JP2000116107A - Fddy-current reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eddy-current reduction gear which can develop a large braking torque when braking is actuated through the gear is compact in the axial direction, and has a light weight and, when braking is released, in addition, does not develop any dragging torque. SOLUTION: An eddy-current reduction gear is provided with a rotor integrally attached to a rotating shaft, a group of permanent magnets 4 which are opposingly supported by the rotor in such a way that the magnets 4 are arranged at regular intervals along the peripheral direction of the rotor so that their magnetic poles may be faced oppositely to each other, a group of switch plates made of a ferromagnetic material and arranged between the magnets 4 and rotor at the same arranging intervals as those of the magnets 4, and supporting members made of a nonmagnetic material and arranged between adjacent switch plates. Each switch plate is divided into at least a switch plate 21 and an auxiliary switch plate 22 in the height wise direction so that the plates 21 and 22 may be rotated relatively to each other by a prescribed angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current reduction device mounted on a large vehicle such as a bus or a truck as a braking auxiliary device.

[0002]

2. Description of the Related Art In recent years, for large vehicles such as buses and trucks, the number of times a foot brake is used on a downhill road is reduced to prevent abnormal lining wear and a fade phenomenon, and to shorten a braking stop distance. For this purpose, an eddy current reduction device has been mounted in addition to a foot brake which is a main brake and an exhaust brake which is an auxiliary brake. In recent years, many of the eddy current reduction devices that use permanent magnets as magnetic poles and do not need to be energized at the time of braking are increasing.

As this eddy current reduction device of the permanent magnet type, for example, Japanese Patent Application Laid-Open Nos. 1-298948 and 1-298894 are disclosed.
7, Japanese Patent No. 2709821, Japanese Patent Publication No. 7-11890
No. 1 has been proposed. Of these, JP-A 1-229
No. 8948 proposes a support ring 3 for a yoke via a bearing 15 on a non-magnetic support 2 which is supported on a rotating shaft 1 via a bearing 14 as shown in FIG. A plurality of permanent magnets 4 are rotatably supported around the support ring 3 with the polarities opposite to each other, and the support 2 is attached to the support 2 so as to face the outer peripheral surface of the group of permanent magnets 4. A plurality of ferromagnetic switch plates 5 which are magnetically insulated from each other are provided around the inner surface of the cylindrical portion 6 a of the rotor 6 fixed to the rotating shaft 1. The support ring 3 is configured to be rotatable by a predetermined angle with respect to the support 2. Note that reference numeral 7 in FIG. 3 denotes a pole piece superimposed on each permanent magnet 4.

Japanese Patent Laid-Open No. 1-298947 proposes, as shown in FIG. 5, a pair of rotors 13a, 13b having disk surfaces 13aa, 13ba opposed to each other at a predetermined interval. 1 and a group of a plurality of switch plates 5a and 5b, which are composed of a plurality of switch plates 5a and 5b, which are opposed to the disk surfaces 13aa and 13ba with a gap and are magnetically insulated from each other and are arranged circumferentially. A ring-type non-magnetic material which is opposed to the switch plate supporting frame 11 supported on the rotating shaft 1 via a bearing 14 at an interval, and further supported on the switch plate supporting frame 11 via a bearing 15; A plurality of permanent magnets 4 having the same shape as the switch plates 5a and 5b are circumferentially arranged in opposite polarities on the permanent magnet support frame 12 of
The magnetic pole surfaces on both sides of these permanent magnets 4 are opposed to the switch plates 5a and 5b groups on both sides, respectively.
And the permanent magnet support frame 12 are configured to be relatively rotatable by a predetermined angle.

In the permanent magnet type eddy current reduction device proposed in Japanese Patent Laid-Open No. 1-298948, as shown in FIG. 4A, the support ring 3 is turned so that the switch plate 5 overlaps the permanent magnet 4. When moved, a magnetic circuit is formed as shown by an arrow by the adjacent permanent magnet 4, the adjacent switch plate 5, and the cylindrical portion 6 a of the rotor 6, so-called braking O
In the N state, the magnetic flux from the permanent magnet 4 acts on the cylindrical portion 6a, an eddy current is generated, and a braking torque is generated.

When the support ring 3 is turned from the above-mentioned braking ON position, as shown in FIG. 4 (b), when one permanent magnet 4 straddles the adjacent switch plate 5 and overlaps half by one. An adjacent permanent magnet 4 and one switch plate 5 constitute a magnetic circuit as shown by an arrow, and a so-called braking OFF state is established. In this state, a magnetic circuit is formed by the adjacent permanent magnet 4 and one switch plate 5, and the magnetic flux generated from the permanent magnet 4 does not act on the cylindrical portion 6a of the rotor 6, so that the vortex is applied to the cylindrical portion 6a. No current flows and no braking torque is generated.

On the other hand, a permanent magnet type eddy current reduction device proposed in Japanese Patent Application Laid-Open No.
As shown in FIG. 6 (a), when the switch plates 5a and 5b overlap with the permanent magnets 4 as shown in FIG.
a, 5b and disk surface 13a of rotors 13a, 13b
At 13a and 13ba, a magnetic circuit is formed as shown by the arrow, and a so-called braking ON state is established. The magnetic flux from the permanent magnet 4 acts on the disk surfaces 13aa and 13ba to generate an eddy current, and the braking torque is increased. Occurs.

Further, the switch plate support frame 11 or the permanent magnet support frame 12 is turned from the above-mentioned braking ON position,
As shown in FIG. 6 (b), when one permanent magnet 4 overlaps the adjacent switch plates 5a and 5b by half, and the adjacent permanent magnets 4 and the switch plates 5a and 5
At b, the magnetic circuit is formed as shown by the arrow, and a so-called braking OFF state is set. In this state, the rotor 13
Since the magnetic fluxes generated from the permanent magnets 4 do not act on the disk surfaces 13aa, 13ba of the disks 13a, 13b, no eddy current flows on the disk surfaces 13aa, 13ba, and no braking torque is generated.

[0009] Further, as disclosed in Japanese Patent No. 2709821, as shown in FIGS. 7 and 8, a rotor 6 is fitted to one end of a rotating shaft 1 and a cylindrical portion separated from the rotor 6. A magnetic shield casing having a plurality of permanent magnets 4 is fixedly disposed adjacent to the rotor 6 and the magnets adjacent to each other have opposite polarities. The length of the pole surface of the permanent magnet 4 in the axial direction from the position facing the rotor 6 entirely with a required gap to the position of the magnetic shield casing where the pole surface is completely separated can be advanced and retracted.

In the permanent magnet type eddy current reduction device proposed in Japanese Patent No. 2709821, as shown in FIG. 7, when the permanent magnet 4 is entirely opposed to the rotor 6, the structure is provided between adjacent permanent magnets 4. An eddy current is generated in the rotor 6 by the magnetic circuit, so that a so-called braking ON state occurs, and a braking torque is generated.

If the permanent magnet 4 is gradually retracted from the brake ON position shown in FIG. 7, the generated braking torque is gradually reduced and the braking force is reduced. Then, when the permanent magnet 4 finishes retreating and comes to a position where it is completely separated from the rotor 6 shown in FIG. 8, the braking is released.

As shown in FIGS. 9 and 10, Japanese Patent Publication No. Hei 7-118901 proposes a rotor 6 provided on a rotating shaft and supported from a fixed side in opposition to the rotor 6. , N poles and S poles at predetermined intervals along the circumferential direction.
A fixed support ring 10a having a permanent magnet 9a group in which the poles are alternately arranged, and a permanent magnet 9b group provided adjacent to the fixed support ring 10a and opposed to the rotor 6 and similar to the fixed support ring 10a , And a switch extending from above the permanent magnets 9a of the fixed support ring 10a to above the rotary support ring 10b. This is a configuration including a plate 5.

In the permanent magnet type eddy current reduction device proposed in Japanese Patent Publication No. Hei 7-118901, as shown in FIG.
When the rotation support ring 10b is moved to a position where the polarity of the two permanent magnets 9a, 9b on the fixed side and the rotation side facing one switch plate 5 is the same, the permanent magnets 9a, 9b, a magnetic circuit is formed between the switch plate 5 and the inner peripheral surface of the cylindrical portion 6a of the rotor 6 as shown by an arrow in FIG. An eddy current occurs on the inner peripheral surface of the portion 6a, and a braking torque is generated.

Further, the turning support ring 10b is turned from the above-mentioned braking ON position, and as shown in FIG. 10, the two permanent magnets 9a and 9b on the fixed side and the turning side facing one switch plate 5 are turned on. When the rotation support ring 10b is rotated to a position where the polarities are opposite to each other, the one switch plate 5 and the two permanent magnets 9a and 9b opposed thereto are connected as shown in FIG.
As shown by arrows, a magnetic circuit is formed, and no magnetic flux generated from the permanent magnets 9a and 9b acts on the inner peripheral surface of the cylindrical portion 6a of the rotor 6, so that no eddy current flows and no braking torque is generated. (Brake OFF state).

[0015]

However, Japanese Patent Application Laid-Open Nos. Hei 1-298948 and Hei 1-298947 describe above.
Although the permanent magnet type eddy current reduction device proposed in the above publication is compact in the axial direction, when the braking is OFF as shown in FIG. 4B or FIG. Leakage may occur. Then, when magnetic leakage occurs, there is a problem that drag torque is generated and fuel economy is deteriorated.

Further, the permanent magnet type eddy current reduction device proposed in Japanese Patent No. 2709821 has a large braking torque,
Further, in the brake OFF state, magnetic leakage can be completely prevented, so that no drag torque is generated. However, since the device becomes longer in the axial direction, the weight becomes heavy, and there is a difficulty in compactness.

Further, the permanent magnet type eddy current reduction device proposed in Japanese Patent Publication No. Hei 7-118901 is compact and lightweight in the axial direction, and has a small magnetic leakage to the rotor even when the brake is in the OFF state. Although the drag torque is small, braking is ON because the permanent magnet is divided into two parts, fixed side and rotating side.
At this time, there is a problem that the magnetic flux directed at right angles to the rotor is small and the braking torque is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. It is compact and lightweight in the axial direction, can generate a large braking torque when braking is ON, and can drag when braking is OFF. It is an object of the present invention to provide an eddy current type reduction gear that does not generate torque.

[0019]

In order to achieve the above-mentioned object, an eddy current type speed reducer according to the present invention comprises a group of ferromagnetic members interposed at the same interval as each permanent magnet of the group of permanent magnets. Each of the ferromagnetic materials is divided into at least two in the height direction or the thickness direction, and both of the ferromagnetic materials divided into at least two are configured to be relatively rotatable by a predetermined angle. . In this way, the braking O
Magnetic leakage at the time of FF can be prevented.

[0020]

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 so as to be in the opposite direction, and a permanent magnet group is 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 reduction gear provided with the provided ferromagnetic material group and the non-magnetic material interposed between the respective ferromagnetic materials of the ferromagnetic material group, the ferromagnetic material is placed in the height direction, or The ferromagnetic body is configured so as to be divided into at least two in the thickness direction, and the two ferromagnetic bodies divided into at least two can be relatively rotated by a predetermined angle.

In the eddy current type speed reducer according to the present invention, when the ferromagnetic material and the permanent magnet which are at least divided into two in the height direction or the thickness direction overlap with each other, the adjacent permanent magnets:
A magnetic circuit is formed by the adjacent at least two-part ferromagnetic material and the cylindrical portion of the rotor or the disk surface, and a so-called braking ON state is established, and the magnetic flux from the permanent magnet acts on the cylindrical portion or the disk surface. As a result, an eddy current is generated and a braking torque is generated.

Also, from the braking ON position described above, one permanent magnet separates the ferromagnetic material on the inner circumferential side or on the permanent magnet side within at least two adjacent sections in the height direction or the thickness direction. When the ferromagnetic material on the outer circumference side or the disk surface side of the rotor completely overlaps by half when straddling, a magnetic circuit is formed by the adjacent permanent magnet and the switch board on the inner circumference side or the permanent magnet side. As a result, a so-called braking OFF state is set. In this state, the magnetic flux generated from the permanent magnet does not act on the cylindrical portion or the disk surface of the rotor, so that the eddy current does not flow on the cylindrical portion or the disk surface, and no braking torque is generated. At this time, no magnetic leakage occurs due to the action of the ferromagnetic material on the outer peripheral side or the disk surface side of the rotor.

The eddy current type speed reducer of the present invention is not limited to a drum type, but also includes a disk type.
The disk type is not limited to a disk in which both sides of a permanent magnet group are sandwiched by disks, but includes a disk in which both sides of one disk are sandwiched by permanent magnet groups.

[0024]

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 to 6 indicate the same or corresponding portions, and a detailed description thereof will be omitted. FIGS. 1A and 1B are explanatory diagrams of a case where the present invention is applied to a so-called drum type eddy current type speed reducer. FIG. 1A is an explanatory diagram showing a magnetic circuit configuration in a brake ON state, and FIG. FIG. 2 is an explanatory diagram showing a magnetic circuit configuration, FIG. 2 is an explanatory diagram showing a case where the present invention is applied to a so-called disk type eddy current type reduction gear transmission, and FIG. 2 (a) is an explanatory diagram showing a magnetic circuit configuration in a braking ON state; FIG. 4B is an explanatory diagram showing a magnetic circuit configuration in a brake OFF state.

In FIG. 1, reference numeral 21 denotes a support (2) rotatably supported on a rotating shaft (1) via a bearing (14).
A switch plate made of a ferromagnetic material which is provided so as to be magnetically insulated from each other and is rotatably supported on the support body (2) via a bearing (15); Are arranged so as to be opposite to each other and to a plurality of permanent magnets 4 provided around at a certain interval so as to have opposite polarities.

Reference numeral 22 denotes an auxiliary switch plate arranged on the outer peripheral side of the switch plate 21 in the same manner as the switch plate 21. The auxiliary switch plate 22 is fixed to the rotating shaft (1) with a predetermined gap. It faces the inner peripheral surface of the cylindrical portion 6a of the rotor (6). The auxiliary switch plate 22 is provided around an auxiliary support 23 which is rotatably supported on the rotating shaft (1) via a bearing on the outer periphery of the support (2) via a bearing. The switch plate 21 and the auxiliary switch plate 22 are configured to be rotatable by a predetermined angle with respect to the support body (2) together with the support ring 3.

A non-magnetic support member 2a, 23a is interposed between adjacent ones of the switch plate 21 and the auxiliary switch plate 22. Further, in this embodiment, the pole piece 7 is attached to the outer periphery of the permanent magnet 4, but the pole piece 7 may be omitted.

In the eddy current type speed reducer shown in FIG. 1, when the switch plate 21 and the auxiliary switch plate 22 and the permanent magnet 4 overlap with each other as shown in FIG. A magnetic circuit is formed by the adjacent switch plate 21 and the auxiliary switch plate 22, and the cylindrical portion 6a of the rotor (6), so that a so-called braking ON state is established, and the magnetic flux from the permanent magnet 4 acts on the cylindrical portion 6a. As a result, an eddy current is generated and a braking torque is generated.

Further, from the braking ON position, the support ring 3 and the auxiliary support body 23 are rotated together by a predetermined angle, and as shown in FIG. 21 and the auxiliary switch plate 22 and the auxiliary switch plate 22 are completely overlapped as in the brake ON state, the adjacent permanent magnet 4 and the switch plate 21 are adjacent to each other.
To form a magnetic circuit, and a so-called braking OFF state is established. In this state, no magnetic flux generated from the permanent magnet acts on the cylindrical portion 6a of the rotor (6), so that no eddy current flows through the cylindrical portion 6a and no braking torque is generated. At this time, magnetic leakage does not occur due to the function of the auxiliary switch plate 22.

The eddy current type speed reducer of the present invention is not limited to the drum type as shown in FIG. 1, but may be a disk type as shown in FIG. That is, in FIG. 2, reference numerals 31a and 31b denote ferromagnetic switch plates, and a switch plate support frame (11) rotatably supported on a rotating shaft (1) via a bearing (14).
It is installed at intervals. These switch plates 31
a and 31b are arranged circumferentially in a state of being magnetically insulated from each other, and a pair of switch plates 31a and 31b composed of the plurality of switch plates 31a and 31b are mounted on the switch plate support frame (11) by bearings (15). ), A plurality of non-magnetic permanent magnet supporting frames (12) rotatably supported via a plurality of permanent magnets 4 arranged circumferentially so as to have opposite polarities.

32a and 32b are the switch plates 31a,
Auxiliary switch plates 32a and 32b are arranged outside the respective 31b (on the side opposite to the permanent magnets 4) in the same manner as the switch plates 31a and 31b. The rotor (13a,
13b) faces the disk surfaces 13aa and 13ba.

The auxiliary switch plates 32a and 32b are
The auxiliary switch plate support frame 33 is rotatably supported on a rotary shaft via a bearing, and is provided around the auxiliary switch plate support frame 33 together with the permanent magnet support frame (12). The switch plates 31a, 31b and the auxiliary switch plates 32a, 32b are relatively rotatable by a predetermined angle by being configured to be rotatable by a predetermined angle with respect to the frame (11).

The switch plates 31a, 31b
The non-magnetic support members 11a and 33a are interposed between adjacent ones of the auxiliary switch plates 32a and 32b, similarly to the drum type shown in FIG. is there. Further, in the embodiment shown in FIG. 2, no pole piece is interposed between the permanent magnet 4 and the switch plates 31a and 31b, but a pole piece may be interposed.

In the eddy current type speed reducer shown in FIG.
As shown in (a), when the switch plates 31a and 31b and the auxiliary switch plates 32a and 32b overlap with the permanent magnet 4,
Adjacent permanent magnets 4 and adjacent switch plates 31a, 3
1b, the auxiliary switch plates 32a, 32b, and the disk surfaces 13aa, 13ba of the rotors (13a, 13b) constitute a magnetic circuit, which is a so-called braking ON state.
A permanent magnet 4 is provided on the disk surfaces 13aa and 13ba.
An eddy current is generated by the action of the magnetic flux from the motor, and a braking torque is generated.

Further, from the braking ON position, the permanent magnet support frame (12) and the auxiliary switch plate support frame 33 are rotated together by a predetermined angle, and as shown in FIG. Are overlapped half by one over the adjacent switch plates 31a and 31b, and the auxiliary switch plates 32a and 32b
b is a completely overlapped state such as a state in which the brake is ON, the adjacent permanent magnet 4 and the switch plates 31a, 31b
To form a magnetic circuit, and a so-called braking OFF state is established. In this state, the magnetic flux generated from the permanent magnet 4 does not act on the disk surfaces 13aa, 13ba of the rotors (13a, 13b).
No eddy current flows through 13ba, and no braking torque is generated. At this time, magnetic leakage does not occur due to the action of the auxiliary switch plates 32a and 32b.

In the embodiment shown in FIG. 2, the permanent magnets 4 are sandwiched on both sides by the disk surfaces 13aa and 13ba. However, it is also possible that one disk is sandwiched on both sides by the permanent magnets. Needless to say. In this embodiment,
Although the switch plate is shown as being divided into two parts, it is needless to say that the switch plate may be divided into three or more parts.

[0037]

As described above, according to the eddy current type speed reducer of the present invention, when braking is OFF, the switch on the inner circumferential side or the permanent magnet side in which the permanent magnet is at least divided into two parts in the thickness direction. By half-overlapping over the plate (ferromagnetic material) and half-overlapping the switch plate (ferromagnetic material) on the outer peripheral side or the disk surface side of the rotor, the outer peripheral side or the rotor disk surface side The switch plate (ferromagnetic material) completely blocks the leakage of the magnetic flux, thereby preventing the magnetic leakage. Therefore, when braking is OFF, no drag torque is generated. Further, the eddy current type speed reducer of the present invention can generate a large braking torque when braking is ON, while being compact and lightweight in the axial direction.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory diagrams showing a case where the present invention is applied to a so-called drum type eddy current type speed reducer, wherein FIG. 1A is an explanatory diagram showing a magnetic circuit configuration in a brake ON state, and FIG. FIG. 3 is an explanatory diagram showing a magnetic circuit configuration of FIG.

FIGS. 2A and 2B are explanatory diagrams of a case where the present invention is applied to a so-called disk type eddy current type speed reducer, wherein FIG. 2A is an explanatory diagram showing a magnetic circuit configuration in a brake ON state, and FIG.
FIG. 4 is an explanatory diagram showing a magnetic circuit configuration in a state of FIG.

FIG. 3 is a side view showing a cross section of an upper half of a so-called drum type eddy current type reduction device proposed in Japanese Patent Application Laid-Open No. 1-298948.

4A and 4B are explanatory diagrams showing a magnetic circuit configuration in the eddy current type reduction gear of FIG. 3, wherein FIG. 4A is a diagram showing a brake ON state, and FIG. 4B is a diagram showing a brake OFF state.

FIG. 5 is a side view showing a cross section of an upper half of a so-called disk type eddy current type reduction device proposed in Japanese Patent Application Laid-Open No. 1-298947.

6A and 6B are explanatory diagrams showing a magnetic circuit configuration in the eddy current type reduction gear of FIG. 5, wherein FIG. 6A is a diagram showing a brake ON state, and FIG. 6B is a diagram showing a brake OFF state.

FIG. 7 is a side view showing a cross section of an upper half of a permanent magnet type eddy current reduction device proposed in Japanese Patent No. 2709821, and is an explanatory diagram showing a state where braking is ON.

FIG. 8 is a cross-sectional side view of an upper half of a permanent magnet type eddy current reduction device proposed in Japanese Patent No. 2709821, showing a state in which braking is OFF.

FIG. 9 is an explanatory view showing a brake ON state of a permanent magnet type eddy current reduction device proposed in Japanese Patent Publication No. Hei 7-118901,
(A) is a longitudinal section side view, (b) is a longitudinal section front view.

FIG. 10 is an explanatory diagram showing a state of braking OFF in FIG. 9;
(A) is a longitudinal section side view, (b) is a longitudinal section front view.

[Explanation of symbols]

 2a support member 3 support ring 4 permanent magnet 13aa disk surface 13ba disk surface 21 switch plate 22 auxiliary switch plate 23a support member 31a switch plate 31b switch plate 32a auxiliary switch plate 32b auxiliary switch plate

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shoka Ishida 5-1-1109, Shimaya, Konohana-ku, Osaka-shi GG09 GG13 GG16 GG18 HH08 HH16 HH18

Claims (1)

[Claims] 1. A rotor integrally mounted on a rotating shaft, and a fixed interval provided so as to face the rotor and to be opposite to each other in the circumferential direction of the rotor so that the directions of magnetic poles are opposite to each other. A permanent magnet group, a ferromagnetic group interposed between the permanent magnet group and the rotor at the same interval as each permanent magnet of the permanent magnet group, In an eddy current type reduction gear provided with a non-magnetic material interposed between each ferromagnetic material of a body group, the ferromagnetic material is configured to be divided at least in a height direction or a thickness direction, and An eddy current type speed reducer characterized in that the two divided ferromagnetic bodies can be relatively rotated by a predetermined angle.