Fig. 3) extending in the discharge direction Y, and the rigidity of the beam member 38 on the line VLx (see Fig. 3) extending in the orthogonal direction X becomes smaller than the rigidity of the beam member 38 on the line VLy (see Fig. 3) extending in the discharge direction Y. As a result, the natural frequency ωy of the mass body 42 in the discharge direction Y can be made higher than the natural frequency ωx in the orthogonal direction X. Of course, the adjustment portion 44 of the beam member 38 located on the rightmost side in Fig. 7 may also be adjusted in a similar manner. The slide member 53 of the beam member 38 located on the line VLy (see Fig. 3) extending in the discharge direction Y may be advanced to make the length L of the flexibly deformable beam member 38 shorter than the lengths L1, L2 of the beam member 38 located on the line VLx (see Fig. 3) extending in the orthogonal direction Y.

[0068] As described above, the adjustment unit 44 of the second embodiment includes the base member 52 disposed on the mounting plate 34 side of the mass body 42, and the slide member 53 movable along the beam member 38 relative to the base member 52. This allows the distance from the mounting plate 34 to the slide member 53, which is the range within which the beam member 38 can be flexibly deformed, i.e., the length L of the beam member 38 from the point of application to the point of effort, to be adjusted for each beam member 38. Therefore, because the spring constant for each beam member 38 is adjusted, the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be reliably adjusted. As a result, vibration of the motor pedestal 30 can be suppressed in accordance with the actual installation floor 1 (see FIG. 1 ), and the natural frequency of the motor pedestal 30 can be prevented from resonating in synchronization with the pump rotation speed.

[0069] (Third embodiment) 7 and 8, in the motor pedestal 30 of the third embodiment, similarly to the second embodiment, mass bodies 42 are fixed to fixed positions of a plurality of beam members 38. An adjustment unit 44 is provided for each beam member 38, and makes it possible to adjust the rigidity (spring constant) of the beam members 38 that are capable of flexibly deforming.

[0070] Beam member 38 is provided with upper flange portion 38e that is placed in surface contact with the underside of mounting plate 34, and lower flange portion 38f that is placed in surface contact with the upper surface of mass body 42. Beam member 38 is cylindrical, and contains granular material 40 (not shown).

[0071] The adjustment unit 44 of the third embodiment includes a hinge member 55 fixed to the beam member 38 and a support member 56 fixed to the hinge member 55, and the support member 56 is rotatable with respect to the beam member 38. The support member 56 has a first end 56a fixed to the hinge member 55 and a second end 56b that abuts against the mass body 42 via a lower flange portion 38f, and is inclined from the first end 56a toward the second end 56b so as to move away from the beam member 38.

[0072] 8, the hinge member 55 allows the support member 56 to rotate from a first angular position where the support member 56 abuts against a first position on the outer peripheral surface of the beam member 38 to a second angular position where the support member 56 abuts against a second position on the outer peripheral surface of the beam member 38. This rotation angle range includes an angular position where the support member 56 extends in the discharge direction Y and an angular position where the support member 56 extends in the perpendicular direction X. However, the support member 56 may be fixed to an annular ring rotatably arranged on the beam member 38, and the arrangement of the support member 56 can be changed as needed as long as it is configured to rotate relative to the beam member 38.

[0073] In the motor stand 30 in which the adjustment section 44 is provided at the base of the beam member 38, the direction in which the support member 56 extends can be adjusted for each beam member 38, thereby adjusting the rigidity of the beam member 38 in the discharge direction Y and the perpendicular direction X, and adjusting the natural frequencies ωy and ωx of the mass body 42.

[0074] When the natural frequency ωx of the motor pedestal 30 in the orthogonal direction X is to be increased above the natural frequency ωy in the discharge direction Y, the adjustment unit 44 is adjusted so that all of the support members 56 extend in the orthogonal direction X. This makes the rigidity of the beam members 38 higher in the orthogonal direction X than in the discharge direction Y, and the spring constant of the beam members 38 in the orthogonal direction X can be increased. As a result, the natural frequency ωx of the mass body 42 in the orthogonal direction X can be increased above the natural frequency ωy in the discharge direction Y.

[0075] On the other hand, when the natural frequency ωy of the motor pedestal 30 in the discharge direction Y is to be increased above the natural frequency ωx in the orthogonal direction X, the adjustment unit 44 is adjusted so that all of the support members 56 extend in the discharge direction Y. This increases the rigidity of the beam members 38 in the discharge direction compared to the orthogonal direction X, thereby increasing the spring constant of the beam members 38 in the discharge direction Y. As a result, the natural frequency ωy of the mass body 42 in the discharge direction Y can be increased above the natural frequency ωx in the orthogonal direction X.

[0076] As described above, the adjustment unit 44 of the third embodiment includes a support member 56 rotatably attached to the beam member 38, and the support member 56 is inclined from the first end 56a to the second end 56b so as to move away from the beam member 38. This allows the rigidity of the beam member 38 in the direction in which the support member 56 extends to be improved by changing the position of the support member 56, thereby increasing the spring constant of the beam member 38. This ensures that the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be reliably adjusted. As a result, vibration of the motor pedestal 30 can be suppressed in accordance with the actual installation floor 1 (see FIG. 1 ), preventing the natural frequency of the motor pedestal 30 from resonating in synchronization with the pump rotation speed.

[0077] (Fourth embodiment) 10 and 11, in the motor frame 30 of the fourth embodiment, similar to the second embodiment, mass bodies 42 are fixed in fixed positions on a plurality of beam members 38. Adjustment units 44 are formed by the beam members 38 themselves, and by changing the posture of the beam members 38, the rigidity (spring constant) of the beam members 38 in the discharge direction Y and the perpendicular direction X can be adjusted.

[0078] The beam member 38 is cylindrical and contains granular material 40 (not shown). The beam main body 38a is rectangular when viewed from the direction in which the axis B of the beam member 38 extends, and has a pair of long sides 38g and a pair of short sides 38h. In other words, the beam main body 38a has a cross-sectional shape having a longitudinal direction and a lateral direction. However, the beam main body 38a may also have an elliptical shape when viewed from the direction in which the axis B extends, as long as it has a cross-sectional shape having a longitudinal direction and a lateral direction.

[0079] A screw shaft 38i is provided at each end of the beam body 38a, and these screw shafts 38i are passed through the mounting plate 34 (see FIG. 1) and the mass body 42, respectively, and the beam body 38a can be held in a predetermined position by screwing nuts. As a result, one end of the beam body 38a abuts against the mounting plate 34, and the other end of the beam body 38a abuts against and is supported by the mass body 42. This embodiment also uses four beam members 38, two of which are arranged on each side of a line VLy extending in the discharge direction Y, and two of which are arranged on each side of a line VLx extending in the perpendicular direction X.

[0080] In this way, in the motor stand 30 in which the adjustment section 44 is formed by the beam member 38 itself, the beam main body 38a can be rotated relative to the mounting plate 34 (see Figure 1) and the mass body 42, and the direction in which the long side surface 38g extends can be adjusted to adjust the rigidity of the beam member 38 in the discharge direction Y and the perpendicular direction X, and the natural frequencies ωy and ωx of the mass body 42 can be adjusted.

[0081] When the natural frequency ωx of the motor pedestal 30 in the orthogonal direction X is to be increased above the natural frequency ωy in the discharge direction Y, the posture of the beam members 38 is adjusted so that the long side surfaces 38g of all beam bodies 38a extend in the orthogonal direction X, as shown in Fig. 11. This makes the rigidity of the beam members 38 higher in the orthogonal direction X than in the discharge direction Y, and the spring constant of the beam members 38 in the orthogonal direction X can be increased. As a result, the natural frequency ωx of the mass body 42 in the orthogonal direction X can be increased above the natural frequency ωy in the discharge direction Y.

[0082] On the other hand, when the natural frequency ωy of the motor pedestal 30 in the discharge direction Y is to be increased above the natural frequency ωx in the orthogonal direction X, the posture of the beam members 38 is adjusted so that the long side surfaces 38g of all beam bodies 38a extend in the discharge direction Y. This makes the rigidity of the beam members 38 higher in the discharge direction than in the orthogonal direction X, and the spring constant of the beam members 38 in the discharge direction Y can be increased. As a result, the natural frequency ωy of the mass body 42 in the discharge direction Y can be increased above the natural frequency ωx in the orthogonal direction X.

[0083] As described above, the adjustment unit 44 of the fourth embodiment is formed by the beam member 38 itself, and the beam member 38 has a rectangular shape having a longitudinal direction and a lateral direction. This improves the rigidity in the longitudinal direction compared to the lateral direction, thereby increasing the spring constant. Therefore, by changing the posture of the beam member 38, specifically by changing the angular position of the beam member 38 in the longitudinal and lateral directions relative to the mass body 42, the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be reliably adjusted. As a result, vibration of the motor pedestal 30 can be suppressed in accordance with the actual installation floor 1 (see FIG. 1), and the natural frequency of the motor pedestal 30 can be prevented from resonating in synchronization with the pump rotation speed.

[0084] (Fifth embodiment) 12, in the motor gantry 30 of the fifth embodiment, the lower ends of the beam members 38 are fixed to the mounting plate 34 and extend upward in the vertical direction Z. In other words, the beam members 38 and the mass body 42 are disposed outside the gantry main body 32. The adjustment units 44 provided for each beam member 38 are the same as in the first embodiment. However, the adjustment units 44 may be the same as in the second to fourth embodiments.

[0085] 13, the mass body 42 of the fifth embodiment is hollow and can accommodate a weight material 61. Specifically, the mass body 42 includes a main body 58 that is open at the top end, and a cover 59 that covers the main body 58.

[0086] The main body 58 includes an annular bottom wall 58a, a cylindrical inner peripheral wall 58b extending from the inner peripheral edge of the bottom wall 58a, and a cylindrical outer peripheral wall 58c extending from the outer peripheral edge of the bottom wall 58a. The main body 58 is also provided with a plurality of (eight in this embodiment) partition walls 58d that are continuous with the bottom wall 58a, the inner peripheral wall 58b, and the outer peripheral wall 58c and extend radially from the output shaft 21 (axis A) of the prime mover 20. The partition walls 58d divide the interior of the main body 58 into a plurality of housing chambers 60. Furthermore, cylindrical portions 58e that correspond to the insertion holes 42b are provided at positions corresponding to the formation positions of the partition walls 58d.

[0087] The cover 59 includes an annular top wall 59a, a cylindrical inner circumferential wall 59b provided on the inner circumferential edge of the top wall 59a, and a cylindrical outer circumferential wall 59c provided on the outer circumferential edge of the bottom wall 58a. The top wall 59a is sized to cover the upper end of the main body 58. The inner circumferential wall 59b is sized to be disposed overlapping the inside of the inner circumferential wall 58b of the main body 58. The outer circumferential wall 59c is sized to be disposed overlapping the outside of the outer circumferential wall 58c of the main body 58. The cover 59 is provided with a tubular portion 59d that is disposed overlapping the inside of the tubular portion 58e and defines the insertion hole 42b.

[0088] The weight material 61 is made up of a fan-shaped plate that can abut against the inner peripheral wall 58b, outer peripheral wall 58c, one partition wall 58d, and cylindrical portion 58e of the main body 58. The thickness of the weight material 61 is thinner than the height of the storage chamber 60, and multiple weight materials 61 can be stored in one storage chamber 60. However, the weight material 61 may also be sand or liquid.

[0089] In the dynamic vibration absorbing mechanism 36 of the third embodiment configured as described above, the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be adjusted by tilting the mass body 42 with respect to the beam member 38, as in the first embodiment. As a result, vibration of the motor pedestal 30 can be suppressed in accordance with the actual installation floor 1 (see FIG. 1), and the natural frequency of the motor pedestal 30 can be prevented from resonating in synchronization with the pump rotation speed.

[0090] Moreover, the mass body 42 of the fifth embodiment is hollow and can accommodate a weight material 61 therein. Thus, by accommodating the weight material 61 as a weight in the mass body 42, the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be further adjusted, and vibration of the motor pedestal 30 can be efficiently suppressed.

[0091] Furthermore, the mass body 42 is divided into a plurality of storage chambers 60 by a plurality of radially extending partition walls 58d. This allows the weight material 61 to be stored as a weight in the storage chamber 60 at an appropriate position relative to the motor pedestal 30. As a result, the natural frequencies ωx and ωy of the mass body 42 in the orthogonal direction X and the discharge direction Y can be reliably adjusted, and vibration of the motor pedestal 30 can be suppressed.

[0092] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

[0093] For example, the mass body 42 of the fifth embodiment may be used as the mass body 42 of the first to fourth embodiments.

[0094] The beam members 38 may be solid and may not be configured to accommodate the granular members 40 for damping.

[0095] The pump using the motor stand 30 may be a centrifugal pump, and any pump having a motor disposed above a pump casing can be used. [Explanation of symbols]

[0096] 1 Installation floor 2 Water absorption tank 10 Vertical pump (pump) 11 Pump casing 12. Lifting pipe (lower part) 13 Discharge elbow (upper part) 14 Base Plate 15 Outlet 16 spindle 17 Impeller 20 Prime Mover 21 Output shaft 25 Coupling 30 Engine stand 32 Stand body 33 Outer wall 33a aperture 34 Loading plate 34a Insertion hole 36 Dynamic vibration absorption mechanism 38 Beam member 38a Beam body 38b Fixation part 38c thread 38d Fixation part 38e Upper flange 38f Lower flange 38g long side 38h short side 38i screw shaft 39 Plug body 40 Granular materials 42 mass body 42a through hole 42b Insertion hole 44 Adjustment part 45 Nut 46 Washer 47 First washer (first component) 47a spherical recess 47b Insertion hole 48 Second washer (second part) 48a Spherical convex part 50 nuts 52 Base material 52a screw groove 53 Slide member 53a Threaded part 53b Insertion hole 55 Hinge member 56 Support member 56a 1st end 56b 2nd end 58 Main Unit 58a bottom wall 58b Inner wall 58c outer wall 58d Partition wall 58e tube part 59 Cover 59a Ceiling wall 59b Inner wall 59c outer wall 59d Cylinder part 60 Containment Room 61 Heavy materials X orthogonal direction (third direction) Y Discharge direction (second direction) Z vertical direction (first direction)

Claims

1. a base body including an outer peripheral wall attached to an upper side of a pump casing and surrounding a part of the upper side, an opening provided in the outer peripheral wall for exposing a discharge port of the pump casing, and a mounting plate provided at an upper end of the outer peripheral wall on which a prime mover is mounted; a plurality of flexible beam members each having one end fixed to the mounting plate and extending in a first direction intersecting the mounting plate; a mass attached to the plurality of beam members; an adjustment section provided on the beam member or the mass body, for adjusting the natural frequency of the mass body in a second direction that is a direction intersecting the first direction and in which liquid is ejected from the ejection port, and in a third direction that intersects both the first direction and the second direction; A pump motor stand comprising:

2. the mass body includes insertion holes through which the beam members can be inserted, each having a size that allows tilting relative to the beam members; the adjustment unit includes a thread groove provided on an outer periphery of the beam member, a nut threaded into the thread groove, and a washer larger than the insertion hole, and is disposed above and below the mass body for each of the beam members, The washer includes a first member having a spherical recess and a second member having a spherical protrusion fitted into the spherical recess. A motor mount for the pump according to claim 1.

3. the mass body is fixed to the plurality of beam members at a position a constant distance from the support plate, The adjustment unit a base member disposed on the support plate side of the mass body for each of the beam members and surrounding the beam members; a slide member having an insertion hole through which the beam member can be inserted and movable along the beam member relative to the base member; 10. The prime mover mount of claim 1, comprising:

4. the mass body is fixed to the plurality of beam members at a position a constant distance from the support plate, the adjustment unit includes a plurality of support members provided for each of the beam members, The support member has a first end rotatably attached to the beam member and a second end abutting the mass body or the mounting plate, and is inclined from the first end toward the second end so as to move away from the beam member. The motor mount according to claim 1.

5. the mass body is fixed to the plurality of beam members at a position a constant distance from the support plate, the adjustment portion is constituted by the beam member itself, the beam member has a cross-sectional shape having a longitudinal direction and a lateral direction when viewed from the direction in which the axis of the beam member extends, and is rotatable around the axis relative to the mounting plate and the mass body. The motor mount according to claim 1.

6. The motor stand according to claim 1 , wherein the beam member is hollow and can accommodate a large number of granular members therein.

7. The motor stand according to claim 1 , wherein the mass body is hollow and can accommodate a heavy material therein.

8. 8. The motor stand according to claim 7, wherein the mass body is annular and is divided into a plurality of accommodation chambers by a plurality of partition walls extending radially from the output shaft of the motor.

Images