JP2015180172A - Eddy current type deceleration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly support a permanent magnet in an omnidirectional manner with the reduction of costs and a production time.SOLUTION: In a deceleration device of an eddy current type, in which a permanent magnet 3 is rotated in a circumferential direction to switch between braking on and off, each permanent magnet 3 adhered to a magnet support ring 4 is supported by the disposition of a non-magnetic elastic fixation member 11 of a bathtub shape between each permanent magnet 3. Thus, the strength of the fixation member can be secured if an impact load acts on the fixation member of the permanent magnet at a switchover between the braking on and off, so that the permanent magnet can be stably fixed over a long term. Also, the reduction of production time and costs is achieved.

Description

  The present invention relates to an eddy current type speed reducer of a type in which a magnet is turned in a circumferential direction to switch between braking on and braking off, and particularly relates to a magnet fixing structure.

  For example, as shown in FIG. 6A, the eddy current type speed reduction device disclosed in Patent Document 1 has a cylindrical braking drum 2 as a braking member fixed to a rotating shaft 1 such as a propeller shaft.

  A ring-shaped magnet support ring 4 is arranged on the inner peripheral side of the brake drum 2 so as to be freely rotatable, and a plurality of permanent magnets 3 are adjacent to the outer peripheral surface of the magnet support ring 4 so that the polarities are opposite to each other. It is installed in the circumferential direction.

  A ferromagnetic pole piece 5 is disposed between the group of permanent magnets 3 and the braking drum 2 at the same angular position as the permanent magnet 3. These pole pieces 5 are supported by a support body 6 in which a nonmagnetic support member 6 a is interposed between the pole pieces 5.

  When the brake is on, the eddy current type speed reducer holds the permanent magnet 3 at a position facing the pole piece 5 as shown in FIG. An eddy current is generated on the inner peripheral surface of the braking drum 2 facing the motor 3. Then, due to the interaction between the eddy current and the magnetic field, a braking force in the direction opposite to the rotation direction is generated in the braking drum that rotates together with the rotation shaft, and the rotation shaft is decelerated.

  On the other hand, at the time of braking off, as shown in FIG. 6 (c), the permanent magnets 3 and the pole pieces 5 are placed on the adjacent pole pieces 5 so as to overlap the pole pieces 5 on both sides. A short circuit magnetic circuit is formed by the magnet support ring 4. In this case, the braking torque generated in the braking drum 2 becomes very small.

  By the way, the following structure is disclosed as a support structure of the permanent magnet in the eddy current type reduction gear of the above configuration.

  For example, Patent Documents 2 and 3 disclose a support structure that prevents the permanent magnet from being displaced in the circumferential direction of the magnet support ring and the axial direction of the rotation shaft.

  In the structure disclosed in Patent Document 2, the engaging ribs are formed on both side end surfaces of the permanent magnet, while the presser foot that presses the permanent magnet against the magnet support ring has an engaging step portion that matches the engaging rib. This prevents the circumferential shift of the magnet support ring. Further, by providing engagement step portions on both side surfaces of the magnet support ring, the axial displacement of the rotating shaft is prevented.

  The structure disclosed in Patent Document 3 is provided with concave or convex engagement step portions on both end surfaces of the permanent magnet, while the presser foot has a convex or concave engagement corresponding to the engagement step portion. By providing the stepped portion, a shift between the circumferential direction of the magnet support ring and the axial direction of the rotating shaft is prevented.

  However, as in the structures disclosed in Patent Documents 2 and 3, in the type that is fixed with the presser fitting and the bolt, it takes time and cost to process the engaging portion of the permanent magnet and the presser fitting. This increases the manufacturing time. In particular, in the type of eddy current type speed reducer in which the number of poles of the permanent magnets is increased to increase the braking efficiency, the number of presser fittings and bolts is also increased, so that the above problem is further increased.

  On the other hand, Patent Document 4 discloses a structure in which a permanent magnet is supported by using an elastic fixing member without providing an engagement rib or an engagement step portion on the permanent magnet or a presser fitting. Patent Document 4 describes that a permanent magnet can be fixed to a holding ring with an adhesive, and an elastic fixing member can be fixed by caulking, welding, rivets, or the like.

  However, Patent Document 4 is a structure for supporting a permanent magnet in a disk-type or drum-type eddy current reduction device that switches between braking on and braking off by moving a magnet in the axial direction of a rotating shaft.

  In addition, it is preferable that the time for switching between braking on and braking off (brake reaction time) after receiving the braking state switching signal is short. Therefore, when switching between braking on and braking off, the magnet support ring should be moved as fast as possible. Will be moved.

  At that time, in the case of a type in which the permanent magnet is rotated in the circumferential direction as in Patent Document 1, if the permanent magnet is rotated after switching the braking state and then stopped, the inertial force acting on the permanent magnet causes the permanent magnet. An impact load is applied to the fixing member (pressing metal of Patent Documents 2 and 3). For this reason, in the type of device that switches the braking state by rotating the permanent magnet in the circumferential direction, a permanent magnet fixing member that can withstand an impact load is required.

  On the other hand, in the case of the type of Patent Document 4 in which the permanent magnet is moved in the axial direction of the rotating shaft, the direction of the inertial force acting on the permanent magnet does not coincide with the direction of the elastic fixing member that fixes the permanent magnet. A large load is not applied.

  That is, when the structure fixed by the elastic fixing member disclosed in Patent Document 4 is applied to a type in which the permanent magnet is rotated in the circumferential direction to switch between braking on and braking off, an impact load is applied to the elastic fixing member. There is a possibility that sufficient strength cannot be secured when loaded.

JP-A-1-298948 Japanese Utility Model Publication No. 3-074185 JP-A-8-336273 JP 2005-176418 A

  The problem to be solved by the present invention is that the permanent magnet support structure disclosed in Patent Documents 2 and 3 requires time and cost to process the engaging portions of the permanent magnet and the presser fitting, and further, bolt fastening. Therefore, the manufacturing time becomes longer. On the other hand, when the support structure disclosed in Patent Document 4 is applied to a type in which the permanent magnet is rotated in the circumferential direction to switch between braking on and braking off, when an impact load is applied to the elastic fixing member. That is, there is a possibility that sufficient strength cannot be secured.

  The present invention is an eddy current type speed reducer of a type in which the permanent magnet is rotated in the circumferential direction to switch between braking on and braking off, and the manufacturing time can be reduced and the cost can be reduced. Further, the permanent magnet can be strengthened in all directions. It aims to be able to support.

The present invention
A braking drum integrally attached to the rotating shaft;
A ferromagnetic magnet support ring in which permanent magnets are arranged at regular intervals so that the magnetic poles adjacent to each other in the circumferential direction of the brake drum are opposite to each other and supported in opposition to the brake drum.
A non-magnetic ferromagnetic pole piece group disposed between the permanent magnet group and the brake drum between each pole piece of the pole piece group. A support body installed with a body support member interposed therebetween,
In the eddy current type reduction device of the type in which the magnet support ring is configured to be capable of turning in the circumferential direction around the rotation axis with a required angle, and switching between braking on and braking off by rotating the permanent magnet in the circumferential direction ,
The main feature is that the permanent magnet bonded to the magnet support ring is supported by disposing, for example, a bathtub-shaped non-magnetic elastic fixing member between the permanent magnets.

  In the present invention, the permanent magnet is supported by disposing a non-magnetic elastic fixing member between the permanent magnets. Therefore, it is not necessary to process the engaging step portion on the permanent magnet or the elastic fixing member, and the time required for the processing. And cost can be reduced.

  Further, in the present invention, for example, since a bathtub-shaped elastic fixing member is used, the strength in the circumferential direction is improved, and both the axial direction of the rotating shaft, the circumferential direction of the magnet support ring, and the radial direction are used. The permanent magnet can be firmly supported.

The shape of the elastic fixing member is not limited to the bathtub shape, and may be the following shape.
a) A shape in which corrugated portions that connect from both side walls of the groove to the bottom wall are formed.
b) A shape in which slits extending from both side walls to the bottom wall are formed at both ends in the longitudinal direction of the groove.
c) A shape in which slits extending from both side walls to the bottom wall are formed on both ends in the longitudinal direction of the groove, and a wavy shape portion connected to the bottom wall from the both side walls is formed on the longitudinal center side of the groove from the slit.

  According to the present invention, in the eddy current type speed reducer of the type in which the permanent magnet is rotated in the circumferential direction to switch between braking on and braking off, when the braking on and braking off are switched, Even when an impact load is applied, the strength of the fixing member can be secured, and the permanent magnet can be stably fixed over a long period of time. In addition, the manufacturing time and cost can be reduced.

(A) (b) is the figure which looked at the different embodiment of the bathtub shape which supports the permanent magnet in the eddy current type reduction gear of this invention from the cross-sectional direction of the rotating shaft, (c) is a bathtub-shaped elastic fixing member. It is a perspective view which shows the state which supported the permanent magnet. (A) is a perspective view of the groove-shaped elastic fixing member that supports the permanent magnet in the eddy current reduction device of the present invention, and (b) is a perspective view showing a state in which the permanent magnet is supported by the groove-shaped elastic fixing member. is there. It is a figure similar to FIG. 2 which shows the 2nd example of a groove-shaped elastic fixing member. It is a figure similar to FIG. 2 which shows the 3rd example of a groove-shaped elastic fixing member. FIG. 6 is a schematic diagram for explaining a deformation mode of a groove-shaped elastic fixing member, where (a) shows a large friction coefficient between the elastic fixing member and the magnet support ring, and (b) shows friction between the elastic fixing member and the magnet support ring. It is the figure which showed the case where a coefficient is small. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the basic structure of the eddy current type reduction gear of this invention, (a) is sectional drawing of a rotating shaft direction, (b) is explanatory drawing of the magnetic circuit structure at the time of braking on, (c) is at the time of braking off It is explanatory drawing of a magnetic circuit structure.

  The present invention is an eddy current type speed reducer of a type in which the permanent magnet is rotated in the circumferential direction to switch between braking on and braking off, and the manufacturing time can be reduced and the cost can be reduced. Further, the permanent magnet can be strengthened in all directions. To achieve the purpose of supporting.

  And the said objective was implement | achieved by arrange | positioning and supporting the permanent magnet which adhere | attached on the magnet support ring between each permanent magnet, for example, a bathtub-shaped nonmagnetic elastic fixing member.

Hereafter, the characteristic structural part of the eddy current type | formula speed reducer of this invention is demonstrated using FIGS. 1-4.
The present invention, for example, shown in FIG. 6 is a single-row swirl type eddy current type speed reducer for rotating magnets arranged in a row in the circumferential direction. 4 to prevent the magnet support ring 4 from moving in the circumferential direction when switching between braking-on and braking-off, and a non-magnetic elastic fixing member 11 disposed between the permanent magnets 3 is provided. The durability of fixing the permanent magnet 3 to the magnet support ring 4 is improved as a shape strong against the impact load in the circumferential direction of the magnet support ring 4 when switching between braking on and braking off.

  Further, depending on the shape of the elastic fixing member 11, not only the permanent magnet 3 moves in the circumferential direction of the magnet support ring 4 but also the movement of the rotary shaft 1 in the axial direction and the movement of the magnet support ring 4 in the radial direction. Can also be effectively prevented.

  In this case, in the present invention, the elastic fixing member 11 does not need to be processed into an engaging step portion in the permanent magnet 3 or the elastic fixing member 11, and the permanent magnet 3 can be fixed without using a bolt. By doing so, the time and cost required for processing are reduced.

  FIG. 1 shows a first embodiment of the elastic fixing member 11, and the outer periphery of the bottom wall 12 having a size and shape that can be inserted between adjacent permanent magnets 3 on the outer peripheral surface of the magnet support ring 4. It is formed in a bathtub shape in which the side wall 13 is raised from the entire end.

  At this time, the elastic fixing member 11 is shaped so that both side walls 13 on the circumferential side of the magnet support ring 4 are in contact with the adjacent permanent magnet 3. In this case, the both side walls 13 that come into contact with the permanent magnet 3 rise vertically from the bottom wall 12 as shown in FIG. 1 (a), or as shown in FIG. 1 (b). You may make it stand up so that it may spread outward toward the upper end.

  When the elastic fixing member 11 has a bathtub shape as shown in FIG. 1, the strength in the circumferential direction of the magnet support ring 4 of the elastic fixing member 11 is improved, so that the permanent magnet 3 can be fixed to the magnet support ring 4. Durability can be improved. Further, since the plate-shaped material can be manufactured simply by press molding, the number of manufacturing steps and the manufacturing cost can be reduced. Furthermore, since it shape | molds from a plate-shaped raw material, it becomes possible to fix to the magnet support ring 4 by the spot welding which is a welding method with high production efficiency, for example, and production efficiency improves. For example, when an austenitic stainless steel plate is used as the plate-like material, a short circuit of the magnetic circuit can be prevented because it is non-magnetic, and further, spot welding can be performed with the steel magnet support ring 4.

  2 to 4 show a second embodiment in which the elastic fixing member 11 is formed in a groove shape having a width that can be inserted between adjacent permanent magnets 3 on the outer peripheral surface of the magnet support ring 4. Is.

  Among these, the 1st example shown in FIG. 2 forms the wavy shape part 14 connected to the bottom wall 12 in the both-sides wall 13, for example on both sides.

  In the second example shown in FIG. 3, slits 15 extending from both side walls 13 to the bottom wall 12 are formed on both ends in the longitudinal direction of the groove-shaped groove, and the side walls 13 positioned on both ends of these slits 15 are provided. The permanent magnet 3 is engaged.

  Further, the third example shown in FIG. 4 is one in which the corrugated portion 14 shown in FIG. 2 and the slit 15 shown in FIG. 3 are formed together. That is, slits 15 extending from both side walls 13 to the bottom wall 12 are formed on both ends in the longitudinal direction of the groove-shaped groove, and corrugations connected from the side walls 13 to the bottom wall 12 from the slits 15 to the center in the longitudinal direction of the groove. The shape portion 14 is formed.

  Also in the second embodiment formed in the groove shape shown in FIGS. 2 to 4, the length of the elastic fixing member 11 in the circumferential direction of the magnet support ring 4 is on the circumferential side of the magnet support ring 4. The side walls 13 are formed to a length that makes contact with the adjacent permanent magnet 3.

  In the case of the first example shown in FIG. 2, as shown in FIG. 2A, both side walls 13 that come into contact with the permanent magnet 3 are raised so that the groove width increases from the bottom wall 12 toward the upper end. Although not shown in the drawings, it may be vertically raised from the bottom wall 12.

  However, in the case of the second and third examples shown in FIGS. 3 and 4, as shown in FIGS. 3A and 4B, the side walls 13 contacting the permanent magnet 3 are grooves from the bottom wall 12 toward the upper end. Stand up to widen. When the elastic fixing member 11 is installed, the permanent magnet 3 adjacent to the central side wall 13 between the slits 15 is pushed in a direction away from the permanent magnet 3.

  In the case of the second embodiment formed in the groove shape shown in FIGS. 2 to 4, the wavy shape portion 14 improves the strength of the magnet support ring 4 in the circumferential direction. Further, the slit 15 restrains the movement of the permanent magnet 3 in the axial direction of the rotating shaft 1.

  Also, in the case of the second embodiment formed in the groove shape shown in FIGS. 2 to 4, since it can be produced simply by press-molding a plate-like material, it is the same as in the case of the first embodiment described in FIG. Has the effect of.

  In the eddy current reduction device of the present invention, for example, after fixing the permanent magnet 3 and the magnet support ring 4 with an adhesive, the elastic fixing member 11 is disposed between the permanent magnets 3 and spot-welded to the magnet support ring 4. This completes the fixing of the permanent magnet 3.

  That is, in the present invention, since the man-hours required for fixing the permanent magnet 3 are reduced, the time required for manufacturing is shortened even in the type of eddy current type speed reducer in which the number of poles of the permanent magnet is increased to increase the braking efficiency. it can.

  By the way, in the durability test conducted by the inventors, when the elastic fixing member is joined to the magnet support ring by spot welding, the contact state between the elastic fixing member and the permanent magnet is determined by the joint between the elastic fixing member and the magnet support ring. It was found to affect the durability of the.

  That is, it has been found that the greater the coefficient of friction between the elastic fixing member and the permanent magnet, the longer the fatigue life of the joint between the elastic fixing member and the magnet support ring.

  That is, when the contact portion between the elastic fixing member 11 and the permanent magnet 3 is slippery, the elastic fixing member 11 slips and a load is applied to the joint portion between the elastic fixing member 11 and the magnet support ring 4 as shown in FIG. The joint will eventually come off.

  On the other hand, when the contact portion between the elastic fixing member 11 and the permanent magnet 3 is difficult to slip, the load is received by the side wall 13 of the elastic fixing member 11 as shown in FIG. The durability of the joint W between the member 11 and the magnet support ring 4 is improved.

  As a means for making it difficult for the contact portion between the elastic fixing member and the permanent magnet to slip, it is conceivable to increase the friction coefficient of the contact portion by the following method, for example.

-After manufacturing the permanent magnet, do not process the side surface of the permanent magnet that comes into contact with the side wall of the elastic fixing member, but use it on the surface skin that has been molded and heat-treated.
The surface roughness is increased by, for example, grinding stone processing, shot blasting, etching, and oxidation treatment on the contact surfaces of the side surfaces of the permanent magnets and the side walls of the elastic fixing member with the side surfaces of the permanent magnets.

  Further, as a means for preventing the contact portion between the elastic fixing member and the permanent magnet from slipping easily, for example, it is conceivable not to lower the friction coefficient of the contact portion by the following method.

-Lubricating oil is not applied to the contact portions of the side surfaces of the permanent magnets and the side surfaces of the elastic fixing members with the side surfaces of the permanent magnets.
・ Remove and wash rust preventive oil and processing oil adhering to the surface of the elastic fixing member.

  If any of the above structures is adopted, even when an impact load is applied to the elastic fixing member when the permanent magnet is rotated when switching between braking on and braking off, the joint between the elastic fixing member and the magnet support ring It is possible to ensure durability. Thereby, the intensity | strength of an elastic fixing member can be ensured and a permanent magnet can be stably fixed over a long period of time.

  It goes without saying that the present invention is not limited to the above-described embodiments, and the embodiments may be appropriately changed within the scope of the technical idea described in each claim.

  For example, in the first embodiment shown in FIG. 2, the elastic fixing member 11 has a bathtub shape, but by raising the side wall 13 from the entire outer peripheral end of the bottom wall 12, the upper part opens to form a space inside. If it is a thing, a cross section may not be an ellipse, but an ellipse or a circle may be sufficient.

  In the above-described embodiment, the single-row swivel type eddy current type reduction device has been described. However, the permanent magnets are arranged in two rows arranged adjacent to a fixed support ring and a movable support ring that can swivel at a required angle. Needless to say, the swirl type eddy current type speed reducer has the same effect.

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Brake drum 3 Permanent magnet 4 Magnet support ring 5 Pole piece 6 Support body 6a Support member 11 Elastic fixing member 12 Bottom wall 13 Side wall 14 Wave shape part 15 Slit

Claims (3)

A braking drum integrally attached to the rotating shaft;
A ferromagnetic magnet support ring in which permanent magnets are arranged at regular intervals so that the magnetic poles adjacent to each other in the circumferential direction of the brake drum are opposite to each other and supported in opposition to the brake drum.
A non-magnetic ferromagnetic pole piece group disposed between the permanent magnet group and the brake drum between each pole piece of the pole piece group. A support body installed with a body support member interposed therebetween,
In the eddy current type reduction device of the type in which the magnet support ring is configured to be capable of turning in the circumferential direction around the rotation axis with a required angle, and switching between braking on and braking off by rotating the permanent magnet in the circumferential direction ,
Between the permanent magnets, the permanent magnets bonded to the magnet support ring,
a) Bathtub-shaped non-magnetic elastic fixing member,
Or
b) a non-magnetic elastic fixing member in which a wavy shape part connected from the groove-shaped side walls to the bottom wall is formed,
Or
c) a non-magnetic elastic fixing member in which slits extending from both side walls to the bottom wall are formed on both longitudinal ends of the groove-shaped groove;
Or
d) A slit extending from both side walls to the bottom wall is formed on both ends in the longitudinal direction of the groove-shaped groove, and a wavy shape portion connected from the both side walls to the bottom wall is formed on the longitudinal center portion side of the groove from the slit. Non-magnetic elastic fixing member,
An eddy current type speed reducer characterized by being supported by arranging   The bathtub-shaped elastic fixing member is such that when the elastic fixing member is viewed from the cross-sectional direction of the rotating shaft, both side walls are raised so as to spread outward from the bottom wall toward the upper end. The eddy current type reduction gear according to claim 1 characterized by things.   2. The eddy current reduction device according to claim 1, wherein the groove-shaped elastic fixing member is formed such that both groove-shaped side walls widen from the bottom wall toward the upper end. .

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