JPH0652383U - Eddy current reducer rotor - Google Patents

Abstract

(57) [Summary] [Object] To provide a rotor of an eddy current type speed reducer capable of increasing a braking torque. [Structure] A support ring, in which a rotor is fitted to one end of a rotating shaft, and a plurality of electromagnets or permanent magnets are circumferentially arranged so that the polarities of adjacent magnets are opposite to each other, and a pole surface of these magnets has a required space. In the eddy current type speed reducer provided to face the rotor magnetically, a surface treatment layer made of a non-magnetic material is provided on the inner peripheral surface of the cylindrical portion of the rotor. [Effects] The braking performance of the eddy current type speed reducer can be improved and the weight of the device can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of an eddy current type speed reducer used for large vehicles such as buses, trucks or construction equipment.

[0002]

[Prior art]

 As a deceleration device or braking device for large vehicles, in addition to the main brake, the foot brake, the auxiliary brake, the exhaust brake, to perform stable deceleration when descending a long slope, and to prevent the foot brake from burning. Eddy current type speed reducer is used. In addition, eddy current brake equipment is used for the trailer cars of the two-story trains on the Shinkansen.

The eddy current type speed reducer includes an electromagnet having an electromagnetic coil wound around an iron core as a magnetic pole, and a permanent magnet as a magnetic pole. The former has a large number of its magnetic poles arranged on both sides of the disk, and generates a magnetic field when energized from a battery power source, and generates a torque in the direction of decelerating the disk by an eddy current phenomenon to obtain a braking force. , The latter is installed around the support ring so that the polarities of adjacent permanent magnets are opposite to each other, and this support ring can be moved forward and backward from the position where the magnetic pole surface faces the rotor through the required air gap to the position where it is magnetically separated. The eddy current phenomenon is generated by the magnetic field generated by the permanent magnet at the position where the magnetic pole surface faces the rotor, and torque is generated in the direction of decelerating the rotor to obtain the braking force (Japanese Patent Laid-Open No. 1-234045). Issue Bulletin, etc.).

The rotor in the above conventional eddy current type speed reducer is usually made of steel. In addition, low alloy steel containing Ni and the like is used in Shinkansen vehicles in consideration of high temperature strength.

[0005]

As described above, since the rotor in the conventional eddy current type speed reducer is made of a single material of steel, which is a ferromagnetic material, a magnetic field for generating an eddy current is applied to the rotor. As a result of analysis using the analytical model shown in FIG. 3A, the magnetic field is dragged by the outer cylinder 2 of the rotor as shown in FIG. 3B, and the direction of the magnetic flux density is the rotating direction. As shown in, the radial direction is applied, and the rotational force effective for braking is reduced.

In view of the present situation, the present invention provides a rotor for an eddy current type speed reducer capable of increasing magnetic flux in the radial direction of the rotor and increasing the rotational component of the Lorentz force to increase the effective braking force. To do.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the rotor in the eddy current type speed reducer of the present invention has a rotor fitted to one end of a rotating shaft and a plurality of electromagnets or permanent magnets so that the polarities of adjacent magnets are opposite to each other. In an eddy current type speed reducer in which a support ring around magnets is installed so that the pole faces of these magnets are magnetically opposed to the rotor with a required air gap, the inner peripheral surface of the cylindrical portion of the rotor is made of a non-magnetic material. The surface treatment layer is provided.

[0008]

[Action]

 Since this invention has a surface treatment layer made of a non-magnetic material on the inner peripheral surface of the rotor facing the magnet, as shown in the analysis result of the magnetic field in FIG. 2, the component of the Lorentz force in the rotational direction is increased. The effective braking force can be increased. This figure shows the analysis result of the edge portion of the permanent magnet 9 as shown in the analysis model of A. Regarding the magnetic flux distribution, the magnetic flux in the surface treatment layer 5 enters in the radial direction as shown by B, and therefore the direction of the magnetic flux density becomes the radial direction as shown by C. Therefore, as shown in D, the component of the Lorentz force in the rotation direction becomes large, and the braking torque can be increased.

[0009]

Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the mounting disk 7 of the rotor 1 is attached to the support member 17 fitted to one end of the rotary shaft 12 by a plurality of bolts 19. In this rotor 1, the outer cylinder 2 and the inner cylinder 3 are opposed to each other with a required space to form a cylindrical portion, and the ends of the outer cylinder 2 and the inner cylinder 3 are connected by a large number of arms 4 so that the outer cylinder 2 A large number of cooling fins 6 oriented in the direction of the rotation axis of the rotor are circumferentially arranged on the outer peripheral surface, and the inner peripheral surface of the outer cylinder 2 has a surface treatment layer 5 made of a non-magnetic material such as austenitic stainless steel. To form. The mounting disk 7 is provided on one end surface of the inner cylinder 3. The surface treatment layer 5 is formed by plating or spraying a non-magnetic material on the inner peripheral surface of the outer cylinder. However, in order to effectively obtain the braking torque, it is necessary to match the characteristics of the non-magnetic material used. Then, the thickness is determined, but the optimum thickness is analytically and experimentally obtained.

In the space between the outer cylinder 2 and the inner cylinder 3, a support ring 14 having a width corresponding to the cylinder length is interposed. The support ring 14 is attached to a support plate 16 axially supported by the rotary shaft 12 via bearings 15 and is supported by a plurality of guide rods 18 projecting in the axial direction of the rotary shaft 12 to support the support ring 14. The rod 8 penetrating in the width direction is moved forward and backward by the cylinder 11, so that the length from the position facing the cylindrical portion of the rotor to the position magnetically deviated is set back and forth. A plurality of permanent magnets 9 made of rare earth magnets are arranged around the outer peripheral surface of the support ring 14 so that the polarities of the adjacent magnets are opposite to each other. The permanent magnet group is attached to the support plate 16 and is housed in a shield case 13 that supports the pole piece 10 at a position facing the magnetic pole surface of each permanent magnet 9.

In comparison with the eddy current type speed reducer according to the embodiment of the present invention shown in FIG. 1, the device of FIG. An eddy current type speed reducer was installed in each 10-ton truck, and the relationship between the braking torque and the rotation speed of the propeller shaft was investigated. The result is shown in FIG. It can be seen from FIG. 4 that the braking torque of the speed reducer of the present invention is larger than that of the conventional speed reducer in the entire speed range of the vehicle, and the braking performance is improved.

[0012]

[Effect of device]

 According to this invention, the braking performance can be improved by a simple process of forming a non-magnetic processing layer on the magnetic pole facing surface of the rotor of the eddy current type speed reducer. In addition, by reducing the thickness of the rotor with the improvement of the damping capability, it became possible to reduce the weight of the device.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an analysis of a magnetic field during braking of an eddy current type speed reducer according to an embodiment of the present invention, where A is an analytical model, B is a magnetic flux distribution, C is a magnetic flux density direction, and D is a magnetic flux density direction. Indicates Lorentz force.

FIG. 3 is an explanatory diagram showing an analysis of a magnetic field during braking of a conventional eddy current type speed reducer, where A is an analytical model, B is a magnetic flux distribution, C is a direction of magnetic flux density, and D is a Lorentz force. Show.

FIG. 4 is a graph showing a braking torque of the present invention and a conventional device in an embodiment in relation to a rotation speed of a propeller shaft.

[Explanation of symbols]

 1 Rotor 2 Outer Cylinder 3 Inner Cylinder 4 Arm 5 Surface Treatment Layer 6 Cooling Fin 7 Mounting Disc 8 Rod 9 Permanent Magnet 10 Pole Piece 11 Cylinder 12 Rotating Shaft 13 Shield Case 14 Support Ring 15 Bearing 16 Support Plate 17 Support Member 18 Guide Rod 19 bolt

Claims (1)

[Scope of utility model registration request] 1. A rotor is fitted to one end of a rotary shaft,
Eddy current type deceleration with a support ring around multiple electromagnets or permanent magnets arranged so that the polarities of adjacent magnets are opposite to each other so that the pole faces of these magnets are magnetically opposed to the rotor with a required gap. A rotor for an eddy current type speed reducer, characterized in that a surface treatment layer made of a non-magnetic material is provided on an inner peripheral surface of a cylindrical portion of the rotor.