JP5859216B2 - Magnetic coupling device - Google Patents

Description

  The present invention provides a first rotating body that is provided so as to face each other in a manner in which their working surfaces are close to and away from each other, and each of which can rotate around a common rotation axis extending along a direction orthogonal to the working surface, and The present invention relates to a magnetic coupling device that includes a second rotating body and transmits torque from a rotating body on one side to a rotating body on the other side by a magnetic force generated between the working surfaces of the first rotating body and the second rotating body. is there.

  Conventionally, the following magnetic coupling devices are known as an example of a rotation transmission mechanism that transmits torque. For example, permanent magnets are provided on the inner peripheral surface of a driving-side rotator that has a cylindrical shape and the outer peripheral surface of a driven-side rotator that has a cylindrical shape disposed on the same rotational axis as the driving-side rotator. It is arranged oppositely through an air gap, and the torque of the driving side rotating body is transmitted to the driven side rotating body using the magnetic force generated between the inner peripheral surface and the outer peripheral surface (see, for example, Patent Document 1). .

JP 2001-165189 A

  However, the magnetic coupling device proposed in Patent Document 1 described above requires a certain size in the direction of the rotation axis because of its structure, and thus it has been difficult to reduce the size of the entire device.

  On the other hand, separately from the magnetic coupling device, the drive-side rotator having a disk-like form and the driven-side rotator having a disk-like form are arranged in such a manner that their working surfaces are spaced apart from each other. A magnetic coupling device is known. In this magnetic coupling device, both the driving-side rotator and the driven-side rotator are configured to be rotatable around a rotation axis extending on the same straight line along a direction orthogonal to the respective action surfaces. Then, torque is transmitted from the driving side rotating body to the driven side rotating body by a magnetic force (magnetic attraction force) generated between the working surfaces of the driving side rotating body and the driven side rotating body. Such a magnetic coupling device has a structure that is short in the direction of the rotation axis and can be flat as a whole, and the entire device can be downsized.

  However, in a magnetic coupling device including a disk-like driving side rotating body and a driven side rotating body, a magnetic attractive force is generated along the rotation axis direction between the driving side rotating body and the driven side rotating body. In addition, the burden on the bearing member that supports the rotating body increases. In particular, as the torque to be transmitted increases, the magnetic attractive force generated along the direction of the rotation axis also increases, so a countermeasure on the mechanism is required.

  In view of the above circumstances, an object of the present invention is to provide a magnetic coupling device capable of reducing the attractive force generated in the direction of the rotation axis and transmitting torque well while reducing the size of the entire device. To do.

In order to achieve the above object, a magnetic coupling device according to the present invention is provided in such a manner that the working surfaces of the magnetic coupling device face each other in such a manner that the working surfaces come close to and away from each other, and each extends along a direction orthogonal to the working surface. The first rotating body and the second rotating body that are rotatable around the rotation axis of the first rotating body and the second rotating body are provided with a magnetic force generated between the working surfaces of the first rotating body and the second rotating body. In the magnetic coupling device for transmitting torque to the rotator, the first rotator and the second rotator are disposed between the inner peripheral regions close to the rotation shaft on the respective working surfaces of the first rotator and the second rotator. A spring member that generates a repulsive force along the axial direction of the rotating shaft by its own restoring force when the separation distance from the body is equal to or less than a predetermined size, the first rotating body, and the second rotation On each working surface of the body A magnetic force unit that generates a magnetic attractive force along the axial direction of the rotary shaft between the outer peripheral regions on the outer diameter side of the location where the spring member is disposed, and the magnetic force unit is provided on the working surface of the first rotating body. A magnet group in which a plurality of permanent magnets are arranged at predetermined intervals in a manner in which magnetic poles adjacent to each other in a circumferential direction centering on the rotation axis are different from each other at locations corresponding to the outer peripheral region, A plurality of magnetic bodies are arranged at predetermined intervals along a circumferential direction centering on the rotation axis at locations where the first rotating body rotates relative to the permanent magnet on the working surface of the second rotating body. Ri formed and a magnetic plate composed disposed, said second rotary member, when exceeding a size that the distance between the first rotary body is determined in advance, apart from the first rotary member Japanese that it is in a direction that is a state that is not biased to To.

  In the magnetic coupling device of the present invention, the spring member is formed between the first rotating body and the second rotating body between the inner peripheral regions close to the rotating shafts on the respective working surfaces of the first rotating body and the second rotating body. When the separation distance is less than or equal to a predetermined size, a repulsive force along the axial direction of the rotation shaft is generated by its own restoring force, and the magnetic unit acts on each of the first rotating body and the second rotating body. A magnetic attraction force is generated along the axial direction of the rotary shaft between the outer peripheral regions on the outer surface of the surface outside the location where the spring member is disposed. Thereby, the force which displaces one rotary body along the axial direction of a rotating shaft can be reduced, ie, a thrust load can be reduced. Then, the magnetic attractive force of the magnet unit acts in the rotation direction around the rotation axis, so that the other rotation body can be rotated in synchronization with the rotation of one rotation body. Torque can be transmitted to the rotating body. Furthermore, a flat configuration in which the rotation axis direction is short is possible, and the entire apparatus can be downsized. Therefore, it is possible to reduce the magnetic attractive force generated along the axial direction of the rotating shaft and to transmit the torque satisfactorily while reducing the size of the entire apparatus.

FIG. 1 is an explanatory diagram schematically showing a partial cross section of a magnetic coupling device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the configuration of the working surface of the driven-side rotator in the magnetic coupling device illustrated in FIG. 1, and is an explanatory diagram illustrating the case viewed from the drive-side rotator. FIG. 3 is a diagram illustrating the configuration of the working surface of the drive side rotator in the magnetic coupling device shown in FIG. 1, and is an explanatory view showing the case viewed from the driven side rotator. FIG. 4 is an explanatory diagram showing a state in which the magnet group of the driven side rotating body and the magnetic disk of the driving side rotating body face each other. FIG. 5 is a partial cross-sectional view illustrating a state in which the driven side rotator and the drive side rotator are close to each other in the magnetic coupling device illustrated in FIG. 1. FIG. 6 is an explanatory view schematically showing a part in cross section of a modification of the magnetic coupling device according to the embodiment of the present invention. FIG. 7 is a partial cross-sectional view illustrating a state in which the driven-side rotator and the drive-side rotator are close to each other in the modified example of the magnetic coupling device illustrated in FIG. 6. FIG. 8 is an explanatory view showing the action of the bimetal member in the modification of the magnetic coupling device shown in FIG.

  Exemplary embodiments of a magnetic coupling device according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is an explanatory view schematically showing a part of a magnetic coupling device according to an embodiment of the present invention in cross section. The magnetic coupling device illustrated here includes a driven side rotating body (first rotating body) 10 and a driving side rotating body (second rotating body) 20.

  The driven-side rotator 10 includes a base 11 that has a disk shape, and a substantially cylindrical shaft holder 12 that protrudes from the center of the base 11 toward the drive-side rotator 20. It is. The shaft holding portion 12 has a hollow portion 121 formed therein, and a screw portion 122 that is screwed with a drive shaft (not shown) is provided on the inner wall on the tip end side. The shaft holding portion 12 holds the drive shaft that is screwed by the screw portion 122, and is rotatable around the central axis L of the hollow portion 121 that coincides with the central axis of the drive shaft. That is, the driven-side rotator 10 can rotate around the rotation axis with the central axis L of the hollow portion 121 as the rotation axis. Here, a drive shaft is connected with a compressor apparatus, for example.

  The base 11 includes a spring holding part 13 and a magnet holding part 14. The spring holding portion 13 is provided in an inner peripheral region that is on the side facing the driving side rotating body 20 and that is outside the diameter of the shaft holding portion 12. In the spring holding portion 13, a coil spring (spring member) 131 is housed in an annular concave portion having an opening formed so as to face the driving side rotating body 20. One end of the coil spring 131 is locked to the spring holding portion 13, and an annular friction plate 132 is connected to the other end, and the friction plate 132 is attached to the driving side rotating body 20 with its own restoring force. It is a force. That is, the coil spring 131 urges the friction plate 132 along the axial direction of the central axis L. Here, the friction plate 132 is restricted from being displaced toward the drive side rotating body 20 by a restricting member 123 provided on the outer surface of the shaft holding portion 12, so that the coil spring 131 exceeds a distance allowed in advance. It is made so that the power of

  The magnet holding portion 14 is provided in an outer peripheral region that is on the outer diameter side of the spring holding portion 13, and an annular surface that faces the driving side rotating body 20 constitutes the working surface 141. A magnet group 15 is provided on the working surface 141 of the magnet holder 14. As shown in FIG. 2, the magnet group 15 includes a plurality (30 in the illustrated example) of permanent magnets 151. These permanent magnets 151 are arranged at equal intervals on a circumference centered on the central axis L. That is, the permanent magnet 151 is disposed along the circumferential direction with the central axis L as the center. These permanent magnets 151 are provided in such a manner that adjacent magnetic poles are different from each other.

  The drive-side rotator 20 has a disk shape having an outer diameter substantially the same as that of the driven-side rotator 10, and a through-hole through which the shaft holding portion 12 of the driven-side rotator 10 passes. 20a is formed. A bearing 21 is disposed between the driving side rotating body 20 and the spring holding portion 13 so that a rotational force is not directly transmitted between the spring holding portion 13 and the driving side rotating body 20.

  Such a drive-side rotator 20 rotates around the central axis L of the shaft holding portion 12 as a rotation axis and is close to the driven-side rotator 10 when a driving force is applied from a drive means (not shown). It slides along the axial direction of the central axis L in a manner of separating.

  In such a drive-side rotator 20, the radially outer side of the location where the bearing 21 is disposed is an outer peripheral region 22 that faces the magnet holding portion 14 of the driven-side rotator 10, and a circle that faces the driven-side rotator 10. An annular surface constitutes a working surface 221. A magnetic disk 23 is provided on the working surface 221. As shown in FIG. 3, the magnetic disk 23 is composed of yoke tooth groups 231 that are a plurality (30 in the illustrated example) of magnetic bodies. The yoke tooth group 231 is arranged on the circumference centered on the central axis L, and has a shape in which each component gradually increases in width as it goes in the radially outward direction. These yoke tooth groups 231 are surrounded by eddy current aluminum 232, in other words, embedded in eddy current aluminum 232.

  By the way, in the present embodiment, the regulating member 123 is disposed at a location where the separation distance between the driven side rotating body 10 and the driving side rotating body 20 is a predetermined size (for example, 2 mm). It is. As a result, when the drive-side rotator 20 slides in a manner in which the driven-side rotator 10 is close to the driven-side rotator 10, the urging force of the coil spring 131 is applied to the drive side when the separation distance exceeds a predetermined size. When the distance between each other is not greater than a predetermined size without acting on the rotating body 20, the urging force (for example, about 700 N) of the coil spring 131 can be applied to the driving-side rotating body 20. Therefore, the coil spring 131 generates a repulsive force along the axial direction of the central axis L by its own restoring force when the separation distance between the driven-side rotator 10 and the drive-side rotator 20 is equal to or less than a predetermined size. It is what is generated.

  In the present embodiment, the area of the permanent magnet 151 and the area of the yoke tooth group 231 paired with the permanent magnet 151 are such that the separation distance between the driven-side rotating body 10 and the driving-side rotating body 20 is not more than a predetermined size. In this case, the magnetic attractive force along the axial direction of the central axis L acting between them is substantially the same as the sum of the repulsive force along the axial direction of the central axis L due to the restoring force of the coil spring 131 and the repulsive force due to the eddy current. The size is adjusted in advance so as to be approximately.

  In the magnetic coupling device having the above-described configuration, torque is transmitted from the driving side rotating body 20 to the driven side rotating body 10 as follows.

  The drive-side rotator 20 is slid in a manner close to the driven-side rotator 10 while rotating around the central axis L by the drive means. When the separation distance between the driven-side rotating body 10 and the driving-side rotating body 20 exceeds a predetermined size, between the magnet group 15 of the driven-side rotating body 10 and the magnetic disk 23 of the driving-side rotating body 20, As shown in FIG. 4, the permanent magnet 151 and the yoke tooth group 231 face each other and a magnetic attraction force acts to follow the rotation around the central axis L of the driving side rotating body 20. It starts to rotate around L.

  As shown in FIG. 5, when the separation distance between the driving side rotating body 20 and the driven side rotating body 10 that slides in a manner close to the driven side rotating body 10 is equal to or smaller than a predetermined size, the driving is performed. When the side rotating body 20 abuts against the friction plate 132 and presses the friction plate 132, the restoring force of the coil spring 131 works, and the repulsive force along the axial direction of the central axis L acts. In this case, since the separation distance between the magnet group 15 and the magnetic disk 23 is also reduced, the magnetic attractive force acting between the permanent magnet 151 and the yoke tooth group 231 is also increased, and as a result, the axial direction of the central axis L is increased. The magnetic attractive force is substantially equal to the repulsive force of the coil spring 131 (repulsive force along the axial direction of the central axis L).

  On the other hand, since the drive-side rotator 20 rotates around the central axis L, the magnetic attractive force in the rotational direction around the central axis L between the magnet group 15 and the magnetic disk 23 also increases. As a result, the driven-side rotator 10 rotates in synchronization with the drive-side rotator 20, whereby torque is transmitted from the drive-side rotator 20 to the driven-side rotator 10.

  In such a magnetic coupling device, the magnetic attraction force along the axial direction of the central axis L generated between the magnet group 15 of the driven-side rotating body 10 and the magnetic disk 23 of the driving-side rotating body 20, and the driven The repulsive force along the axial direction of the central axis L by the coil spring 131 provided on the side rotating body 10 acts, thereby reducing the force that displaces the driven-side rotating body 10 along the axial direction of the central axis L. That is, the thrust load can be reduced. In the rotational direction around the central axis L, a magnetic attractive force acting between the magnet group 15 and the magnetic disk 23 acts, so that the driven-side rotator 10 is synchronized with the rotation of the drive-side rotator 20. It can be rotated, and torque can be transmitted from the driving side rotating body 20 to the driven side rotating body 10. Further, the driven-side rotator 10 and the drive-side rotator 20 can have a flat configuration in which the length along the axial direction of the central axis L is structurally short, and the entire apparatus can be reduced in size. Is possible.

  Therefore, according to the magnetic coupling device of the present embodiment, it is possible to reduce the magnetic attractive force generated along the axial direction of the central axis L and to transmit the torque well while reducing the size of the entire device. it can.

  In the above magnetic coupling device, the repulsive force by the coil spring 131 is applied when the separation distance between the driven side rotating body 10 and the driving side rotating body 20 is equal to or smaller than a predetermined size. Until the separation distance from the rotating body 10 reaches a predetermined size, the driving-side rotating body 20 can be slid in a manner of approaching the driven-side rotating body 10 without receiving the repulsive force of the coil spring 131. As a result, the sliding movement of the driving side rotator 20 can be performed smoothly, and the switching force required for the sliding movement of the driving side rotator 20 can be reduced.

  This will be described in more detail as follows. If the repulsive force along the axial direction of the central axis L between the driven-side rotator 10 and the drive-side rotator 20 is to be realized by the magnetic repulsive force, the driven-side rotator 10 and the drive-side rotator 20 are considered in terms of magnetism. Regardless of the magnetic repulsive force, the magnetic repulsive force always works regardless of the difference. In addition, when the difference between the rotational speed of the driving-side rotator 20 and the rotational speed of the driven-side rotator 10 is large, the repulsive force due to the eddy current is also generated synergistically to be brought close to the driven-side rotator 10. The switching force required for the sliding movement of the drive-side rotating body 20 becomes excessive. In this regard, by using the repulsive force of the coil spring 131, the driven-side rotator 10 is not subjected to the repulsive force of the coil spring 131 until the distance from the driven-side rotator 10 becomes a predetermined distance. It can be slid in a manner to be close to. Moreover, in the middle of bringing the drive side rotator 20 close to the driven side rotator 10, the driven side rotator 10 rotates in a form that follows the drive side rotator 20 by the magnetic attractive force acting between them. Since the rotational speed difference can be reduced, the repulsive force due to the eddy current can also be reduced, and as a result, the switching force required for the sliding movement of the drive side rotating body 20 can be reduced.

  Further, in the above magnetic coupling device, the permanent magnet is compared with the case where the repulsive force along the axial direction of the central axis L between the driven-side rotator 10 and the drive-side rotator 20 is to be realized by the magnetic repulsive force. The amount of (151) used can be reduced, which makes it possible to reduce the manufacturing cost.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made. A modification will be described below.

  FIG. 6 is an explanatory view schematically showing a part in cross section of a modification of the magnetic coupling device according to the embodiment of the present invention. In addition, the same code | symbol is attached | subjected to what has the same structure as the magnetic coupling apparatus which is embodiment mentioned above, and the description is abbreviate | omitted.

  The magnetic coupling device illustrated here includes a driven side rotating body (first rotating body) 100 and a driving side rotating body 20.

  The driven side rotating body 100 is different from the driven side rotating body 10 of the magnetic coupling device according to the embodiment described above in that a bimetal member 16 is provided. The bimetal member 16 is disposed in the spring holding portion 13 and is interposed between one end of the coil spring 131 and the spring holding portion 13. The bimetal member 16 is deformed when it reaches a predetermined temperature (for example, 120 ° C.) or higher, and presses the coil spring 131 toward the drive side rotating body 20.

  Also in such a magnetic coupling device, as shown in FIG. 7, the separation distance between the driving side rotating body 20 and the driven side rotating body 100 that slides in a manner close to the driven side rotating body 100 is a predetermined distance. When the size is less than or equal to the size, the restoring force of the coil spring 131 works by the driving-side rotating body 20 abutting against the friction plate 132 and pressing the friction plate 132, and the repulsive force along the axial direction of the central axis L Will act. In this case, since the separation distance between the magnet group 15 and the magnetic disk 23 is also reduced, the magnetic attractive force acting between the permanent magnet 151 and the yoke tooth group 231 is also increased, and as a result, the axial direction of the central axis L is increased. The magnetic attractive force is substantially equal to the repulsive force of the coil spring 131 (repulsive force along the axial direction of the central axis L). On the other hand, since the drive-side rotating body 20 rotates around the central axis L, the magnetic attraction force in the rotational direction around the central axis L between the magnet group 15 and the magnetic disk 23 also increases. The body 100 rotates in synchronization with the drive-side rotator 20, whereby torque is transmitted from the drive-side rotator 20 to the driven-side rotator 100.

  By the way, for example, due to the lock of the compressor device or the like, the rotation of the driven-side rotator 100 and the rotation of the drive-side rotator 20 may be in a so-called step-out state without being synchronized. In such a step-out state, the temperature of the permanent magnet 151 becomes high due to heat generated from the eddy current effect, and as a result, the permanent magnet 151 may be demagnetized, and torque may not be transmitted well.

  When the temperature of the permanent magnet 151 rises and the bimetal member 16 reaches a predetermined temperature or more, as shown in FIG. 8, the bimetal member 16 is deformed and presses the coil spring 131 toward the driving side rotating body 20, thereby The drive-side rotator 20 slides in a direction away from the driven-side rotator 100. Thereby, the separation distance between the driven-side rotator 100 and the drive-side rotator 20 can be increased, and the eddy current effect can be reduced.

  As described above, the magnetic coupling device according to the present invention is provided on one side by the magnetic force generated between the working surfaces of the first rotating body and the second rotating body provided in such a manner that the working surfaces are spaced apart from each other. This is suitable for transmitting torque from the rotating body to the other rotating body.

10 Driven side rotating body (first rotating body)
20 Drive-side rotating body (second rotating body)
123 Restricting member 13 Spring holding portion 14 Magnet holding portion 131 Coil spring (spring member)
132 Friction plate 141 Working surface 15 Magnet group 151 Permanent magnet 22 Outer peripheral area portion 221 Working surface 23 Magnetic plate 231 Yoke tooth group L Central axis (rotating shaft)

Claims (1)

A first rotating body and a second rotating body that are provided so as to face each other in such a manner that their working surfaces are close to and away from each other, and are rotatable about a common rotation axis that extends along a direction orthogonal to the working surface. A magnetic coupling device that transmits torque from a rotating body on one side to a rotating body on the other side by a magnetic force generated between the working surfaces of the first rotating body and the second rotating body.
A separation distance between the first rotating body and the second rotating body is equal to or less than a predetermined size between the inner peripheral areas close to the rotating shaft on the respective working surfaces of the first rotating body and the second rotating body. A spring member that generates a repulsive force along the axial direction of the rotating shaft by its own restoring force when
A magnetic force unit that generates a magnetic attractive force along the axial direction of the rotating shaft between outer peripheral areas on the outer surfaces of the first rotating body and the second rotating body on the outer diameter side of the place where the spring member is disposed. And
The magnetic unit is
A plurality of permanent magnets are arranged at predetermined intervals at a position corresponding to the outer peripheral region on the working surface of the first rotating body in such a manner that magnetic poles adjacent to each other are different from each other along the circumferential direction around the rotation axis. A group of magnets,
A plurality of magnetic bodies are arranged at predetermined intervals along a circumferential direction centering on the rotation axis at locations where the first rotating body rotates relative to the permanent magnet on the working surface of the second rotating body. in Ri formed and a magnetic plate made is arranged,
The second rotating body is not biased in a direction away from the first rotating body when a separation distance from the first rotating body exceeds a predetermined size. A magnetic coupling device.

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