JP2008141814A - Eddy current speed reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eddy current speed reducer having its thrust load to a rotating shaft reduced without impairing a braking force. <P>SOLUTION: The eddy current speed reducer 1 includes a disk-shaped rotor 3 having a support body connected to the rotary shaft 2 and a braking force operation part, and a magnetic force generating means 4 fixed to the non-rotary part, wherein the magnetic force generating means 4 is brought closer to the braking force operation part at braking to generate a braking force by eddy current. The braking force operation part is constituted of a member 3a made of a ferromagnetic body and a member 3b made of a conductor body other than the ferromagnetic body, wherein the member 3a made of the ferromagnetic body and the member 3b made of the conductor body other than the ferromagnetic body are disposed on a surface opposite to the magnetic force generating means 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a disk-type eddy current reduction device that assists a main brake used in a vehicle such as an automobile.

  In braking systems for automobiles such as trucks and buses, in addition to the foot brake as the main brake and the exhaust brake as the auxiliary brake, stable deceleration on long downhill slopes, etc. In order to prevent burning, an eddy current reduction device is used.

  Recently, demands for eddy current reduction devices have also diversified, and there has been a strong demand for improving mountability on vehicles so as to reduce manufacturing costs and enable mounting on small vehicles. In order to improve the mountability, it is required to be small and light, and to have a simple structure and excellent economy.

  In response to the above request, for example, as disclosed in Patent Documents 1 to 4, a device has been developed that generates a braking torque on the disk itself by causing the magnetic pole surface of the permanent magnet to approach the braking disk. With this disk type braking device, the magnetic field lines of the permanent magnet can be added to the braking disk with a short magnetic path length, so that the magnetic resistance of the magnetic circuit is reduced, the magnetic efficiency is improved, and the braking torque is increased. it can.

  FIG. 10 is a schematic diagram showing a device configuration of a disk-type eddy current reduction device. In addition, (a) and (b) in FIG. 10 show the state at the time of non-braking and the state at the time of braking, respectively.

  As shown in FIG. 10, the eddy current reduction device 1 includes a disk-shaped rotor 3 connected to a rotating shaft 2 and magnetic force generating means 4 fixed to a non-rotating portion. Examples of the rotor 3 include those made of a ferromagnetic material and those in which a ferromagnetic material is fitted on a support. The rotor 3 is configured to form a magnetic field on at least the disk surface facing the magnetic force generating means 4. . The magnetic force generating means 4 is supported by a non-rotating part such as a vehicle and is attached to the holding body 7 in the guide cylinder 5. The holding body 7 is connected to the rod 9 of the actuator 6. A portion of the guide tube 5 that faces the rotor 3 is covered with a cover 8.

  As shown in FIG. 10 (a), during non-braking, the magnetic force generating means 4 is held at a position away from the rotor 3 by the actuator 6 and no eddy current is generated, but it is shown in FIG. 10 (b). Thus, when the magnetic force generating means 4 is brought closer to the rotor 3 during braking, an eddy current is generated in the ferromagnetic portion of the rotor 3 to generate a braking force.

JP-A-1-298947 JP 2003-333824 A JP 2004-48978 A Japanese Patent Laid-Open No. 2004-489888

  FIG. 11 is a schematic diagram showing the shape of a rotor of a conventional eddy current reduction device. As shown in FIG. 11, in the conventional eddy current reduction device, the rotor 3 is constituted by a member whose entire surface of the braking force acting portion is made of a ferromagnetic material 3 a. However, in the conventional eddy current reduction device having such a rotor, a high attractive force acts during braking between the magnetic force generating means (electromagnet or permanent magnet) fixed to the non-rotating part and the rotor 3, and this rotates. A thrust load is applied to the shaft bearing. For this reason, from the viewpoint of the braking force, it is better that the magnetic attractive force is strong. However, if the attractive force is excessively large, the life of the bearing portion may be shortened.

  The present invention has been made to solve the above problem, and provides an eddy current reduction device that can reduce a thrust load due to a magnet attractive force without impairing the braking force as the eddy current reduction device. For the purpose.

  The gist of the present invention is an eddy current reduction device shown in the following (1) to (3).

(1) A disk-shaped rotor having a support and a braking force acting part connected to a rotating shaft, and a magnetic force generating means fixed to a non-rotating part, and approaching the braking force acting part during braking An eddy current reduction device for generating braking force by eddy current,
The braking force acting part is composed of a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material, and the member made of the ferromagnetic material and the member made of the conductor other than the ferromagnetic material are subjected to magnetic force. An eddy current reduction device, characterized in that the eddy current reduction device is disposed on a surface facing the generating means.

(2) A disk-shaped rotor having a support body and a braking force acting part connected to the rotating shaft, and a magnetic force generating means fixed to the non-rotating part, and the magnetic force generating means approaches the braking force acting part during braking. An eddy current reduction device for generating braking force by eddy current,
An eddy current reduction device, wherein the braking force acting portion is formed by alternately arranging a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material in the circumferential direction.

(3) A disk-shaped rotor having a support and a braking force acting part connected to a rotating shaft, and a magnetic force generating means fixed to the non-rotating part, and the magnetic force generating means approaches the braking force acting part during braking. An eddy current reduction device for generating braking force by eddy current,
An eddy current reduction device, wherein the braking force acting portion is formed by alternately arranging members made of a ferromagnetic material and members made of a conductor other than the ferromagnetic material in a radial direction.

  In the eddy current reduction devices (1) to (3) described above, the member made of a ferromagnetic material and the member made of a conductor other than the ferromagnetic material are preferably arranged with a gap. The braking surface of the member made of a ferromagnetic material and / or the member made of a conductor other than the ferromagnetic material may be covered with a coating.

  The braking force acting part may be joined to the support via a back plate. The back plate may be divided in the circumferential direction or the radial direction. A member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material are joined to the divided back plate.

  At this time, either one of a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material may be bonded to each of the divided back plates. It is preferable that both members made of a conductor other than the ferromagnetic material are joined. When both of these members are bonded to one back plate, either one of the member made of a ferromagnetic material and the member made of a conductor other than the ferromagnetic material has the circumferential direction of the other member and It is more desirable that the end face in the radial direction is covered and the end face of the other member is not exposed. As the back plate, for example, a material made of a ferromagnetic material or a high thermal conductivity material can be used.

  The member made of a ferromagnetic material or the member made of a conductor other than the ferromagnetic material and the back plate may be integrally formed.

  According to the present invention, the thrust force generated between the ferromagnetic material and the magnet can be reduced, and the thrust load on the rotating shaft can be reduced without impairing the braking force.

  1A and 1B are schematic views illustrating a rotor used in an eddy current reduction device according to the present invention. FIG. 1A is a diagram illustrating an overall configuration of the device, and FIG. 1B is a diagram illustrating a rotor. As shown in FIG. 1 (a), the eddy current reduction device of the present invention is fixed to, for example, a disk-shaped rotor 3 having a support and a braking force acting part connected to a rotating shaft 2, and a non-rotating part. The magnetic force generating means 4 is provided, and at the time of braking, the magnetic force generating means 4 is brought close to the braking force acting portion to generate a braking force by an eddy current. This is the same as the apparatus shown in FIG. Further, as shown in FIG. 1B, in the eddy current reduction device according to the present invention, for example, the braking force acting part includes a member 3a made of a ferromagnetic material and a member 3b made of a conductor other than the ferromagnetic material. The rotor 3 comprised by these can be used.

  The rotor 3 shown in FIG. 1 (b) surrounds a member whose surface (referred to as a braking surface) facing the magnetic force generating means in the braking force acting portion is made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material. It is the structure which has arrange | positioned alternately in the direction.

  By adopting such a configuration, the area of the ferromagnetic material (referred to as the facing area) on the surface (referred to as the braking surface) facing the magnetic force generating means in the braking force acting portion is reduced, so that the thrust load is reduced. On the other hand, at the time of braking, eddy currents are generated not only in the ferromagnetic member of the braking force acting part but also in a conductor other than the ferromagnetic material, so that a braking force comparable to the conventional braking disk can be maintained.

  Carbon steel, ferritic stainless steel, and martensitic stainless steel are preferably used as a member made of a ferromagnetic material that constitutes the braking force acting portion. In particular, it is preferable to use a material having high conductivity and high high-temperature strength.

  As the member made of a conductor other than the ferromagnetic material, copper, copper alloy, aluminum, aluminum alloy, austenitic stainless steel, or the like is preferably used. In the case of usage in which the rotor temperature does not increase so much, aluminum or an aluminum alloy is preferably used. This is because the rotor can be reduced in weight. The member made of a ferromagnetic material and the member made of a conductor other than the ferromagnetic material can be joined to the support by welding, pressure bonding or other known methods. The support may be configured integrally with one braking member.

  Here, paying attention to the conductivity of a member made of a conductor other than a ferromagnetic material, for example, when a material having a particularly excellent conductivity such as copper is used, a member made of a conductor other than a ferromagnetic material is used for braking. Eddy current further increases. That is, as compared with a conventional disk made of only a ferromagnetic material, the braking force is increased and the attractive force is reduced with the same magnetic force. On the contrary, when trying to obtain the same braking force as that of the conventional device, the magnetic force dose can be reduced as compared with the conventional device. Therefore, when a permanent magnet is used as the magnetic force generating means, the size can be made smaller. it can. In addition, when an electromagnet is used as the magnetic force generating means, the amount of winding and the current value can be reduced. Therefore, it is possible to reduce the size and weight of the apparatus and save power consumption.

  As the magnetic force generating means 4, a permanent magnet may be used or an electromagnet may be used. The magnetic force generating means 4 is fixed by the holding body 7 so that the magnetic poles adjacent in the circumferential direction are alternately reversed. As the holding body 7, one made of a ferromagnetic material can be used. The holding body is accommodated in a fixed guide cylinder 5.

  A cooling fin can be attached to the member 3a made of a ferromagnetic material and / or the member 3b made of a conductor other than the ferromagnetic material. Thereby, the rise in rotor temperature can be suppressed.

  FIG. 2 is a schematic view showing another example of a rotor used in the eddy current reduction device according to the present invention. As shown in FIG. 2, in the eddy current reduction device according to the present invention, for example, the braking force acting part includes a gap between a member 3 a made of a ferromagnetic material and a member 3 b made of a conductor other than the ferromagnetic material. The provided rotor 3 can be used. The member 3 a made of a ferromagnetic material and the member 3 b made of a conductor other than the ferromagnetic material can be attached to the support 10.

  Thus, by providing the member 3a made of a ferromagnetic material and the member 3b made of a conductor other than the ferromagnetic material with a gap, the braking member easily expands in the circumferential direction due to heat generated during braking. Become. For this reason, the amount of strain generated in the braking member is suppressed, and durability is improved.

  FIG. 3 is a schematic view showing another example of a rotor used in the eddy current reduction device according to the present invention. As shown in FIG. 3, in the eddy current reduction device according to the present invention, for example, the braking force acting part is constituted by a member 3 a made of a ferromagnetic material and a member 3 b made of a conductor other than the ferromagnetic material, It is possible to use a rotor 3 in which members 3a made of a ferromagnetic material and members 3b made of a conductor other than a ferromagnetic material are alternately arranged in the radial direction. In this rotor as well as the rotor shown in FIG. 1, since the area of the member 3a made of a ferromagnetic material is small, the thrust load can be suppressed. On the other hand, the member 3b made of a conductor other than the ferromagnetic material also has a vortex. Since an electric current is generated, the braking force does not drop.

  In this rotor, for example, a member 3b made of a conductor other than the ring-shaped ferromagnetic material is combined on the inner peripheral surface of the member 3a made of an outermost ring-shaped ferromagnetic material by welding, press-fitting, or other known methods, This can be repeated to form an integral ring.

  FIG. 4 is a schematic view showing another example of a rotor used in the eddy current reduction device according to the present invention. As shown in FIG. 4, in the eddy current reduction device according to the present invention, for example, the braking force acting part includes a gap between a member 3 a made of a ferromagnetic material and a member 3 b made of a conductor other than the ferromagnetic material. The provided rotor 3 can be used. The member 3 a made of a ferromagnetic material and the member 3 b made of a conductor other than the ferromagnetic material can be attached to the support 10.

  By arranging the member 3a made of a ferromagnetic material and the member 3b made of a conductor other than the ferromagnetic material by providing a gap as described above, the braking member easily expands in the radial direction due to heat generated during braking. Become. For this reason, the amount of distortion generated in the braking member is suppressed and the durability is improved as in the case of FIG.

  5 to 9 are schematic views showing other examples of the rotor used in the eddy current reduction device according to the present invention. As shown in FIGS. 5 to 9, in the eddy current reduction device according to the present invention, for example, the braking force acting part is constituted by a member 3 a made of a ferromagnetic material and a member 3 b made of a conductor other than the ferromagnetic material. The rotor 3 in which these members are joined to the support 10 through the back plate 11 can be used.

  In these rotors as well as the rotor shown in FIG. 1, since the area of the member 3a made of a ferromagnetic material is small, the thrust load can be suppressed, while also in the member 3b made of a conductor other than the ferromagnetic material. Since eddy currents are generated, the braking force does not drop.

  At this time, a cooling fin can be attached to the member 3a made of a ferromagnetic material and / or the member 3b made of a conductor other than the ferromagnetic material. The cooling fins can also be attached to the back plate. Thereby, the rise in rotor temperature can be suppressed.

  The material of the back plate is not particularly limited, but it is desirable to use a ferromagnetic material such as carbon steel, ferritic stainless steel or martensitic stainless steel. When a back plate made of a ferromagnetic material is used, the magnetic lines of force from the magnetic force generating means are attracted to the back plate, so the amount of magnetic force reaching the material made of a conductor other than the ferromagnetic material increases. The braking torque can be greatly improved.

  When the back plate is made of a ferromagnetic material, the overall attractive force is increased as compared with the case without the back plate. However, since the reaction force during braking increases as the braking force increases significantly, the suction force is offset by the braking reaction force. For this reason, the thrust load to the bearing hardly increases. Optimize the opposing area between the member made of a ferromagnetic material and the member made of a conductor other than the ferromagnetic material, the conductivity of the material, the magnetic permeability, and the thickness of the member made of a conductor other than the ferromagnetic material. It is good.

  As the material of the back plate, a material having high thermal conductivity such as aluminum or aluminum alloy can be used. When such a high thermal conductivity material is used, the heat generated in the braking portion is efficiently transmitted to the support and the fins, and an increase in the rotor temperature can be suppressed.

  The method for attaching the braking member to the back plate is not particularly limited. For example, brazing a brazing material between members, applying a high pressure between the members at a temperature exceeding 800 ° C and holding them for a certain period of time. The method of joining is mentioned. As for the temperature at the time of joining, pressurizing conditions, surface roughness of parts, gaps between parts, etc., the optimum conditions may be selected depending on the joining method.

  When the back plate and one braking member are made of the same material, for example, when the back plate is made of a ferromagnetic material, or when the back plate and the member made of a conductor other than the ferromagnetic material are aluminum alloys, casting The back plate and the one braking member may be integrally manufactured by forging or the like.

  As shown in FIG. 6, the eddy current reduction device according to the present invention of the present invention has, for example, a ring-shaped back plate 11, a member 3 a made of a ferromagnetic material, and a conductor other than the ferromagnetic material. The member 3b may be configured to be attached to the back plate 11 with gaps provided alternately in the circumferential direction, and the back plate 11 is attached to the support body 10. As described above, by providing a gap in the circumferential direction, each member can freely expand in the circumferential direction as in the case described above, and durability is improved.

  As shown in FIG. 7, when the back plate 11 is used instead of the ring shape and divided into the same shape as the braking members 3 a and 3 b, the heating / heating used at the time of joining the back plate 11 and the braking members 3 a and 3 b is performed. Since the capacity restriction of the pressure device is relaxed, it can be processed by a smaller device. In addition, the volumetric efficiency can be increased so that many processes can be performed at once.

  As shown in FIG. 8, a member 3 a made of a ferromagnetic material and a member 3 b made of a conductor other than the ferromagnetic material may be attached to one back plate 11. In this case, since one member 3a arranges the other member 3b on both end surfaces in the circumferential direction, when there is a difference in oxidation resistance between the braking members 3a and 3b, a material excellent in oxidation resistance is placed outside. By disposing on the (end face side), it is possible to prevent oxidation of the material having poor oxidation resistance from the circumferential end face.

  In FIG. 8, the conductors 3a other than the ferromagnetic material are arranged on both end surfaces in the circumferential direction of the member 3b made of a ferromagnetic material. However, the oxidation resistance of the member 3a made of a ferromagnetic material is a ferromagnetic material. If it is inferior to the other conductors 3b, it is preferable to replace 3a and 3b in the figure. As shown in FIG. 9, the oxidation resistance of the braking member can be further improved by disposing a material excellent in oxidation resistance not only in the circumferential direction but also in the radial direction on the outer peripheral end face and the inner peripheral end face. .

  Although not shown, in the eddy current reduction device according to the present invention, it is preferable to use a rotor in which a braking surface of a member made of a ferromagnetic material and / or a member made of a conductor other than the ferromagnetic material is covered with a film. . The film may be composed of a single material or may be composed of a combination of a plurality of materials. At this time, if the braking member is covered with a coating having excellent oxidation resistance, oxidation of the braking member can be suppressed. Moreover, if it covers with the film which has high electroconductivity, since an eddy current will generate | occur | produce also in a film part, it becomes possible to exhibit a higher braking force.

  As the coating, for example, a multilayer structure of austenitic stainless steel, Ni alloy, Ni alloy and copper alloy is preferable. Ferromagnetic carbon steel having a thin film thickness may be used. The appropriate range of the thickness varies depending on the material, but it is preferable that the thickness be in the range of 0.05 mm to 2 mm.

  According to the present invention, the thrust force generated between the ferromagnetic material and the magnet can be reduced, and the thrust load on the rotating shaft can be reduced without impairing the braking force.

The schematic diagram which illustrates the eddy current reduction device which concerns on this invention. (a) is a figure which shows the whole structure, (b) is a figure which shows a rotor. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the other example of the rotor used with the eddy current reduction device which concerns on this invention. The schematic diagram which shows the apparatus structure of a disk type eddy current reduction device. The schematic diagram which shows the shape of the rotor of the conventional eddy current reducer.

Explanation of symbols

1. 1. Eddy current reduction device 2. Rotating shaft Rotor 4. Magnetic force generating means5. Guide tube 6. Actuator 7. Holder 8. Cover 9. Rod 10. Support 11. Back plate

Claims (14)

A disk-shaped rotor having a support body and a braking force acting part connected to a rotating shaft, and a magnetic force generating means fixed to the non-rotating part. During braking, the magnetic force generating means is brought close to the braking force acting part to An eddy current reduction device that generates a braking force by electric current,
The braking force acting part is composed of a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material, and the member made of the ferromagnetic material and the member made of the conductor other than the ferromagnetic material are subjected to magnetic force. An eddy current reduction device, characterized in that the eddy current reduction device is disposed on a surface facing the generating means. A disk-shaped rotor having a support body and a braking force acting part connected to a rotating shaft, and a magnetic force generating means fixed to the non-rotating part. During braking, the magnetic force generating means is brought close to the braking force acting part to An eddy current reduction device that generates a braking force by electric current,
An eddy current reduction device, wherein the braking force acting portion is formed by alternately arranging a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material in a circumferential direction. A disk-shaped rotor having a support body and a braking force acting part connected to a rotating shaft, and a magnetic force generating means fixed to the non-rotating part. During braking, the magnetic force generating means is brought close to the braking force acting part to An eddy current reduction device that generates a braking force by electric current,
An eddy current reduction device, wherein the braking force acting portion is formed by alternately arranging members made of a ferromagnetic material and members made of a conductor other than the ferromagnetic material in a radial direction.   The eddy current reduction device according to any one of claims 1 to 3, wherein a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material are arranged with a gap therebetween. .   The eddy current according to any one of claims 1 to 4, wherein a braking surface of a member made of a ferromagnetic material and / or a member made of a conductor other than a ferromagnetic material is covered with a film. Reducer.   The eddy current reduction device according to any one of claims 1 to 5, wherein the braking force acting part is joined to the support via a back plate.   The eddy current reduction device according to claim 6, wherein the back plate is divided in the circumferential direction.   The eddy current reduction device according to claim 6, wherein the back plate is divided in a radial direction.   9. The eddy current according to claim 7, wherein either one of a member made of a ferromagnetic material and a member made of a conductor other than the ferromagnetic material is joined to each of the divided back plates. Reducer.   9. The eddy current reduction device according to claim 7, wherein both the member made of a ferromagnetic material and the member made of a conductor other than the ferromagnetic material are joined to each of the divided back plates. .   11. The member of any one of a member made of a ferromagnetic material and a member made of a conductor other than a ferromagnetic material covers an end face in the circumferential direction and / or radial direction of the other member. The eddy current reducer described in 1.   The eddy current reduction device according to any one of claims 6 to 11, wherein the back plate is made of a ferromagnetic material.   The eddy current reduction device according to any one of claims 6 to 11, wherein the back plate is made of a highly thermally conductive material. The eddy current reduction device according to any one of claims 6 to 13, wherein a member made of a ferromagnetic material or a member made of a conductor other than a ferromagnetic material and the back plate are integrally formed.

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