JP2009275528A - Shaft coupling and pump device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft coupling having a function of shaft lock and torque transmission and improved to attain cost reduction and miniaturization by reducing the number of parts and to be advantageous in assembly and management. <P>SOLUTION: The shaft coupling interlockingly connects the drive shaft 1 and the driven shaft 2 while having a locking mechanism n and a torque transmitting mechanism t, wherein the torque transmitting mechanism t is formed by engagement of a recess 7 at a shaft end 1a of the drive shaft 1 and a projection 8 at a shaft end 2A of the driven shaft 2 and the locking mechanism n is formed by screwing and fitting a tubular body 12, which has a right-hand female screw 15 at one end and a left-hand female screw 16 at the other end, astride a right-hand male screw 4 formed on a counter-shaft end side of the recess 7 at the drive shaft end 1A and a left-hand male screw 9 formed on a counter-shaft end side of the projection 8 at the driven shaft end 2A. The recess 7 is the tip-flared recess having a pair of opposed taper surfaces 7A, 7A and the projection 8 is the tip-narrowed projection having a pair of contact surfaces 8A, 8A which can respectively surface-contact with the pair of taper surfaces 7A, 7A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shaft coupling suitable for transmitting torque while a tensile force acts on a shaft, such as a shaft transmission portion in a vertical shaft pump, and a pump apparatus including the shaft coupling.

  As a shaft coupling (coupling) for interlockingly connecting a main shaft and a pump shaft of a vertical shaft pump, those disclosed in FIGS. 1 and 4 in Patent Document 1 are known. The conventional shaft coupling is employed as a structure shown in FIGS. That is, by using a shaft joint J provided with a retaining mechanism n and a torque transmission mechanism t that prevent the main shaft 31 that is a drive shaft and the pump shaft 32 that is a driven shaft from moving away from each other in the axial direction. Linked together.

  The shaft lower end portion 31A, which is the shaft end of the main shaft 31, and the shaft upper end portion 32A, which is the shaft end of the pump shaft 32, each have a narrow diameter shaft portion 31a, 32a and a diameter larger than the constricted shaft portion. The shaft endmost flange shaft portions 31b and 32b having a smaller diameter than the shafts 31 and 32 are formed. And the engagement cylinder part fitted to the constriction shaft parts 31a and 32a is provided at both ends, the outer diameter is the same diameter as the shaft lower end part 31A and the shaft upper end part 32A, the cross-sectional shape is U-shaped, and the axial view A pair of half-split members 33, 33 having a C-shape are fitted to a shaft lower end portion 31A and a shaft upper end portion 32A that are attached to each other and face each other. Accordingly, a retaining mechanism n that prevents the pump shaft 32 from moving downward from the main shaft 31 is configured.

  Further, a torque transmission mechanism t that rotates integrally by a key coupling structure in which the shaft ends 31A and 32A and a sleeve 34 that is a cylindrical member that is externally fitted across the shaft ends is coupled via a key 35 is provided. ing. That is, a pair of keys 35, 35 are provided at two locations in the direction of the axis P across the key grooves 31k, 32k formed on the shaft ends 31A, 32A and the key groove 34k formed on the inner surface side of the sleeve 34. At the same time, the keys 35 and 35 and the sleeve 34 are relatively locked and fixed using a small screw 36. The sleeve 34 also has a function of preventing the pair of half-split members 33, 33 from being pulled out in the radial direction by inner peripheral portions on both sides of the intermediate cutout portion 34a.

  In the conventional shaft coupling means J, as shown in FIGS. 7 and 8, a key groove 34k is required in the sleeve 34 in order to adopt a key coupling structure that constitutes the torque transmission mechanism t, and the strength of the key groove 34k portion is increased. Therefore, since the necessary thickness of the sleeve is determined, the outer diameter of the sleeve tends to be large. In order to secure the strength of the half split member 33 constituting the retaining mechanism n while making the constricted shaft portions 31a and 32a that are the minimum diameter portions have sufficient strength, the main shaft 31 and the pump shaft 32 are inevitably required. The shaft diameter of this was also increased.

In addition, the shaft coupling as a whole has a large number of parts, which is disadvantageous in terms of assembly work, parts management, and cost. Such various disadvantages are the same in the shaft coupling having the structure disclosed in Patent Document 2.
JP 2004-27877 A Japanese Utility Model Publication No. Hei 6-12836

  An object of the present invention is to provide an improved shaft that has the necessary functions of retaining the shaft and transmitting torque, and is advantageous in terms of assembly and management by reducing the number of parts and reducing the size. The object is to provide a joint and a pump device including the joint.

The invention according to claim 1 includes a retaining mechanism n and a torque transmission mechanism t that prevent the axial movement of the drive shaft 1 and the driven shaft 2 from each other, and the drive shaft 1 and the driven shaft 2. For shaft couplings that are linked together,
The torque transmission mechanism t is engaged with a concave portion 7 formed at one shaft end 1A of the drive shaft 1 and the driven shaft 2 and a convex portion 8 formed at the other shaft end 2A. The concave portion 7 is a flared concave portion having at least a pair of taper surfaces 7A and 7A facing each other, and the convex portion 8 can be brought into contact with each of the pair of taper surfaces 7A and 7A. A first male screw 4 which is a tapered convex portion having contact surfaces 8A, 8A, and wherein the retaining mechanism n is formed on the opposite axial end side of the concave portion 7 at the one axial end 1A; A first female screw 15 that is externally screwed to the first male screw 4 at one end is formed across the second male screw 9 formed on the opposite shaft end side of the convex portion 8 at the other shaft end 2A. A second female screw 16 formed on the other end and externally engaged with the second male screw 9 is formed at the other end. It is characterized in that comprising a tubular body 12 which is by fitting screwed out.

  According to a second aspect of the present invention, in the shaft coupling according to the first aspect, the one shaft end 1A is formed in a bifurcated shape by the flared concave portion 7 having the pair of tapered surfaces 7A, 7A, and the tip The constricted convex portion 8 includes a pair of contact surfaces 8A and 8A that contact the pair of tapered surfaces 7A and 7A, and inclined surfaces 8a and 8a formed between the contact surfaces. It is a quadrangular pyramid-shaped convex part which has.

  According to a third aspect of the present invention, in the shaft joint according to the second aspect, the first male screw 4 and the second male screw 9 are opposite to each other, and the first male screw is engaged with the first male screw 4 and the second male screw 9. The female screw 15 and the second female screw 16 are opposite to each other.

  According to a fourth aspect of the present invention, in the shaft coupling according to any one of the first to third aspects, a cylindrical portion is provided on each of the opposite ends of the male screws 4 and 9 at the shaft ends 1A and 2A. 6 and 11 are formed, and fitting cylindrical ends 13 and 13 are formed on both ends of the cylindrical body 12 so as to be fitted to the cylindrical portions 6 and 11, respectively. In the assembled state in which the concave portion 7 and the convex portion 8 are fitted to each other by being screwed into the second male screws 4 and 9, the fitting cylinder ends corresponding to the cylindrical portions 6 and 11, respectively. 13 and 13 are closely fitted to each other so that a centering function for matching the shaft centers of the drive shaft 1 and the driven shaft 2 can be exhibited.

  According to a fifth aspect of the present invention, in the pump device, the drive shaft 1 is a main shaft that is interlockedly connected to the prime mover side, and the driven shaft 2 is a pump shaft having an impeller at a lower portion, and the shaft transmission of the pump As a means, the shaft coupling according to any one of claims 1 to 4 is provided.

  According to the first aspect of the present invention, a concave portion formed at one of the shaft ends of the drive shaft and the driven shaft, specifically, a flared concave portion having at least a pair of tapered surfaces facing each other, and the other The torque is transmitted by occlusion with a convex portion formed at the shaft end of the shaft, specifically, with a tapered convex portion having a contact surface capable of contacting each of the pair of tapered surfaces, that is, by direct occlusion between the shafts. Therefore, a pair of keys (refer to the part to which the code | symbol 35 was attached | subjected of FIG. 7) required with the conventional shaft coupling becomes unnecessary. And, the anti-extraction mechanism consisting of forward and reverse male screws formed on the outer periphery of each shaft end and a cylindrical body having a pair of female screws screwed to each male screw resists tension between shafts. Therefore, a pair of half-split members (refer to the component denoted by reference numeral 33 in FIG. 7) that is necessary in the conventional shaft coupling is also unnecessary. Further, the diameter of the shaft and the cylindrical pair can be reduced by the amount that the constriction shaft portion and the key groove for retaining are unnecessary, and it is possible to contribute to the reduction of water flow resistance.

  As a result, while providing the necessary functions of preventing shaft disengagement and torque transmission, we offer improved shaft couplings that are advantageous in terms of assembly and management by reducing costs and reducing size by reducing the number of parts. can do. In addition, in the torque transmission mechanism, it is formed by the engagement of the flared concave portion and the tapered convex portion, and the torque is transmitted by the contact between the tapered surfaces. It is possible to obtain a rational configuration in which the support strength can be sufficiently obtained while the length can be made relatively long and advantageous in terms of surface pressure.

  According to the invention of claim 2, although described in detail in the section of the embodiment, the contact state between the bifurcated concave portion and the tapered convex portion at the time of torque transmission due to contact between the tapered surfaces is indicated by a point. Therefore, it is possible to provide a shaft joint that is less likely to be damaged such as deformation at the contact portion between the concave portion and the convex portion, and has improved durability.

  According to the invention of claim 3, in the retaining mechanism, the shaft ends are brought closer to each other when the cylindrical body is turned in either the forward or reverse direction, and the shaft ends are moved away from each other if the tubular body is turned to the other. The function (turnbuckle-like function) is achieved, and the operation of connecting the shaft ends and the operation of engaging the concave portion with the convex portion can be performed easily and conveniently. In this case, the occlusal state of the concave portion and the convex portion is such that as the shafts are pressed in a direction approaching each other in the axial direction, effective torque transmission can be performed without rattling. As a result of the tightening of the shaped body, a favorable action is produced in which the concave portion and the convex portion are relatively approached, and there is also an advantage that a synergistic effect is achieved in that the effectiveness of the torque transmission mechanism is promoted by the function of the retaining mechanism.

  According to the invention of claim 4, a pair of shafts is formed by fitting between the spigot shaft portion formed on the opposite shaft end side of the threaded portion between the cylindrical body and each shaft end and the spigot inner peripheral surface, that is, the spigot portion. It becomes possible to make the axial centers of each other more precisely match. In addition, there is an advantage that a separate function for that purpose is unnecessary, and a centering function can be added without increasing the number of parts.

  According to the fifth aspect of the present invention, it is possible to provide a pump device in which torque can be transmitted while a thrust force is applied to the shaft by using a shaft coupling that is compact and advantageous in terms of assembly and management.

  Hereinafter, embodiments of a shaft coupling according to the present invention and a pump device including the same will be described with reference to the drawings when applied to a vertical shaft pump. FIG. 1 is a partially cutaway sectional view showing the structure of a shaft coupling, FIGS. 2 and 3 are bottom and plan views showing recesses and projections, respectively, and FIG. 4 is an exploded view showing shaft end shapes of the main shaft and pump shaft. FIG. 5 is a stress diagram of the lower end of the main shaft and the upper end of the shaft of the pump shaft, FIG. 6 is a Mises stress diagram of each shaft end in the shaft coupling of Example 2, and FIGS. It is sectional drawing of the principal part which shows the structure of the conventional shaft coupling, and sectional drawing of the principal part.

[Example 1]
As shown in FIG. 1, the shaft coupling A according to the first embodiment includes a motor-side main shaft (an example of a drive shaft) 1 and an impeller at a lower end in a vertical shaft pump (an example of a pump device) used in a drainage facility or the like. A pump shaft (an example of a driven shaft) 2 is interlockedly connected to each other, and a retaining mechanism that prevents the shafts 1A and 2A and the sleeve 12 from moving apart in the axial direction between the shafts 1 and 2 n and a torque transmission mechanism t.

  A shaft lower end 1A, which is the shaft end of the main shaft 1, is formed in this order from the shaft lower end to the shaft end 3, the right male thread 4, the constricted shaft 5, and the spigot shaft 6 having a recess 7. Is made up of. The shaft upper end portion 2A of the pump shaft 2 is formed by forming a convex portion 8, a left male screw portion 9, a constricted shaft portion 10, and an inlay shaft portion 11 in this order from the upper end of the shaft downward. . The sleeve 12 includes inner spigot inner circumferential surfaces 13 and 13 at both ends, a relief large-diameter portion 14 in the axial center, a right female screw portion 15 screwed to the right male screw portion 4, and a left female screwed to the left male screw portion 9. A cylindrical body having a screw portion 16 is formed.

  As shown in FIGS. 1, 2, and 4, the recess 7 forms an angle of 45 degrees with the shaft center P at a shaft end portion 3 that is slightly smaller in diameter than the right male screw portion 4, and has a 90 ° included angle. The shaft end portion 3 is formed in a bifurcated shape, which is a tip-shaped concave portion having a pair of tapered surfaces 7A, 7A. Both the tapered surfaces 7A and 7A are connected via a smooth concave curved surface 7a, and the tips of the tapered surfaces 7A and 7A are formed on chamfered surfaces 7b and 7b which are cut so as not to be sharp.

  As shown in FIGS. 1, 3 and 4, the convex portion 8 is formed into a quadrangular pyramid-shaped convex portion having the same four tapered surfaces 8A, 8a, 8A and 8a. Of these inclined surfaces 8A, 8a, 8A, 8a, a pair of two opposingly arranged, that is, 8A, 8A and 8a, 8a are configured to be able to come into surface contact with the tapered surfaces 7A, 7A, respectively. . In this embodiment, the convex portion 8 is a tapered convex portion, and has four inclined surfaces that form a pair of contact surfaces 8A and 8A and an inclined surface 8a formed between the inclined surfaces. It is formed in a pyramidal convex part. A top surface 17 that is cut so as not to be sharp is formed at the shaft end.

  That is, the torque transmission mechanism t is formed by occlusion between the concave portion 7 formed in the shaft lower end portion 1A that is the shaft end of the main shaft 1 and the convex portion 8 formed in the shaft upper end portion 2A that is the shaft end of the pump shaft 2. It is configured. The retaining mechanism n includes a right male screw portion (an example of a first male screw) 4 formed on the opposite shaft end side of the concave portion 7 at the shaft lower end portion 1A, and a counter shaft of the convex portion 8 at the shaft upper end portion 2A. A right female screw portion (an example of a first female screw) 15 that is fitted to the right male screw portion 4 at one end across a left male screw portion (an example of a second male screw) 9 formed on the end side. And a sleeve 12 in which a left female screw portion (an example of a second female screw) 16 that is externally screwed to the left male screw portion 9 is screwed and fitted to the other end is screwed. Yes.

  In order to assemble the shaft coupling A, the shaft lower end portion 1A of the main shaft 1 and the shaft upper end portion 2A of the pump shaft 2 are relative to each other in the positional relationship where the recess 7 and the protrusion 8 just fit around the axis P. It rotates and is spaced apart to the extent that the sleeve 12 is interposed. Then, after the sleeves 12 are sequentially screwed between the shaft ends 1A and 2A, the sleeves 12 are turned and tightened. Further, if each of the shaft ends 1A and 2A is provided with markings (punch marks, paint application, etc.) indicating the relative positions where the concave portion 7 and the convex portion 8 are engaged, both shaft ends 1A and 2A by the sleeve 12 are used. During the tightening operation, the relative angular posture of the main shaft 1 and the pump shaft 2 can be adjusted to the rotational positional relationship where the concave portion 7 and the convex portion 8 are engaged, and is limited to the above-described assembling means. Absent.

  As shown in FIG. 1, in the assembled state in which the sleeve 12 is rotated and the main shaft 1 and the pump shaft 2 are tightened so that there is no gap between both shafts, the concave portion 7 and the convex portion 8 are transmitted so that torque is transmitted. And the sleeve 12 screwed to both the main shaft 1 and the pump shaft 2 prevent the shafts 1 and 2 from moving away from each other in the direction of the axis P. In addition, each of the spigot shaft portions 6, 11 and the corresponding spigot inner peripheral surfaces 13, 13 are precisely fitted so that the shaft center of the main shaft 1 and the shaft center of the pump shaft 2 coincide with each other. The centering action of the shaft center P is also demonstrated.

  Although illustration is omitted, a screw portion is formed on the upper side of the spigot shaft portion 6 of the main shaft 1 and the lower side of the spigot shaft portion 11 of the pump shaft 2 so that a lock nut can be screwed, By fastening to the end of the sleeve 12, the shaft joint A with a lock nut that can maintain the assembled state of the shafts 1 and 2 by the sleeve 12 can be maintained.

  As shown in FIG. 5, the torque transmission state when the concave portion 7 and the convex portion 8 are engaged with each other is such that the ridge line 18 at the boundary with the lower inclined surface 8a and the one taper in the rotational direction of the one abutting surface 8A. A pair of line contact states that the surface 7A is in contact with each other and the ridge line 18 at the boundary with the lower inclined surface 8a in the rotation direction of the other contact surface 8A and the other tapered surface 7A are in contact with each other. ing. As shown in FIG. 5, this situation per line is supported by a Mises stress diagram by computer analysis.

  As a comparative example of the analysis diagram, FIG. 6 shows a result of the concave portion 7 and the convex portion 8 having the shape according to the second embodiment. A convex portion 8 having a shape (like a tip of a minus screwdriver) having a triangular shape in a side view having no inclined surfaces 8a and 8a and having only a pair of contact surfaces 8A and 8A, and the concave portion 7 shown in FIG. In the case of the occlusion, there is an advantage that the number of processing steps for the convex portion is smaller than that in the first embodiment. However, as shown in FIG. 6, it can be understood from the computer analysis that the contact state is close to a point contact. That is, it can be seen that the use of the quadrangular pyramid-shaped convex portion 8 (Example 1) that seems to be difficult to transmit torque at first glance is more advantageous because it can transmit torque more effectively by line contact.

  According to the shaft coupling A according to the first embodiment, the shaft diameter can be reduced compared to the prior art that requires a circumferential groove, and the key coupling structure is a forward / reverse screw coupling structure. The diameter can also be reduced. In the convex portion 8, the pair of contact surfaces 8 </ b> A and the pair of inclined surfaces 8 a are formed on the same plane inclined by 45 degrees with respect to the axis P, and are easy to process. Compared with the conventional key connection structure, the number of parts requiring processing accuracy is reduced, and there is an advantage that cost reduction and quality improvement can be achieved.

[Another Example]
As shown in FIG. 6, the concave portion 7 and the convex portion 8 constituting the torque transmission mechanism t may be configured such that the flared concave portion 7 and the triangular convex portion 7 are engaged with each other. And the angle which an inclined surface and the axis P make is not limited to 45 degree | times, You may form so that the angle may differ for every inclined surface. In addition, although not shown, a torque transmission mechanism may be used by engaging a concave portion having a rectangular cross section that is recessed in the axial direction and a convex portion having a quadrangular pyramid shape extending in the axial direction, and various modifications are possible. Moreover, you may form in the outer peripheral part of the sleeve 12 the two surface width | variety part and hexagon part which enable application of tightening tools, such as a spanner.

Sectional view showing the structure of a shaft coupling (Example 1) Bottom view showing the lower end of the main shaft Plan view showing the upper end of the pump shaft Exploded perspective view schematically showing shaft end shapes of main shaft and pump shaft Diagram of Mises stress at the lower end of the main shaft and at the upper end of the pump shaft Stress diagram of each shaft end in the shaft coupling of Example 2 having a triangular convex portion Sectional drawing of the principal part which shows the structure of the conventional shaft coupling Aa line sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive shaft 1A One shaft end 2 Driven shaft 2A The other shaft end 6 Cylindrical part 7 Concave part 7A Tapered surface 8 Convex part 8A Contact surface 8a Inclined surface 9 Second male screw 11 Cylindrical part 12 Cylindrical body 13 Fitting cylinder End 15 First female screw 16 Second female screw n Detachment mechanism t Torque transmission mechanism

Claims (5)

A shaft coupling that interlocks the drive shaft and the driven shaft with a retaining mechanism and a torque transmission mechanism that prevent the drive shaft and the driven shaft from moving apart in the axial direction;
The torque transmission mechanism is configured by occlusion of a concave portion formed at one of the shaft ends of the drive shaft and the driven shaft and a convex portion formed at the other shaft end, and the concave portion A concavity that has at least a pair of tapered surfaces facing each other, and the convex portion is a tapered convex portion having a contact surface that can contact each of the pair of tapered surfaces, and A retaining mechanism includes a first male screw formed on the opposite shaft end side of the concave portion at the one shaft end and a second male screw formed on the opposite shaft end side of the convex portion at the other shaft end. A first female screw that is externally screwed to the first male screw is formed at one end, and a second female screw that is externally screwed to the second male screw is formed at the other end. A shaft coupling formed by screwing a cylindrical body.   The one shaft end is formed in a bifurcated shape by the flared concave portion having the pair of tapered surfaces, and the tapered convex portion forms a pair of abutting surfaces that abut each of the pair of tapered surfaces. The shaft coupling according to claim 1, which is a quadrangular pyramid-shaped convex portion having an inclined surface formed between the inclined surface and each contact surface.   The first male screw and the second male screw are screws opposite to each other, and the first female screw and the second female screw engaged with the first male screw and the second male screw are screws opposite to each other. The shaft coupling according to 1 or 2.   A cylindrical part is formed on each of the opposite axial end sides of each male screw at each axial end, and a fitting cylindrical end that is externally fitted to the cylindrical part is formed at each of both ends of the cylindrical body, In the assembled state in which the cylindrical body is screwed into each of the first and first male threads and the concave portion and the convex portion are fitted, the fitting cylindrical ends corresponding to the column portions. The shaft coupling according to any one of claims 1 to 3, wherein each of the shaft coupling is configured so as to be capable of exhibiting a centering function for matching the shaft centers of the drive shaft and the driven shaft. .   The shaft according to any one of claims 1 to 4, wherein the drive shaft is a main shaft that is interlocked and connected to the prime mover side, and the driven shaft is a pump shaft having an impeller and serves as a shaft transmission means of the pump. Pump device equipped with a joint.

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