JP2002186245A - Eddy current speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eddy current speed reducer wherein an eddy current flows effectively in a control drum and heat due to the eddy current is cooled effectively. SOLUTION: A magnet supporting cylinder 18 combined with a rotating shaft 21 is disposed in an immovable control drum 2 constituted of electric conductor. On the outer peripheral surface of the cylinder 18, many electromagnets 12 having magnetic pole segments 15 facing the inner peripheral surface of the drum 2 are combined with each other at an equal interval in the peripheral direction. Thus, the eddy current speed reducer is constituted. In the control drum 2, a cylinder 5 which is constituted of pure iron, low carbon steel, etc., and faces the magnetic pole segments 15 is combined with a main body 3 which is constituted of common steel, cast steel, etc., and has a trench type section, thereby forming a water chamber 4 in which cooling water percolates.

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 for assisting a friction brake of a vehicle or the like, and more particularly, to a permanent magnet and / or eddy current reduction device.
Alternatively, the present invention relates to an eddy current reduction device in which heat based on eddy current generated in one rotating body is effectively cooled by relative rotation between an electromagnet and a braking drum.

[0002]

2. Description of the Related Art Heretofore, the following is known as a water-cooled eddy current reduction device. That is, the stationary brake drum (stator) fixed to the wall or the like of the gear transmission is configured such that cooling water circulates in a water chamber provided therein.
A magnet support cylinder disposed inside the brake drum is connected to an output rotation shaft of the gear transmission. When electricity is supplied to the electromagnet supported by the magnet support cylinder, a magnetic circuit is formed between the braking drum and the magnet support cylinder, and a braking force based on the eddy current is generated in the rotating magnet support cylinder. The above-mentioned eddy current reduction device uses ordinary steel materials (carbon steel, cast steel,
Alloy steel) is used, so that the efficiency of the generated braking force is not good.

[0003]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an eddy current reduction device in which an eddy current efficiently flows through a braking drum and heat generated by the eddy current is efficiently cooled. It is in.

[0004]

In order to solve the above-mentioned problems, according to the structure of the present invention, a magnet support cylinder connected to a rotating shaft is disposed inside an immovable brake drum made of an electric conductor, and the magnet support is provided. In an eddy current reduction device in which a number of magnets having magnetic pole pieces facing the inner circumferential surface of the braking drum on the outer circumferential surface of a cylinder are connected at equal intervals in a circumferential direction, the braking drum is provided in a main body having a groove-shaped cross section, A cylindrical body made of a ferromagnetic and conductive material is coupled to a surface facing the base member.

[0005]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, it is preferable that the cylinder constituting the inner peripheral wall of the braking drum where an eddy current is generated is made of a material having a low magnetic resistance and a low electric resistance, for example, low carbon steel close to pure iron. From both ends of the cylinder of the braking drum to both end walls,
For example, it is assembled using aluminum having a small electric resistance. The cylinder body of the braking drum is joined to the main body made of aluminum by casting, welding, or by press-fitting bolts.

The axial dimension of the cylinder constituting the inner peripheral wall of the braking drum may be substantially the same as the width of the pole piece of the electromagnet of the magnet support cylinder. An annular body such as aluminum is provided. When casting a reinforcing cylinder such as cast steel into the inside of the cylindrical body, aluminum is previously coated on the surface of the reinforcing cylinder in order to improve the adhesion between the material of the cylindrical body and aluminum. A permanent magnet is embedded in the iron core of the electromagnet so that a strong magnetic field can be obtained even if the number of turns of the electromagnetic coil is reduced or the current is weakened.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, an eddy current reduction device according to the present invention includes a stationary braking drum 2 and a magnet support tube 18 connected to a rotating shaft 21. A mounting flange 22 is spline-fitted to the rotating shaft 21 and fastened by a nut 23. The mounting piece 18a connected to the inner peripheral surface of the magnet support cylinder 18 is superimposed on the mounting flange 22, and is connected to the bolt 20 by a nut. A large number of electromagnets 12 are connected to the outer peripheral surface of the magnet support cylinder 18 at regular intervals in the circumferential direction.

The electromagnet 12 has a winding frame 14 fitted around an iron core 17 connected to a magnet support cylinder 18, and an electromagnetic coil 13
Is wound around. Permanent magnet 1 inside iron core 17
6 is buried to reduce the current load on the electromagnetic coil 13. A pole piece 15 made of a ferromagnetic material is fastened to the iron core 17 at the end of the iron core 17 facing the cylinder 5 of the braking drum 2. The iron core 17 is connected to the magnet support cylinder 18 by bolts (not shown). In this way, the magnet support tube 18 to which the many electromagnets 12 are connected is disposed concentrically inside the immobile brake drum 2. For example, a braking drum 2 fixed to a wall of a gear transmission has a main body 3 having a groove-shaped cross section and a cylindrical body 5 facing a magnetic pole piece 15 connected by bolts 6 to form a water chamber 4 therein.
Is partitioned. Cooling water is supplied to the water chamber 4 from an inlet 25 and discharged from an outlet 26 to the outside. Lubricating oil or the like for lubricating the gear transmission may flow through instead of the cooling water. The magnet support tube 18, the iron core 17, and the pole piece 15 may be integrally formed of a plate material such as an electromagnetic steel plate laminated in the rotation axis direction.

The braking drum 2 has a groove-shaped main body 3 made of ordinary steel, cast steel, or the like having high heat resistance. However, in terms of manufacturing cost, when the main body 3 is cast from aluminum.
It is preferable to cast the cylindrical body 5 made of pure iron or a material close to pure iron, a ferromagnetic material such as low carbon steel, and made of a material having a small electric resistance. However, the bolts 6 are inserted into the portions 3b thinned by the cutouts of both end walls 3a of the main body 3 with the cylindrical body 5 interposed therebetween.
May be combined. In particular, since the end wall 3a of the main body 3 made of aluminum is coupled to both ends of the cylindrical body 5, the eddy current flowing through the cylindrical body 5 is promoted in the axial direction,
The braking torque is increased.

As shown in FIG. 3, a cylinder 5 made of low carbon steel or the like is connected to a main body 3 made of aluminum by bolts, and further, copper or copper is attached to an inner peripheral surface of the cylinder 5 facing the pole piece 15. Coatings 5 of copper alloy, nickel alloy, nickel, etc.
a is preferably formed by coating, plating, or the like.

In the embodiment shown in FIG. 4, when connecting the cylinder 5 facing the pole piece 15 to the main body 3 made of aluminum, cast steel or a general steel material, the cylinder 5 is disposed between the end wall 3a and both ends of the cylinder 5. , Copper, copper alloy, etc., is connected with a bolt by sandwiching the annular body 5b, or the annular body 5b is welded to the thin portion 3b of the end wall 3a, nickel brazing, powder overlay, TIG welding overlay. And so on. Annular body 5
b further promotes the spread of the eddy current generated in the cylindrical body 5 in the axial direction. As shown in FIG. 5, it is more effective to arrange the annular body 5b made of a good electric conductor close to the axial end of the iron core 17. In FIG. 5, a cylindrical main body 3 made of aluminum and an annular end wall 3a are connected by welding or connected by bolts.

In the embodiment shown in FIG. 6, a cylindrical body 5 made of low-carbon steel or low-carbon alloy steel close to pure iron is joined to a main body 3 made of aluminum, cast steel, or a general steel material.
An annular body 5c made of copper, a copper alloy, or the like and having an L-shaped cross section is joined to a portion from to the peripheral wall portion in contact with the end of the cylindrical body 5.

In the embodiment shown in FIG. 7, when the main body 3 and the cylindrical body 5 are integrally cast from aluminum, a reinforcing cylinder 5d made of cast steel or the like is cast inside the cylindrical body 5. In this case, it is preferable that the surface of the reinforcing cylinder 5d is previously melted with aluminum to increase the degree of coupling with the main body 3.

In the embodiment shown in FIGS. 8 and 9, a plurality of electromagnets 12 arranged in the axial direction are connected to the magnet support tube 18, and the heat dissipation of the braking drum 2 and the electromagnets 12 is enhanced.

In the embodiment shown in FIG. 10, a V-groove 31 extending in the circumferential direction is provided at a central portion of the pole piece 15 of the electromagnet 12 in the axial direction.
And a reinforcing cylinder 5d made of a ferromagnetic material such as cast steel.
And a circumferential groove 32 having a rectangular cross section facing the V-groove 31.
And a groove 32 is cast with aluminum or an annular body made of aluminum is fitted. 11 and 12
In the embodiment shown in FIG. 1, a plurality of electromagnets 1 arranged in the axial direction are provided.
A groove 32 having a rectangular cross section is provided on the inner peripheral surface of the reinforcing cylinder 5d, and aluminum is cast into the groove 32, or an annular body made of aluminum is fitted. According to the configuration of FIGS. 10 to 12, the eddy current generated in the reinforcing cylinder 5 d is divided in the axial direction, and the pole pieces 15 of the respective electromagnets 12 arranged in the axial direction.
An annular body made of aluminum or copper is fitted on both sides of the pole piece 15 to the opposing reinforcing cylinder 5C to generate an efficient eddy current and enhance the braking capacity.

In the second embodiment of the present invention shown in FIG. 13, an immovable brake drum 42 is disposed inside a magnet support cylinder 58 connected to a rotating shaft 61. A magnet support cylinder 58 made of a ferromagnetic material such as cast steel has a rotating shaft
Are spline-fitted and fastened by nuts 63. A gear 68 is coupled to the other end of the rotating shaft 61,
For example, it meshes with a gear connected to the output rotation shaft of the transmission. An iron core 57 having a permanent magnet 56 embedded therein is connected to the inner peripheral surface of the magnet support cylinder 58, and a winding frame 54 supported by the iron core 57 is provided.
An electromagnet 52 is formed by winding an electromagnetic coil 53 around the electromagnet 52.
The inner peripheral surface of the iron core 57 is formed by the pole piece 15.

The braking drum 42 has two end walls 42a,
1 is rotatably supported by bearings 67 and is secured to the wall of a gear transmission by suitable means, for example. A cylindrical body 45 made of a ferromagnetic conductive material (preferably a material with low electric resistance) such as low carbon steel is provided at a portion of the braking drum 42 facing the inner peripheral surface of the pole piece 15.
Cast when the braking drum 42 is cast from aluminum. Preferably, the inner space 69 of the braking drum 42
Cooling water or cooling oil is supplied from an inlet 65 and discharged from an outlet 66.

The present invention relates to each of the above embodiments.
Even if a permanent magnet alone is used without using an electromagnet, it works as an eddy current reduction device. Take.

[0019]

According to the present invention, since the cylinder constituting the peripheral surface of the brake drum facing the magnetic pole piece is made of a material having a small electric resistance, such as pure iron, a material close to pure iron, and low carbon steel. The magnetic field is easy to pass, the flow of the eddy current is improved, and the braking ability is enhanced.

Since the water chamber is defined by welding or bolting the cylindrical body to a body made of aluminum or the like having a groove shape in cross section, heat due to eddy current can be efficiently removed.

The axial dimension of the cylinder is the same as the width of the pole piece of the electromagnet, and aluminum having a low electric resistance is pre-cast at both ends of the cylinder, so that a groove-shaped main body is cast from aluminum. The degree of coupling when casting the cylinder into the cylinder is increased.

By embedding a permanent magnet in the core of the electromagnet, the number of turns of the electromagnetic coil can be reduced, and power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an eddy current reduction device according to the present invention.

FIG. 2 is a side sectional view of the eddy current reduction device.

FIG. 3 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 4 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 5 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 6 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 7 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 8 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 9 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 10 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 11 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 12 is a side sectional view showing a main part of the eddy current reduction device.

FIG. 13 is a side sectional view of an eddy current reduction device according to a second embodiment of the present invention.

[Explanation of symbols]

2: braking drum 3: body 3a: end wall 4: water chamber
5: cylindrical body 5d: reinforcing cylinder 12: electromagnet 13: electromagnetic coil 14: winding frame 15:
Magnetic pole piece 16: Permanent magnet 17: Iron core 18: Magnet support cylinder 21: Rotating shaft 22:
Mounting flange 25: Inlet 26: Outlet 42: Brake drum 42a: End wall 45: Cylindrical body 52: Electromagnet 5
3: electromagnetic coil 54: winding frame 56: permanent magnet 57:
Iron core 58: Magnet support cylinder 61: Rotating shaft 65: Inlet
66: outlet 67: bearing 68: gear 69: inner space

Claims (3)

[Claims] A magnet support cylinder connected to a rotating shaft is disposed inside an immovable braking drum made of an electric conductor, and a magnetic pole piece is provided on an outer peripheral surface of the magnet supporting cylinder and opposed to an inner peripheral surface of the braking drum. In the eddy current reduction device in which a number of magnets having the following are coupled at equal intervals in the circumferential direction, the braking drum is provided in a main body having a groove-shaped cross section,
An eddy current reduction device, wherein a cylindrical body made of a ferromagnetic and conductive material is coupled to a surface facing the pole piece. 2. The eddy current reduction device according to claim 1, wherein a cooling medium flows through a space defined by the main body of the braking drum and the cylindrical body. 3. The eddy current reduction device according to claim 1, wherein the main body of the braking drum is made of aluminum.