JP2003209965A - Eddy current speed reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eddy current speed reducer which has a mechanism for automatically returning a magnet support cylinder to a non-braking position, prevents the occurrence of drag torque at the time of non-braking, and possesses a simple device configuration. <P>SOLUTION: The eddy current speed reducer is equipped with a brake drum 7 coupled with a rotating shaft, an immovable guide cylinder disposed in the brake drum and provided with an inner cavity with a rectangular cross section, a magnet support cylinder 14 provided in the inner cavity, a plurality of magnets 24 provided on the outer peripheral surface of the magnet support cylinder at equal intervals in the peripheral direction so that polarities alternately change, and a plurality of ferromagnetism parts provided on positions corresponding to the magnets. The respective ferromagnetism parts 121 and coupled parts 122 form an integral ferromagnetic 15, and an actuator 20 is provided which is connected to the magnet support cylinder 14 so as to rotate the magnet support cylinder 14 in the peripheral direction and in the direction opposite to the usual rotation of the brake drum 7 from the non- braking position, in which two adjacent magnets with different polarities are disposed partly facing to the shared ferromagnetism part 121 to the braking positions opposed to the respective magnets. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current speed reducer, and more particularly to a permanent magnet type eddy current speed reducer for assisting a friction brake of an automobile.

[0002]

2. Description of the Related Art A conventional electromagnet type eddy current reduction device for assisting a friction brake of an automobile has a large device configuration.
Moreover, since it is heavy, it is difficult to mount it on a car. Further, since the current consumption is large, it is necessary to increase the capacity of the power supply battery.

Therefore, a high-performance rare earth permanent magnet (hereinafter,
A permanent magnet type eddy current speed reducer is applied to the eddy current speed reducer. According to this permanent magnet type eddy current speed reducer, the size and weight of the device can be reduced, so that the device can be easily installed in an automobile, and since it does not consume power, it is not necessary to increase the capacity of the power supply battery. Is.

The permanent magnet type eddy current speed reducer is of a braking drum type (see Japanese Patent Laid-Open No. 1-298948).
And a braking disc type (see Japanese Patent Publication No. 2701390). By switching a magnet, switching between non-braking and braking is performed.

In the case of a braking drum type eddy current speed reducer,
On the outer peripheral surface of the magnet support cylinder disposed inside the braking drum (rotor), a large number of magnets are arranged at equal intervals in the circumferential direction and the polarities are alternately different in the circumferential direction (N, S, N, ... like)
It is provided. Between the inner surface of the braking drum and the outer surface of the magnet, a ferromagnetic material (pole piece) is placed at a position facing each magnet.
A guide tube having is provided. During braking, by overlapping each ferromagnetic material and each magnet (braking position), the magnetic field from each magnet reaches the braking drum through each ferromagnetic material, and the magnetic field is generated between each magnet and the braking drum. Form a circuit. At this time,
Eddy current is generated in the rotating braking drum, and braking torque is generated. Also, when releasing the braking, move each magnet so that each magnet is placed between the ferromagnetic material (non-magnetic member).
The magnetic field from each magnet forms a short-circuit magnetic circuit with each ferromagnetic material by moving the magnet to the (non-braking position), and the magnetic field from each magnet hardly reaches the braking drum.

[0006]

By the way, in this braking drum type eddy current speed reducer, the magnets are located between the ferromagnetic bodies during non-braking. There is a problem that the magnetic flux may slightly leak from the non-magnetic member between them, and as a result, drag torque is generated, resulting in deterioration of fuel efficiency.

When the braking drum type eddy current speed reducer is mounted on an automobile, the magnet support cylinder is not attached to the magnet support cylinder during braking due to, for example, failure of the pneumatic system (flexible air pipe, solenoid valve, etc.). It is possible that compressed air for returning from the braking position to the non-braking position cannot be supplied to the pneumatic actuator. If the magnet support cylinder continues to run while in the braking position, the braking drum may overheat, which may cause thermal deformation of the braking drum, resulting in violent vibration or bursting.
Fail-safe design is required. That is, even if compressed air for returning the magnet supporting cylinder from the braking position to the non-braking position cannot be supplied to the pneumatic actuator, a mechanism for automatically returning the magnet supporting cylinder to the non-braking position is provided. Is required. As an eddy current speed reducer having this mechanism, there are a braking drum type disclosed in Japanese Patent Application No. 2-112026 and a braking disc type disclosed in Japanese Patent Application No. 2-201817.

These eddy current speed reducers are provided with a movable magnet support cylinder and a stationary magnet support cylinder, and two magnets of the same polarity face one ferromagnetic body during braking. Therefore, the two magnets repel each other, and a force acts to return to the non-braking position. Further, since two magnets having different polarities face one ferromagnetic body when not braking, the two magnets attract each other and are stabilized at the non-braking position. However, these eddy current deceleration devices have a problem that the cost of the device (manufacturing cost) increases because the number of parts constituting the device is large.

An object of the present invention, which was devised in view of the above circumstances, is to provide a mechanism for automatically returning the magnet support cylinder to the non-braking position so that drag torque will not be generated when non-braking, and An object is to provide an eddy current speed reducer having a simple device configuration.

[0010]

In order to achieve the above object, an eddy current speed reducer according to the present invention is provided with a braking drum connected to a rotating shaft, and a braking drum provided inside the braking drum and having a substantially rectangular cross section. An immovable guide cylinder having an inner space, a magnet support cylinder provided in the inner space of the guide cylinder, and an outer peripheral surface of the magnet support cylinder at equal intervals in the circumferential direction and with polarities alternating in the circumferential direction. In the eddy current reducer including a large number of magnets provided on the outer peripheral surface of the guide cylinder and a large number of ferromagnetic portions provided on the peripheral surface of the outer peripheral portion of the guide cylinder at positions corresponding to the magnets, The ferromagnetic part and the connecting part are integrally connected to each other to form a ferromagnetic body, and at the time of braking, the magnet supporting cylinder is partially connected to a common ferromagnetic part in which two adjacent magnets having different polarities are common. From the non-braking position facing each other to the braking position where each magnet faces each ferromagnetic part. In the circumferential direction and to rotate in the normal direction of rotation opposite to the direction of the brake drum, it is provided with a actuator connected to the magnet support tube.

Further, the eddy current speed reducer according to the present invention comprises a braking disc connected to the rotating shaft, an immovable guide ring provided to face at least one end face of the braking disc, and A magnet support ring provided on the outer side of the guide ring, a large number of magnets provided on the end face of the magnet support ring on the side of the braking disc at equal intervals in the circumferential direction, and the polarities of which alternately alternate in the circumferential direction, and the guide ring. In an eddy current reduction device having a plurality of ferromagnetic parts provided at positions corresponding to each magnet, the ferromagnetic parts and the connecting parts are integrally connected by a ring body made of a magnetic material. To form a ferromagnetic material, and at the time of braking, the magnet support ring,
Circumferentially from the non-braking position where two adjacent magnets of different polarities partially oppose the common ferromagnetic part to the braking position where each magnet opposes each ferromagnetic part, and in the braking circle. In order to rotate the plate in the direction opposite to the normal rotation direction, an actuator is provided in connection with the magnet support ring.

Further, the eddy current speed reducer according to the present invention is
A pair of braking discs connected to the rotating shaft, an immovable guide cylinder provided between the braking discs and having an inner hollow portion having a substantially rectangular cross section, and a magnet provided in the inner hollow portion of the guide barrel. The support ring, a large number of magnets provided on the inner peripheral portion of the magnet support ring at equal intervals in the circumferential direction, and having polarities alternately different in the circumferential direction, fixed to the guide cylinder, and each braking disc. In an eddy current reduction device including a pair of a plurality of ferromagnetic parts provided at positions corresponding to the respective magnets between the magnets and the magnets, each ferromagnetic part and the connecting part are made of a ring body made of a magnetic material. A ferromagnetic body that is integrally connected is formed, and at the time of braking, the magnet supporting ring is formed from a non-braking position where two adjacent magnets having different polarities partially oppose a common ferromagnetic portion, To the braking position where each magnet faces each ferromagnetic part, in the circumferential direction, and the normal rotation direction of the braking disc. To rotate in the direction of the pair, it is provided with a actuator connected to the magnet support tube.

The ferromagnetic material is provided with ferromagnetic portions and connecting portions alternately in the circumferential direction, and the thickness of the ferromagnetic portion in the radial direction or the axial direction is
It may be formed thicker than the radial or axial thickness of the connecting portion.

The ferromagnetic material may be formed by stacking ring-shaped thin steel plates in the axial direction.

A hole may be formed in the connecting portion of the ferromagnetic material, and a non-magnetic member may be inserted and arranged in the hole.

When the brake is released, a spring that pushes back the magnet supporting cylinder or the magnet supporting ring about half the stroke from the braking position to the non-braking position is provided inside the actuator, the inner space of the guide cylinder, or the above. It may be housed and provided in the inner peripheral portion of the guide ring.

When the brake is released, the spring that pushes back the magnet support cylinder or the magnet support ring with a strong force for about half of the stroke from the braking position to the non-braking position and with a weak force for the remaining half of the stroke. It may be housed inside the actuator, inside the guide cylinder, or inside the guide ring.

The braking position of each magnet may be a position slightly offset from the position where each magnet faces each ferromagnetic portion to the non-braking position side.

According to the above construction, a mechanism for automatically returning the magnet support cylinder to the non-braking position is provided, and since the ferromagnetic parts are connected by the same member, the magnet support cylinder is not dragged. It is possible to obtain an eddy current reduction device that does not generate torque and has a simple device configuration.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

In the present invention, during braking, the magnet supporting cylinder (or magnet supporting ring) is moved from the non-braking position to the braking position in the normal rotation direction of the braking drum (or the braking disc) (rotational direction when the vehicle is running forward). The mechanism is to rotate in the opposite direction. When the rotation speed of the braking drum is 800 rpm or more, the magnet support cylinder automatically returns from the braking position to the non-braking position. The reason why the magnet support cylinder automatically returns from the braking position to the non-braking position is that the repulsive magnetic field from the eddy current generated in the braking drum generates a force to move the magnet support cylinder in the rotation direction of the braking drum. . The braking drum is rotating at low speed (80
At 0 rpm or less), it is difficult for the magnet support cylinder to return to the non-braking position. Therefore, the entire stroke (stroke) from the braking position to the non-braking position or about half of the stroke is returned by the force of the spring. Therefore, the spring is housed inside the actuator or inside the guide tube. 1 is a side sectional view of the eddy current speed reducer according to the first embodiment, FIG. 2 is a front sectional view of the eddy current speed reducer in FIG. 1 when not braking, and FIG. Figure 3 is a front sectional view of
Shown in.

As shown in FIGS. 1 to 3, the eddy current reduction gear device according to the first embodiment includes, for example, a braking drum 7 made of a conductor coupled to an output rotary shaft 1 of a vehicle transmission, and a braking device. A guide cylinder 10 made of a non-magnetic material such as aluminum disposed inside the drum 7, and a movable magnet support cylinder 1 housed in an inner space of the guide cylinder 10 having a rectangular cross section (substantially rectangular cross section).
4 and.

The braking drum 7 is a flange portion 5a of the boss 5.
Together with the end wall portion of the braking drum 3 of the parking brake are superposed on the mounting flange 2 fixed to the rotary shaft 1 by spline fitting, and fastened by a plurality of bolts 4 and nuts. A base end of a braking drum 7 provided with heat radiation fins 8 is coupled to a large number of support arms (spokes) 6 extending radially from the boss 5. Here, the pole pieces 15 on both end surfaces (only the left end surface in FIG. 1) and the inner peripheral surface of the braking drum 7 are provided.
The annular plates 9a to 9c made of a good conductor such as copper may be provided in a portion that does not face the ferromagnetic portion 121. As a result, the eddy current flowing inside the braking drum 7 spreads in the axial direction (the left-right direction in FIG. 1), and the braking torque can be increased.

A guide tube 10 having an inner space with a rectangular cross section.
Is made of a non-magnetic material and has, for example, a tubular shape with an L-shaped cross section, and has a radial flange portion 10a and an axial inner guide tube 10b. The guide tube 10 is fixed to the gear box (not shown) of the transmission by any suitable means. An annular end wall plate 11 made of a non-magnetic material is coupled to the end portion 10c of the inner guide cylinder 10b with a plurality of bolts or the like.

As shown in FIG. 12, a ring-shaped ferromagnetic material (pole piece) 15 made of a soft magnetic material or a magnetic material is a soft magnetic material such as steel and faces the inner peripheral surface of the braking drum 7. Many thick-walled parts (ferromagnetic parts) corresponding to magnetic plates 1
21 and the thin portion (connecting portion) 122 alternately in the circumferential direction,
Moreover, they are integrally formed at equal intervals in the circumferential direction. Here, the circumferential length of the ferromagnetic portion 121 is longer than the circumferential length of the connecting portion 122, that is, the pole piece 15 is formed.
The area of the outermost peripheral portion is smaller than the area of the inner peripheral portion. Further, both side edges in the axial direction of the pole piece 15 are preferably bent inward in the radial direction, and the bent portions are fitted to the flange portion 10 a of the guide cylinder 10 and the upper end portion of the end wall plate 11. Further, a reinforcing plate made of a non-magnetic material may be attached to the outer peripheral surface of the connecting portion. Alternatively, a hole (not shown) may be formed in the connecting portion 122, and a non-magnetic member (not shown; for example, stainless steel) may be inserted and arranged in the hole. As a result, it is possible to improve the strength of the pole piece 15, prevent water and dust from entering, and prevent leakage of magnetic flux to the adjacent ferromagnetic portion 121 during braking.

The method of manufacturing the pole piece 15 is not particularly limited, and the following method may be mentioned.

Grooves are formed at equal intervals in the circumferential direction along the longitudinal direction on the outer peripheral surface and / or the inner peripheral surface of the ring member formed of a magnetic material, and the ferromagnetic portion 121 and the connecting portion 122 are integrally formed. .

A ring member having substantially the same shape as the target pole piece is formed of cast steel, and is appropriately cut to improve the dimensional accuracy of the connecting portion, and the ferromagnetic portion 121 and the connecting portion 1 are formed.
22 and 22 are integrally formed.

Roll forging is applied to the outer peripheral surface of the ring member formed of a magnetic material, grooves are formed at equal intervals in the circumferential direction along the longitudinal direction on the outer peripheral surface, and further cutting processing is performed as finishing processing of the groove, The ferromagnetic part 121 and the connecting part 122 are integrally formed.

As shown in FIG. 18, a thin steel plate for processing (thin plate material;
For example, electromagnetic steel plate, general-purpose rimmed steel plate (SPCC), etc.)
A plurality of 180 are stacked in the axial direction and pressure-bonded to integrally form the ferromagnetic portion 121 and the connecting portion 122. Here, the manufacturing method of, after rolling a flat plate having a certain thickness to form a ring shape (finally connecting both end faces to form a ring member), press punching, and then, Since the pole piece can be manufactured by laminating and crimping or by laminating and crimping the ring member which has been punched beforehand, the manufacturing is easy,
The manufacturing cost can be reduced as compared with the manufacturing method described above. Further, when the pole piece is formed of an electromagnetic steel sheet, it is preferable to impregnate each steel sheet and / or the outer peripheral portion of the pole piece with a heat-resistant sealant or impregnating agent in order to secure the sealability between the steel sheets. Further, the pole piece member 19 shown in FIGS.
1, 201, and each pole piece member 191, 20
1 end portion in the circumferential direction (left end portion in FIGS. 19 and 20) 1
92, 193 to the adjacent pole piece members 191, 2
01 other end in the circumferential direction (right end in FIGS. 19 and 20)
The pole piece 15 may be formed by connecting (or fitting) with the 193, 203. The joining (or fitting) shape is not particularly limited, and various shapes can be applied.

A movable magnet support cylinder 14 made of a magnetic material is housed in the inner space of the guide cylinder 10. The movable magnet support cylinder 14 is supported by the bearing 12 so as to be rotatable forward and backward with respect to the inner guide cylinder 10b. The arm 16 extending in the axial direction from the magnet support cylinder 14 is connected to the rod of the actuator 20 via an arc-shaped slit 18 a provided in the end wall of the guide cylinder 10. Each ferromagnetic portion 12 on the outer peripheral surface of the magnet support cylinder 14
The magnet 24 is provided at a position facing 1 so that the polarities facing the ferromagnetic portion 121 are alternately different in the circumferential direction.
Here, as shown in FIG. 4, stepped portions 44a are formed at both ends in the circumferential direction of each magnet 44, and the holding metal fitting 21 having a T-shaped cross section is sandwiched between the magnets 44 and seated on the stepped portion 44a. Each magnet 44 may be fastened and fixed to the magnet support cylinder 14 by 22.

As shown in FIGS. 2 and 3, an actuator 20 for rotating the movable magnet support cylinder 14 in the forward and reverse directions has a piston 17 in a cylinder 18 formed integrally with a flange portion 10a (see FIG. 1). The both end chambers 31, 32 are formed by being fitted and the rod 33 connected to the piston 17 is connected to the end chamber 31.
Is projected from the outside. The arm 16 protruding from the magnet support cylinder 14a to the outside through the slit 18a of the flange portion 10a.
Is connected to the rod 34, and the rod 34 and the rod 33
And are connected by a pin so that they do not exceed a predetermined bending angle. A spring (or a spring having a nonlinear spring constant) 35 is arranged in the end chamber 31.

In the eddy current speed reducer of this embodiment,
When not braking, as shown in FIGS. 1 and 2, the magnet support cylinder 14
Two magnets 24 arranged in the circumferential direction and having different polarities partially face a common ferromagnetic portion 121. At this time, a short-circuit magnetic circuit w is generated between the magnet support cylinder 14 and each ferromagnetic portion 121, and the magnetic field of the magnet 24 hardly exerts the magnetic field on the braking drum 7.

Next, during braking, as shown in FIG. 3, each magnet 24 of the magnet support cylinder 14 faces each ferromagnetic portion 121. The magnet 24 applies a magnetic field to the braking drum 7 via the ferromagnetic portion 121, and when the rotating braking drum 7 crosses the magnetic field, an eddy current flows in the braking drum 7 and a braking torque T is generated in the braking drum 7. At this time, in each magnet 24, a magnetic circuit z is generated between the braking drum 7 and the magnet support cylinder 14.
By the way, the rotation number of the braking drum 7 is 3600 to 800 r.
In pm, when the magnet support cylinder 14 is rotated from the non-braking position to the braking position, as indicated by lines 37 and 38 in FIG.
When the magnet support cylinder 14 is rotated in the direction opposite to the rotation direction y of the braking drum 7, as indicated by lines 27 and 28 in FIG.
Rather than rotating the magnet support cylinder 14 in the same direction as the rotation direction y of the braking drum 7, the magnet support cylinder 14 returns to the non-braking position more easily, and the magnet support cylinder 14 brakes even when the rotation speed of the braking drum 7 is near 800 rpm. Automatically returns from the position to the non-braking position. The reason why the magnet supporting cylinder 14 automatically returns from the braking position to the non-braking position is that the reaction magnetic field based on the eddy current generated in the braking drum 7 causes the magnet supporting cylinder 14 to move in the rotation direction y of the braking drum 7. Is due to work. This phenomenon became clear as a result of the dynamic electromagnetic field analysis that has rapidly developed recently,
The force to operate the magnet support cylinder 14 can also be calculated.

In the present embodiment, regardless of whether the actuator is a pneumatic actuator, a hydraulic actuator, or an electric motor, the magnet support cylinder 14 is not provided in consideration of a case where the fluid pressure system or the electrical system fails. The rotation direction when rotating from the braking position to the braking position is the rotation direction y of the braking drum 7.
And the opposite direction. Further, even when the braking drum 7 is rotating at a low speed, in order to automatically return the magnet support cylinder 14 to the non-braking position, about half of the stroke from the braking position to the non-braking position is set by the spring. Either use force to return, or use strong force to return to about half of the stroke, and then use weak force to return to almost the entire stroke.
For this reason, a spring (or a spring having a non-linear spring constant) that is half the length of the entire stroke is used. Specifically, as shown in FIGS. 2 and 3, the end chamber 31 accommodates the spring 35 having a stroke length of about half the braking position to the non-braking position.

Further, as shown in FIG. 4, the magnet 4 during braking is
Even if the braking drum 7 is rotating at a high speed, if the position of 4 is slightly shifted to the non-braking position,
It becomes easy for the magnet support cylinder 14 to return to the non-braking position.

Further, the pole piece is made up of the ferromagnetic parts 12
1 is connected by a connecting portion 122 to form an integral structure, and is entirely made of a ferromagnetic material. Therefore, each ferromagnetic part 121
Are equal in the circumferential direction, and each ferromagnetic part 1
No magnetic flux leaks from the connecting portion 122 between the two to the braking drum 7, and all the magnetic flux that has entered the connecting portion 122 flows to the ferromagnetic portion 121, and as shown in FIG. 2, the short-circuit magnetic circuit w1.
Occurs. Therefore, drag torque is not generated during non-braking, and fuel economy can be improved.

Further, when the braking drum 7 is actually rotating at a high speed, the magnetic circuit z is dragged in the rotation direction y of the braking drum 7, so that it will be described later.
The cross-sectional shape of each ferromagnetic portion 121 in the pole piece 15 is preferably rectangular as shown in FIGS. 13 to 15 rather than rectangular.

Specifically, as shown in FIG. 13, the outermost peripheral surface 133 and both circumferential end surfaces 13 of each ferromagnetic body 131.
The pole pieces 135 may be chamfered at the boundaries with the 4a and 134b to form the inclined surfaces 136a and 136b. As a result, the magnetic flux from the magnet 24 can be guided to the braking drum 7 in a state where the magnetic flux from the magnet 24 is reduced (the state where the magnetic flux density is increased), so that the braking torque can be increased especially when the braking drum is rotating at a medium speed. it can. Also, FIG.
As shown in FIG. 4, both end surfaces of each ferromagnetic body 141 in the circumferential direction are inclined toward the rotational direction y of the braking drum (not shown) to form inclined surfaces 143a and 143b, which are parallelogrammic in cross section. It may be the pole piece 145. Thus, when the braking drum is rotating at a high speed, the magnetic flux from the magnet 24 can be narrowed down to the front part (the left part in FIG. 14) of the ferromagnetic bodies 141 in the braking drum rotation direction y. Furthermore, as shown in FIG.
The pole piece 1 in which a step portion 153 is formed at a rear portion (right side portion in FIG. 15) of the braking drum 51 in the rotation direction y of the braking drum.
It may be 55. As a result, when the braking drum is rotating at high speed, the magnetic flux from the magnet 24 is transferred to each ferromagnetic material 1
Further, it is possible to further narrow down to the front part (the left side part in FIG. 15) in the braking drum rotation direction y in 51.

Further, as shown in FIGS. 12 to 15, the formation position of the connecting portion for connecting the ferromagnetic portions of the pole piece is not limited to the inner side in the radial direction. For example,
As shown in FIG. 16, the pole piece 161 is formed by connecting the radially outer portions of the ferromagnetic portions 161 by the connecting portions 162. As shown in FIG. 17, the radially central portion of the ferromagnetic portions 171 is formed by the connecting portions 172. It may be the connected pole piece 171.

Next, another embodiment of the present invention will be described with reference to the accompanying drawings.

5 is a side sectional view of the eddy current speed reducer according to the second embodiment, FIG. 6 is a front sectional view of the eddy current speed reducer in FIG. 5, and non-braking of the eddy current speed reducer in FIG. FIG. 7 shows a developed plane sectional view of the eddy current speed reducer in FIG. 5, and FIG.

As shown in FIGS. 5 to 8, the eddy current speed reducer according to the second embodiment has a braking disc 43 composed of a pair of left and right conductors coupled to the rotating shaft 42, and a braking disc 43. An immovable guide tube 61 made of a non-magnetic material, a magnet support ring 50 rotatably and rotatably supported in an inner space of the guide tube 61, and both end surfaces in the axial direction of the guide tube 61. And a ferromagnetic material (pole piece) 46 provided.

The braking disc 43 is integrally formed with a plurality of support arms 43b extending radially from the boss 43a and an air guide passage 43c, and the boss 43a is spline-fitted to the rotary shaft 42.

The guide cylinder 61 is formed integrally with a support arm 45b extending from the boss 45a in the radial direction, and the boss 45a is supported by the rotating shaft 42 by a bearing 48. The guide tube 61 is fixed to the gear box of the transmission by any suitable means.

The magnet support ring 50 made of a non-magnetic material is rotatably supported by the bearing 47 in the inner space of the guide cylinder 61 having a rectangular cross section. A magnet 52 is arranged inside the magnet support ring 50 at a position facing a ferromagnetic portion (described later) 211 of the pole piece 46. Lubricating oil-impregnated thin slide plates 54 are coupled to both end surfaces of the magnet support ring 50 in the axial direction, and are slidably contactable with the pole pieces 46.

As shown in FIG. 21, a thin plate ring-shaped ferromagnetic pole piece 46 made of a soft magnetic material or a magnetic material.
Is a large number of thick-walled portions (ferromagnetic portions) 211 and thin-walled portions (coupling portions) 212 corresponding to the magnetic plates facing the braking disc 43.
And are integrally formed alternately in the circumferential direction and at equal intervals in the circumferential direction. In FIG. 21, the connecting portion 212 is formed below the pole piece 46.

As shown in FIG. 6, a fan-shaped magnet 52 is provided on the magnet support ring 50 and each ferromagnetic portion 211 of the pole piece 46.
And the polarities facing the ferromagnetic portion 212 are alternately arranged in the circumferential direction. A small gear 55 of an actuator (electric motor) 56 fixed to a guide cylinder 61 is meshed with a partial gear 58 formed on the outer peripheral wall of the magnet support ring 50, and the magnet support ring 50 is positive by a half arrangement pitch p of the magnets 52. It is provided so that it can rotate in the reverse direction.

In the eddy current speed reducer of this embodiment,
During non-braking, as shown in FIG. 7, the polarities are different from each other.
Since the two magnets 52 partially oppose the common ferromagnetic portion 211, a short-circuit magnetic circuit w occurs between the pair of left and right ferromagnetic bodies 46, and the magnetic field does not reach the braking disc 43.

During braking, as shown in FIG. 8, each magnet 52 is rotated by the actuator 56 by rotating the magnet support ring 50 by the half arrangement pitch P of the magnets 52.
11 is almost entirely opposed. As a result, each magnet 52 exerts a magnetic field on the braking disc 43 via the ferromagnetic portion 211. At this time, the rotating braking disc 43 crosses the magnetic field, so that an eddy current is generated in the braking disc 43 and the braking disc 43 receives the braking torque. At this time, the magnetic circuit z is generated between the pair of braking discs 43.

In the present embodiment, the rotation direction when the magnet support ring 50 is rotated from the non-braking position to the braking position is set in consideration of the case where the electric system or the fluid pressure system fails. The direction is opposite to the rotation direction y of the disc 43. further,
Even when the braking disc 43 is rotating at a low speed, in order to automatically return the magnet support ring 50 to the non-braking position, about half the stroke from the braking position to the non-braking position is performed by the spring force. Try to put it back by. Therefore, the spiral return spring is locked between the small gear 55 and the non-rotating portion of the actuator 56. The return spring may be sized to return the magnet support ring 50 by about half a stroke from the braking position to the non-braking position (by a spring having a non-linear spring constant,
It may be possible to return almost the entire process). Of course, Figure 2
The magnet support ring 50 may be rotated by the actuator 20 including the spring 35 as shown in FIG.

If the position of the magnet 24 during braking is set to a position slightly shifted toward the non-braking position, the braking disc 43
The magnet support ring 50 is likely to return to the non-braking position even when is rotating at high speed.

Furthermore, the cross-sectional shape of each ferromagnetic portion 211 in the pole piece 46 is not limited to the rectangular shape shown in FIG. 21, but the cross-sectional shape shown in FIGS. 13 to 15. May be.

Further, each ferromagnetic portion 21 of the pole piece 46
The formation position of the connecting portion 212 connecting the 1 is not limited to the lower side of the pole piece 46 as shown in FIG. 21, but as shown in FIG. 16 and FIG.
It may be on the upper side or the center of 6.

Further, also in the eddy current reduction gear of the present embodiment, the same effect as that of the eddy current reduction gear of the previous embodiment can be obtained.

FIG. 9 is a side sectional view of the eddy current reduction gear device according to the third embodiment. The same members as those in FIGS. 5 to 8 are designated by the same reference numerals.

As shown in FIG. 9, the eddy current speed reducer according to the third embodiment includes one braking disc 43 connected to the rotary shaft 42, and a guide ring 61 for supporting the pole pieces 46, 46. , A pair of magnet support rings 50, 5 supporting the magnet 52
It has 0 and.

The guide ring 61 having a gate-shaped cross section has a connecting portion 61.
a and the flange portions 61b and 61b, the connecting portion 61a connects the outer peripheral surface of the braking disc 43 to the flange portions 61b and 6b.
1b is provided so as to surround the outer peripheral portions of both end surfaces of the braking disc 43, and a connecting portion 61a is provided so as to be fixed to a non-rotating portion such as a vehicle body. The pole piece 46 is provided by fitting into a hole 61c formed in the flange portion 61b of each guide ring 61.

The pair of magnet support rings 50, 50 is formed by the guide ring 6.
1 is provided so as to face each of the flange portions 61b and 61b,
The magnets 52 are provided on the end faces of the magnet support rings 50, 50 on the flange portion side so as to face the ferromagnetic portion 211 of the pole piece 46 so that the polarities alternate in the circumferential direction.

A plurality of arcuate slits 61d formed in the connecting portion 61a of the guide ring 61 are provided with connecting members 50a having an arcuate cross section through bearings 47, 47a. A pair of magnet support rings 50, 50 are coupled to both end surfaces of the connecting member 50a, whereby the magnet support rings 50, 50 can rotate in the circumferential direction in the forward and reverse directions.

During braking, an actuator (not shown) rotates the magnet support ring 50 in a direction opposite to the normal rotation direction of the braking disc 43, so that two magnets 52 arranged in the circumferential direction and having different polarities are arranged. , A non-braking position that partially opposes a common ferromagnetic portion 211 is switched to a braking position that each magnet 52 faces each ferromagnetic portion 211.

FIG. 10 is a side sectional view of the eddy current speed reducer according to the fourth embodiment. The same members as those in FIG. 9 are designated by the same reference numerals.

In the eddy current speed reducer according to the third embodiment shown in FIG. 9, the guide ring 61 is fixed and the magnet support ring 50,
50 was rotated in the circumferential direction.

On the other hand, as shown in FIG.
The eddy current speed reducer according to the embodiment of the present invention includes one braking disc 43 coupled to the rotating shaft 42 and the pole pieces 46, 46.
The guide ring 61 for supporting the magnet and the magnet supporting ring 100 for supporting the magnet 52 are provided.

The guide ring 61 having a gate-shaped cross section has a connecting portion 61.
a and the flange portions 61b and 61b, the connecting portion 61a connects the outer peripheral surface of the braking disc 43 to the flange portions 61b and 6b.
1b is provided so as to surround the outer peripheral portions of both end surfaces of the braking disc 43. The pole piece 46 is provided by fitting into a hole 61c formed in the flange portion 61b of each guide ring 61.

The magnet support ring 100 having a gate-shaped cross section has a connecting portion 100a and flange portions 100b and 100b, and is provided so as to surround the guide ring 61.
00a is fixedly provided on a non-rotating portion such as a vehicle body.
Magnets 52 are provided on the end surfaces of the flange portions 100b, 100b facing the ferromagnetic portion 211 of the pole piece 46 on the end face on the guide ring 61 side so that the polarities are alternately different in the circumferential direction.

The connecting portion 61a of the guide ring 61 and the magnet support ring 1
The coupling portion 100a of No. 00 is coupled via the bearing 47, whereby the guide ring 61 can rotate in the forward and reverse directions in the circumferential direction.

At the time of braking, the guide ring 61 is rotated in the normal rotation direction of the braking disc 43 by an actuator (not shown), and two magnets 52 having different polarities arranged in the circumferential direction have a certain common strength. Each of the magnets 52 is switched from the non-braking position that partially faces the magnetic portion 211 to the braking position that faces each ferromagnetic portion 211.

In the eddy current reduction gears according to the third and fourth embodiments, the flange portion 61b of the guide ring 61 and the magnet support ring 50 are opposed to only one end surface of the braking disc 43.
Even if (or 100b) are arranged in order, the function as an eddy current reduction device can be achieved.

Also in the eddy current reduction gears according to the third and fourth embodiments, the magnet support ring 50 is moved from the non-braking position in consideration of the failure of the electric system or the fluid pressure system. The direction of rotation to the braking position is opposite to the rotation direction y of the braking disc 43. In order to automatically return the magnet support ring 50 to the non-braking position when the braking disc 43 is rotating at a low speed, about half the stroke from the braking position to the non-braking position is returned by the force of the spring. To do. If the position of the magnet 52 during braking is shifted slightly toward the non-braking position, the magnet support ring 50 can easily return to the non-braking position even when the braking disc 43 is rotating at high speed.

Further, in the eddy current reduction gears of the third and fourth embodiments, the same effect as that of the eddy current reduction gears of the first and second embodiments can be obtained.

It is needless to say that the embodiments of the present invention are not limited to the above-mentioned embodiments, and various other embodiments are possible. Specifically, the invention of the present application is a braking disc type eddy current speed reducer disclosed in Japanese Patent Application Laid-Open No. 1-2989847, and Japanese Patent Application Laid-Open No. 6-38504 that prevents magnetic flux from leaking to a braking body when not braking. Eddy current reducer disclosed in Japanese Patent Laid-Open No. 2000-116106 and the like, eddy current reducer including two rows of magnet support cylinders in the axial direction as disclosed in Japanese Patent Laid-Open No. 2000-236655, and It can also be applied to an eddy current speed reducer including a rotatable magnet support cylinder in two or more rows as disclosed in Japanese Patent Application No. 8-257521. Further, it can be applied to an eddy current reduction device in which pole pieces are continuously and integrally formed in the circumferential direction. Moreover, the actuator is not limited to the fluid pressure actuator, and a motor actuator (electric motor, servo motor, voice coil motor, linear motor, etc.) can be used.

[0073]

In summary, according to the present invention, the following excellent effects are exhibited. (1) When the magnet supporting cylinder is returned to the non-braking position by rotating the magnet supporting cylinder in the direction opposite to the braking drum during braking, when the braking drum is rotating at a low speed or the actuator Even without supplying pressurized air to the end chamber, the magnet supporting cylinder can be returned to the non-braking position by the returning force of the spring and the returning force of the repulsive magnetic field. (2) The same applies to (1) in an eddy current reduction device of a type in which a magnet support ring is arranged so as to face the braking disc.

[Brief description of drawings]

FIG. 1 is a side sectional view of an eddy current reduction device according to a first embodiment.

FIG. 2 is a front cross-sectional view of the eddy current speed reducer in FIG. 1 during non-braking.

FIG. 3 is a front sectional view of the eddy current speed reducer in FIG. 1 during braking.

FIG. 4 is a front sectional view showing a modified example of FIG.

FIG. 5 is a side sectional view of an eddy current reduction device according to a second embodiment.

6 is a front cross-sectional view of the eddy current reduction device in FIG.

FIG. 7 is a developed plan sectional view of the eddy current reduction device in FIG. 5 when not braking.

8 is a developed plan sectional view of the eddy current speed reducer in FIG. 5 during braking.

FIG. 9 is a side sectional view of an eddy current reduction device according to a third embodiment.

FIG. 10 is a side sectional view of an eddy current reduction device according to a fourth embodiment.

FIG. 11 is a diagram showing the force with which the magnet support cylinder tries to return from the braking position to the non-braking position.

FIG. 12 is a partial front view showing an example of a pole piece of the eddy current speed reducer in FIG.

13 is a partial front view showing a first modified example of the pole piece of FIG.

FIG. 14 is a partial front view showing a second modification of the pole piece of FIG.

FIG. 15 is a partial front view showing a third modification of the pole piece of FIG.

16 is a partial front view showing a fourth modified example of the pole piece of FIG.

FIG. 17 is a partial front view showing a fifth modification of the pole piece of FIG.

18 is a partial perspective view showing an example of a method of manufacturing the pole piece of FIG.

FIG. 19 is a partial front view showing a sixth modification of the pole piece of FIG.

FIG. 20 is a partial front view showing a seventh modification of the pole piece of FIG.

21 is a partial perspective view showing an example of a pole piece of the eddy current speed reducer in FIG.

[Explanation of symbols]

1, 42 Rotation shaft 7 Braking drum 10, 61 Guide cylinder 14 Magnet support cylinder 15, 46, 135, 145, 155, 165, 175
Ferromagnetic material 20,56 Actuator 24,52 Magnet 35 Spring 43 Braking disc 61 Guide ring 50,100 Magnet support ring 121,131,141,151,161,171,2
11 ferromagnetic parts 122, 162, 172, 212 connecting parts

Claims (9)

[Claims] 1. A braking drum connected to a rotary shaft,
An immovable guide cylinder provided inside the braking drum and having an inner hollow portion having a substantially rectangular cross section, a magnet support cylinder provided in the inner hollow portion of the guide cylinder, and a circumferential direction or the like on the outer peripheral surface of the magnet support barrel. Vortex provided with a large number of magnets arranged at intervals and with different polarities alternately in the circumferential direction, and a large number of ferromagnetic parts provided at positions corresponding to the magnets on the outer peripheral surface of the outer peripheral portion of the guide cylinder. In the current reduction device, a ring body made of a magnetic material forms a ferromagnetic body in which each ferromagnetic portion and the connecting portion are integrally connected, and during braking,
From the non-braking position where two adjacent magnets having mutually different polarities partially face a common ferromagnetic portion to the braking position where each magnet faces each ferromagnetic portion, the magnet supporting cylinder is circumferentially arranged. In addition, an eddy current reduction device characterized in that an actuator is provided in connection with the magnet support cylinder in order to rotate the braking drum in a direction opposite to the normal rotation direction. 2. A braking disc provided so as to be coupled to a rotary shaft, an immovable guide ring provided so as to face at least one end surface of the braking disc, and a magnet support provided outside the guide ring. A ring,
A large number of magnets provided on the end face of the magnet support ring on the side of the braking disc at equal intervals in the circumferential direction and having different polarities alternately in the circumferential direction, and a position fixed to the guide ring and corresponding to each magnet. In the eddy current speed reducer including a large number of ferromagnetic parts provided in, a ferromagnetic body in which each ferromagnetic part and the connecting part are integrally connected by a ring body made of a magnetic material is formed. ,
The magnet supporting ring is circumferentially arranged from a non-braking position where two adjacent magnets having mutually different polarities partially face a common ferromagnetic portion to a braking position where each magnet faces each ferromagnetic portion. In addition, an eddy current reduction device characterized in that an actuator is provided in connection with the magnet support ring in order to rotate the braking disc in a direction opposite to the normal rotation direction. 3. A pair of braking discs connected to a rotating shaft, an immovable guide cylinder provided between the braking discs and having an inner space portion having a substantially rectangular cross section, and an inner space of the guide cylinder. A magnet supporting ring provided on the guide part, a plurality of magnets provided on the inner peripheral part of the magnet supporting ring at equal intervals in the circumferential direction, and having polarities alternately different in the circumferential direction, and fixed to a guide tube, and In an eddy current reduction device including a pair of a plurality of ferromagnetic portions provided at positions corresponding to the magnets, between the braking discs and the magnets, each ferromagnetic portion is a ring body made of a magnetic material. And the connecting portion form an integrally connected ferromagnetic body, and at the time of braking, the magnet supporting ring partially opposes a common ferromagnetic portion of two adjacent magnets having polarities different from each other. From the non-braking position to the braking position where each magnet faces each ferromagnetic part, in the circumferential direction, and the normal braking disc An eddy current decelerating device comprising an actuator connected to the magnet support cylinder so as to rotate in a direction opposite to the rotation direction of the. 4. The ferromagnetic body is provided with ferromagnetic parts and connecting parts alternately in the circumferential direction, and the thickness of the ferromagnetic part in the radial direction or the axial direction is greater than the thickness of the connecting part in the radial direction or the axial direction. The eddy current reduction device according to claim 1, wherein the eddy current reduction device is formed thick. 5. The eddy current reduction device according to claim 1, wherein the ferromagnetic material is formed by stacking ring-shaped thin steel plates in the axial direction. 6. A hole is formed in the connecting portion of the ferromagnetic material,
A non-magnetic member is inserted and arranged in the hole portion.
The eddy current reduction device according to. 7. When the brake is released, a spring that pushes back the magnet supporting cylinder or the magnet supporting ring about half the stroke from the braking position to the non-braking position is provided inside the actuator, in the inner space of the guide cylinder, Alternatively, the eddy current reduction device according to any one of claims 1 to 6, wherein the eddy current reduction device is housed and provided in an inner peripheral portion of the guide ring. 8. A spring for pushing back the magnet support cylinder or the magnet support ring with a strong force for about half the stroke from the braking position to the non-braking position and a weak force for the remaining about half stroke when releasing the braking. And the inside of the actuator, the inner space of the guide cylinder, or the inner circumference of the guide ring.
7. The eddy current speed reducer according to any one of 1 to 6. 9. The eddy current deceleration according to claim 1, wherein the braking position of each magnet is a position slightly offset from the position where each magnet faces each ferromagnetic portion to the non-braking position side. apparatus.