JP5318798B2 - Pulley structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley structure promptly damping the rotational fluctuation caused in a rotor without using a rubber elastic body. <P>SOLUTION: A plurality of first magnets 17 provided on a pulley 2 are configured so that a condition in which magnetic pole faces of homopolarity of two first magnets 17 adjoining in the circumferential direction are opposed across a magnetic body 25 sandwiched by homopolar magnetic faces and a condition in which magnetic pole faces of heteropolarity are opposed across a magnetic body 26 sandwiched by heteropolar magnetic faces, appear alternately in the circumferential direction. A plurality of second magnets 18 provided on a hub 3 are configured so that different magnetic poles appear alternately in the circumferential direction in magnetic pole faces opposed to the first magnets 17 or the magnetic bodies 25, 26. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a pulley structure having two rotating bodies capable of relative rotation.

  Conventionally, as a pulley structure having two rotating bodies connected so as to be relatively rotatable, when a rotational fluctuation occurs in one of the two rotating bodies, a structure having a configuration for attenuating the rotational fluctuation is provided. Are known.

  For example, a pulley structure described in Patent Document 1 includes a pulley around which a belt is wound, and a hub that is provided inside the pulley so as to be relatively rotatable with respect to the pulley and is connected to an output shaft of an engine. And a rubber elastic body (rubber coupling) for connecting the pulley and the hub. When the rotation fluctuation occurs in the hub in accordance with the engine torque fluctuation, the rubber elastic body between the hub and the pulley is elastically deformed to absorb the rotation fluctuation.

  Moreover, the pulley structure described in Patent Document 2 includes a damper main body assembled to the crankshaft and a damper mass provided inside the damper main body. A plurality of permanent magnets arranged in the circumferential direction are fixed to the damper mass, while a copper plate facing the plurality of permanent magnets of the damper mass is fixed to the damper main body. When a rotational speed difference is generated between the damper main body and the damper mass due to the torsional vibration generated in the crankshaft, an eddy current is generated in the copper plate due to the speed difference between the permanent magnet and the copper plate. At this time, a force that reduces the speed difference between the two rotating bodies (damper main body and damper mass) acts between the two rotating bodies (damper main body and damper mass) due to the eddy current generated in the copper plate, and the rotational fluctuation of the damper main body is suppressed.

Japanese Utility Model Publication No. 63-68540 JP 2002-286094 A

  However, when two rotating bodies are connected by a rubber elastic body as in the pulley structure of Patent Document 1, a failure due to aged deterioration or fatigue failure of the rubber elastic body occurs. In addition, when an excessive rotation fluctuation occurs in one of the rotating bodies, an excessive force exceeding the elastic deformation range acts on the rubber elastic body, and the rubber elastic body may be damaged. Furthermore, the pronunciation of the rubber elastic body during elastic deformation may be a problem.

  On the other hand, as in the pulley structure of Patent Document 2, an eddy current generated in the copper plate due to the speed difference between the permanent magnet and the copper plate suppresses the two rotors to reduce the speed difference between them. In the configuration in which the above is applied, since it is not necessary to use a rubber elastic body, the above-described problem does not occur. However, the restraining force that can be applied to the two rotating bodies by the eddy current is quite small, and when the rotational fluctuation generated in one rotating body is large, it is difficult to quickly attenuate the rotational fluctuation. is there.

  An object of the present invention is to provide a pulley structure that can quickly attenuate a rotational fluctuation generated in a rotating body without using a rubber elastic body.

Means for Solving the Problems and Effects of the Invention

A pulley structure according to a first aspect of the present invention includes a first rotating body, a second rotating body that can rotate relative to the first rotating body, a plurality of first magnets provided on the first rotating body, A plurality of second magnets provided on the second rotating body so as to face the plurality of first magnets;
The plurality of first magnets are arranged with the magnetic body sandwiched in the circumferential direction of the rotating body, and the magnetic pole surfaces of the two first magnets adjacent in the circumferential direction are opposed to each other via the magnetic body. The plurality of first magnets are in a state in which the magnetic pole surfaces of the same polarity of two first magnets adjacent to each other in the circumferential direction face each other with the magnetic material in between and a state in which the magnetic pole surfaces of different polarity face each other with the magnetic material in between Are configured to appear alternately in the circumferential direction,
The plurality of second magnets are arranged in the circumferential direction of the rotating body, and their magnetic pole surfaces are opposed to the first magnet or the magnetic body, and further, the plurality of second magnets are those magnetic pole surfaces. In FIG. 1, the magnetic poles are configured so that different magnetic poles appear alternately in the circumferential direction.

  According to the present invention, the plurality of first magnets provided in the first rotating body are arranged in the circumferential direction, and their magnetic pole surfaces are opposed in the circumferential direction with the magnetic body interposed therebetween. In addition, the plurality of first magnets are in a state in which the magnetic pole surfaces of the same polarity of two first magnets adjacent in the circumferential direction face each other with the magnetic material therebetween, and the magnetic pole surfaces of different polarities face each other with the magnetic material sandwiched therebetween. The state to perform appears alternately in the circumferential direction. A magnetic body sandwiched between magnetic pole surfaces of different polarities (hereinafter referred to as magnetic bodies between different polarities) passes a magnetic flux in the circumferential direction, whereas a magnetic body sandwiched between magnetic pole surfaces of the same polarities (hereinafter referred to as magnetic bodies) In this case, the magnetic flux from the two first magnets on both sides flows out to the outside (or the magnetic flux flowing from the outside flows to the two first magnets). For this reason, a magnetic flux flows between the interpolar magnetic body and the second magnet having the magnetic pole surface facing the first magnet or the magnetic body. Therefore, when a rotational speed difference (phase difference) occurs between the first rotating body and the second rotating body, and the phase of the first magnet (magnetic body) and the second magnet shifts, the interpolar magnetic body The torque that eliminates the rotational speed difference acts between the first rotating body and the second rotating body due to the magnetic force between the first magnet and the second magnet, so that the rotational fluctuation generated in one rotating body is attenuated. Is done.

  Here, the magnetic force acting on the first rotating body and the second rotating body so as to reduce the rotational speed difference is much stronger than the suppression force acting on the rotating body by the conventional eddy current. Therefore, even when a large rotational fluctuation occurs in one of the rotating bodies, the rotational fluctuation can be quickly attenuated. Further, since the rubber elastic body is not used to attenuate the rotational fluctuation, problems such as aging deterioration of the rubber elastic body, fatigue failure, or sound generation at the time of elastic deformation of the rubber elastic body do not occur.

  In the present invention, the magnetization direction of the first magnet (the direction of the magnetic pole surface) is the circumferential direction, while the magnetization direction of the second magnet is the direction facing the first magnet and is different from the circumferential direction. Therefore, no direct magnetic flux flows between the first magnet and the second magnet, and no magnetic force acts. And like this 1st magnet and the 1st magnet, it has the structure where the interpolar magnetic body in which magnetic flux flows in the circumferential direction is interposed between the above-mentioned interpolar magnetic bodies where the magnetic force acts with the second magnet. ing. Therefore, when the phase difference between the first rotating body and the second rotating body is small and the phase between the interpolar magnetic body and the second magnet is slightly shifted, the interpolar magnetic body and the second magnet are still Since it is in a largely separated state, the magnetic force acting between the two is small. Therefore, the torque that acts to eliminate the rotational speed difference does not become too large, and resonance can be prevented from occurring between the first rotating body and the second rotating body.

  Further, since the magnetic flux between the different poles flows in the circumferential direction in the magnetic body between the different poles, the magnet structure composed of the magnetic pole between the different poles and the two first magnets on both sides has one magnetized in the circumferential direction. It can be regarded as equivalent to a large magnet. In other words, when one large magnet is used, a part of this large magnet is replaced with a magnetic material, and the amount of the magnet portion that is more expensive than the magnetic material is reduced, and the equivalent rotational fluctuation attenuation performance is exhibited. be able to.

  The pulley structure according to a second aspect of the present invention is the pulley according to the first aspect, wherein the second magnet is formed in a sector shape whose both end surfaces in the circumferential direction are parallel to the radial direction of the rotating body. The two first magnets are formed in a substantially rectangular parallelepiped shape and opposite magnetic pole faces of different polarities, and the magnetic body interposed between the different magnetic pole faces of the two first magnets. The magnet structure has a sector shape concentric with the second magnet.

  The fact that both end faces in the circumferential direction of the sector-shaped second magnet are parallel to the radial direction of the rotating body means that the center of the sector shape of the second magnet coincides with the center of the rotating body. On top of that, the first magnet and the magnetic body arranged in the circumferential direction, like the second magnet, have a sector shape whose center position coincides with the rotating body. Naturally, it is desirable from the viewpoint of being able to use it. However, from the viewpoints of magnet manufacturing ease and cost, the magnet shape is preferably a rectangular parallelepiped shape rather than a sector shape. Therefore, in the present invention, the first magnet is formed in a substantially rectangular parallelepiped shape, and the two first magnets with opposite pole faces facing each other are interposed between the opposite pole faces of the two first magnets. A magnet structure composed of a magnetic body between different poles has a concentric sector shape with the same center position as the corresponding second magnet.

  The pulley structure according to a third aspect of the present invention is the pulley structure according to the first or second aspect, wherein a yoke made of a magnetic material is provided on the magnetic pole surface of the plurality of second magnets on the side opposite to the first magnet. It is characterized by being.

  According to this structure, the leakage of the magnetic flux from the magnetic pole surface on the opposite side to the 1st magnet and a magnetic body of a 2nd magnet can be suppressed as much as possible.

  The pulley structure according to a fourth aspect of the invention is any one of the first to third aspects, wherein the plurality of first magnets and the plurality of second magnets arranged in the circumferential direction of the rotating body are respectively It is characterized by constituting an annular magnet body.

  According to this configuration, since the plurality of magnets and the plurality of magnetic bodies are distributed over the entire circumference, a torque is equally applied in the circumferential direction between the first rotating body and the second rotating body. Can be made.

It is a schematic structure figure of an auxiliary machinery drive system concerning an embodiment of the present invention. It is sectional drawing regarding the surface containing the rotating shaft of a pulley structure. It is a perspective view of the annular magnet body arrange | positioned between a pulley and a hub. (A) is the figure which looked at the 1st annular magnet body from the rotation axis direction, (b) is the figure which looked at the 2nd annular magnet body from the rotation axis direction. It is the figure which looked at a part of 1st annular magnet body from the radial direction outer side. It is a figure which shows the annular magnet body which substituted the two 1st magnets of FIG.4 (b), and the magnetic body between different poles with one big sector magnet. It is a figure which shows the positional relationship of a 1st annular magnet body and a 2nd annular magnet body when there is no rotational speed difference between a pulley and a hub. It is a figure which shows the positional relationship of a 1st annular magnet body and a 2nd annular magnet body when there exists a small rotational speed difference between a pulley and a hub. It is a figure which shows the positional relationship of a 1st annular magnet body and a 2nd annular magnet body when there exists a big rotational speed difference between a pulley and a hub. It is sectional drawing regarding the surface containing a rotating shaft of the pulley structure which concerns on a change form. It is sectional drawing regarding the surface containing a rotating shaft of the pulley structure of another modification. It is the figure which looked at the cyclic | annular magnet body of the pulley structure of FIG. 11 from the rotating shaft direction. It is a graph which shows the relationship between a rotation angle and the torque of the pulley structure of Example 1,2. It is a graph which shows the relationship between a rotation angle and a torque of the pulley structure of Examples 3 and 4. It is a graph which shows the relationship between a rotation angle and a torque of the pulley structure of a comparative example.

  Next, an embodiment of the present invention will be described. This embodiment is an example in which the present invention is applied to a pulley structure used in an accessory drive system that drives an accessory by the torque of the output shaft of an automobile engine.

  FIG. 1 is a schematic configuration diagram of an auxiliary machine drive system according to this embodiment. As shown in FIG. 1, an accessory drive system 100 includes a drive pulley 105 connected to an engine output shaft 101 (a reciprocating engine crankshaft, a rotary engine eccentric shaft, etc.), and various types such as a water pump and an alternator. Drive shafts (auxiliary shafts) 102 and 103 respectively connected to the accessory, a driven pulley 104 attached to the driven shaft 102, and a pulley 2 of the pulley structure 1 according to the present embodiment attached to the driven shaft 103. And a drive pulley 105, a driven pulley 104, and a transmission belt 106 that spans the pulley 2 of the pulley structure 1. In the present embodiment, a V-ribbed belt having a plurality of V-ribs 106a extending in parallel with each other along the belt longitudinal direction is used as the transmission belt 106 (see FIG. 2).

  When the drive pulley 105 is rotationally driven by the torque of the output shaft 101, the transmission belt 106 is driven by the rotation of the drive pulley 105. Then, as the transmission belt 106 travels, the driven pulley 104 and the pulley 2 of the pulley structure 1 are driven to rotate, so that auxiliary equipment such as a water pump and an alternator connected to the driven shafts 102 and 103 is obtained. Each is driven.

  Next, the pulley structure 1 of this embodiment that transmits torque transmitted from the output shaft 101 via the transmission belt 106 to the driven shaft (auxiliary shaft) 103 will be described in detail. FIG. 2 is a cross-sectional view relating to the plane including the rotation axis C of the pulley structure 1 of the present embodiment. As shown in FIG. 2, the pulley structure 1 includes a cylindrical pulley 2 around which the transmission belt 106 is wound, and a hub 3 connected to a driven shaft (auxiliary shaft) 103 and provided inside the pulley 2. It has. In the present embodiment, the pulley 2 corresponds to the first rotating body in the present invention, and the hub 3 corresponds to the second rotating body in the present invention. The pulley 2 and the hub 3 are connected to each other via a bearing 5 so as to be relatively rotatable. The right side in FIG. 2 is defined as the distal end side of the pulley structure 1 and the left side in FIG. 2 (the driven shaft (auxiliary shaft) 103 side) is defined as the proximal end side of the pulley structure 1 and will be described below.

  A plurality of V grooves 11 extending along the circumferential direction are formed on the outer peripheral portion of the pulley 2. The transmission belt 106 is wound around the outer circumference of the pulley 2 with a plurality of V ribs 106 a formed on the abdominal surface side engaged with the plurality of V grooves 11.

  The hub 3 has two cylindrical members 3a and 3b arranged coaxially along the rotation axis direction, and these two cylindrical members 3a and 3b are connected and integrated in a portion not shown. The distal end portion of the driven shaft 103 is fitted into the two cylindrical members 3a and 3b of the hub 3, and the driven shaft 103 and the hub 3 are connected so as not to be relatively rotatable by appropriate connecting means such as bolts. The two cylindrical members 3a and 3b constituting the pulley 2 and the hub 3 are each made of a nonmagnetic material (paramagnetic material, diamagnetic material, or antiferromagnetic material). Examples of the nonmagnetic material include austenitic stainless steel, aluminum alloy, titanium alloy, and synthetic resin.

  Of the two cylindrical members 3a and 3b, the cylindrical member 3a located on the proximal end side is provided with a bearing 5, and the pulley 2 is rotatably connected to the cylindrical member 3a via the bearing 5. On the other hand, an annular magnet housing chamber 16 is formed between the cylindrical member 3b located on the distal end side and the pulley 2, and one first annular magnet fixed to the pulley 2 is formed in the magnet housing chamber 16. The body 20 and two second annular magnet bodies 21 fixed to the cylindrical member 3b of the hub 3 are accommodated. The first annular magnet body 20 fixed to the pulley 2 and the two second annular magnet bodies 21 fixed to the hub 3 are alternately arranged with a gap in the direction of the rotation axis C of the pulley 2. ing. In other words, the first annular magnet body 20 is sandwiched between the two second annular magnet bodies 21 in the rotation axis direction.

  3 is a perspective view of the annular magnet bodies 20 and 21 shown in FIG. 2, and FIGS. 4A and 4B are views of the annular magnet bodies 20 and 21 viewed from the direction of the rotation axis C of the pulley 2. FIG. . As shown in FIG. 2, the 1st annular magnet body 20 is being fixed to the pulley 2 in the outer peripheral surface. As shown in FIGS. 3 and 4A, the first annular magnet body 20 includes a plurality of first magnets 17 and a plurality of magnetic bodies 25 and 26. As an example, FIGS. 3 and 4A show a first annular magnet body 20 including 12 first magnets 17 and 12 magnetic bodies 25 (26).

  The plurality of first magnets 17 are arranged in the circumferential direction of the pulley 2 with the magnetic body 25 (26) interposed therebetween. Further, as shown in FIG. 4A, each first magnet 17 is formed in a substantially rectangular parallelepiped shape, and as shown by an arrow in FIG. 4A, the magnetization direction of the first magnet 17 is rotated. A rectangular short direction when viewed from the axial direction, which is substantially parallel to the circumferential direction of the pulley 2. That is, both circumferential end surfaces of the first magnet 17 in contact with the magnetic body 25 (26) are the magnetic pole surfaces. Further, in the plurality of first magnets 17, two poles of the same polarity of two first magnets 17 adjacent in the circumferential direction are opposed to each other with the magnetic body 25 interposed therebetween, and magnetic pole surfaces of different polarities sandwich the magnetic body 26. The opposed states are arranged alternately in the circumferential direction. In other words, focusing on one first magnet 17, one magnetic pole surface of one first magnet 17 has the same polarity as that of another first magnet 17 via a magnetic body 25. The other magnetic pole surface is opposed to the magnetic pole surface of another pole of another first magnet 17 through the magnetic body 26.

  The plurality of magnetic bodies 25 and 26 are each formed of a magnetic material (preferably a soft magnetic material). As described above, the plurality of magnetic bodies 25, 26 are both arranged between the plurality of first magnets 17, but the magnets sandwiched between the magnetic pole surfaces of the same polarity of the two adjacent first magnets 17. It is divided into a body 25 (magnetic body between same poles) and a magnetic body 26 (magnetic body between different poles) sandwiched between magnetic pole faces of different polarities of the two first magnets 17. Both the interpolar magnetic body 25 and the heteropolar magnetic body 26 are formed in a sector shape, but have a sector shape with a different center position (not a concentric sector shape). The reason for this will be described later together with the reason why the first magnet 17 has a substantially rectangular parallelepiped shape.

  As shown in FIG. 2, the 2nd annular magnet body 21 is being fixed to the hub 3 in the internal peripheral surface. As shown in FIGS. 3 and 4B, the second annular magnet body 21 includes a plurality (six in the figure) of second magnets 18 arranged in the circumferential direction. The plurality of second magnets 18 are each formed in a fan shape, and the center of the fan shape coincides with the rotation center of the pulley 2. In other words, both end surfaces in the circumferential direction of the sector-shaped second magnet 18 are parallel to the radial direction of the pulley 2. Unlike the first magnet 17, the magnetization direction of the second magnet 18 is the rotation axis direction of the pulley 2, and both surfaces in the direction of the rotation axis C of the second magnet 18 are magnetic pole surfaces. . Therefore, as can be seen from FIG. 3, one magnetic pole surface of the second magnet 18 faces the first magnet 17 or the magnetic bodies 25 and 26 constituting the first annular magnet body 20.

  In addition, the 1st magnet 17 and the 2nd magnet 18 are comprised with the permanent magnet, respectively. As the permanent magnet, a material containing neodymium, samarium cobalt, ferrite, alnico, platinum, chromium, iron, manganese, aluminum, praseodymium, or the like can be used. Moreover, as a magnetic material which comprises the magnetic bodies 25 and 26, soft iron, a ferrite (Ni-Zn type ferrite, Mn-Zn type ferrite), etc. are mentioned. In addition, permalloy, sendust, permendur, silicon steel, etc. can be used.

  FIG. 5 is a view of a part of the first annular magnet body 20 as viewed from the outside in the radial direction, and shows the flow of magnetic flux in the first annular magnet body 20. In FIG. 5, the magnetic body 25 (26) is hatched so that the first magnet 17 and the magnetic body 25 (26) are clearly distinguished. As shown in FIG. 5, in the interpolar magnetic body 26, a magnetic flux flows in the circumferential direction from one first magnet 17 to the other first magnet 17. On the other hand, the interpolar magnetic body 25 has an effect of allowing a magnetic flux to flow in and out between the first annular magnet body 20 and the outside. That is, when the magnetic poles on both sides of the interpolar magnetic body 25 are N poles, the magnetic flux from the two first magnets 17 flows out to the outside, and when the magnetic poles on both sides are S poles, Current flux flows into the two first magnets 17.

  Since the magnetization direction of the first magnet 17 is the circumferential direction, the magnetization direction of the second magnet 18 is the direction of the rotation axis C and is different from the circumferential direction. No magnetic flux flows directly between them, and no magnetic force acts. However, since the magnetic flux between the magnetic poles 25 flows into and out of the interpolar magnetic body 25, magnetic flux interference occurs with the second magnet 18, thereby causing the interpolar magnetic body 25 and the second magnet 18 to interfere with each other. A magnetic force will be generated during this period.

  In addition, as described above, the interpolar magnetic body 26 is a magnetic flux that flows from one first magnet 17 to the other first magnet 17 in the circumferential direction. A configuration composed of the two first magnets 17 on both sides (a portion indicated by an angle β in FIG. 4A) can be regarded as one large magnet. That is, the first annular magnet body 20 of FIG. 4A, the interpolar magnetic body 26 and the two first magnets 17 on both sides thereof are replaced with one large magnet 37, and the annular magnet body 51 of FIG. Then, the flow of magnetic flux in the replaced portion is in the circumferential direction, and there is no difference. In other words, the present embodiment can reduce the amount of expensive magnet portions by replacing a part of the magnet 37 in FIG. Furthermore, performance equivalent to that of the configuration of FIG. 6 can be exhibited.

  By the way, the 1st magnet 17 arrange | positioned in the circumferential direction and the magnetic body 25 (26) like the 2nd magnet 18 are made into the fan shape which the pulley 2 and the center position corresponded, making magnet arrangement compact, Of course, it is desirable from the viewpoint that magnetic energy can be used effectively. However, when manufacturing a fan-shaped magnet, it is necessary to magnetize in the string direction, and there is a problem that the surface magnetic flux density tends to be non-uniform. There is also a problem that the energy of the magnet cannot be used effectively, leading to an increase in cost. Therefore, in consideration of the ease of manufacturing the magnet and the cost, the first magnet 17 has a substantially rectangular parallelepiped shape in the present embodiment.

  In addition, in the present embodiment, a magnet structure including two first magnets 17 having a rectangular parallelepiped shape and an interpolar magnetic body 26 interposed between the two first magnets (FIG. 4 ( The portion indicated by the angle β in a) has the same sector shape as that of the second magnet 18 corresponding thereto. As a result of the above configuration, the shape of the interpolar magnetic body 26 sandwiched between the different polarities of the two first magnets 17 is a sector shape having a center different from that of the interpolar magnetic body 25, and both end surfaces of the pulley 2 are It is no longer parallel to the radial direction.

  In the present embodiment, as shown in FIG. 2, among the three annular magnet bodies 21, 20, 21 arranged alternately with respect to the direction of the rotation axis C, the first annular magnet body 20 located at the center is a pulley. It is directly attached to the inner surface of 2. As an attachment method, methods such as adhesion, press-fitting, or fixing with screws, bolts, or the like can be employed. On the other hand, the two second annular magnet bodies 21 located outside in the rotation axis direction are attached to the outer peripheral surface of the hub 3 (cylindrical member 3b) through two annular support members 22 and 23, respectively. As a method of attaching the two support members 22 and 23 to the hub 3, a method such as adhesion, press-fitting, or fixing with screws, bolts, or the like can be employed. In addition, as a method of attaching the two second annular magnet bodies 21 to the support members 22 and 23, a method such as adhesion, press-fitting, or fixing with screws, bolts, or the like can be employed.

  The support members 22 and 23 are provided so as to cover the surfaces of the two second annular magnet bodies 21 (second magnets 18) to be supported on the opposite side to the surface facing the first annular magnet body 20. . That is, the support member 22 on the base end side (left side in FIG. 2) covers the surface on the base end side (left side surface in the drawing) of the second annular magnet body 21, and the support member 23 on the tip end side is the second annular magnet. The front surface of the body 21 (the right surface in the figure) is covered. The two support members 22 and 23 are each made of a magnetic material (ferromagnetic material). Examples of the magnetic material constituting the support members 22 and 23 include soft iron and ferrite (Ni—Zn ferrite, Mn—Zn ferrite, Ba ferrite, or Ferroc planar ferrite). The support members 22 and 23 made of these magnetic materials serve as a yoke, and the leakage of magnetic flux from the surface of the second magnet 18 opposite to the surface facing the first annular magnet body 20 is suppressed.

  Of the two support members 22 and 23, the support member 23 that supports the second annular magnet body 21 on the distal end side (right side in FIG. 2) also covers the outer peripheral surface of the second annular magnet body 21. In addition, an annular sliding member 24 is provided on the inner peripheral surface of the pulley 2, and an outer peripheral portion 23 a of the support member 23 covering the second annular magnet body 21 slides with respect to the sliding member 24. It is rotating. That is, the outer peripheral portion 23a of the support member 23 and the sliding member 24 serve as a bearing. The sliding member 24 is preferably made of a material having a small surface friction resistance and excellent wear resistance. For example, molybdenum disulfide, tungsten disulfide, graphite, boron nitride, brass, plating treatment Brass, bronze, and bronze that has been plated can be used. Or synthetic resin materials, such as nylon, polytetrafluoroethylene, and high molecular weight polyethylene, can also be used.

  Next, the effect | action of the pulley structure 1 of this embodiment is demonstrated with reference to FIGS. First, FIG. 7 is a diagram showing a positional relationship between the first annular magnet body 20 and the second annular magnet body 21 when there is no rotational speed difference between the pulley 2 and the hub 3. 7 to 9, the magnets and magnetic bodies arranged in the circumferential direction, which are respectively included in the annular magnet bodies 21, 20 and 21, are shown as viewed from the outside in the radial direction of the annular magnet body.

  As shown in FIG. 7, in the state where there is no rotational speed difference (phase difference) between the pulley 2 and the hub 3, the interpolar magnetic body 25 of the first annular magnet body 20 fixed to the pulley 2 and the hub 3. The magnetic force in a direction attracting between the second annular magnet body 21 fixed to the second magnet 18 acts, and the interpolar magnetic body 25 and the second magnet 18 attracting the same are in the rotation axis direction (in FIG. 7). (In the left-right direction).

  Thus, since there is no difference in rotational speed between the pulley 2 and the hub 3 and both are rotating integrally, torque fluctuation generated in the engine is transmitted via the belt 106, and rotational fluctuation occurs in the pulley 2. When this occurs, a rotational speed difference (phase difference) occurs between the pulley 2 and the hub 3. FIG. 8 is a diagram showing a positional relationship between the first annular magnet body 20 and the second annular magnet body 21 when the rotational speed difference is small. FIG. 9 is a diagram showing the positional relationship between the first annular magnet body 20 and the second annular magnet body 21 when the rotational speed difference is large. When a rotational speed difference occurs between the pulley 2 and the hub 3, as shown in FIGS. 8 and 9, according to the rotational speed difference, the same-polarity magnetic body 25 of the first annular magnet body 20 and the second The circumferential position (phase) of the second magnet 18 of the annular magnet body 21 is shifted.

  As shown in FIG. 8, when the rotational speed difference (phase difference) is small, as shown by the arrow a in FIG. Although it is a little closer to the two magnets 18, it is still far away, so the repulsive force acting between them is weak. Therefore, even if torque is generated between the pulley 2 to which the first annular magnet body 20 is fixed and the hub 3 to which the second annular magnet body 21 is fixed so as to reduce the rotational speed difference between the two, The torque is relatively weak. That is, when the rotational fluctuation is small and the difference in rotational speed between the pulley 2 and the hub 3 is small, the torque that acts to eliminate the rotational speed difference does not become too large. It is possible to prevent resonance between the two.

  On the other hand, as shown in FIG. 9, when the rotational speed difference is large, the distance between the in-polar magnetic body 25 and the second magnet 18 repelling the same decreases as shown by the arrow b in FIG. Since the repulsive force increases, a large torque is generated between the pulley 2 and the hub 3. Therefore, when the rotational fluctuation is large and the rotational speed difference between the pulley 2 and the hub 3 is large, a large torque acts on both to eliminate the rotational speed difference, so that the large rotational fluctuation can be quickly attenuated. it can.

  According to the pulley structure 1 of this embodiment, when a rotational speed difference occurs between the pulley 2 and the hub 3, the pulley structure 1 is provided on the pulley 2 and is sandwiched between the magnetic pole surfaces of the same polarity of the first magnet 17. A magnetic force that reduces the rotational phase difference is generated between the interpolar magnetic body 25 in which magnetic flux flows in and out from the outside and the second magnet 18 provided in the hub 3. This magnetic force is much stronger than the restraining force acting on the rotating body by the conventional eddy current. Therefore, even when a large rotation fluctuation occurs between the pulley 2 and the hub 3, the rotation fluctuation can be quickly attenuated. Further, since the rubber elastic body is not used to attenuate the rotational fluctuation, problems such as aging deterioration of the rubber elastic body, fatigue failure, or sound generation at the time of elastic deformation of the rubber elastic body do not occur.

  While the magnetization direction of the first magnet 17 is the circumferential direction, the magnetization direction of the second magnet 18 is a direction different from the circumferential direction (the direction of the rotation axis C: the direction facing the first magnet 17). No direct magnetic flux flows between the first magnet 17 and the second magnet 18, and no magnetic force acts. In addition, the interpolar magnetic body 26, in which magnetic flux flows in the circumferential direction, like the first magnet 17 and the first magnet 17, is between the interpolar magnetic bodies 25 where magnetic force acts between the second magnet 18. It has a structure intervening. Therefore, when the difference in rotational speed between the pulley 2 and the hub 3 is small and the phase between the in-polar magnetic body 25 and the second magnet 18 is slightly shifted, the in-polar magnetic body 25 and the second repulsion are repelled. The two magnets 18 are still far away from each other, and the magnetic force acting between them is small. Therefore, the torque that acts to eliminate the rotational speed difference does not become excessively large, and the occurrence of resonance between the pulley 2 and the hub 3 can be prevented.

  In addition, since the magnetic flux flows in the circumferential direction in the interpolar magnetic body 26, the magnet structure including the interpolar magnetic body 26 and the two first magnets 17 on both sides is magnetized in the circumferential direction. It can be regarded as equivalent to a single large magnet. In other words, when one large magnet is used, by replacing a part of this large magnet with the magnetic body 26, the amount of the expensive magnet portion can be reduced and the equivalent rotational fluctuation attenuation performance can be exhibited. it can.

  In the present embodiment, the support member 22 made of a magnetic material is provided on the surface of the second magnet 18 (second annular magnet body 21) opposite to the first magnet 17 and the first annular magnet body 20 made of a magnetic material. , 23 are provided, and the support members 22, 23 serve as yokes. Accordingly, leakage of magnetic flux from the magnetic pole surface of the second magnet 18 opposite to the first magnet 17 and the magnetic body is suppressed, and the energy of the magnetic force is reduced between the first annular magnet body 20 and the second annular magnet body 21. Therefore, the torque can be efficiently transmitted between the pulley 2 and the hub 3.

  In the present embodiment, a plurality (12) of first magnets 17 and a plurality (12) of magnetic bodies 25 (26) are arranged in the circumferential direction to constitute the first annular magnet body 20, and a plurality of them. (Six) second magnets 18 are arranged in the circumferential direction to constitute a second annular magnet body 21. According to this, since the 1st magnet 17, the magnetic body 25 (26), and the 2nd magnet 18 are disperse | distributed and arrange | positioned over the perimeter, it is equal regarding the circumferential direction between the pulley 2 and the hub 3. Torque can be applied to.

  Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals and description thereof is omitted as appropriate.

  1] The size, shape, number, material, arrangement, and the like of the first magnet 17, the magnetic bodies 25 and 26, and the second magnet 18 depend on the shape of the pulley 2 and the hub 3 and the degree of rotation fluctuation that can occur. And can be changed as appropriate.

  For example, the number of the annular magnet bodies 20 and 21 arranged in the direction of the rotation axis of the pulley 2 is limited to three (one first annular magnet body 20 and two second annular magnet bodies 21) as in the above embodiment. It is not a thing. For example, like the pulley structure 1A shown in FIG. 10, the number of the 1st annular magnet bodies 20 and the 2nd annular magnet bodies 21 arrange | positioned regarding the direction of the rotating shaft C may each be one. In the embodiment of FIG. 10, the support member 22A provided on the outer surface of the first annular magnet body 20 (the surface opposite to the surface facing the second annular magnet body 21) is replaced with a magnetic body (yoke). Then, since the magnetic flux emitted from the interpolar magnetic body 25 flows in the support member 22A, the support member 22A is preferably a non-magnetic body. Further, four or more first annular magnet bodies 20 and 21 may be provided so as to be alternately arranged in the rotation axis direction.

  Further, the number of magnets 17 and 18 and magnetic bodies 25 and 26 constituting one annular magnet body 20 and 21 can be appropriately changed. Further, the first magnet 17 may be formed in a fan shape as in the second magnet 18 instead of the rectangular parallelepiped shape as in the above-described embodiment. Furthermore, it is not necessary that the first magnet 17 and the magnetic bodies 25 and 26 or the second magnet 18 be arranged over the entire circumference in the circumferential direction to form an annular magnet body. The structure by which the magnetic bodies 25 and 26 are arrange | positioned may be sufficient.

  Moreover, in the said embodiment, although the 1st magnet 17 and the magnetic bodies 25 and 26 were provided in the pulley 2 side, and the 2nd magnet 18 was provided in the hub 3 side, the reverse may be sufficient. That is, a plurality of second magnets 18 arranged in the circumferential direction may be provided on the pulley 2 side, and a plurality of first magnets 17 arranged in the circumferential direction may be provided on the hub 3 side with the magnetic bodies 25 and 26 interposed therebetween. In this embodiment, the hub 3 provided with the first magnet 17 and the magnetic bodies 25 and 26 corresponds to the first rotating body of the present invention, and the pulley 2 provided with the second magnet 18 is the second of the present invention. Corresponds to a rotating body.

  2] In the above embodiment, the first annular magnet body 20 composed of the first magnet 17 and the magnetic bodies 25 and 26 and the second annular magnet body 21 composed of the second magnet 18 are opposed to each other in the rotational axis direction. One magnet and a magnetic body may be opposed to the second magnet in the radial direction of the pulley 2. For example, in the pulley structure 1B shown in FIG. 11, the first annular magnet body 20B is fixed to the pulley 2B via an annular support member 22B made of a nonmagnetic material, while the hub 3B Two annular magnet bodies 21B are fixed via an annular support member 23B made of a magnetic material. In addition, the first annular magnet body 20B on the pulley 2B side is formed to have a diameter larger than the diameter of the second annular magnet body 21B on the hub 3B side, and then radially inward of the first annular magnet body 20B. The second annular magnet body 21B is disposed with a gap therebetween.

  As shown in FIG. 12, the first annular magnet body 20B located on the outside is composed of a plurality of first magnets 17B and a plurality of magnetic bodies 25B, 26B arranged alternately in the circumferential direction. Further, the plurality of first magnets 17B are respectively magnetized in the circumferential direction, and a state in which the magnetic pole surfaces of the same polarity are opposed to each other between the two adjacent first magnets 17B with the interpolar magnetic body 25B sandwiched therebetween is different. The magnetic pole surfaces of the poles are arranged so as to alternately appear in the circumferential direction with the opposite poled magnetic bodies 26B facing each other.

  Moreover, the 2nd annular magnet body 21B located inside is comprised by the several 2nd magnet 18B arrange | positioned in the circumferential direction. The plurality of second magnets 18B are respectively magnetized in the radial direction, and the magnetic poles on the outer peripheral surface (the surface facing the first magnet 17B) are reversed between the two second magnets 18B adjacent in the circumferential direction. Yes.

  The operation of the pulley structure 1B when a rotational speed difference is generated between the pulley 2B and the hub 3B is basically the same as that of the pulley structure 1 of the above embodiment. That is, when a rotational speed difference is generated between the pulley 2B and the hub 3B, the circumferential positions of the interpolar magnetic body 25B of the first annular magnet body 20B and the second magnet 18B of the second annular magnet body 21B are shifted. However, when the rotational speed difference (phase difference) is small, an excessive torque is generated in a direction to eliminate the rotational speed difference because the distance between the in-polar magnetic body 25B and the repulsive second magnet is large. Never do.

  5] In the above embodiment, the support members 22 and 23 for attaching the second annular magnet body 21 composed of the plurality of second magnets 18 to the hub 3 are formed of a magnetic material, but the present invention is in such a form. It is not limited. For example, after the first magnet 17 and the second magnet 18 are directly fixed to the corresponding pulley 2 and the hub 3, a magnetic material serving as a yoke is separately provided on the first magnet 17 and the second magnet 18. Also good. Alternatively, part or all of the pulley 2 and the hub 3 may be formed of a magnetic material, and the first magnet 17 and the second magnet 18 may be attached to the magnetic portion so as to serve as a yoke.

  As described above, an example in which the present invention is applied to a pulley structure of an engine accessory drive system has been described as an embodiment of the present invention. However, the application target of the present invention is not limited to this. For example, in the fields of building materials, furniture, machinery, etc., it is used for various applications such as pulley structures used to change torque according to the opening / closing angle of opening / closing members such as windows, doors, lids, etc. The present invention can also be applied to a pulley structure.

  Next, specific examples of the present invention will be described together with comparative examples.

Example 1
As the first magnet 17, a neodymium magnet having a rectangular parallelepiped shape (magnetized in the direction of 5.6 mm) of 5.6 mm × 15.4 mm × 6 mm was used. Twelve neodymium magnets were arranged radially so that the magnetization direction was the circumferential direction, and S25C magnetic bodies 25 and 26 were inserted between the magnets to produce one first annular magnet body 20. The first magnet 17 is arranged so that a state in which the same magnetic pole surfaces face each other and a state in which the different magnetic pole surfaces face each other appear alternately in the circumferential direction. The first annular magnet body 20 obtained as described above has an outer diameter of 56 mm, an inner diameter of 24 mm, and a thickness of 6 mm. The central angle of the interpolar magnetic body 25 (α in FIG. 4A) is 10 degrees, The angle between the two end faces of the two first magnets 17 sandwiching the intermagnetic body 26 (β in FIG. 4A) is 50 degrees.

  As the second magnet 18, a neodymium magnet magnetized in the thickness direction with a sector shape having an outer diameter of 58 mm, an inner diameter of 28 mm, a thickness of 6 mm, and a central angle of 60 degrees was used. Then, the six second magnets 18 were alternately arranged in the circumferential direction so that the magnetic poles were reversed, and two second annular magnet bodies 21 were produced.

  In addition, one first annular magnet body 20 and two second annular magnet bodies 21 are arranged at intervals of 0.5 mm, and on the surface of the outer two second annular magnet bodies 21 that does not face the first annular magnet body 20. S25C material was laminated as a back yoke. These three annular magnet bodies 21, 20, 21 were attached to the hub 3 and the pulley 2 shown in FIG. 1 to produce a pulley structure.

The total volume of the magnets used in Example 1 was 5.6 × 15.4 × 6 × 12 (first magnet) + 2 × (1/4) × (58 × 58−28 × 28) × π. X6 (second magnet) = 30525 (mm ³ ).

(Example 2)
The specifications were the same as in Example 1 except that the first magnet was 4.4 mm × 15.7 mm × 6 mm (magnetized in the direction of 4.4 mm), α was 20 degrees, and β was 40 degrees. The total volume of the magnet used in Example 2 was 4.4 × 15.7 × 6 × 12 (first magnet) + 2 × (1/4) × (58 × 58−28 × 28) × π × 6. (Second magnet) = 29290 (mm ³ ).

(Example 3)
Twelve first magnets are arranged in the circumferential direction as 6.5 mm × 14.3 mm × 6 mm (magnetized in the direction of 6.5 mm), the outer diameter is 58 mm, the inner diameter is 28 mm, the thickness is 6 mm, α is 10 degrees, and β is 50. Two first annular magnet bodies 20 of the same degree were produced. Moreover, one second annular magnet body 21 was produced using six second magnets 18 having an outer diameter of 56 mm, an inner diameter of 24 mm, a thickness of 6 mm, and a central angle of 60 degrees. Then, the two first annular magnet bodies 20 are arranged so as to sandwich the second annular magnet body 21 in the rotation axis direction, and the three annular magnet bodies 20, 21, 20 are attached to the pulley 2 and the hub 3. It was. However, the back yoke was not attached to the outer surface of the first annular magnet body 20 located outside. The total volume of the magnet used in Example 3 was 6.5 × 14.3 × 6 × 24 (first magnet) + (1/4) × (56 × 56−24 × 24) × π × 6 ( Second magnet) = 25449 (mm ³ ).

Example 4
Sixteen first magnets are arranged in the circumferential direction as 3.8 mm × 14.8 mm × 6 mm (magnetized in the direction of 3.8 mm), α is 15 degrees, β is 30 degrees, outer diameter is 58 mm, inner diameter is 28 mm, thickness Two 6 mm first annular magnet bodies 20 were produced. Further, one second annular magnet body 21 was produced using eight second magnets 18 having an outer diameter of 56 mm, an inner diameter of 24 mm, a thickness of 6 mm, and a central angle of 45 degrees. Then, three annular magnet bodies 20, 21, 20 were attached to the pulley 2 and the hub 3 in the same manner as in Example 3. The back yoke was not attached to the first annular magnet body 20 located outside. The total volume of the magnet used in Example 4 is 3.8 × 14.8 × 6 × 32 (first magnet) + (1/4) × (56 × 56−24 × 24) × π × 6 ( Second magnet) = 22862 (mm ³ ).

(Comparative example)
Six fan-shaped magnets with an outer diameter of 56 mm, an inner diameter of 24 mm, a thickness of 6 mm, and a central angle of 50 degrees, which are magnetized in the circumferential direction, Further, the magnetic body (S25C) was inserted between the six magnets to produce one annular magnet body (annular magnet body 51 in FIG. 6). In addition, two second annular magnet bodies 21 made of the same six second magnets 18 as in Example 1 were produced. And these three annular magnet bodies were attached to the pulley and the hub, and it was set as the pulley structure. The total volume of the magnet used in this comparative example is (1/4) × (56 × 56-24 × 24) × π × 6 × (300/360) (magnet of FIG. 6) + (1/4) × It is (58 * 58-28 * 28) * (pi) * 6 * 2 (2nd magnet) = 34369 (mm < ³ >).

  FIG. 13 is a graph showing the relationship between the rotation angle and torque of the pulley structure of Example 1 and Example 2, and FIG. 14 shows the relationship between the rotation angle and torque of the pulley structure of Example 3 and Example 4. FIG. 15 is a graph showing the relationship between the rotation angle and torque of the pulley structure of the comparative example. Table 1 shows the total volume and maximum torque of the magnets used in Examples 1 to 4 and Comparative Examples.

  As can be seen from FIGS. 13 to 15 and Table 1, in Examples 1 to 4 in which the interpolar magnetic body 26 is inserted between the two first magnets, the amount of magnets used is larger than that of the other comparative examples. (30% or less in Example 4). Nevertheless, in Examples 1 to 4, the maximum torque equivalent to that of the comparative example is obtained.

1, 1A, 1B Pulley structure 2, 2A, 2B Pulley 3, 3A, 3B Hub 17, 17B First magnet 18, 18B Second magnet 25, 25B Magnetic body 26, 26B Magnetic body

Claims (4)

A first rotating body;
A second rotating body rotatable relative to the first rotating body;
A plurality of first magnets provided on the first rotating body;
A plurality of second magnets provided on the second rotating body so as to face the plurality of first magnets;
The plurality of first magnets are arranged with a magnetic body sandwiched in the circumferential direction of the rotating body, and the magnetic pole surfaces of two first magnets adjacent in the circumferential direction are opposed to each other via the magnetic body,
Further, in the plurality of first magnets, the same polarity magnetic pole surfaces of two first magnets adjacent to each other in the circumferential direction are opposed to each other with the magnetic material interposed therebetween, and different magnetic pole surfaces sandwich the magnetic material. The opposing state is configured to appear alternately in the circumferential direction,
The plurality of second magnets are arranged in the circumferential direction of the rotating body, and their magnetic pole faces face the first magnet or the magnetic body,
Furthermore, the plurality of second magnets are configured such that different magnetic poles appear alternately in the circumferential direction on their magnetic pole surfaces. The second magnet is formed in a sector shape in which both end faces in the circumferential direction are parallel to the radial direction of the rotating body,
The first magnet is formed in a substantially rectangular parallelepiped shape,
A magnet structure composed of two first magnets with opposite pole faces facing each other and the magnetic body interposed between the pole faces of different poles of the two first magnets, The pulley structure according to claim 1, wherein the pulley structure has a sector shape concentric with the magnet.   3. The pulley structure according to claim 1, wherein a yoke made of a magnetic material is provided on a magnetic pole surface of the plurality of second magnets on the side opposite to the first magnet.   The plurality of first magnets and the plurality of second magnets arranged in the circumferential direction of the rotating body each constitute an annular magnet body. The pulley structure described.

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