JP5849343B2 - Magnetic coupling and stirring device - Google Patents

Description

  The present invention relates to a magnetic coupling that transmits a rotational force in a non-contact manner and a stirring device to which the magnetic coupling is applied.

  As a device for stirring the liquid stored in the stirring tank, there are a stirring blade (rotary body) disposed inside the stirring tank and an output shaft (rotation) of a drive unit such as a motor disposed outside the stirring tank. In some cases, a magnetic coupling is applied to the stirring body to transmit the rotational force of the drive unit to the stirring blade in a non-contact manner. In this type of magnetic coupling, an attraction magnet unit and a repulsion magnet unit are disposed at portions of the agitation blade and the output shaft of the drive unit that are opposed to each other. Thus, the stirring blade is kept floating, and the rotational force is transmitted in a non-contact manner by the attractive force of the attractive magnet unit (see, for example, Patent Document 1).

JP 2006-35098 A

  By the way, in the above-described magnetic coupling, when the suction force between the stirring blade and the output shaft of the drive unit is set large with respect to the repulsive force between the stirring blade and the drive unit, the stirring blade floats inside the stirring tank. The liquid cannot be stirred because it cannot be made to occur. That is, in the above stirring device, it is necessary to set the magnetic force of each magnet unit so that the repulsive force between the stirring blade and the output shaft of the drive unit exceeds the attractive force between them.

  According to the magnetic coupling in which the magnetic force of the magnet unit is set as described above, even if the mutual distance along the axial center between the stirring blade and the output shaft is reduced, the repulsive force acting between each other reduces the stirring. The blades are lifted and adjusted so that the distance from the drive unit becomes large again, and the situation where the stirring blades come into contact with the bottom wall of the stirring tank can be prevented.

  However, after the mutual distance along the axial center between the stirring blade and the output shaft increases, the force that brings them closer together no longer acts, and the mutual distance increases and the rotational force is increased as it is. May be difficult to communicate.

  In view of the above circumstances, the present invention provides a magnetic cup capable of continuously transmitting power without contact even when the mutual distance along the axis between the rotating body and the rotating body increases. An object is to provide a ring and a stirring device.

In order to achieve the above object, the magnetic coupling according to the present invention has a repulsion between a rotating body whose axial center is arranged in a vertical direction and a rotated body arranged on an extension of the rotating body. A magnet unit for attraction and a magnet unit for attraction are provided, and the revolving force of the repulsion magnet unit keeps the rotated body floated with respect to the rotating body, and the attraction force of the attraction magnet unit In the magnetic coupling in which the rotational force is transmitted in a non-contact manner between the rotating body and the rotated body, the repulsion magnet unit and the attraction magnet unit are each configured by a combination of permanent magnets. It is intended, for the said repulsive force of the repulsive magnet unit suction when mutual distance along the axis is less than a predetermined threshold value between the rotating member and the driven rotating body Each magnetic force is set so that the attraction force of the attraction magnet unit exceeds the repulsion force of the repulsion magnet unit when the attraction force exceeds the attraction force of the stone unit and the mutual distance increases beyond the threshold value. It is characterized by that.

  Further, the present invention provides the magnetic coupling described above, wherein the attraction magnet unit is disposed at a central portion of the rotating body, and the repulsion magnet unit is disposed at an outer peripheral portion of the attraction magnet unit, The attraction magnet unit is configured by alternately arranging a plurality of magnets in the circumferential direction so that adjacent ones have different polarities, and the repulsion magnet unit has a plurality of ring shapes having different outer diameters. The magnets are characterized by being arranged concentrically in such a manner that adjacent magnets have different polarities.

  Further, the present invention provides a magnetic coupling that acts between the rotating body and the rotated body when the axis of the rotating body and the axis of the rotated body are matched. And a magnetic unit for preventing lateral displacement is provided in which the magnetic force is unbalanced when the rotating magnetic body and the rotating body are misaligned with each other.

  Further, in any one of the magnetic couplings described above, the stirring device according to the present invention is provided with a stirring blade on the rotated body, and the rotated body is disposed inside a stirring tank for stirring the liquid. On the other hand, the drive part which drives the said rotary body outside the said stirring tank is arrange | positioned, The said to-be-rotated body and the said rotary body are made to mutually oppose.

  According to the present invention, when the mutual distance along the axis between the rotating body and the rotated body increases, the attractive force of the attractive magnet unit exceeds the repulsive force of the repulsive magnet unit, and Since the magnetic force is set so that the repulsive force of the repulsive magnet unit exceeds the attractive force of the attractive magnet unit when the distance decreases, the distance between the rotating body and the rotating body is increased. When a force is applied, the attractive force exceeds the repulsive force, and the mutual distance decreases. Therefore, it is possible to continuously apply a suction force between the rotating body and the rotating body and transmit power without contact.

1 is a cross-sectional view showing a magnetic coupling according to a first embodiment of the present invention. FIG. 2 is a diagram showing an arrangement of the repulsion magnet unit and the attraction magnet unit applied to the magnetic coupling shown in FIG. FIG. 3 shows the mutual distance along the axis between the rotating body and the rotated body of the magnetic coupling shown in FIG. 1 and the repulsive force of the repelling magnet unit and the attractive force of the attracting magnet unit. It is a graph which shows a relationship. FIG. 4 is a graph showing the relationship between the mutual distance along the axis between the rotating body and the rotated body of the magnetic coupling shown in FIG. 1 and the force acting between them. FIG. 5 is a diagram conceptually showing a stirring device to which the magnetic coupling shown in FIG. 1 is applied. FIG. 6 is a cross-sectional view showing a magnetic coupling according to the second embodiment of the present invention. FIG. 7 is a perspective view showing an arrangement mode of magnets provided on the rotating body of the magnetic coupling shown in FIG. FIG. 8 is a perspective view partially broken away showing an arrangement mode of magnets provided on the rotating body of the magnetic coupling shown in FIG.

  Hereinafter, preferred embodiments of a magnetic coupling and stirring device according to the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1)
1 and 2 show a magnetic coupling according to the first embodiment of the present invention. The magnetic coupling exemplified here has an electric motor (not shown) arranged with the output shaft (rotating body) 1 oriented vertically upward, and a shaft center vertically at a portion above the output shaft 1. It is applied between a driven shaft (driven body) 2 arranged along the direction and transmits a rotational force between the output shaft 1 and the driven shaft 2 in a non-contact manner. Unit holders 10 and 20 are provided at the end and the end of the driven shaft 2, respectively. The unit holders 10 and 20 have a disk shape having the same outer diameter. The unit holder 10 of the output shaft 1 is fixed to the output shaft 1 with its own axis aligned with the axis of the output shaft 1, and the unit holder 20 of the driven shaft 2 is fixed to its own axis. The center of the driven shaft 2 is fixed to the end of the driven shaft 2 in a state where the core is aligned with the axis of the driven shaft 2. The individual unit holders 10 and 20 are provided with a suction magnet unit 30 and a repulsion magnet unit 40 on their respective end faces.

  The attraction magnet unit 30 applies an attractive force between the unit holder 10 of the output shaft 1 and the unit holder 20 of the driven shaft 2, and the unit of the driven shaft 2 from the unit holder 10 of the output shaft 1. This is for transmitting the rotational force to the holding body 20 in a non-contact manner. In the first embodiment, four permanent magnets (hereinafter referred to as “attracting magnets 31N and 31S”) having substantially the same fan shape are disposed at the center of the unit holders 10 and 20, respectively. A magnet unit 30 is configured. Each of the attracting magnets 31N and 31S has an exposed end face as a north pole or a south pole, adjacent ones are different from each other, and the outer shape of a combination of the four is a circle having a center hole. In a mode of presenting a plate shape, the unit holders 10 and 20 are alternately arranged in the circumferential direction around the axial center. The attraction magnet unit 30 configured on the unit holder 10 of the output shaft 1 and the attraction magnet unit 30 configured on the unit holder 20 of the driven shaft 2 are configured to have the same shape. .

  The repulsion magnet unit 40 applies a repulsive force between the unit holder 10 of the output shaft 1 and the unit holder 20 of the driven shaft 2, and causes the unit holder 20 of the driven shaft 2 to be a unit of the output shaft 1. This is for maintaining the surface floating from the holding body 10. In the first embodiment, three permanent magnets (hereinafter referred to as “repulsion magnets 41N, 41S, 41N”) having a ring shape with different outer diameters are disposed on the outer peripheral portion of the attraction magnet unit 30. The repulsion magnet unit 40 is constituted by the above. The repulsion magnets 41N, 41S, and 41N each have a north pole or a south pole on the entire periphery of the exposed end face, and the adjacent ones are different from each other, with the axis of the unit holders 10 and 20 being centered. Are arranged in parallel on the same concentric line. The repulsion magnet unit 40 configured on the unit holder 10 of the output shaft 1 and the repulsion magnet unit 40 configured on the unit holder 20 of the driven shaft 2 have the same shape and the same magnetic poles. It is configured.

  In the unit holders 10 and 20 provided with the attracting magnet unit 30 and the repelling magnet unit 40 as described above, the rebound magnets 41N, Since 41S and 41N are opposed to each other with the same polarity, a repulsive force acts between them, and the unit holder 20 of the driven shaft 2 floats from the unit holder 10 along the axial direction of the output shaft 1. Maintained. On the other hand, in the magnet unit 30 for attraction | suction, when the unit holding bodies 10 and 20 rotate relatively appropriately, opposite poles will be made to oppose and it will stop in the state which the attraction force acted between.

  Here, unless the repulsive force of the repulsive magnet unit 40 is set larger than the attractive force of the attractive magnet unit 30, the unit holder 20 of the driven shaft 2 is moved relative to the unit holder 10 of the output shaft 1. It cannot be kept floating. However, when the repulsive force of the repulsive magnet unit 40 is simply set larger than the attractive force of the attractive magnet unit 30, the unit holder 10 of the output shaft 1 and the unit holder 20 of the driven shaft 2 If a force acts so as to increase the mutual distance D along the axial center, the mutual distance D increases as it is, and it becomes difficult to transmit the rotational force thereafter.

  Therefore, in the above-described magnetic coupling, as shown in FIGS. 3 and 4, the mutual distance along the axial center between the unit holder 10 of the output shaft 1 and the unit holder 20 of the driven shaft 2. When D is smaller than a preset threshold value, the repulsive force of the repulsive magnet unit 40 is set to exceed the attractive force of the attracting magnet unit 30 and the mutual distance D is equal to the above-described threshold value. The magnetic force is set so that the attractive force of the attractive magnet unit 30 exceeds the repulsive force of the repulsive magnet unit 40 when the repulsive magnet unit 40 increases. That is, the repulsive force of the repulsive magnet unit 40 is set so as to change more rapidly with respect to the above-described change in the mutual distance D with respect to the attractive force acting between the attractive magnet units 30. is there.

  The repulsive force of the repulsive magnet unit 40 against the change in the mutual distance D along the axis between the unit holder 10 of the output shaft 1 and the unit holder 20 of the driven shaft 2 attracts the magnet unit 30 for suction. For example, it is preferable to reduce the number of poles of the attracting magnets 31N and 31S as much as possible. This is because when the number of poles of the attracting magnets 31N and 31S is large and the mutual distance D increases, the lines of magnetic force that have entered and exited between the attracting magnets 31N and 31S of the opposing attracting magnet unit 30 are: This is because the attraction force acting between the attraction magnet units 30 abruptly decreases because the attraction magnets 31N and 31S of the same attraction magnet unit 30 come in and out. On the other hand, in the repulsion magnet unit 40, it is preferable to apply the repulsion magnets 41N, 41S, 41N having the smallest possible radial width. Similarly to the above, when the above-described distance D increases, the lines of magnetic force that have entered and exited between the repulsion magnets 41N, 41S, and 41N of the opposing repulsion magnet unit 40 have the same repulsion magnet unit 40. This is because the repulsive force acting between the repulsive magnet units 40 is abruptly reduced because the repulsive magnets 41N, 41S, 41N are moved in and out.

  According to the magnetic coupling configured as described above, the repulsive force of the repulsive magnet unit 40 and the attractive force of the attracting magnet unit 30 are balanced, and the driven shaft 2 with respect to the unit holder 10 of the output shaft 1 is balanced. The unit holder 20 is maintained in a floating state. If an electric motor (not shown) is driven from this state, the unit holder 10 of the output shaft 1 is not contacted with the rotation of the unit holder 10 of the output shaft 1 by the attractive force acting between the suction magnet units 30. The driven shaft 2 is transmitted to the holding body 20 and rotates in the same direction as the output shaft 1.

  In this state, if a force is applied to the driven shaft 2 so that its axis is displaced in the horizontal direction, the attracting magnets 31N and 31S disposed on the unit holder 10 of the output shaft 1 and the driven shaft 2 The area facing the attracting magnets 31N and 31S disposed on the unit holder 20 is unbalanced. As a result, the attraction force acting between the attraction magnets 31N and 31S is also unbalanced, and the force acts so that the axis of the driven shaft 2 matches the axis of the output shaft 1. Therefore, according to the magnetic coupling, the shaft center of the output shaft 1 and the shaft center of the driven shaft 2 are always automatically adjusted to coincide with each other.

  On the other hand, when a force acts on the unit holder 20 of the driven shaft 2 so that the mutual distance D along the axis from the unit holder 10 of the output shaft 1 increases, the repulsion magnet unit 40 repels. Both the force and the attractive force of the attractive magnet unit 30 are reduced. However, since the reduction rate of the repulsive force is larger than the reduction rate of the suction force, a suction force acts between the unit holding body 10 of the output shaft 1 and the unit holding body 20 of the driven shaft 2, and mutual The distance D decreases. Therefore, the distance D between the two unit holders 10 and 20 stops again at a position where the repulsive force of the repulsive magnet unit 40 and the attractive force of the attracting magnet unit 30 are balanced, and the unit holder of the output shaft 1 10, the unit holder 20 of the driven shaft 2 is maintained in a floating state. As a result, it is possible to continuously apply a suction force between the driven shaft 2 and the output shaft 1 of the electric motor (not shown), and transmit power without contact.

  FIG. 5 shows a stirring device to which the above-described magnetic coupling is applied. In this stirring apparatus, an electric motor (drive unit) 60 is attached to a base 50 with the output shaft 1 facing vertically upward, and a repulsion magnet unit 40 and a suction magnet unit 30 are attached to the upper end of the output shaft 1. The unit holding body 10 provided with is fixed.

  On the other hand, a stirring tank 70 is attached to the upper part of the base 50. The stirring tank 70 is formed in a hollow rectangular parallelepiped shape with a nonmagnetic material, and is fixed to the upper surface of the base 50 via legs 72 provided at the four corners of the bottom wall 71 thereof. As is clear from FIG. 5, the bottom wall 71 of the agitation tank 70 is arranged in parallel and close to the upper surface of the unit holder 10 provided on the output shaft 1.

  Inside the agitation tank 70, the driven shaft 2 is disposed together with the liquid to be agitated. A unit holder 20 including a repulsion magnet unit 40 and a suction magnet unit 30 is fixed to the lower end portion of the driven shaft 2. A stirring blade 2 a is attached to the upper end portion of the driven shaft 2 with the axis of the driven shaft 2 as the rotational axis.

  Other configurations similar to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

  Also in the stirring device configured as described above, the repulsive force of the repulsive magnet unit 40 and the attractive force of the attracting magnet unit 30 are balanced, and the unit of the driven shaft 2 with respect to the unit holder 10 of the output shaft 1. The holding body 20 is maintained in a floating state. If the electric motor 60 is driven from this state, the rotation of the unit holder 10 of the output shaft 1 is brought into non-contact with the unit holder 20 of the driven shaft 2 by the attractive force acting between the suction magnet units 30. As a result, the driven shaft 2 rotates in the same direction as the output shaft 1. When the driven shaft 2 rotates, the stirring blade 2a attached to the driven shaft 2 rotates, and the liquid in the stirring tank 70 is stirred.

  While the liquid is being stirred, when a force is applied to the driven shaft 2 so that its axis is displaced in the horizontal direction, or along the axis between the driven shaft 2 and the electric motor 60. When a force is applied to increase the mutual distance D, the liquid is automatically restored by the above-described magnetic coupling action, so that the liquid can be continuously stirred.

  In the first embodiment described above, the suction magnet unit 30 is exemplified by a configuration in which four suction magnets 31N and 31S having a substantially fan shape are arranged. The configuration of the permanent magnets constituting 30 is not limited to these. Permanent magnets having other shapes may be applied, and the number of poles is not limited to four. Similarly, the repulsion magnet unit 40 is illustrated as being configured by arranging three repulsion magnets 41N, 41S, 41N having ring shapes with different outer diameters, but has other shapes. A permanent magnet may be applied, and the number of poles is not limited to three.

  Moreover, although Embodiment 1 mentioned above illustrates what rotates a to-be-driven shaft by non-contact by the drive of an electric motor, as a to-be-rotated body, it does not necessarily need to be a shaft member.

  Furthermore, in Embodiment 1 mentioned above, although the bottom wall 71 has illustrated flat plate shape as the stirring tank 70, it is not necessarily limited to this. For example, when applied to an agitation tank having a tapered bottom wall that inclines upward from the center toward the outer periphery, the liquid can be agitated more efficiently.

(Embodiment 2)
6 to 8 show the magnetic coupling according to the second embodiment of the present invention. As in the first embodiment, the magnetic coupling exemplified here includes an electric motor (not shown) arranged with the output shaft (rotating body) 1 ′ vertically upward, and the output shaft 1 ′. Is applied between a driven shaft (rotated body) 2 ′ having an axial center disposed along the vertical direction at a position above, and non-contact between the output shaft 1 ′ and the driven shaft 2 ′. The unit holding bodies 100 and 200 are provided at the end of the output shaft 1 'and the end of the driven shaft 2', respectively. A unit holding body of the output shaft 1 ′ (hereinafter referred to as “first unit holding body 100” for distinction) has a base portion 101 having a cylindrical shape larger in diameter than the output shaft 1 ′ and an outer peripheral surface of the base portion 101. The flange portion 102 is provided, and is fixed to the output shaft 1 ′ in a state where the shaft center of the base portion 101 matches the shaft center of the output shaft 1 ′. A unit holder of the driven shaft 2 ′ (hereinafter referred to as “second unit holder 200” for distinction) is provided on a cylindrical base part 201 having an open lower end and an outer peripheral surface of the open end part of the base part 201. The base portion 201 is fixed to the end portion of the driven shaft 2 ′ in a state where the shaft center is aligned with the axis of the driven shaft 2 ′. The base 201 of the second unit holder 200 is formed to have an inner diameter that can accommodate the base 101 of the first unit holder 100. The flange portion 202 of the second unit holder 200 is formed so that the outer diameter of the flange portion 102 of the first unit holder 100 is substantially the same. The individual unit holders 100 and 200 are provided with an attraction magnet unit 130, a repulsion magnet unit 140, and a lateral displacement prevention magnet unit 150.

  The attraction magnet unit 130 applies an attractive force between the first unit holding body 100 and the second unit holding body 200, and generates a rotational force from the first unit holding body 100 to the second unit holding body 200 without contact. It is for transmission. In the second embodiment, four permanent magnets (hereinafter referred to as “attraction magnets 131N and 131S”) having the same substantially fan shape are disposed at the center of the end surface of the base 101 in the first unit holder 100. In addition, four permanent magnets (hereinafter referred to as “suction magnets 131N and 131S”) having the same substantially fan shape are disposed at the center of the inner end surface of the base 201 in the second unit holding body 200 for suction. A magnet unit 130 is configured. Each of the attracting magnets 131N and 131S has an exposed entire end face as an N pole or an S pole, adjacent ones are different from each other, and the outer shape of a combination of the four is a circle having a center hole. In a mode of presenting a plate shape, the unit holders 100 and 200 are alternately arranged in the circumferential direction around the axis. The attraction magnet unit 130 configured on the first unit holding body 100 and the attraction magnet unit 130 configured on the second unit holding body 200 are configured to have the same shape.

  The repulsion magnet unit 140 applies a repulsive force between the first unit holding body 100 and the second unit holding body 200, and maintains the second unit holding body 200 in a state of floating from the first unit holding body 100. Is for. In the second embodiment, three permanent magnets (hereinafter referred to as “repulsive use”) having a ring shape with different outer diameters are formed on the flange portion 102 of the first unit holding body 100 and the flange portion 202 of the second unit holding body 200, respectively. Magnets 141N, 141S, and 141N ”are provided to form a repulsion magnet unit 140. The repulsion magnets 141N, 141S, and 141N each have an entire circumference of the exposed end surface being an N-pole or an S-pole, and the adjacent ones are different from each other, and are centered on the axis of the unit holder 100 or 200. Are arranged in parallel on the same concentric line. The repulsion magnet unit 140 configured in the first unit holder 100 and the repulsion magnet unit 140 configured in the second unit holder 200 are configured to have the same shape and the same magnetic pole. .

  Also in the magnetic coupling of the second embodiment, as in the first embodiment, the mutual distance D ′ along the axis between the first unit holding body 100 and the second unit holding body 200 is a preset threshold value. Is set so that the repulsive force of the repulsive magnet unit 140 exceeds the attractive force of the attractive magnet unit 130, and when the above-mentioned mutual distance D ′ increases beyond the threshold value, the attractive magnet unit Each magnetic force is set so that the attractive force 130 exceeds the repulsive force of the repulsive magnet unit 140.

  The lateral slip prevention magnet unit 150 balances the magnetic force acting between each other when the axis of the output shaft 1 ′ and the axis of the driven shaft 2 ′ coincide with each other, for example, the repulsive force, and outputs the balance. When the axis of the shaft 1 ′ and the axis of the driven shaft 2 ′ are shifted from each other, the repulsive force is unbalanced, so that the axis of the output shaft 1 ′ and the axis of the driven shaft 2 ′ are always Are maintained in a state in which they match each other. In the second embodiment, permanent magnets (hereinafter referred to as “aperture magnets”) that form ring-like portions at the mutually opposing portions of the outer peripheral surface of the base 101 in the first unit holder 100 and the inner peripheral surface of the base 201 in the second unit holder 200. By providing the prevention magnets 151N and 151N ”, the lateral slip prevention magnet unit 150 is configured. The prevention magnet 151 </ b> N provided on the base 101 of the first unit holder 100 has an entire outer peripheral surface that is exposed, for example, as an N pole, and is disposed at the upper end of the base 101. The prevention magnet 151N provided on the base 201 of the second unit holding body 200 is such that the entire inner peripheral surface exposed is the same N pole as the prevention magnet 151N of the first unit holding body 100. Arranged at the lower end.

  In the unit holders 100 and 200 including the magnet unit for attraction 130 and the magnet unit for repulsion 140 as described above, the rebound magnets 141N, Since 141S and 141N are opposed to each other with the same polarity, a repulsive force acts between each other, and the second unit holding body 200 is maintained in a state of being levitated from the first unit holding body 100. On the other hand, in the magnet unit 130 for attraction | suction, when the unit holding bodies 100 and 200 rotate relatively appropriately, opposite poles will be made to oppose and it will stop in the state which the attraction force acted between each other. If an electric motor (not shown) is driven from this state, the rotation of the first unit holding body 100 is transmitted to the second unit holding body 200 in a non-contact manner by the attractive force acting between the suction magnet units 130. As a result, the driven shaft 2 'rotates in the same direction as the output shaft 1'.

  In this state, if a force is applied to the driven shaft 2 'so that the axis of the driven shaft 2' is displaced in the horizontal direction from the axis of the output shaft 1 ', the prevention magnets 151N and 151N The repulsive force acting on is unbalanced. In the lateral slip prevention magnet unit 150 in which the repulsive force is unbalanced, a force is applied so that the repulsive force is balanced over the entire circumference, and the axial center position of the driven shaft 2 ′ is aligned with the axial center of the output shaft 1 ′. Modified to match. Therefore, according to the magnetic coupling described above, the axis of the output shaft 1 'and the axis of the driven shaft 2' are always automatically adjusted to coincide with each other. Moreover, as described in the first embodiment, the opposing areas of the attraction magnets 131N and 131S disposed on the first unit holder 100 and the attraction magnets 131N and 131S disposed on the second unit holder 200 are as follows. Since the force resulting from the unbalance also acts at the same time, it is possible to more reliably prevent a situation where the axis of the driven shaft 2 'is deviated from the output shaft 1'.

  On the other hand, when a force is applied to the second unit holding body 200 so that the mutual distance D ′ along the axis between the first unit holding body 100 and the first unit holding body 100 increases, the repulsive force of the repulsion magnet unit 140 is increased. In addition, the attractive force of the attractive magnet unit 130 is reduced. However, since the reduction rate of the repulsive force is larger than the reduction rate of the suction force, a suction force acts between the first unit holding body 100 and the second unit holding body 200, and the mutual distance D ′ is Will be reduced. Accordingly, the distance D ′ between the two unit holders 100 and 200 stops again at a position where the repulsive force of the repulsive magnet unit 140 and the attractive force of the attracting magnet unit 130 are balanced, and the first unit holder 100. In contrast, the second unit holding body 200 is maintained in a floating state. As a result, it is possible to continuously apply a suction force between the driven shaft 2 ′ and the output shaft 1 ′ of an electric motor (not shown) to transmit power without contact.

  Although not clearly shown in the figure, also in the second embodiment, the driven shaft 2 ′ is disposed in the stirring tank 70 ′ together with the liquid to be stirred, and the second unit holding body 200 is provided at the lower end thereof. On the other hand, if an electric motor is installed outside the stirring tank 70 'and the first unit holding body 100 is provided at the upper end of the output shaft 1', a stirring device can be configured. However, when the second embodiment is applied, it is necessary to form the bottom wall of the stirring tank 70 ′ in a concavo-convex shape along the shape of the unit holders 100 and 200 as shown in FIG.

  In the second embodiment described above, the suction magnet unit 130 is exemplified by a configuration in which four suction magnets 131N and 131S having a substantially fan shape are disposed. The configuration of the permanent magnets constituting 130 is not limited to these. Permanent magnets having other shapes may be applied, and the number of poles is not limited to four. Similarly, the repulsion magnet unit 140 is exemplified by a configuration in which three repulsion magnets 141N, 141S and 141N having different ring shapes are arranged, but other shapes are formed. A permanent magnet may be applied, and the number of poles is not limited to three. Furthermore, the laterally-preventing magnet unit 150 is provided at a portion where the outer peripheral surface of the first unit holder 100 and the inner peripheral surface of the second unit holder 200 face each other. If it is a site | part which opposes, you may make it provide between end surfaces. In this case, the lateral slip prevention magnet unit need not be provided between the attraction magnet unit and the repulsion magnet unit, and may be provided, for example, on the outermost peripheral portion of the unit holder.

  In the second embodiment described above, the two prevention magnets 151N and 151N having the same axial length are illustrated as the lateral deviation prevention magnet unit 150, but the two prevention magnets are in the axial direction. Different lengths may be used. In this case, when the second unit holding body 200 is kept floating from the first unit holding body 100 by the repulsive force acting between the repulsion magnets 141N, 141S, 141N, the axial length is prevented from being small. It is preferable to set so that the working magnet 151N is positioned at the center in the height direction with respect to the preventing magnet 151N having a large axial length.

  Further, in the second embodiment described above, an example in which the driven shaft 2 ′ is rotated in a non-contact manner by driving the electric motor is illustrated, but the driven shaft 2 ′ is not necessarily a shaft member.

1, 1 'Output shaft 2, 2' Driven shaft 2a Agitation blade 10, 20 Unit holder 30 Suction magnet unit 31N, 31S Suction magnet 40 Repulsion magnet unit 41N, 41S, 41N Repulsion magnet 60 Electric motor 70 , 70 'Agitation tank 100, 200 Unit holder 130 Suction magnet unit 131N, 131S Suction magnet 140 Repulsion magnet unit 141N, 141S, 141N Repulsion magnet 150 Prevention magnet unit 151N Prevention magnet

Claims (4)

A repulsion magnet unit and a suction magnet unit are disposed between a rotating body having an axial center disposed in a vertical direction and a rotated body disposed on an extension of the rotating body. The rotating body is maintained in a floating state with respect to the rotating body by the repulsive force of the magnet unit, and is not contacted between the rotating body and the rotating body by the attraction force of the attracting magnet unit. In a magnetic coupling designed to transmit rotational force,
The repulsion magnet unit and the attraction magnet unit are each configured by a combination of permanent magnets,
The repulsion force of the repulsion magnet unit exceeds the attraction force of the attraction magnet unit when the mutual distance along the axis between the rotating body and the rotated body is smaller than a preset threshold value, And each magnetic force is set so that the attraction force of the attraction magnet unit exceeds the repulsion force of the repulsion magnet unit when the mutual distance increases beyond the threshold value. . The attraction magnet unit is disposed at the center of the rotating body, and the repulsion magnet unit is disposed at an outer periphery of the attraction magnet unit;
The attraction magnet unit is configured by alternately arranging a plurality of magnets in the circumferential direction so that adjacent ones have different polarities, and the repulsion magnet unit has a plurality of ring shapes having different outer diameters. 2. The magnetic coupling according to claim 1, wherein the magnets are concentrically arranged so that adjacent magnets have different polarities.   When the axis of the rotating body and the axis of the rotated body match between the rotating body and the rotated body, the magnetic force acting between them is balanced, and the axis of the rotating body is The magnetic coupling according to claim 1, wherein a magnet unit for preventing lateral displacement is provided in which the magnetic force is unbalanced when the axis of the rotating body and the axis of the rotated body are displaced from each other.   In the magnetic coupling according to any one of claims 1 to 3, while the stirring member is provided with a stirring blade and the rotating member is disposed inside a stirring tank for stirring the liquid, A stirrer characterized in that a drive unit for driving the rotating body is disposed outside the stirring tank, and the rotated body and the rotating body are opposed to each other.

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