JP2014039361A - Eddy current type reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eddy current type reduction gear capable of effectively suppressing temperature rise of a permanent magnet during braking with a simple configuration.SOLUTION: A reduction device includes; a brake disk 1 which is fixed to a rotary shaft of a vehicle; a magnet holding disk 4 which holds a plurality of permanent magnets 5 whose magnetic polarities are mutually and alternately arranged over a circumferential direction while being opposite to a main surface of the brake disk 1, and which is rotatably supported by the rotary shaft; and a friction brake which makes the magnet holding disk 4 rest during braking. A magnet cover 20 of a nonmagnetic metal material composed of a thin plate covering a front surface opposite to the main surface of the brake disk 1 together with a magnet 5 is attached to the magnet holding disk 4. Between magnets adjacent in the circumferential direction, a heat transfer block 21 of the nonmagnetic metal material is arranged which is in contact with the magnet cover 20 and the magnet holding disk 4.

Description

  The present invention relates to an eddy current speed reducer mounted as an auxiliary brake on a vehicle such as a truck or a bus, and more particularly to an eddy current speed reducer using a permanent magnet to generate a braking force.

  In general, an eddy current type speed reducer (hereinafter also simply referred to as “speed reducer”) using a permanent magnet (hereinafter also simply referred to as “magnet”) has a braking member fixed to a rotating shaft such as a propeller shaft, During braking, an eddy current is generated on the surface of the braking member facing the magnet by the action of the magnetic field from the magnet, thereby generating a braking force in the direction opposite to the rotational direction on the braking member that rotates integrally with the rotating shaft, The rotating shaft is decelerated. The speed reducer is roughly divided into a drum type and a disk type according to the shape of a braking member that generates eddy current to provide a braking force, and a magnet holding member that holds the magnet and forms a pair with the braking member. There are also various structures for switching between non-braking and non-braking.

  2. Description of the Related Art In recent years, in order to meet the demand for downsizing of a device, a reduction device has been proposed in which a magnet holding member that holds a magnet is rotatably supported on a rotating shaft and the magnet holding member is stopped by a friction brake during braking. (For example, refer to Patent Documents 1 to 5). As shown below, this speed reduction device is referred to as a synchronous rotation type speed reduction device because the magnet holding member and the braking member rotate integrally in synchronism during non-braking.

  FIG. 1 is a longitudinal sectional view showing a configuration example of a conventional synchronous rotation speed reduction device. The speed reduction device shown in the figure is of a disk type, and includes a braking disk 1 as a braking member and a magnet holding disk 4 that faces the main surface of the braking disk 1 and holds a permanent magnet 5 as a magnet holding member.

  In FIG. 1, the brake disc 1 is configured to rotate integrally with a rotary shaft 11 such as a propeller shaft. Specifically, the connecting shaft 12 is fixed coaxially with the rotating shaft 11 by a bolt or the like, and a sleeve 13 with a flange is inserted into the connecting shaft 12 while being engaged with the spline 12 and fixed with a nut 14. The brake disc 1 is fixed to the flange of the sleeve 13 integrated with the rotating shaft 11 with a bolt or the like, and thereby rotates integrally with the rotating shaft 11.

  The brake disk 1 is provided with heat radiating fins 2 on the outer periphery, for example. The heat radiating fins 2 are formed integrally with the brake disc 1 and play a role of cooling the brake disc 1 itself. The brake disk 1 is made of a ferromagnetic material such as iron or a weak magnetic material such as ferritic stainless steel.

  In FIG. 1, the magnet holding disk 4 is configured to be rotatable with respect to the rotating shaft 11. The magnet holding disk 4 is formed integrally with the annular member 3 concentric with the connecting shaft 12 or is individually formed and fixed to the annular member 3 with a bolt or the like. The annular member 3 is supported by a sleeve 13 integrated with the rotating shaft 11 via bearings 15 a and 15 b, whereby the magnet holding disk 4 can freely rotate with respect to the rotating shaft 11. The bearings 15a and 15b are filled with lubricating grease, and the lubricating grease is prevented from leaking by ring-shaped seal members 16a and 16b attached to both front and rear ends of the annular member 3.

  A plurality of permanent magnets 5 are fixed to the magnet holding disk 4 in the circumferential direction on the surface facing the main surface of the brake disk 1. The permanent magnets 5 are arranged such that the magnetic poles (N pole, S pole) are oriented in the axial direction of the magnet holding disk 4 and the magnetic poles are alternately different between those adjacent in the circumferential direction.

  In FIG. 1, a magnet cover 20 made of a thin plate is attached to the magnet holding disk 4 so as to cover the entire permanent magnet 5. The magnet cover 20 not only protects the permanent magnet 5 from iron powder and dust, but also blocks the radiant heat from the braking disk 1 in order to prevent the magnetic force possessed by the permanent magnet 5 from being lowered by the heat effect. Take on. The material of the magnet cover 20 is a nonmagnetic material so as not to affect the magnetic field from the permanent magnet 5.

  The speed reducer shown in FIG. 1 includes a disk brake as a friction brake that stops the magnet holding disk 4 during braking. This disc brake is driven behind the magnet holding disc 4 by a brake disc 6 integrated with the annular member 3, a brake caliper 7 having brake pads 8 a and 8 b sandwiching the brake disc 6, and the brake caliper 7. And an electric linear actuator 9. The brake disk 6 is attached to the annular member 3 with a bolt or the like, and is integrated with the annular member 3.

  The brake caliper 7 has a pair of brake pads 8a and 8b at the front and rear, and a bolt mounted with a spring in a state where the brake disc 6 is disposed between the brake pads 8a and 8b with a predetermined gap therebetween. For example, the bracket 17 is urged and supported. The bracket 17 is attached to a non-rotating portion such as a vehicle chassis or a cross member. The bracket 17 surrounds the annular member 3 behind the brake disc 6 and is rotatably supported by the annular member 3 via a bearing 18. The bearing 18 is also filled with lubricating grease, and leakage of the lubricating grease is prevented by ring-shaped seal members 19a and 19b attached to the front and rear ends of the bracket 17.

  An actuator 9 is fixed to the brake caliper 7 with a bolt or the like. The actuator 9 is driven by the electric motor 10, converts the rotational motion of the electric motor 10 into a linear motion, and linearly moves the rear brake pad 8 b toward the brake disk 6. As a result, the rear brake pad 8b presses the brake disc 6 and the reaction force caused thereby moves the front brake pad 8a toward the brake disc 6. As a result, the brake disc 6 is moved forward and backward. The pad 8a, 8b is strongly sandwiched.

  In the speed reducer shown in FIG. 1, the disc brake (friction brake) is not operated during non-braking. At this time, as the brake disk 1 rotates integrally with the rotating shaft 11, the magnet holding disk 4 integrated with the annular member 3 is synchronized with the brake disk 1 by the magnetic attraction action between the permanent magnet 5 and the brake disk 1. And rotate together. For this reason, there is no relative rotational speed difference between the brake disk 1 and the permanent magnet 5, so no braking force is generated.

  On the other hand, at the time of braking, the disc brake (friction brake) is operated, and the brake disc 6 is sandwiched between the brake pads 8a and 8b. 4 stops. If only the magnet holding disk 4 is stationary while the brake disk 1 is rotating, a relative rotational speed difference is generated between the brake disk 1 and the permanent magnet 5. An eddy current is generated on the main surface of the brake disk 1, and a braking force can be generated on the rotating shaft 11 via the brake disk 1.

  As described above, the speed reduction device shown in FIG. 1 has a configuration in which a magnet holding disk 4 as a magnet holding member is rotatably supported on a rotary shaft 11 in order to be realized as a synchronous rotation type speed reduction device. As in the case of a speed reducer, the magnet holding disk 4 is supported so as to be movable in the direction along the rotating shaft 11, and the magnet holding disk 4 is kept stationary while being brought close to the braking disk 1 during braking, and the magnet holding disk is not braked. The configuration is also possible in which 4 is separated from the brake disk 1 (see, for example, Patent Document 6).

  In the case of this speed reducer, when not braked, the magnet holding disk is separated from the brake disk, so that the magnetic field from the permanent magnet does not act on the brake disk that rotates integrally with the rotating shaft. For this reason, no eddy current is generated on the main surface of the braking disk, and no braking force is generated.

  On the other hand, at the time of braking, the magnet holding disk moves toward the braking disk by the operation of the actuator or the like, and stops in a state of approaching the braking disk. Then, since the magnetic field from the permanent magnet in the magnet holding disk acts on the braking disk that rotates integrally with the rotating shaft, the relative rotational speed difference between the braking disk and the permanent magnet causes the main surface of the braking disk. Eddy current is generated. For this reason, a braking force is generated in the rotating braking disk, and the rotation of the rotating shaft can be decelerated through the braking disk.

  Moreover, although the speed reducer described above is a disk type, it can also be a drum type. In the case of a drum-type speed reducer, a brake drum is fixed to the rotating shaft of the vehicle, and a magnet holding drum that holds a plurality of permanent magnets in the circumferential direction is disposed opposite to the inner peripheral surface of the brake drum.

JP-A-4-331456 Japanese Utility Model Publication No. 5-80178 JP 2011-97696 A JP 2011-139574 A JP 2011-182574 A JP 2003-339150 A

  By the way, in the conventional speed reducer described above, the kinetic energy of the rotating shaft is converted into thermal energy by the eddy current generated in the braking member during braking, and the braking member generates heat by this thermal energy. At this time, the permanent magnet is close to the heat generation area of the braking member (the main surface of the braking disk in the case of the disc type, and the inner peripheral surface of the braking drum in the case of the drum type). It is in.

  If the temperature of the magnet rises above the heat-resistant temperature, the magnet itself undergoes thermal demagnetization, which reduces the braking force, so that the performance required as a reduction gear cannot be ensured. In order to prevent this, the braking time may be controlled so that the magnet temperature does not exceed the heat resistance temperature. In this case, the time during which continuous braking is possible is shortened. Furthermore, in order to increase the heat-resistant temperature, the magnet generally contains rare earth such as Dy (dysprosium). However, due to the recent rapid rise in the price of rare earth, not only the product cost becomes unstable, Securing rare earths can be difficult.

  Therefore, establishment of the technique which suppresses the temperature rise of the magnet at the time of braking is strongly desired. In this regard, for example, in the reduction gear described in Patent Document 1, a ferromagnetic plate called a pole piece is disposed on the surface of the magnet on the braking member side. In this case, since the distance from the heat generating area of the braking member to the magnet is increased by at least the thickness of the ferromagnetic plate, the temperature rise of the magnet is slowed down. At this time, since the heat generated in the braking member is once absorbed by the ferromagnetic plate, the heating rate of the magnet at the time of braking is moderated. The temperature rise of the magnet is inevitable.

  Further, for example, the speed reduction device described in Patent Document 6 has a structure in which a cooling medium is sprayed on the heat generation region of the braking member, and the braking member is actively cooled, and accordingly, the temperature of the magnet is increased. Can be suppressed. However, this speed reduction device requires a tank for storing the cooling medium, a device for supplying the cooling medium, and a space for installing them.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an eddy current reduction device that can effectively suppress a temperature increase of a permanent magnet during braking with a simple configuration. .

  The present inventors have considered a phenomenon in which the temperature of a magnet rises as the braking member generates heat during braking in a reduction gear using a permanent magnet, and on that basis, the above object can be achieved. The following findings were obtained through extensive studies on the configuration.

  FIG. 2 is a schematic diagram showing the arrangement relationship between the braking member and the magnet in order to explain the phenomenon in which the temperature of the permanent magnet rises during braking. In the same figure, the corresponding part of the reduction gear shown in FIG. 1 is enlarged and the magnet cover 20 is omitted.

  As shown in FIG. 2, during braking, when the magnet holding disk as the magnet holding member holding the magnet 5 is stationary, while the braking disk 1 as the braking member is rotating, the difference in rotational speed between the two holds. As a result, a strong flow of the atmospheric gas (air) occurs in the gap between the main surface of the brake disk 1 and the surface of the magnet 5 (see the dotted arrow in FIG. 2). For this reason, the ambient gas is heated by flowing in the heat generating area (main surface) of the brake disk 1. The magnet 5 is heated by convection heat transfer (heat exchange) with the atmospheric gas flowing at such a high temperature, and further by radiant heat transfer from the heat generation region of the brake disk 1 (see the wavy arrow in FIG. 2). Is also heated.

  Thus, the temperature rise of the magnet at the time of braking is due to convective heat transfer and radiant heat transfer accompanying heat generation of the brake member. Therefore, in order to avoid direct heating of the magnet by convective heat transfer and radiant heat transfer, first, a thin plate magnet made of a nonmagnetic metal material as shown in FIG. 1 is provided in the gap between the brake member and the magnet. Provide a cover.

  Here, heat is applied to the magnet cover by convective heat transfer and radiant heat transfer. At this time, if the magnet cover is in contact with the magnet, the heat received by the magnet cover is transferred to the magnet by heat conduction. For this reason, it is good to fix a magnet cover to a magnet holding member, maintaining a non-contact state with a magnet. If the material of the magnet cover is a ferromagnetic material, the magnet cover is attracted to the magnet by a magnetic force, so that the magnet cover itself is deformed, which makes it difficult to ensure a non-contact state with the magnet. .

  However, with only the magnet cover, the magnet is heated by heat conduction or gentle convection heat transfer using air in the gap between the magnet and the medium as a medium. Therefore, if a heat transfer block made of a non-magnetic metal material with excellent thermal conductivity is arranged between the magnets adjacent in the circumferential direction so that the heat of the magnet cover can be preferentially released in addition to the magnet. Good.

  The heat transfer block is fixed to the magnet holding member while being in contact with both the magnet cover and the magnet holding member in order to efficiently receive heat from the magnet cover and release heat to the magnet holding member. The magnet holding member has a heat capacity far greater than that of the heat transfer block. In particular, in the case of a synchronous rotation type reduction device, the magnet holding member rotates with the rotating shaft during non-braking and actively dissipates heat. Thereby, the magnet holding member is always maintained at a low temperature, and as a result, it is possible to effectively suppress the temperature rise of the magnet.

  From the above, a thin plate-shaped magnet cover made of a non-magnetic metal material is disposed in a gap between the heat generation area of the braking member and the magnet, and the magnet is adjacent to each other in the circumferential direction. If a heat transfer block made of a non-magnetic metal material is placed in contact with both the magnet cover and the magnet holding member, the heat flow from the heat generating area can be controlled to bypass the magnet, and the temperature of the magnet rises. Can be suppressed.

  The present invention has been completed based on the above findings, and the gist thereof is an eddy current type speed reducer shown in the following (1) and (2).

(1) The eddy current type speed reducer of the present invention is
A braking disk fixed to a rotating shaft of the vehicle, and a magnet holding disk that holds a plurality of permanent magnets that are arranged in a circumferential direction opposite to the main surface of the braking disk and that are alternately arranged. An eddy current type speed reducer,
The magnet holding disk is provided with a magnet cover made of a non-magnetic metal material made of a thin plate that covers the front surface facing the main surface of the brake disk together with the permanent magnet, and the magnet holding disk is disposed between the permanent magnets adjacent in the circumferential direction. An eddy current type speed reducer characterized in that a heat transfer block made of a nonmagnetic metal material in contact with a magnet cover and the magnet holding disk is disposed.

  In the reduction gear of (1), the magnet holding disk is rotatably supported by the rotating shaft, and can be configured to be stationary by a friction brake during braking.

  In the reduction gear of (1), the magnet holding disk is supported so as to be movable in the direction along the rotation axis, and can be configured to be stationary in the state of approaching the braking disk during braking. is there.

  In the reduction gear of the above (1), it is preferable that a radiating fin is provided on the back surface of the magnet holding disk corresponding to the position where the heat transfer block is disposed.

  Moreover, in the reduction gear of said (1), it is preferable that the heat insulation coating film is laminated | stacked on the inner surface of the said magnet cover corresponding to the position where the said permanent magnet is arrange | positioned.

(2) The eddy current speed reducer of the present invention is
A brake drum fixed to a rotating shaft of the vehicle, and a magnet holding drum holding a plurality of permanent magnets arranged alternately and differently in the circumferential direction facing the inner peripheral surface of the brake drum. Eddy current type reduction device,
The magnet holding drum is provided with a magnet cover made of a non-magnetic metal material made of a thin plate that covers an outer peripheral surface facing the inner peripheral surface of the brake drum together with the permanent magnet, and between the permanent magnets adjacent in the circumferential direction. The eddy current type speed reducer is characterized in that a heat transfer block made of a non-magnetic metal material in contact with the magnet cover and the magnet holding drum is disposed.

  In the speed reducer of (2), the magnet holding drum is rotatably supported on the rotating shaft, and can be configured to be stationary by a friction brake during braking.

  In the deceleration device according to (2), the magnet holding drum is supported so as to be movable in a direction along the rotation shaft, and may be configured to be stationary while approaching the braking drum during braking. is there.

  Moreover, in the speed reducer of said (2), it is preferable that the inner peripheral surface of the said magnet holding drum is provided with the radiation fin corresponding to the position where the said heat-transfer block is arrange | positioned.

  Moreover, in the reduction gear of said (2), it is preferable that the heat insulation coating film is laminated | stacked on the inner peripheral surface of the said magnet cover corresponding to the position where the said permanent magnet is arrange | positioned.

  According to the speed reducer of the present invention, even if the braking member (braking disc, braking drum) generates heat during braking, the heat is first transmitted to the magnet cover, and then has priority over the heat transfer block in contact with the magnet cover. Since the heat is transmitted to the magnet holding member (magnet holding disk, magnet holding drum) in contact with the heat transfer block and radiated, the temperature of the magnet can be effectively prevented from rising. . In addition, this speed reduction device does not require a special structure for blowing a cooling medium to the heat generation area of the braking member, unlike the conventional speed reduction device, and has a very simple configuration.

It is a longitudinal cross-sectional view which shows the structural example of the conventional synchronous rotation type reduction gear. It is a schematic diagram which shows the arrangement | positioning relationship between a braking member and a magnet in order to demonstrate the phenomenon that the temperature of a permanent magnet rises at the time of braking. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the principal part of the eddy current type reduction gear device which is 1st Embodiment of this invention, The same figure (a) is sectional drawing which looked at the magnet holding disk corresponded to a magnet holding member from the front side. FIG. 2B is a cross-sectional view taken along the line AA in FIG. 1A, and FIG. 2C is a cross-sectional view taken along the line BB in FIG. It is a schematic diagram which shows the principal part of the eddy current type | formula speed reducer which is 2nd Embodiment of this invention, The same figure (a) is sectional drawing which looked at the magnet holding disc corresponded to a magnet holding member from the front side. FIG. 2B is a sectional view taken along the line C-C in FIG. 2A, and FIG. 2C is a sectional view taken along the line D-D in FIG. It is a schematic diagram which shows the principal part of the eddy current type reduction gear device which is 3rd Embodiment of this invention, The same figure (a) is sectional drawing which looked at the magnet holding disk corresponded to a magnet holding member from the front side. FIG. 2B is a cross-sectional view taken along line EE in FIG. 2A, and FIG. 2C is a cross-sectional view taken along line FF in FIG. It is a schematic diagram which shows the structural example of the eddy current type | formula speed reducer which is 4th Embodiment of this invention, The figure (a) is a longitudinal cross-sectional view which shows the whole structure, The figure (b) is equivalent to a magnet holding member. FIG. 4C is a developed sectional view of the main part of the magnet holding drum viewed from the outer peripheral surface side, FIG. 5C is a sectional view taken along line GG in FIG. 5B, and FIG. -H sectional views are shown respectively.

  Hereinafter, embodiments of the eddy current type speed reducer of the present invention will be described in detail.

<First Embodiment>
FIG. 3 is a schematic view showing a main part of the eddy current reduction device according to the first embodiment of the present invention. FIG. 3 (a) is a cross-sectional view of a magnet holding disk corresponding to a magnet holding member as seen from the front side. The figure, (b) shows the AA sectional view of the figure (a), and (c) shows the BB sectional view of the figure (a), respectively. The speed reduction device of the first embodiment shown in the figure is based on the configuration of the disk-type and synchronous rotation type speed reduction device shown in FIG.

  As shown in FIG. 3, the speed reduction device of the first embodiment includes a braking disk 1 as a braking member that is fixed to the rotating shaft and rotates integrally with the rotating shaft, and faces the main surface of the braking disk 1. As a magnet holding member that holds a plurality of permanent magnets 5 in which magnetic poles are alternately arranged over the circumferential direction, a magnet holding disk 4 that is rotatably supported on a rotating shaft is provided. The magnet holding disk 4 is stopped by a friction brake (disk brake) during braking.

  In the first embodiment, a magnet cover 20 made of a thin plate is attached to the magnet holding disk 4 so as to cover the surface facing the main surface of the braking disk 1, that is, the front surface holding the permanent magnet 5 together with the permanent magnet 5. ing. The material of the magnet cover 20 is a nonmagnetic metal material such as aluminum or austenitic stainless steel. On the other hand, the material of the magnet holding disk 4 is a ferromagnetic metal material such as iron.

  Further, the magnet holding disk 4 is provided with a heat transfer block 21 between the magnets 5 adjacent in the circumferential direction in contact with both the magnet cover 20 and the magnet holding disk 4. The heat transfer block 21 is first joined to the magnet holding disk 4, and the magnet cover 20 is fixed to the magnet holding disk 4, whereby the heat transfer block 21 is brought into contact with the magnet cover 20. On the contrary, the heat transfer block 21 may be brought into contact with the magnet holding disk 4 by first joining the magnet cover 20 and fixing the magnet cover 20 to the magnet holding disk 4.

  The material of the heat transfer block 21 may be a nonmagnetic metal material and has a sufficiently higher thermal conductivity than the magnet 5, and aluminum, austenitic stainless steel, or the like can be employed. A clad material in which two types of nonmagnetic metal materials are bonded together can be used for the heat transfer block 21 to achieve both thermal conductivity and strength.

  Here, the magnet cover 20 is fixed to the magnet holding disk 4 while maintaining a non-contact state with the magnet 5. In order to maintain the non-contact state between the magnet cover 20 and the magnet 5, the thickness of the heat transfer block 21 may be slightly thicker than the thickness of the magnet 5. Moreover, it is preferable that the heat transfer block 21 is in a non-contact state with the magnet 5, and the shape and the number thereof are not particularly limited as long as they can be arranged between the magnets 5.

  According to the speed reducer having such a configuration, even when the braking disk 1 corresponding to the braking member generates heat during braking, the heat is first transmitted to the magnet cover 20 and then the heat conduction in contact with the magnet cover 20. Since the heat is transmitted preferentially to the heat transfer block 21 having high properties and is transferred to the magnet holding disk 4 in contact with the heat transfer block 21, the temperature of the magnet 5 is effectively prevented from rising. be able to. As a result, it is possible to avoid a reduction in braking force due to thermal demagnetization of the magnet 5, and it is possible to extend the time during which continuous braking is possible. Furthermore, the amount of rare earth (Dy: dysprosium) that increases the heat-resistant temperature of the magnet 5 can be made small or unnecessary in some cases, thereby reducing the cost. In addition, this speed reduction device does not require a special structure for spraying a cooling medium to the heat generation region of the braking member, unlike the conventional speed reduction device described in Patent Document 6, and has a very simple configuration.

  In particular, the speed reduction device according to the first embodiment is a synchronous rotation system, and the magnet holding disk 4 rotates together with the rotating shaft during non-braking, so that the heat held by the magnet holding disk 4 can be actively dissipated. is there.

Second Embodiment
FIG. 4 is a schematic view showing a main part of an eddy current reduction device according to a second embodiment of the present invention. FIG. 4 (a) is a sectional view of a magnet holding disk corresponding to a magnet holding member as seen from the front side. The figure, (b) shows the CC sectional view of the figure (a), the figure (c) shows the DD sectional view of the figure (a), respectively. The speed reducer according to the second embodiment shown in the figure is based on the configuration of the speed reducer according to the first embodiment shown in FIG.

  That is, as shown in FIG. 4, the magnet holding disk 4 of the speed reducer according to the second embodiment is provided with heat radiation fins 22 on the back side opposite to the front side holding the magnet 5. Here, the radiation fin 22 is limited to a position corresponding to the position where the heat transfer block 21 is arranged, that is, a position behind the heat transfer block 21 with the magnet holding disk 4 interposed therebetween. A plurality are provided in the circumferential direction. The radiating fins 22 are formed integrally with the magnet holding disk 4.

  In the speed reduction device of the second embodiment having such a configuration, the heat transmitted to the magnet holding disk 4 is actively radiated through the heat radiating fins 22, so that both the heat transfer block 21 and the magnet 5 have a cooling ability. improves. At this time, since the radiating fins 22 are provided only at positions corresponding to the positions where the heat transfer blocks 21 are disposed, the cooling ability of the radiating fins 22 is stronger than the magnets 5 with respect to the heat transfer blocks 21. Thus, the cooling of the heat transfer block 21 is promoted. For this reason, the heat from the magnet cover 20 is more easily transmitted to the heat transfer block 21 and is relatively less likely to be transmitted to the magnet 5, and as a result, the temperature rise of the magnet 5 can be further suppressed.

<Third Embodiment>
FIG. 5 is a schematic view showing a main part of an eddy current reduction device according to a third embodiment of the present invention. FIG. 5 (a) is a sectional view of a magnet holding disk corresponding to a magnet holding member as seen from the front side. The figure, (b) shows the EE sectional view of the figure (a), the figure (c) shows the FF sectional view of the figure (a), respectively. Similarly to the second embodiment, the speed reduction device of the third embodiment shown in the figure is based on the configuration of the speed reduction device of the first embodiment shown in FIG. It is a thing.

  That is, as shown in FIG. 5, the heat insulating coating 23 is laminated on the inner surface facing the magnet 5 in the magnet cover 20 of the reduction gear according to the third embodiment. Here, the heat insulating coating film 23 is laminated only in a position corresponding to the position where the magnet 5 is arranged, that is, a position facing the magnet 5. For example, the heat insulating coating 23 is made by using a liquid paint composed of hollow glass beads, silicone resin, silica powder, and a solvent as a raw material, and applying the liquid raw material to a corresponding region on the inner surface of the magnet cover 20 and drying it. It is formed as a rubber-like film that can withstand high temperature environments.

  When there is no heat-insulating coating film 23 as in the conventional reduction gear, the magnet 5 may be heated by gentle convection heat transfer using air as a medium in the gap between the magnet 5 and the magnet cover 20. In the speed reducer of the embodiment, since the heat insulating coating film 23 exists between the magnet 5 and the magnet cover 20, it is possible to completely eliminate the heating of the magnet 5 due to such convective heat transfer. Furthermore, even if the magnet cover 20 is thermally deformed, the non-contact state between the magnet cover 20 itself and the magnet 5 can be reliably ensured. As a result, the temperature rise of the magnet 5 can be further suppressed.

  Such a heat-insulating coating film 23 can be applied not only to the reduction gear of the first embodiment but also to the reduction gear of the second embodiment.

<Fourth embodiment>
FIG. 6 is a schematic diagram showing a configuration example of an eddy current reduction device according to a fourth embodiment of the present invention. FIG. 6A is a longitudinal sectional view showing the overall configuration, and FIG. FIG. 4C is a sectional development view of the main part of the magnet holding drum corresponding to the member viewed from the outer peripheral surface side, FIG. 5C is a sectional view taken along line GG in FIG. 4B, and FIG. The HH sectional view of b) is shown respectively. The speed reducer of the fourth embodiment shown in the figure has the same basic configuration as the speed reducer of the first embodiment shown in FIG. 3 and is a synchronous rotation system, but is the drum type. It is different from the form.

  That is, as shown in FIG. 6, in the reduction gear device of the fourth embodiment, the brake disk 1 corresponding to the brake member in the first embodiment is changed to a cylindrical brake drum 31, and accordingly, the magnet holding member The magnet holding disk 4 corresponding to the above is changed to a cylindrical magnet holding drum 32. The brake drum 31 is fixed to the rotating shaft 11 and rotates integrally with the rotating shaft 11. The magnet holding drum 32 is disposed inside the brake drum 31 and is supported so as to be rotatable integrally with the annular member 3 with respect to the rotating shaft 11.

  A plurality of permanent magnets 5 are fixed to the magnet holding drum 32 on the outer peripheral surface facing the inner peripheral surface of the brake drum 31 in the circumferential direction. The permanent magnets 5 are arranged such that the magnetic poles (N pole, S pole) are oriented in the radial direction of the magnet holding drum 32 and the magnetic poles are alternately different between those adjacent in the circumferential direction.

  In the fourth embodiment, the magnet cover 20 similar to that of the first embodiment has a surface facing the inner peripheral surface of the brake drum 31, that is, the outer peripheral surface of the magnet holding drum 32 that holds the permanent magnet 5. 5 is attached to the magnet holding drum 32 so as to cover it. Further, in the magnet holding drum 32, the heat transfer block 21 similar to that in the first embodiment is in contact with both the magnet cover 20 and the magnet holding drum 32 between the magnets 5 adjacent in the circumferential direction. Is arranged in.

  In the speed reducer of the fourth embodiment having such a configuration, when the brake is not braked, the magnet holding drum 32 integrated with the annular member 3 is replaced with the permanent magnet 5 as the brake drum 31 rotates integrally with the rotary shaft 11. By the magnetic attraction action between the brake drum 31 and the brake drum 31, the brake drum 31 rotates integrally with the brake drum 31. For this reason, since a relative rotational speed difference does not occur between the brake drum 31 and the permanent magnet 5, no braking force is generated.

  On the other hand, at the time of braking, the magnet holding drum 32 integrated with the annular member 3 is stopped by the operation of the disc brake (friction brake). If only the magnet holding drum 32 is stationary while the brake drum 31 is rotating, a relative rotational speed difference is generated between the brake drum 31 and the permanent magnet 5. An eddy current is generated on the inner peripheral surface of the brake drum 31, and a braking force can be generated on the rotary shaft 11 via the brake drum 31.

  According to the speed reducer of the fourth embodiment, since the magnet cover 20 and the heat transfer block 21 are the same as those of the first embodiment, even if the brake drum 31 corresponding to the brake member generates heat during braking, the heat Is first transmitted to the magnet cover 20, then preferentially transmitted to the heat transfer block 21 in contact with the magnet cover 20, and then transferred to the magnet holding drum 32 in contact with the heat transfer block 21 to be radiated. . Therefore, the reduction gear according to the fourth embodiment has the same effect as that of the first embodiment.

  Note that the radiating fins 22 of the second embodiment can also be applied to the reduction gear of the fourth embodiment. That is, with reference to FIG. 6, the magnet holding drum 32 has a position corresponding to the position where the heat transfer block 21 is disposed on the inner peripheral surface opposite to the outer peripheral surface holding the magnet 5. That is, a configuration in which a plurality of radiating fins are provided in the circumferential direction of the magnet holding drum 32 is limited to the position inside the heat transfer block 21 with the magnet holding drum 32 interposed therebetween.

  Moreover, the heat insulation coating film 23 of the said 3rd Embodiment is also applicable to the deceleration device of 4th Embodiment. That is, with reference to FIG. 6, the magnet cover 20 is limited to the position corresponding to the position where the magnet 5 is disposed on the inner peripheral surface facing the magnet 5, that is, the position facing the magnet 5. And it can be set as the structure which laminated | stacked the heat insulation coating film.

  In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, each of the above embodiments is a synchronous rotation type speed reduction device, and a magnet holding member (a magnet holding disk, a magnet holding drum) is stopped by a friction brake at the time of braking. The present invention is not limited to a disc brake in which a brake disc separate from the holding member is sandwiched between a pair of brake pads. The friction member may be pressed against the brake disk from only one direction, or the friction member may be pressed directly against the magnet holding member.

  In addition, since each of the above embodiments is a synchronous rotation type reduction device, a magnet holding member (magnet holding disk, magnet holding drum) is rotatably supported on a rotation shaft. Like a speed reducer, the magnet holding member is supported so as to be movable in the direction along the rotation axis, and the magnet holding member is kept stationary while being brought close to the braking member (braking disc, braking drum) at the time of braking, and the magnet at the time of non-braking It is also possible to apply the magnet cover 20 and the heat transfer block 21 as well as the heat radiating fins 22 and the heat insulating coating film 23 to a speed reducer configured to separate the holding member from the braking member.

  The eddy current type speed reducer of the present invention is useful as an auxiliary brake for any vehicle.

1: braking disk, 2: heat radiation fin, 3: annular member,
4: magnet holding disc, 5: permanent magnet, 6: brake disc,
7: Brake caliper, 8a, 8b: Brake pad,
9: Electric linear actuator, 10: Electric motor, 11: Rotating shaft,
12: connecting shaft, 13: sleeve, 14: nut,
15a, 15b: bearings, 16a, 16b: seal members,
17: Bracket, 18: Bearing, 19a, 19b: Seal member
20: Magnet cover, 21: Heat transfer block, 22: Radiation fin,
23: Thermal insulation coating film 31: Braking drum 32: Magnet holding drum

Claims (10)

A braking disk fixed to a rotating shaft of the vehicle, and a magnet holding disk that holds a plurality of permanent magnets that are arranged in a circumferential direction opposite to the main surface of the braking disk and that are alternately arranged. An eddy current type speed reducer,
The magnet holding disk is provided with a magnet cover made of a non-magnetic metal material made of a thin plate that covers the front surface facing the main surface of the brake disk together with the permanent magnet, and the magnet holding disk is disposed between the permanent magnets adjacent in the circumferential direction. An eddy current type speed reducer comprising a magnet cover and a heat transfer block made of a nonmagnetic metal material in contact with the magnet holding disk.   2. The eddy current reduction device according to claim 1, wherein the magnet holding disk is rotatably supported by the rotating shaft and is stationary by a friction brake during braking.   2. The eddy current according to claim 1, wherein the magnet holding disk is supported so as to be movable in a direction along the rotation axis, and is stationary while being close to the braking disk during braking. Type speed reducer.   The eddy current reduction device according to any one of claims 1 to 3, wherein a radiating fin is provided on a back surface of the magnet holding disk corresponding to a position where the heat transfer block is disposed. .   5. The eddy current reduction device according to claim 1, wherein a heat insulating coating film is laminated on an inner surface of the magnet cover so as to correspond to a position where the permanent magnet is disposed. A brake drum fixed to a rotating shaft of the vehicle, and a magnet holding drum holding a plurality of permanent magnets arranged alternately and differently in the circumferential direction facing the inner peripheral surface of the brake drum. Eddy current type reduction device,
The magnet holding drum is provided with a magnet cover made of a non-magnetic metal material made of a thin plate that covers an outer peripheral surface facing the inner peripheral surface of the brake drum together with the permanent magnet, and between the permanent magnets adjacent in the circumferential direction. The eddy current type speed reducer is characterized in that a heat transfer block made of a non-magnetic metal material in contact with the magnet cover and the magnet holding drum is disposed.   The eddy current type reduction device according to claim 6, wherein the magnet holding drum is rotatably supported on the rotating shaft and is stationary by a friction brake during braking.   The eddy current according to claim 6, wherein the magnet holding drum is supported so as to be movable in a direction along the rotation axis, and is stationary in a state of approaching the braking drum during braking. Type speed reducer.   The eddy current type according to any one of claims 6 to 8, wherein a heat radiating fin is provided on an inner peripheral surface of the magnet holding drum corresponding to a position where the heat transfer block is disposed. Reducer.   The eddy current type deceleration according to any one of claims 6 to 9, wherein a heat insulating coating is laminated on an inner peripheral surface of the magnet cover corresponding to a position where the permanent magnet is disposed. apparatus.

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