JP2001224161A - Eddy current type deceleration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate extra processes for improving accuracy by providing the magnetic circuit efficiency and simplifying fixing a permanent magnet to a support ring. SOLUTION: A group of permanent magnets 3 is allocated through opposite support of a rotor 1, that is mounted integrally to a rotating shaft with the directions of magnetic poles being inverted from each other, along the circumference of the rotor 1 and a constant interval provided for a ferromagnetic support ring 2. A group of ferromagnetic switch plates 4 is also provided between the group of permanent magnets 3 and rotor 1, providing an interval which is same as that of respective permanent magnets 3 of the group of permanent magnets 3. Between respective switch plates 4 of the group of switch plates 4, a nonmagnetic support body 5 is provided. The support body 5 is divided into the internal cylinder side 5a and external cylinder side 5b, including the group of switch plates 4 and thereby the external cylinder side 5b is tunable and movable by a prescribed angle for an internal cylinder side 5a. The support ring 2 is fixed to the internal cylinder side 5a of the support body 5. Thereby, magnetic circuit efficiency can be improved, in comparison with the existing structure. Moreover, fixing of the permanent magnet to the support ring can be simplified, and extra processes for accuracy improvement can also be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current type speed reducer mounted on a large vehicle such as a bus or a truck as a brake assist device.

[0002]

2. Description of the Related Art In recent years, large vehicles such as buses and trucks perform stable deceleration on long downhills and the like to reduce the number of times of using a foot brake to prevent abnormal wear of a lining and a fade phenomenon. At the same time, in order to reduce the braking stop distance, an eddy current type speed reducer has been mounted in addition to a foot brake which is a main brake and an exhaust brake which is an auxiliary brake. As the eddy current type speed reducer, there are a type using an electromagnet and a type using a permanent magnet as a magnet. Recently, many types use a permanent magnet that does not need to be energized during braking. I have.

As an eddy current type speed reducer using this permanent magnet, for example, the one proposed by the present applicant in Japanese Patent Application No. 11-228267 is integrally mounted on a rotating shaft as shown in FIG. A rotor 1 and a ferromagnetic support ring 2 which are supported opposite to the rotor 1 and are spaced apart from each other along a circumferential direction of the rotor 1 so that the magnetic poles are opposite to each other. A group of permanent magnets 3 and a group of ferromagnetic switch plates 4 interposed between the group of permanent magnets 3 and the rotor 1 at the same intervals as the respective permanent magnets 3 of the group of permanent magnets 3 And a non-magnetic support member 5 interposed between the switch plates 4 of the group of switch plates 4, and a braking unit in which the permanent magnet 3 overlaps the switch plate 4 via the support ring 2 by the driving unit 6. ON or one permanent magnet 3 is adjacent Be one or no braking OFF the overlapping halves across the switch plate 4 is obtained by defining the thickness and spacing of the switch plate 4 so as to maintain an optimum relationship. In FIG. 3, reference numeral 1 a denotes a cylindrical portion of the rotor 1, 1 b denotes a cooling fin of the rotor 1, 7 is interposed between the inner peripheral surface side and one side wall side of the support ring 2 and the support 5, respectively.
3 shows a bearing that rotatably supports the support ring 2.

[0004] The applicant of the present invention is disclosed in Japanese Patent Application No. 11-228267.
An eddy current type speed reducer of the single-row turning type proposed in Japanese Patent Application Laid-Open No. 4-12659 discloses a rotor 1 provided on a rotating shaft, as shown in FIG. A fixed support ring 9 having a group of permanent magnets 8 which are supported from the fixed side in opposition to each other and in which N poles and S poles are alternately arranged at predetermined intervals along the circumferential direction, and the same as the fixed support ring 9 A movable support ring 11 having a group of permanent magnets 10 and rotatable with respect to the fixed support ring 9, and a movable support ring 11 interposed between the rotor 1 and the group of permanent magnets 8 and 10. A plurality of ferromagnetic switch plates 4 extending from above each permanent magnet 8 to above the movable support ring 11
And the number of parts can be greatly reduced as compared with a double-row turning type eddy current type reduction gear provided with a non-magnetic support member 5 interposed between the switch plates 4, so that the durability reliability is improved. As a result, the cost can be reduced, and the turning angle of the permanent magnet can be reduced to half, so that the cylinder can be downsized and the air consumption can be reduced.

[0005]

By the way, the ambient temperature of the eddy current type reduction gear at the time of starting the vehicle is in a temperature range of -20 to -30.degree.
The temperature during use of the eddy current type speed reducer during traveling increases to 70 to 90 ° C. due to heating by heat transfer from the rotor 1 located on the outer peripheral portion.

On the other hand, in the eddy current type speed reducer described above, the support 5 is generally made of an aluminum alloy casting or the like in order to reduce the weight, secure non-magnetism, and secure heat radiation. , High coefficient of thermal expansion. Therefore, the dimensional change of the support body 5 due to temperature change is remarkable with respect to the steel bearing 7 and the support ring 2.

For this reason, the gap ε ₁ between the switch plate 4 and the permanent magnet 3 is determined so that the switch plate 4 and the permanent magnet 3 do not interfere with each other even at the lowest temperature when the vehicle is started. Also, the gap ε ₂ between the support 5 and the bearing 7 is determined to a value that can secure an appropriate gap as the bearing 7 at the maximum temperature when the eddy current type reduction gear is used during traveling.

However, at low temperatures, the bearing 7 and the support 5
Gap ε due to the difference in the coefficient of thermal expansion of_Two To increase the gap
Interval ε₁ It is necessary to take this increase into account when making decisions.
From the above, the support ring 2 is supported on the inner peripheral surface side of the support 5 and
In the conventional structure, ₁ Grows larger than necessary
Would. Gap ε₁ Is large on the magnetic circuit.
It becomes a resistance and lowers the efficiency of the magnetic circuit, which is expensive
The use amount of the permanent magnet 3 is increased.

When switching between braking ON and braking OFF, since the support ring 2 pivots on the support 5 at high speed via the bearing 7, the fixing of the permanent magnet 3 to the support ring 2 is strengthened. In addition to the above, it is required that the gaps ε ₁ and ε ₂ in the support 5 have high precision in the configuration surface, and the sliding surface of the support 5 facing the bearing 7 is hardened to ensure durability. It is necessary to devise processing and the like, which also causes an increase in manufacturing cost.

The present invention has been made in view of the above-mentioned conventional problems, and has been made in consideration of a gap ε between a switch plate and a permanent magnet.
Minimum clearance ε without increasing ₁ more than necessary
_An eddy current type speed reducer that can improve the magnetic circuit efficiency, simplify the fixing of the permanent magnet to the support ring, and omit extra processing for improving accuracy, etc. It is intended to provide.

[0011]

In order to achieve the above object, an eddy current type speed reducer according to the present invention comprises a support member divided into an inner cylinder and an outer cylinder including a switch plate group. The outer cylinder side is configured to be able to pivot by a predetermined angle with respect to the side, and the support ring is fixed to the inner cylinder side of the support. Then, by doing so, as a switch plate with a gap epsilon ₁ minimum necessary size of between permanent magnets, it is possible to improve the magnetic circuit efficiency, simplifies the fixation of the permanent magnet to the support ring can do.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An eddy current type speed reducer according to the present invention has a rotor integrally mounted on a rotating shaft and a rotor supported opposite to the rotor and having magnetic poles oriented along the circumferential direction of the rotor. A permanent magnet group arranged at a fixed interval on a ferromagnetic support ring so as to be in the opposite direction, and between the permanent magnet group and the rotor, the same as each permanent magnet of the permanent magnet group. An eddy current type reduction gear comprising: a ferromagnetic switch plate group interposed at intervals and a non-magnetic support member interposed between the switch plates of the switch plate group. The body is divided into an inner cylinder side and an outer cylinder side including the switch plate group, and the outer cylinder side is configured to be able to pivot by a predetermined angle with respect to the inner cylinder side, and the support ring is provided as a support body. It is fixed to the inner cylinder side.

In the eddy current type speed reducer of the present invention, the support is divided into the inner cylinder side and the outer cylinder side including the switch plate group, and the outer cylinder side can be turned by a predetermined angle with respect to the inner cylinder side. The support ring is fixed to the inner cylinder side of the support, and the switching between the braking ON and the braking OFF is performed by the turning movement of the outer cylinder including the switch plate group. Compared to the one that rotates by a predetermined angle,
Now shows a dimensional change of about the same shape and size gap epsilon ₂ between the gap epsilon ₁ and the support and the bearing of the permanent magnet and the switch plates is to temperature change, unnecessarily large clearance epsilon ₁ The required minimum size can be achieved without any problem. In addition, since the permanent magnet is housed and fixed to the support via the support ring, the fixation of the permanent magnet to the support ring can be simplified, and the support ring and the support are integrated by casting and the like. It is possible to
Extra processing for improving accuracy can be omitted.

In the eddy current type speed reducer of the present invention having the above-described structure, when a seal member is provided between the inner cylinder side and the outer cylinder side of the support, foreign matter and water, etc. Intrusion can be effectively prevented.

In the eddy current type speed reducer of the present invention, when the switch plate and the permanent magnet overlap by the turning movement of the outer cylinder including the switch plate group, the support ring, the adjacent permanent magnet and the adjacent switch plate, A magnetic circuit is formed by the cylindrical portion of the rotor, and a so-called braking ON state occurs. When the cylindrical portion of the rotating rotor crosses the magnetic field from the permanent magnet, the action of the eddy current and the magnetic field generated in the cylindrical portion of the rotor causes the rotor to rotate. A braking torque is generated in the cylindrical portion.

Further, from the above-mentioned brake ON position, when one permanent magnet is brought into a brake OFF state in which the two permanent magnets overlap each other over the adjacent switch plate, a support ring and
A short-circuit magnetic circuit is formed by the adjacent permanent magnets and the switch plate straddling these permanent magnets, and the magnetic field hardly acts on the cylindrical portion of the rotor, so that the braking force becomes extremely small.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An eddy current type speed reducer according to the present invention will be described below with reference to the embodiments shown in FIGS. 1 and 2, the same reference numerals as those in FIGS. 3 and 4 denote the same or corresponding parts, and a detailed description thereof will be omitted. FIG. 1 is an enlarged explanatory view showing a main part of an eddy current type reduction gear of the present invention, and FIG. 2 is a view similar to FIG. 1 showing another embodiment of the eddy current type reduction gear of the present invention.

FIGS. 1 and 2 show an eddy current type speed reducer according to the present invention, which is similar to the one proposed by the present applicant in Japanese Patent Application No. 11-228267 described with reference to FIG. A rotor 1 integrally attached to a shaft;
And a group of permanent magnets 3 arranged at regular intervals on a ferromagnetic support ring 2 so that the directions of the magnetic poles are opposite to each other along the circumferential direction of the rotor 1. A group of four ferromagnetic switch plates interposed between the group of permanent magnets 3 and the rotor 1 at the same intervals as the respective permanent magnets 3 of the group of permanent magnets 3, and a group of switch plates 4 of this type The structure has a non-magnetic support member 5 interposed between the switch plates 4.

In the eddy current type speed reducer of the present invention, in the above-mentioned structure, the support 5 is divided into an inner cylinder side 5a and an outer cylinder side 5b including the switch plate 4 group. The outer cylinder side 5b is configured to be capable of turning by a predetermined angle by the drive unit 6, and the support ring 2 is integrally fixed to the inner cylinder side 5a of the support body 5 by, for example, casting. is there.

In the embodiment shown in FIG. 1, a bearing is provided at a position where the inner cylinder side 5a and the outer cylinder side 5b are opposed to each other so that the outer cylinder side 5b can be swiveled with respect to the inner cylinder side 5a. In the embodiment shown in FIG. 2, the support ring 2 is opposed to the outer cylinder side 5b, and a bearing 7 is provided at a position where the support ring 2 and the outer cylinder side 5b face each other. This is shown.

Reference numeral 12 denotes an inner cylinder side 5a and an outer cylinder side 5b of the support body 5.
A seal is interposed therebetween to prevent foreign substances, water, and the like from entering the support body 5. The seal 12 also withstands the case where the outer cylinder side 5b is turned with respect to the inner cylinder side 5a. You can do it.

In the eddy current type speed reducer shown in FIGS. 1 and 2, the drive unit 6 turns the outer cylinder side 5 a including the switch plate 4 group, thereby turning the switch plate 4.
When the permanent magnet 3 and the permanent magnet 3 overlap, a magnetic circuit is formed by the support ring 2, the adjacent permanent magnet 3, the adjacent switch plate 4, and the cylindrical portion 1a of the rotor 1, so-called braking ON.
When the rotating cylindrical portion 1a crosses the magnetic field from the permanent magnet 3, a braking torque is generated in the cylindrical portion 1a by the action of the eddy current and the magnetic field generated in the cylindrical portion 1a.

Further, from the braking ON position, the outer cylinder side 5a including the switch plate 4 group is rotated, and the three rows of permanent magnets are turned by the half array pitch of the magnets. In this state, one permanent magnet 3 is connected to the adjacent switch plate 4
And the support ring 2, the adjacent permanent magnet 3 and the switch plate 4 form a short-circuit magnetic circuit, and a so-called braking OF is formed.
The state becomes F.

Since the eddy current type speed reducer of the present invention employs the above-described structure, the gap ε ₁ between the permanent magnet 3 and the switch plate 4 and the gap ε ₂ between the support 5 and the bearing 7 change with temperature. Of the same size and size. Therefore, when determining the gap ε ₁ between the permanent magnet 3 and the switch plate 4, the gap ε between the support 5 and the bearing 7 is determined.
It is not necessary to consider the second increase margin, can be a minimum size without increasing more than necessary clearance epsilon _1, the magnetic circuit efficiency is improved.

The eddy current type speed reducer according to the present invention has a conventional structure in which the permanent magnet 3 is housed and fixed in the support 5 via the support ring 2 so that the support ring is turned at a predetermined angle and at a high speed. The fixing of the permanent magnet 3 to the support ring 2 can be simplified as compared with the case of FIG.

In the eddy current type speed reducer of the present invention, since the support ring 2 and the support 5 can be integrated by casting or the like, unnecessary processing for improving accuracy or the like is omitted. Can be.

In the eddy current type speed reducer of the present invention, since the outer cylinder side 5b is swiveled with respect to the inner cylinder side 5a of the support 5, the drive unit 6 can be installed outside the support 5. As a result, the structure for preventing water from entering the permanent magnet 3 and mixing of foreign matter is simplified.

In the embodiment shown in FIGS. 1 and 2, the pole piece is omitted, but the pole piece may be attached to the outer periphery of the permanent magnet 3.

[0029]

As described above, according to the eddy current type speed reducer of the present invention, the gap ε between the permanent magnet and the switch plate is smaller than that of the conventional structure in which the support ring is turned by a predetermined angle. since the gap epsilon ₂ between ₁ and the support and the bearing exhibits a substantially dimensional changes of the same shape and size with respect to the temperature change, it can be sized for minimum clearance epsilon _1. Therefore, the magnetic circuit efficiency is improved as compared with the conventional structure in which the support ring is turned by a predetermined angle.

Further, according to the eddy current type speed reducer of the present invention, since the permanent magnet is housed and fixed in the support via the support ring, the fixing of the permanent magnet to the support ring can be simplified. . Further, since the support ring and the support can be integrated by casting or the like, extra processing for improving accuracy or the like can be omitted. In addition, since the driving unit can be installed outside the support, the structure for preventing water from entering the permanent magnet and preventing foreign matter from being mixed in can be simplified.

[Brief description of the drawings]

FIG. 1 is an enlarged explanatory view showing a main part of an eddy current type speed reducer of the present invention.

FIG. 2 is a view similar to FIG. 1, showing another embodiment of the eddy current type speed reducer of the present invention.

FIG. 3 is an explanatory view showing an enlarged main part of a single-row turning type eddy current type speed reducer proposed by the present applicant in Japanese Patent Application No. 11-228267.

FIG. 4 is a side view of an eddy current type reduction gear proposed in Japanese Patent Application Laid-Open No. 4-12659, in which an upper half is shown in cross section.

[Explanation of symbols]

 Reference Signs List 1 rotor 2 support ring 3 permanent magnet 4 switch plate 5 support 5a inner cylinder side 5b outer cylinder side 7 bearing 12 seal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H649 AA03 BB02 BB07 GG09 GG13 GG16 HH08 HH16 JK03 PP02 PP08 PP13

Claims (2)

[Claims] 1. A rotor integrally mounted on a rotating shaft, and a ferromagnetic support ring supported opposite to the rotor and having magnetic poles opposite to each other along the circumferential direction of the rotor. And a ferromagnetic body interposed between the permanent magnet group and the rotor at the same interval as each permanent magnet of the permanent magnet group. In the eddy current type speed reducer provided with a switch plate group and a nonmagnetic support member interposed between the switch plates of the switch plate group, the support member includes the inner cylinder side and the switch plate group. The outer cylinder side is divided into the outer cylinder side, and the outer cylinder side is configured to be able to pivot by a predetermined angle with respect to the inner cylinder side,
An eddy current type reduction gear wherein the support ring is fixed to an inner cylinder side of a support. 2. The eddy current type reduction gear according to claim 1, wherein a seal member is provided between the inner cylinder side and the outer cylinder side of the support.