JP2012031915A - Torque transmission device - Google Patents

Abstract

A rotational force transmission device that transmits rotational force from a driving side shaft to a driven side shaft and having a configuration different from a conventional configuration is provided.
A permanent magnet is attached to each of a first shaft (driving shaft) side to which a rotational force is applied and a second shaft (driven shaft) side to which the rotational force is transmitted. , A rotational force transmission device for transmitting rotational force between the first and second shafts by a magnetic circuit formed between the two permanent magnets, the N pole of the permanent magnet 141a on the drive shaft side and the The S pole of the permanent magnet 143a on the driven shaft side faces, and the S pole of the permanent magnet 141a on the drive shaft side faces the N pole of the permanent magnet 143a on the driven shaft side. The configuration.
[Selection] Figure 6

Description

  The present invention relates to a rotational force transmission device, and more particularly to a rotational force transmission device that transmits rotational force without contact between magnets by magnetic coupling between permanent magnets.

  The non-contact power transmission technology using magnet magnetic force has been actively introduced to rotational drive parts of industrial equipment that does not require relatively high torque, such as agitators for foodstuffs, wheel conveyors in clean rooms, and the like. Non-contact technology that does not require lubrication such as grease and does not generate dust due to wear is most suitable for the semiconductor and sanitary industries.

  However, non-contact torque using magnetic attraction, repulsive force, etc. is generally inferior to the torque of a transmission mechanism having contact of the same diameter. Further, when a large magnet with high magnetic force for obtaining a high non-contact torque is employed, the mechanism is inevitably increased in size, and there is a concern that the magnetism of the power transmission unit may adversely affect other mechanical electronic devices.

  As an example of a non-contact power transmission technique using magnetic force, a spindle drive device is disclosed in Patent Document 1 in which a drive shaft and a spindle are magnetically coupled in a non-contact state to transmit rotation on the drive shaft side to the spindle. Yes.

  Japanese Patent Application Laid-Open No. 2004-228688 discloses a technique for shifting the driven side shaft in the radial direction in a device that transmits the torque on the driving shaft side to the driven shaft side in a non-contact manner by magnetic force.

Japanese Patent Application Laid-Open No. 6-1553489

JP 2001-165189 A

  In paragraph 0016 and FIG. 2 of Patent Document 1, there is a description that the N-pole and the S-pole are alternately provided to improve the followability in the radial direction. However, as far as FIG. 3 of Patent Document 1 is referred to, the state of the magnetic poles of the opposing permanent magnets is as shown in FIG. 13, and the N pole of the driving side magnet 901 shown in FIG. There is a problem that the magnetic force from the back surface of each of the S poles of the side magnet 902, that is, the S pole of the drive side magnet 901 and the N pole of the driven side magnet 902, is not sufficiently utilized for transmitting the rotational force. is there. This point is understood to be the same for the technique described in Patent Document 2.

  The present invention has been made in view of the above points. Unlike the example shown in FIG. 13, it is possible to effectively utilize the magnetic force of the magnet and efficiently transmit the rotational force. It aims at providing a torque transmission device.

  In order to solve the above problems, a rotational force transmission device according to the present invention includes a first drive shaft side to which a rotational force is applied and a second driven shaft side to which the rotational force is transmitted. And a rotational force transmitting device for transmitting rotational force between the first and second shafts by means of a magnetic circuit formed between the two magnets, the side of the first shaft being The N pole of the magnet on the second axis and the S pole of the magnet on the second axis side face each other, and the S pole of the magnet on the first axis side and the N pole of the magnet on the second axis side are It is characterized by being arranged to face each other.

  With the configuration of the present invention, it is possible to effectively utilize the magnetic force of the magnet and efficiently transmit the rotational force.

  A plurality of magnets may be attached to the first shaft side and the second shaft side, respectively, and arranged so as to face each other.

  The first shaft side and the second shaft side may be configured such that the distances from the axial centers of the plurality of magnets are substantially equal.

  Both the plurality of magnets on the first axis side and the plurality of magnets on the second axis side are arranged so that the direction from the S magnet to the N pole is the same in the circumferential direction. It can be configured. By adopting such an arrangement, it is considered that repulsive force described later is generated and the transmittable torque is increased. However, the point where the transmittable torque is increased may be due to factors different from the repulsive force.

  If the magnetic attraction generating surface between the magnet on the first shaft side and the magnet on the second shaft side has an arc shape, torque can be transmitted effectively, and the mutual magnet It is possible to increase the area.

  At least one of the magnet on the first shaft side and the magnet on the second shaft side may be configured to be detachable. Specifically, a configuration in which a magnet holder is provided to make the holder detachable can be considered, but the configuration is not limited to the configuration in which the holder is provided. By doing so, it is easy to adjust the transmittable torque.

  A gap is arranged between the first shaft side magnet and the second shaft side magnet so that when the transmittable torque is exceeded, an idle rotation occurs between the two shafts. If it is used as a torque limiter, it becomes a preferable configuration when idling with overtorque.

  The number of the plurality of magnets may be four or more on both the first axis side and the second axis side. In the following embodiment, the case of 6 pairs and 12 pairs will be described. However, if the number of pairs is 4 or more, it is easy to make the circumferences substantially equal on the circumference, and the magnets can be used when the distances are substantially equal. It is expected that the repulsive force described later may be generated by adjusting the size and the like.

  The magnet may be a permanent magnet made of neodymium (Nd), iron (Fe), boron (B), and Dy (dysprosium), and may have a residual magnetic flux density Br = 1300 mT or more. By using a neodymium magnet, it is possible to reduce the size and weight of the magnet while maintaining a large transmittable torque.

  The repulsive force is exerted between the magnet attached to the first shaft and the magnet disposed adjacently between any of the magnets attached to the second shaft, so that the driving side and the target It is considered that the magnetic force lines X between the driving sides are concentrated between both the driving side and driven side magnets, and the transmittable torque is increased. However, the reason why the transmittable torque is large may be different from the repulsive force.

  According to the rotational force transmission device according to the present invention, in the rotational force transmission device that transmits the rotational force in a non-contact manner between the driving side magnet and the driven side magnet by the magnetic force, more effective use of the magnetic force of the magnet is achieved. There is an effect that it is possible to plan.

It is a perspective view for demonstrating the whole structure of the rotational force transmission apparatus of the 1st Embodiment of this invention. It is a side view of the rotational force transmission apparatus 100 in 1st Embodiment. It is the top view which looked at the rotational force transmission apparatus 100 in 1st Embodiment from the drive side axis | shaft 110 side. It is a figure showing the cross section (end surface) of the rotational force transmission apparatus 100 in 1st this Embodiment, and is a figure for demonstrating in detail the mode of the rotational force transmission mechanism 120. FIG. It is a schematic diagram for demonstrating permanent magnet arrangement | positioning in 1st Embodiment. It is a schematic diagram for demonstrating the size of a permanent magnet pair in 1st Embodiment, a positional relationship, etc. FIG. It is a perspective view of the rotational force transmission apparatus 200 of the 2nd Embodiment of this invention. It is a side view of the rotational force transmission apparatus 200 in 2nd Embodiment. It is the top view which looked at the rotational force transmission apparatus 200 in 2nd Embodiment from the drive side axis | shaft 210 side. It is a figure which shows the cross section (end surface) containing the axial direction center of the drive side axis | shaft 210 and the driven side axis | shaft 230 in the rotational force transmission apparatus 200 in 2nd Embodiment. It is a schematic diagram for demonstrating in detail about the size, a shape, a positional relationship, etc. taking one of the permanent magnet pairs (for example, 214a and 227a) in 2nd Embodiment as an example. It is a schematic diagram for demonstrating the magnetic force line of the permanent magnet pair in 1st Embodiment and 2nd Embodiment. It is a figure which shows the mode of the magnetic pole of the permanent magnet which opposes in background art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a perspective view for explaining the overall configuration of the rotational force transmission device 100 according to the first embodiment of the present invention. FIG. 2 is a side view of the rotational force transmission device 100 in the present embodiment, and FIG. 3 is a plan view of the rotational force transmission device 100 as viewed from the drive side shaft 110 side. The rotational force transmission device 100 includes a rotational force transmission mechanism 120 that transmits the rotational force of the driving side shaft 110 to the driven side shaft 130.

  The rotational force transmission mechanism 120 includes a drive-side transmission plate 121 fixed by a drive-side shaft 110 and a screw 111, a drive-shaft side magnet mounting portion 122 fixed to the drive-side transmission plate 121, and in the present embodiment, substantially on the circumference. And a driven shaft side transmission portion 123 to which six magnet holders 142a to 142f provided at equal intervals are attached.

  Six permanent magnets 141a to 141f are mounted on the drive shaft side magnet mounting portion 122 at substantially equal intervals on the circumference. On the other hand, permanent magnets 143a to 143f are fitted to the magnet holders 142a to 142f so as to face the permanent magnets 141a to 141f on the drive shaft side. The shapes and the like of the drive-side magnets 141a to 141f and the driven-side magnets 143a to 143f will be described in detail later. The magnets 141a to 141f on the drive shaft 110 side and the driven side magnets fitted to the magnet holders 142a to 142f face each other, and the magnets are not in contact with each other, and a magnetic circuit generated between the magnets Thus, the rotational force applied to the driving side shaft 110 is transmitted to the driven side shaft 130.

  FIG. 4 is a diagram illustrating a cross section of the rotational force transmission device 100 according to the present embodiment. Specifically, FIG. 4 is a diagram illustrating a state in which an end surface of the AA line cross section in FIG. FIG. 4 shows the rings 112 and 132 with bearings not shown in FIGS. A ring 112 is inserted into the drive shaft 110, and a plurality of bearings 1121 are arranged in the ring 112. A ring 132 is inserted into the driven side shaft 130, and a plurality of bearings 1321 are arranged in the ring 132. In this way, by inserting the rings with bearings on both sides on the driving side and the driven side, both the driving side shaft 110 and the driven side shaft 130 can rotate with both rings fixed. It is configured. However, the rings 112 and 132 are not necessarily provided. Since FIG. 4 is a diagram showing an outline of the end face, details of the magnets 141b, 141c, etc. existing on the back side of FIG. 4 are omitted.

  In the present embodiment, the bearings 1121 and 1321 and the screws 111 and 131 are formed of stainless steel (SUS304), and other parts are made of aluminum (for example, to reduce weight and reduce the influence on the magnet). Although high-strength aluminum alloy A7075) is used, it is needless to say that the material is not limited to these.

  As shown in FIG. 4, in the present embodiment, bearings 151, 152, etc. are inserted between the driving side shaft 110 and the driven side shaft 130 (inside the rotational force transmission mechanism 120). As shown in the drawing, the permanent magnet 141a engaged through the aluminum tube 1411a, for example, and the permanent magnet 141d engaged through the aluminum tube 1411d are attached to the drive shaft side magnet mounting portion 122 side by the magnet holders 142a and 142d. The magnet 141a and the magnet 143a, the magnet 141d and the magnet 143d, etc. are not in contact with each other by a magnetic circuit generated between the magnets 143a and 143d (other driven shaft side magnets are not shown). Thus, the rotational force applied to the driving side shaft 110 is transmitted to the driven side shaft 130. If the drive-side magnets 141a to 141f are also detachably attached to the holder, the limit transmission torque can be easily adjusted by changing the number of magnet pairs. The bearings 151 and 152 smoothly move when a load exceeding the torque that can be transmitted by the magnetic force between the magnets 141a to 141f on the driving side shaft 110 side and the magnets 143a to 143f on the driven side shaft 130 side is applied. It plays the role of rotating the driving side shaft 110 and the driven side shaft 130.

  FIG. 5 is a schematic diagram for explaining the arrangement of permanent magnets in the present embodiment, and FIG. 6 is a schematic diagram for explaining the size, positional relationship, etc. of the permanent magnet pair in the present embodiment.

  As shown in FIG. 5, the permanent magnets 143a to 143f inserted into the magnet holder (for example, the magnet holder 142a shown in FIG. 4) on the driven shaft side transmission portion 123 (not shown in FIG. 5) are A plate-shaped magnet having a radius of curvature (R), which will be described later. On the other hand, the permanent magnets 141a to 141f on the drive shaft 110 side are engaged with the drive shaft side magnet mounting portion 122 through the engagement holes 1412a to 1412f, for example, via the aluminum pipe (see FIG. 4) as described above. . The magnets 141a to 141f and the magnets 143a to 143f are arranged to face each other so as to be substantially equidistant on the circumference. FIG. 6 is a front view for explaining in more detail the size, shape, positional relationship, etc. of one of the permanent magnet pairs of the present embodiment (for example, 141a and 143a) (FIG. 6A). ) And a side view (FIG. 6B).

In the present embodiment, each of the permanent magnets 141a and 143a is a magnet made of Nd (neodymium), Fe (iron), B (boron), and Dy (dysprosium), and its chemical component (wt%). Used Nd27-30%, Fe60-70%, B1-2%, Dy2-8% magnets. The residual magnetic flux density Br = 1320 to 1380 mT, the combined volume of both the magnet 141a and the magnet 143a is 4522 mm ³ , and the distance between the magnet 141 a and the magnet 143 a is 4 mm over the entire area of the effective area 433 mm ² in the present embodiment. is there. The radius of curvature R of the outer peripheral surface of the magnet 143a is 26 (see FIG. 6B), and the radius of curvature R of the inner peripheral surface of the magnet 143a is 23 (see FIG. 6B). On the other hand, in the magnet 141a, the radius of curvature R = 19 (see FIG. 6B) on the side facing the magnet 143a is set, and the distance between both magnets is made constant at 4 mm over the entire effective area of both magnets. By placing a predetermined distance (for example, 4 mm) between the two magnets, the torque limiter operates smoothly when the transmittable torque is exceeded. Although the same applies to the second embodiment, it is possible to effectively transmit torque and increase the area of the mutual magnets by making the magnetic attractive force generation surface arc-shaped. By using a neodymium magnet having a residual magnetic flux density of Br = 1300 mT or more, the magnet can be made small and light while maintaining a large transmittable torque.

  Further, as shown in FIG. 6A, the polarity of the permanent magnet pair in the present embodiment is such that the north pole of the magnet 143a on the holder side faces the south pole of the magnet 141a on the drive shaft side. The S pole of 143a is configured to face the N pole of the magnet 141a. This is a feature of the present invention, and the arrangement of the magnetic poles makes it possible to effectively use the magnetic forces from the N and S poles of both magnets.

  As shown in FIG. 6 (b), the magnet 141a has an insertion hole 1411a through which the aluminum tube is inserted, and a magnet in a direction perpendicular to the insertion hole 1411a, the lower portion of the insertion hole 1411a. The width of 141a is 17 mm. As shown in FIG. 6A, the width of the magnet 141a in the direction parallel to the insertion direction of the insertion hole 1411a (not shown in FIG. 6A) is 12 mm, and the magnet 143a facing the magnet 141a has a width of 12 mm. The width was 18 mm. When six permanent magnet pairs having a specific configuration described in detail above were provided as shown in FIG. 1 and the like, the transmittable torque was 4.5 Nm.

  Incidentally, the transmittable torque was measured by attaching servo motors (drive shaft side motor and driven shaft side motor) to both the drive shaft and the driven shaft. The rotation speed and torque of the servo motor were controlled by a servo amplifier, and a torque that can be transmitted from the servo amplifier using data directly recorded on the PC via the RS232C was determined.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. FIG. 7 is a perspective view of the rotational force transmission device 200 of the present embodiment, FIG. 8 is a view seen from the side, and FIG. 9 is a plan view seen from the drive shaft 210 side.

  In the rotational force transmission device 200 of the present embodiment, there are 12 pairs of permanent magnets, and the shape of the permanent magnets has been devised. As a result, even when compared with the torque transmission device 100 of the first embodiment, it is possible to transmit a larger torque (for example, about 20 Nm, which is a torque required for moving a 250 cc class motorcycle). It has become possible.

  The general configuration is substantially the same as that of the first embodiment, and a rotational force transmission unit 220 is provided between the driving side shaft 210 and the driven side shaft 230. As shown in the perspective view of FIG. 7 and the plan view of FIG. 9, the screws (12 pieces of 224a to 224l) for attaching the permanent magnets and the nuts (12 pieces of 225a to 225l) are substantially equidistant on the circumference. 12 permanent magnet pairs are arranged in a portion such as 222a shown in FIG.

  FIG. 10 is a schematic diagram showing a cross section including the center in the axial direction of the driving side shaft 210 and the driven side shaft 230 in the rotational force transmission device 200. More specifically, FIG. 10 is a diagram showing an end surface of the cross section taken along line BB in FIG. Since it is an end surface, illustration is abbreviate | omitted about the back | inner side rather than the BB line in FIG.

  A driving side transmission plate 221 is disposed on the driving side shaft 210, and a driven side transmission plate 223 is disposed on the driven side shaft 230, and a rotational force transmission unit 220 is provided therebetween. In the present embodiment, the drive side transmission plate 221 and the driven side transmission plate 223 have a diameter of 120 mm, but it is obvious that the diameter is not limited to this. Permanent magnet pairs (in this embodiment, 12 pairs at approximately equal intervals on the circumference) are arranged in the rotational force transmission unit 220 in such a manner that the magnets are not in contact with each other. In the present embodiment, the magnet holder for fitting the driven side shaft magnet is sandwiched between bolts 224a to 224l and nuts 225a to 225l.

  As described above, permanent magnets (for example, 227d and 227j in FIG. 10) to be inserted into a magnet holder (for example, 226d and 226j in FIG. 10), and a magnet mounting member (see FIG. 10) directly connected to the drive side shaft 210. 10 (213d, 213j in FIG. 10) and permanent magnets (for example, 214d, 214j in FIG. 10) mounted on the drive shaft side are arranged to face each other. The same applies to other magnets not shown in FIG. FIG. 11 is a front view for explaining in more detail the size, shape, positional relationship, etc. of one of the permanent magnet pairs of this embodiment (for example, 214a and 227a) as an example (FIG. 11 (a)). ) And a side view (FIG. 11B).

As in the first embodiment, the permanent magnets 214a and 227a are all neodymium magnets made of Nd, Fe, B, and Dy, and the residual magnetic flux density Br = 1320 to 1380 mT, both the magnet 214a and the magnet 227a ( one pair) the combined volume of the can 4372Mm ^3, the distance between the magnet 214a and the magnet 227a is 2mm over the entire effective area 576mm ^2. That is, the radius of curvature R = 15 in the vertical direction of the outer periphery of the magnet 227a (see FIG. 11B), the radius of curvature R in the vertical direction of the outer periphery of the magnet 214a is set to 10 (see FIG. 11B), and the thickness of the magnet 227a is set. It was 3 mm.

  Further, as shown in FIG. 11A, the polarity of the permanent magnet pair in the present embodiment is such that the north pole of the magnet 227a on the holder side faces the south pole of the magnet 214a on the drive side shaft 210 side. The south pole of the magnet 227a on the side faces the north pole of the magnet 214a on the drive side shaft 210 side. With such an arrangement of magnetic poles, the magnetic forces from the N and S poles of both magnets are effectively utilized, as in the first embodiment. Incidentally, in the case of one specific configuration (12 permanent magnet pairs) described in detail above, the transmittable torque was measured as 22.0 Nm.

  In the second embodiment, compared to the first embodiment, the reason that about five times the torque can be transmitted is that the number of permanent magnet pairs is doubled, and the magnet shape is devised. In addition to increasing the effective area and shortening the distance between the magnets to 2 mm, the following reasons were considered.

  FIG. 12 is a schematic diagram showing the magnetic poles of the second embodiment. As described above, the drive shaft side N pole and the driven side S pole, and the drive shaft side S pole and the driven side N pole face each other (see FIG. 12A). . Here, as in the second embodiment, when the distance to the adjacent permanent magnet pair approaches (as shown in FIG. 9, the angle between the adjacent magnet pair is 30 °, and FIG. As shown in (a), the width of the magnet in the circumferential direction is 10 mm, the diameter of the driving side and driven side discs is 120 mm, between the N pole on the driven side and the N pole on the adjacent driving side. It is considered that the repulsive force works and the magnetic force lines X between the driving side and the driven side are concentrated between the magnets on the driving side and the driven side (see FIG. 12B).

  This repulsive force prevents the magnetic flux between the N pole on the driven side and the S pole on the driving side from spreading outside the effective area range, and the magnetic flux density within the effective area range increases, thereby It is thought that it works in the direction of increasing the possible torque. This is also the case with the six magnet pairs as illustrated in the first embodiment. For example, a change in the state of the magnetic flux is detected also by three-dimensional electrostatic field analysis using the finite element method. I was able to.

  As described above, it has become clear that a large torque of, for example, more than 20 Nm can be transmitted by the torque transmission device of the present embodiment. As described above, the particularly characteristic point is the arrangement of the magnetic poles on the driving side and the driven side, and the magnet size, shape, distance between the magnets, and the like are the examples described in the above embodiment. Besides, it is possible to design appropriately.

  The present invention can be applied to, for example, a rotational force transmission device that transmits rotational force from a driving side shaft to a driven side shaft.

100, 200 Rotational force transmission device 110, 210 Drive side shaft 120, 220 Rotational force transmission unit 130, 230 Driven side shaft 141a-141f Permanent magnet 142a-142f Magnet holder 143a-143f Permanent magnet 214d, 214j Permanent magnet 226d, 226j Magnet holder 227d, 227j Permanent magnet

Claims (10)

Magnets are attached to each of the first drive shaft side to which the rotational force is applied and the second driven shaft side to which the rotational force is transmitted, and by a magnetic circuit formed between the two magnets, A rotational force transmission device for transmitting rotational force between the first and second shafts,
The north pole of the magnet on the first shaft side and the south pole of the magnet on the second shaft side face each other, and the south pole of the magnet on the first shaft side and the second shaft side. It is arranged so that the north pole of the magnet may be opposed. The torque transmission device according to claim 1, wherein a plurality of magnets are attached to the first shaft side and the second shaft side, respectively, and are arranged so as to face each other. The rotational force transmission device according to claim 2, wherein the first shaft side and the second shaft side have substantially the same distance from the shaft center of the plurality of magnets. Both the plurality of magnets on the first axis side and the plurality of magnets on the second axis side are arranged so that the direction from the S magnet to the N pole is the same in the circumferential direction. The rotational force transmission device according to claim 2 or 3, wherein 5. The magnetic attraction generating surface between the magnet on the first shaft side and the magnet on the second shaft side has an arc shape. 6. Rotational force transmission device. The torque transmission device according to any one of claims 2 to 5, wherein at least one of the magnet on the first shaft side and the magnet on the second shaft side is configured to be detachable. . A gap is arranged between the first shaft side magnet and the second shaft side magnet so that when the transmittable torque is exceeded, an idle rotation occurs between the two shafts. The rotational force transmission device according to any one of claims 2 to 6, wherein The rotational force transmission according to any one of claims 2 to 7, wherein the number of the plurality of magnets is four or more on both the first shaft side and the second shaft side. apparatus. The magnet is a permanent magnet made of neodymium (Nd), iron (Fe), boron (B), and Dy (dysprosium), and has a residual magnetic flux density Br = 1300 mT or more. The rotational force transmission device according to claim 8. A repulsive force acts between a magnet attached to the first shaft and a magnet disposed adjacently between any of the magnets attached to the second shaft. The rotational force transmission device according to any one of 2 to 9.

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