JP2011169381A - Electromagnetic coupling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the hitting noise of an armature with a friction member in a simple constitution. <P>SOLUTION: The electromagnetic clutch 1 (electromagnetic coupling device) includes an armature 3 which is arranged movably in the axial direction of a rotary shaft of a coupled device, a field core 7 which has an excitation coil 7a to attract the armature 3 by the magnetic force generated by the conduction to the excitation coil 7a, an energizing means 4 for energizing the armature 3 in the separating direction from the field core 7, a friction part 5 which is provided opposite to the armature 3, friction-engaged with the armature 3 by the magnetic force, and has a recessed part 5b on a friction surface 5a side with the armature 3, and an elastically deforming facing part 6 which is provided in the recessed part 5b with at least part thereof being projected from the friction surface 5a. A deformation permitting part 12 for permitting the deformation in the direction orthogonal to the axial direction of the facing part 6 when pressing the armature 3 against the friction part 5 is formed in the recessed part 5b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetic coupling device.

  The electromagnetic coupling device is an electromagnetic clutch that couples the respective rotation shafts of two connected devices, or an electromagnetic brake that applies a braking force to the rotation shaft of the connected device. An example of a conventional electromagnetic coupling device is shown in FIG.

  The electromagnetic clutch 91 in FIG. 7 includes a hub 92 attached to a rotating body (not shown) of one driven device so as to be integrally rotatable, an armature 93 attached to the hub 92 so as to be axially movable, and the other A friction member (rotor) 95 connected to the rotating shaft 98 of the connected device so as to rotate integrally, a field core 97 having an exciting coil 97a fixed to the other connected device (not shown), and the armature 93 are frictioned. And a leaf spring 94 urging in a direction away from the member 95.

  When a current is supplied to the exciting coil 97a, a magnetic circuit A indicated by a broken line in FIG. 7A is formed, and the armature 93 is attracted to the field core 97 by the magnetic force and frictionally engages with the friction member 95. A rotational force is transmitted between the two connected devices. On the other hand, when the excitation coil 97a is not energized, the armature 93 is separated from the friction member 95 by the urging force of the leaf spring 94, and the transmission of the rotational force is cut off.

  As shown in FIG. 7, the friction member 95 faces the armature 93 as shown in FIG. 7 for the purpose of stably generating a frictional force between the friction member 95 and the armature 93 and suppressing wear of the friction member 95 and the armature 93. An annular facing portion 96 may be provided on the surface. The facing portion 96 is formed by blending a binder, a filler, a friction property improving agent, or the like using a metal fiber or the like as a base material. Usually, the surface of the facing portion 96 is substantially flush with the friction surface 95 a of the friction member 95.

  In such a conventional electromagnetic coupling device, when the armature 93 and the friction member 95 are brought into contact with each other, a large collision sound is generated due to the contact between the metal surfaces. For example, Patent Documents 1 and 2 disclose electromagnetic coupling devices that reduce the collision noise.

  In the electromagnetic clutch described in Patent Document 1, a facing portion including two layers of a wear-resistant member and an elastic member is provided on a surface of the friction member (rotor) facing the armature. The wear resistant member and the elastic member are stacked in the axial direction of the rotating shaft, and a part of the wear resistant member protrudes from the surface of the friction member. According to this electromagnetic coupling device, when the armature and the friction member are brought close to each other, the armature first contacts the facing portion and contacts the friction member while compressing and deforming the elastic member of the facing portion in the axial direction. Therefore, the collision force between the armature and the friction member is alleviated, and the collision noise between the metal surfaces is reduced.

  Patent Document 2 aims to prevent a collision sound between the outermost peripheral portions by focusing on the fact that a particularly loud collision sound is generated when the outermost peripheral portions of the armature and the friction member collide with each other. In the electromagnetic clutch described in Patent Document 2, an annular facing portion that protrudes a minute amount from this surface is provided on the surface of the friction member (rotor) facing the armature. In addition, the surface of the friction member facing the armature is stepped so that the outer (outer peripheral) portion of the facing portion is deeper than the inner (inner peripheral) portion of the facing portion. ing. According to this electromagnetic coupling device, even when the facing portion is worn, the metal surfaces are in contact with each other at least at the inner peripheral side portion of the friction member, and the armature and the friction member are in contact only at the outermost peripheral portion. As a result, the collision noise is reduced.

  In the electromagnetic clutch of Patent Document 2, the size of the step between the inner peripheral portion and the outer peripheral portion of the friction surface is set to a minute value of about 0.05 mm. This is because if the level difference is large, the gap between the outer peripheral side portion of the friction member and the armature becomes large, and the magnetic attractive force acting on the armature decreases.

Japanese Patent Laid-Open No. 9-329157 JP-A-4-236825

However, in the electromagnetic clutch described in Patent Document 1, since the facing portion is composed of two layers of the wear-resistant member and the elastic member, it takes time to manufacture the facing portion, and the manufacturing cost increases.
Further, when the armature and the friction member are brought into contact with each other, the elastic member of the facing portion is compressed in the axial direction and at the same time extends in the radial direction, so that peeling is likely to occur at the joint surface between the elastic member and the wear-resistant member.

Moreover, in the electromagnetic clutch of patent document 2, the friction surface of a friction member is formed so that the outer peripheral side part may be in a position recessed about 0.05 mm from the inner peripheral part. Since the friction surface has such a minute step shape, it takes time to process the friction surface, and the manufacturing cost increases.
Even if the step size is set to such a small value as described above, there is a problem that the magnetic attractive force is slightly reduced as long as there is a gap between the outer peripheral portion of the friction surface and the armature.

  Then, an object of this invention is to provide the electromagnetic coupling device which can reduce the collision sound of an armature and a friction member by simple structure.

Means for Solving the Problems and Effects of the Invention

  The electromagnetic coupling device according to the present invention includes an armature arranged to be movable in the axial direction of the rotating shaft of the coupled device and an exciting coil, and a field that draws the armature by a magnetic force generated by energizing the exciting coil. A core, biasing means for biasing the armature in a direction away from the field core, and opposed to the armature, and frictionally engaged with the armature by the magnetic force or the biasing force of the biasing means. And a friction portion having a recess on the friction surface side with the armature, and an elastically deformable facing portion provided in the recess and protruding at least partially from the friction surface. A deformation allowing portion that allows deformation in a direction perpendicular to the axial direction of the facing portion when pressed against the portion; Characterized in that it is formed in a recess or in the armature-side surface of the facing portion.

  According to this configuration, since the facing portion protrudes at least partially from the friction surface of the friction portion, when the armature is moved to the friction portion side by a magnetic force or a biasing force, the armature first contacts the facing portion. To do. Since the armature contacts the friction surface of the friction portion while pressing the deforming portion in the axial direction of the rotating shaft, the collision force between the armature and the friction portion is reduced, and the collision sound is reduced. .

Since deformation in the direction perpendicular to the axial direction of the rotation axis of the facing portion is allowed by the deformation allowing portion formed in the recess or on the armature side surface of the facing portion, when the facing portion is pressed by the armature, The facing part can be easily deformed. Therefore, since the facing portion can be easily deformed even if it is formed of a material having relatively high hardness, the facing portion has a multilayer structure of wear-resistant material and elastic material like a conventional electromagnetic coupling device. There is no need to configure.
In addition, the friction portion only needs to be formed with a recess for accommodating the facing portion, and a complicated shape such as a minute step is not required as in the conventional electromagnetic coupling device.
Thus, since the structure for reducing a collision sound is simple, manufacturing cost can be reduced.

  In the present invention, the concave portion is formed in an annular shape concentric with the rotating shaft, and the facing portion is composed of a plurality of facing pieces arranged at a predetermined interval in the circumferential direction of the rotating shaft, It is preferable that a deformation | transformation permission part is a clearance gap between the two said facing pieces adjacent to the said circumferential direction.

  According to this configuration, since a gap (deformation allowing portion) is formed between adjacent facing pieces, when the facing piece is pressed in the axial direction by the armature, the facing piece can be expanded and deformed in the circumferential direction.

  In the present invention, the concave portion and the facing portion are annular, and the deformation allowing portion is formed on the armature side surface of the facing portion with a predetermined interval in the circumferential direction and extending in the radial direction. It is preferable that there are a plurality of grooves.

  According to this configuration, since the radially extending groove (deformation permitting portion) is formed on the armature side surface of the facing portion, when the facing portion is pressed in the axial direction by the armature, the facing portion is in the circumferential direction. Can be expanded and deformed.

  In the present invention, it is preferable that the concave portion and the facing portion are annular, and the deformation allowing portion is an annular concave portion formed on the armature side surface of the facing portion.

  According to this configuration, since the annular recess (deformation allowing portion) is formed on the armature side surface of the facing portion, the facing portion can be expanded and deformed in the radial direction when the facing portion is pressed in the axial direction by the armature.

It is a figure which shows the state at the time of the deenergization of the electromagnetic clutch which concerns on 1st Embodiment of this invention, Comprising: (a) is sectional drawing of an axial center direction, (b) is the II sectional view taken on the line of (a). FIG. It is the II-II arrow directional view of Fig.1 (a). It is a figure which shows the state at the time of electricity supply of the electromagnetic clutch which concerns on 1st Embodiment of this invention, Comprising: (a) is sectional drawing of an axial center direction, (b) is the III-III sectional view taken on the line of (a). It is. It is a figure which shows the electromagnetic clutch which concerns on 2nd Embodiment of this invention, Comprising: (a) is the elements on larger scale of axial direction sectional drawing, (b) is the IV-IV sectional view taken on the line of (a). . It is a figure which shows the electromagnetic clutch which concerns on 3rd Embodiment of this invention, Comprising: (a) is the elements on larger scale of axial direction sectional drawing, (b) is the VV sectional view taken on the line of (a). . It is sectional drawing of the axial center direction of the electromagnetic brake which concerns on 4th Embodiment of this invention. It is a figure which shows the conventional electromagnetic clutch, Comprising: (a) is sectional drawing of an axial center direction, (b) is the VII-VII sectional view taken on the line of (a).

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described. In the present embodiment, an example in which the electromagnetic coupling device of the present invention is applied to an electromagnetic clutch will be described.

  As shown in FIG. 1, the electromagnetic clutch 1 of the present embodiment is a dry electromagnetic clutch, and is attached to a rotating body (not shown) of a driven device (connected device, not shown) so as to be integrally rotatable. The hub 2, the armature 3 and the leaf spring (biasing means) 4 attached to the hub 2, and the rotor (friction part) 5 fixed to the rotating shaft 8 of the drive side device (connected device, not shown). And a facing portion 6 provided in the rotor 5 and a field core 7 fixed to the drive side device. The axis of the rotating body of the driven device and the axis of the rotating shaft of the driving device are the same. Hereinafter, the axial direction of the rotating shaft 8 will be described as the axial direction. In addition, the horizontal direction in FIGS. 1A and 3A is defined as the horizontal direction and will be described below. The same applies to FIGS. 4A, 5A, and 6 of the second to fourth embodiments described later.

  In this embodiment, the rotating shaft of the driven device is connected to the hub 2 and the rotating shaft 8 of the driving device is connected to the rotor 5. Conversely, the rotating shaft of the driving device is connected to the hub 2. Then, the rotating shaft 8 of the driven device may be connected to the rotor 5.

  The hub 2 is a substantially cylindrical member, and has a flange portion on the left side portion. As shown in FIG. 2, a plurality of (three in FIG. 2) bolt insertion holes 2a arranged in the circumferential direction are formed in the flange portion, and the hub 2 is inserted into the bolt insertion holes 2a. It is fixed to a rotating body (not shown) of the driven side device by a bolt (not shown).

  The armature 3 is an annular flat plate member made of magnetic metal (for example, iron). The armature 3 is attached to the outer peripheral surface of the right portion of the hub 2 so as to be movable in the axial direction and integrally rotatable. The right end surface of the armature 3 is orthogonal to the axial direction.

  The leaf spring 4 is annular and has an inner peripheral portion attached to the hub 2 and an outer peripheral portion attached to the armature 3. The leaf spring 4 biases the armature 3 in the left direction (on the side opposite to the rotor 5 described later).

  The field core 7 is composed of an exciting coil 7a and a yoke 7b incorporating the exciting coil 7a. The yoke 7b is a ring-shaped member having an annular groove opened on the left side, and is formed of a metal having magnetism. The right end surface of the yoke 7b is fixed to the fixed plate 10 of the drive side device. The inner peripheral surface of the yoke 7 b is attached to the rotary shaft 8 of the drive side device via a sliding bearing 9 and is rotatable relative to the rotary shaft 8.

  A lead wire 11 for supplying current to the exciting coil 7a is drawn out from the outer peripheral surface of the yoke 7b. When a current is supplied to the exciting coil 7a, the armature 3 is attracted to the yoke 7b.

  The rotor (friction part) 5 is an annular member, and is formed of a metal having magnetism like the armature 3. The rotor 5 is disposed between the field core 7 and the armature 3. The inner peripheral surface of the rotor 5 is fixed to the rotary shaft 8 and can rotate integrally with the rotary shaft 8.

  The left end surface of the outer peripheral side portion of the rotor 5 faces the armature 3. An annular recess 5 b is formed on the left end surface of the outer peripheral portion of the rotor 5. Of the left end surface of the outer peripheral portion of the rotor 5, a region excluding the recess 5 b (hereinafter, this region is referred to as a friction surface 5 a) can contact the armature 3. In addition, a plurality of through holes 5c for controlling the magnetic circuit A are formed side by side in the circumferential direction on the bottom surface (back surface) of the recess 5b. In addition, in FIG.1 (b), the display of the through-hole 5c is abbreviate | omitted.

  The facing part 6 is accommodated in the recess 5b. As shown in FIG. 1B, the facing portion 6 includes a plurality (four in this embodiment) of arcuate facing pieces 6 a arranged at a predetermined interval in the circumferential direction of the rotating shaft 8. As shown in FIG. 1A, the facing piece 6a has a right end surface fixed to the bottom surface of the recess 5b with an adhesive or the like, and a left end surface 6b protruding from the friction surface 5a. The radial length of the facing piece 6a is substantially the same as the radial width of the recess 5b. Let the clearance gap formed between the two facing pieces 6a adjacent to the circumferential direction be the deformation | transformation permission part 12. FIG. Although details will be described later, the deformation allowing portion 12 is for allowing deformation of the facing portion 6.

  The facing piece 6a has a lower hardness than the material constituting the armature 3 and the rotor 5, and is made of an elastically deformable material. Considering wear resistance and the like, it is preferable that the hardness is high. Specifically, the facing piece 6a is formed by blending many components such as a binder, a filler, and a friction property improver with a metal fiber and a metal powder as a base material to a predetermined thickness with a grinding machine. It is made by finishing. As the binder, thermosetting resins such as phenol resin, melamine resin, and polyimide resin are used. As the filler, carbon, calcium carbonate, magnesium carbonate, barium sulfate and the like are used. Further, as the friction property improver, solid lubricants such as graphite and molybdenum disulfide, cashew dust, and the like are used. Further, a rubber composition such as NBR (acrylonitrile-butadiene copolymer rubber) or SBR (styrene butadiene rubber), or cork powder may be added to the facing piece 6a.

  In addition, depending on the use conditions of the electromagnetic clutch 1, it replaces with the facing piece 6a which consists of a mixed material which used the metal fiber and the metal powder as a base material as mentioned above, and the facing piece which consists of a cork, a rubber composition, or a resin composition 6a may be used.

  Next, the operation of the electromagnetic clutch 1 will be described.

  In a state where no current is supplied to the exciting coil 7a, the armature 3 is separated from the rotor 5 by the urging force of the leaf spring 4 as shown in FIG. Therefore, the rotation of the rotor 5 is not transmitted to the hub 2.

  On the other hand, when a current is supplied to the exciting coil 7a, the yoke 7b is magnetized as shown in FIG. 3A to form a magnetic circuit A indicated by a broken line in FIG. It is drawn to the rotor 5 side and first comes into contact with the end faces 6b of the plurality of facing pieces 6a, and the facing pieces 6a are pressed and deformed in the axial direction. Thereafter, the armature 3 comes into frictional engagement with the friction surface 5a of the rotor 5 while pressing and deforming the facing portion 6. Thereby, the rotation of the rotor 5 is transmitted to the hub 2.

  Thus, since the armature 3 contacts the friction surface 5a while deforming the facing portion a, the collision force between the armature 3 and the friction surface 5a is relieved, and the collision sound between the metal surfaces can be reduced.

Since a gap (deformation allowable portion) 12 is formed between the adjacent facing pieces 6a, the facing piece 6a is compressed and deformed in the axial direction and simultaneously expanded in the circumferential direction when pressed by the armature 3 in the axial direction. Can be transformed. That is, since the expansion due to the compressive deformation in the axial direction can be released to the deformation allowing portion 12, the facing piece 6a can be easily deformed. Accordingly, the facing portion 6 can be easily deformed even if it is formed of a material having a relatively high hardness. Therefore, the facing portion 6 has a multi-layer structure of a wear-resistant material and an elastic material as in the conventional electromagnetic coupling device. There is no need to configure the part.
Further, the rotor 5 only needs to be formed with an annular recess 5b for accommodating the facing portion 6 and does not require a complicated shape such as a minute step as in the conventional electromagnetic coupling device. Further, since the facing portion 6 has a simple shape composed of a plurality of arcuate facing pieces 6a, it is easy to manufacture and manufactured at substantially the same cost as the facing portion 96 of the conventional electromagnetic clutch 91 as shown in FIG. can do.
Thus, since the structure for reducing a collision sound is simple, manufacturing cost can be reduced.

  Further, since the facing portion 6 can be easily deformed, the facing portion 6 is less likely to be worn compared to the case where the deformation allowing portion 12 is not provided. Therefore, the state in which the facing portion 6 protrudes from the friction surface 5a can be maintained for a long time, and the collision noise can be reduced over a long period of time.

  Further, since the facing portion 6 is elastically deformed, the armature 3 and the friction surface 5a can be reliably brought into contact with each other even when the accuracy of the protruding amount of the facing portion 6 from the friction surface 5a is low. As a result, the magnetic resistance of the magnetic circuit A is reduced and the magnetic attractive force is increased, so that the transmission torque can be improved.

  Further, the configuration for reducing the collision noise of the electromagnetic clutch 1 includes the facing portion 6 and the deformation allowing portion 12 and is a simple configuration, and therefore can be applied to a small electromagnetic clutch.

Second Embodiment
Next, a second embodiment of the present invention will be described. However, about the thing which has the structure similar to the said 1st Embodiment, the description is abbreviate | omitted suitably using the same code | symbol.

  The electromagnetic clutch 201 of the present embodiment is the same as the electromagnetic clutch 1 of the first embodiment, except that the facing portion 206 housed in the recess 5b of the rotor 5 is different from the facing portion 6 of the first embodiment. It has the composition of.

  As shown in FIGS. 4A and 4B, the facing portion 206 is formed in an annular shape, and is fixed to the bottom surface of the recess 5b with an adhesive or the like. The material of the facing part 206 is the same as the material of the facing part 6 of the first embodiment. The inner diameter and outer diameter of the facing portion 206 are substantially the same as the inner diameter and outer diameter of the recess 5b. On the left end face of the facing portion 206, eight groove portions (deformation allowing portions) 206b extending in the radial direction are formed at predetermined intervals in the circumferential direction. Of the left end face of the facing part 206, a part excluding the groove part 206 b (hereinafter referred to as end face 206 a) protrudes from the friction surface 5 a of the rotor 5. The bottom surface of the groove 206b is located on the substantially same plane as the friction surface 5a, but may be located deeper than the friction surface 5a.

  In the electromagnetic clutch 201 of the present embodiment, when a current is supplied to the exciting coil 7a, the armature 3 is attracted to the rotor 5 side by a magnetic attractive force, and first comes into contact with the end face 206a of the facing portion 206. Then, the facing portion 206 is pressed and deformed in the axial direction, and is brought into contact with the friction surface 5 a of the rotor 5 to be frictionally engaged with the rotor 5. Thereby, the rotation of the rotor 5 is transmitted to the hub 2.

Since a radially extending groove 206b is formed on the left end surface of the facing portion 206, the facing portion 206 is compressed and deformed in the axial direction when pressed by the armature 3 in the axial direction, and at the same time in the circumferential direction. Can expand and deform. In other words, since the expansion due to the compressive deformation in the axial direction can be released to the groove 206b, the facing portion 206 can be easily deformed. Accordingly, since the facing portion 206 can be easily deformed even if it is formed of a material having a relatively high hardness, the facing portion 206 has a multi-layer structure of a wear-resistant material and an elastic material as in a conventional electromagnetic coupling device. There is no need to configure the part.
Further, since the facing portion 206 has a simple shape of an annular member having a plurality of groove portions 206b formed on the end face, it is easy to manufacture and is almost the same as the facing portion 96 of the conventional electromagnetic clutch 91 as shown in FIG. Can be manufactured at the same cost. Furthermore, since the facing portion 206 is annular, it can be easily installed in the recess 5b.
Thus, since the structure for reducing a collision sound is simple, manufacturing cost can be reduced.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. However, about the thing which has the structure similar to the said 1st Embodiment, the description is abbreviate | omitted suitably using the same code | symbol.

  The electromagnetic clutch 301 of the present embodiment is the same as the electromagnetic clutch 1 of the first embodiment, except that the facing portion 306 housed in the recess 5b of the rotor 5 is different from the facing portion 6 of the first embodiment. It has the composition of.

  As shown in FIGS. 5A and 5B, the facing portion 306 is formed in an annular shape, and is fixed to the bottom surface of the concave portion 5b with an adhesive or the like. The material of the facing part 306 is the same as the material of the facing part 6 of the first embodiment. The inner diameter and outer diameter of the facing portion 306 are substantially the same as the inner diameter and outer diameter of the recess 5b. As shown in FIG. 5A, an annular concave portion (deformation allowing portion) 306b that is recessed from the outer peripheral portion is formed in the inner peripheral portion of the left end surface of the facing portion 306. An outer peripheral side portion (hereinafter referred to as an end surface 306 a) of the left end surface of the facing portion 306 protrudes from the friction surface 5 a of the rotor 5. The inner surface of the recess 306b is located substantially flush with the friction surface 5a, but may be located deeper than the friction surface 5a.

  In the electromagnetic clutch 301 of the present embodiment, when a current is supplied to the exciting coil 7 a, the armature 3 is attracted to the rotor 5 side by a magnetic attractive force, and first comes into contact with the end surface 306 a of the facing portion 306. The facing portion 306 is pressed and deformed in the axial direction, and is brought into contact with the friction surface 5 a of the rotor 5 to be frictionally engaged with the rotor 5. Thereby, the rotation of the rotor 5 is transmitted to the hub 2.

Since the annular recess 306b is formed on the left end face of the facing portion 306, the facing portion 306 can be deformed in the radial direction and simultaneously expanded and deformed in the radial direction when being pressed in the axial direction by the armature 3. In other words, since the expansion due to the compressive deformation in the axial direction can be released to the concave portion 306b, the facing portion 306 can be easily deformed. Accordingly, since the facing portion 306 can be easily deformed even if it is formed of a material having a relatively high hardness, the facing portion 306 has a multi-layer structure of a wear-resistant material and an elastic material as in a conventional electromagnetic coupling device. There is no need to configure the part.
Further, since the facing portion 306 has a simple shape of an annular member in which an annular recess 306b is formed on the inner peripheral side portion of the end face, the manufacturing is easy, and the conventional electromagnetic clutch 91 shown in FIG. The facing portion 96 can be manufactured at substantially the same cost. Furthermore, since the facing portion 306 is annular, it can be easily installed in the recess 5b.
Thus, since the structure for reducing a collision sound is simple, manufacturing cost can be reduced.

  In the present embodiment, the annular recess (deformation allowing portion) 306b is formed on the inner peripheral portion of the left end face of the facing portion 306, but may be formed on the outer peripheral portion of the left end face. Moreover, you may form in the middle of the radial direction of the left end surface, and in this case, the annular recessed part 306b may be formed in multiple numbers along with the radial direction.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. In the present embodiment, an example in which the electromagnetic coupling device of the present invention is applied to an electromagnetic brake will be described. However, about the thing which has the structure similar to the said 1st Embodiment, the description is abbreviate | omitted suitably using the same code | symbol.

  As shown in FIG. 6, the electromagnetic brake 401 of the present embodiment includes a hub 402, a friction member 405, and a field core 407 instead of the hub 2, the rotor 5, and the field core 7 of the electromagnetic clutch 1 of the first embodiment. Have

  The hub 402 is a cylindrical member, and a rotation shaft (not shown) of the connected device is fitted inside the inner peripheral portion. The field core 407 includes an exciting coil 407a and a yoke 407b that incorporates the exciting coil 407a, and is fixed to the connected device via the fixed plate 10. The friction member 405 is attached to the left end portion of the field core 407 so as to face the armature 3. An annular recess 405b is formed on the left end surface of the friction member 405, and the facing portion 6 including a plurality of facing pieces 6a arranged in the circumferential direction is accommodated in the recess 405b. The left end surface 6b of the facing piece 6a protrudes from the friction surface 405a of the friction member 405.

  In the electromagnetic brake 401 of the present embodiment, when a current is supplied to the exciting coil 407a, the armature 3 is attracted to the friction member 405 side by a magnetic attractive force, and first contacts the end face 6b of the facing portion 6. The facing portion 6 is brought into contact with the friction surface 5 a of the rotor 5 and is frictionally engaged with the rotor 5 while being pressed and deformed in the axial direction. As a result, a braking force is applied to the rotation of the hub 402.

  The electromagnetic coupling devices of the first to fourth embodiments are excitation actuated electromagnetic clutches in which the armature 3 and the friction portions 5 and 405 are in contact with each other when the excitation coil 7a is energized. The present invention may be applied to a non-excitation operation type electromagnetic coupling device in which the armature 3 and the friction portions 5 and 405 come into contact with each other when shut off. In this case, the electromagnetic coupling device includes an urging means such as a leaf spring that urges the armature toward the rotor (ie, in a direction away from the field core).

1 Electromagnetic clutch 2 Hub 3 Armature 4 Leaf spring (biasing means)
5 Rotor (friction part)
5a Friction surface 5b Recess 6 Facing part 6a Facing piece 6b End face 7 Field core 7a Excitation coil 7b Yoke 12 Deformation allowance part 201, 301 Electromagnetic clutch 206, 306 Facing part 206a, 306a End face 206b Groove part (deformation allowance part)
306b Concavity (deformation allowance)
401 Electromagnetic brake 405 Friction member 407 Field core

Claims (2)

An armature arranged so as to be movable in the axial direction of the rotating shaft of the connected device;
A field core that has an exciting coil and attracts the armature by a magnetic force generated by energizing the exciting coil;
Biasing means for biasing the armature in a direction away from the field core;
A friction portion provided facing the armature, frictionally engaged with the armature by the magnetic force or the biasing force of the biasing means, and having a recess on the friction surface side with the armature;
An elastically deformable facing portion provided in the recess and at least a portion protruding from the friction surface;
A deformation allowing portion that allows deformation in a direction perpendicular to the axial direction of the facing portion when the armature is pressed against the friction portion is formed in the recess or on the armature side surface of the facing portion. An electromagnetic coupling device. The recess is formed in an annular shape concentric with the rotating shaft;
The facing portion is composed of a plurality of facing pieces arranged at predetermined intervals in the circumferential direction of the rotating shaft,
The electromagnetic coupling device according to claim 1, wherein the deformation allowing portion is a gap between two facing pieces adjacent in the circumferential direction.

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