JPH01234043A - Eddy current type speed reducer - Google Patents

Abstract

PURPOSE:To facilitate control of braking force by sliding, in the axial direction, a supporting ring, which reversed the polarity of a plurality of permanent magnets which are adjacent to each other and arranged them at the periphery, to a rotor mounted at the end on one side of a rotary shaft so as to make them contract or separate. CONSTITUTION:At the end on one side of a rotary shaft 1 is mounted a rotor 3 which has a cooling fin 2 having U-shaped cross section at the outside. Supporting members 5 (the figure show one) extending in the axial direction are projected, in radial arrangement, from the shaft receiving box 4 of the rotary shaft 1, and guide rails 6 are provided at the outside. A slide saddle 8 is bestridden on a guide rail 6. A supporting ring 7, a permanent magnet 10, and e pole piece 9 are united with the slide saddle 8, and they are shifted along the guide rail 6 in the direction shown by the arrow with a screw bar 14 and a nut 13. When it most nears the rotor 3 shown in the figure, it exhibits the maximum braking force and as it shifts to the right, it becomes gradually brake less condition. Hereby, the braking force is controlled easily over the wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to improvements in eddy current speed reducers used in large motor vehicles such as buses and trucks.

Conventional technology In addition to the main brake, which is a foot brake, and the auxiliary brake, which is an exhaust brake, the deceleration device or 111 motion device for a large vehicle provides stable deceleration, such as when descending a long slope, and prevents burnout of the foot brake. Eddy current reduction devices are used to prevent this.

This eddy current type reduction gear consists of an electromagnet with an electromagnetic coil wound around an iron core, and many of its magnetic poles are arranged on both sides of one disk.A magnetic field is generated by electricity from a battery power supply, and an eddy current is generated. The braking force is increased by generating torque in the direction of decelerating the disk by means of an electric current phenomenon (Japanese Patent Laid-Open No. 50-61574).

Problems to be Solved by the Invention Conventional eddy current reduction gears use electromagnets with electromagnetic coils wound around iron cores as magnetic poles, so they have a simple assembly type and large external dimensions, so they require limited space. Vehicle towers and 戊 are at a disadvantage. Also, when the brake is on, it is necessary to keep the power on all the time, and the battery power consumption is severe, so increasing the battery capacity and power generation is necessary.

This invention aims to eliminate such problems by:
It is an object of the present invention to provide an eddy current type speed reduction device that requires only a short time of energization during operation.

Means for Solving the Problem In order to achieve the desired distribution, in an eddy current reduction gear, a rotor is fitted to one end of the rotating shaft, and the polarities of adjacent magnets are opposite to each other. A support ring having a plurality of permanent magnets surrounding it is provided so as to be movable back and forth in the axial direction of the rotating shaft, from a position where the pole faces of the permanent magnets completely face the rotor with a required gap to a position where they completely separate from the rotor. It's in particular.

The permanent magnets mentioned above are rare earth cobalt magnets, rare earth magnets,
It is desirable to use rare earth magnets with excellent magnetic properties, such as iron/boron magnets.

Operation When the support ring surrounding the permanent magnets of the speed reducer configured as described above is moved so that the permanent magnets completely face the rotor, the magnetic circuit configured between adjacent permanent magnets causes the rotor to move. , eddy currents flow and large braking torque is generated.

Then, when the permanent magnets facing the rotor are gradually retreated, the generated braking torque gradually decreases and the braking force is reduced, and when the permanent magnets completely separate from the rotor after retreating, the braking is released.

Example Embodiments of this invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a rotor (3) having a U-shaped cross section and cooling fins (2) on the outer peripheral surface is fitted to one end of the rotating shaft (1). ) is supported by supporting parts vJ(
A plurality of kite rails (6) are provided on the top surface of the support member (5).
to be installed. The guide rail (6) is attached to the inner peripheral surface of the support ring (7) with a cylinder length corresponding to the cylindrical part of the rotor (3).
A slide saddle (8) is provided that straddles the support ring (7).
is provided so that it can move on the guide rail (6) and move forward and backward with respect to the rotor (3). And the support ring (7)
There are a plurality of permanent magnets (10) made of rare earth magnets (12 in the drawing) with pole pieces (9) attached to the outer peripheral surface of the
(showing the case of even @ pieces)) are placed around the circumference so that the magnetic poles of adjacent magnets are oriented in opposite directions.

A cylinder (11) with the same inner diameter is placed on the extension line of the cylindrical part of the rotor (3), separated from the rotor (3), and a bearing housing cylinder (
The lid plate (12) attached to the end face of the cylinder (1)
1) and the cover plate (12) form a magnetically shielded casing to prevent magnetism from leaking outside the device.

In addition, the rotor (3) and the inner cylinder (1
1) A material that allows magnetic flux to pass through easily (such as Fθ)
With this structure, the permanent magnet (10) can be moved back and forth smoothly. The structure of the casing is not limited to the one shown in the embodiment, but any structure can be selected as long as it has a magnetic shielding effect and does not hinder the movement of the permanent magnet (10). A nut (13) is attached to each intermediate point of the three slide saddles (8) provided on the inner peripheral surface of the support ring (7).
is provided in a protruding manner, and one end of a threaded rod (14) which is screwed into this nut is pivotally supported by a bearing (15) attached to the cover plate (12). A gear (16) is located near the shaft support end of the screw foot (14).
is provided and meshes with a large-diameter intermediate gear (18) that is pivotally supported by a bearing (17) in a bearing box tube (4). Furthermore, the intermediate gear (18) is a motor (19) attached to the cover plate (12).
The drive gear (20) (see Fig. 4) meshes with the drive gear (20) provided on the main shaft.

The above reduction gear is mounted on a cylinder (11) with a metal fitting (21).
) to the vehicle body, and connect both ends of the rotating shaft (the moon) to the middle of the propeller and shaft via cross joints.

As shown in Fig. 3, this speed reduction device has a support ring (7).
When the permanent magnet group is in a position separated from the rotor (3) after (after) v, no eddy current flows in the rotor (3), so the rotor (3) rotates with a predetermined torque, It is in a so-called brake OFF state.

If the motor (19) is started with the brake OFF, the drive gear (20), intermediate gear (18), and teeth (
16), the threaded rod (14) rotates, and the nut (13)
The support ring (7) advances toward the rotor (3) through the
Finally, the entire surface of the pole piece (9) faces the inner surface of the cylindrical portion of the rotor (3) with a predetermined gap in between. At this time, the maximum braking torque of 1 to 17 is applied, and the vehicle is greatly decelerated.

From this state where the maximum braking torque is obtained, the motor (19
) is rotated in the opposite direction to the previous one and the support ring (7), that is, the permanent magnet group is retreated, the 111 dynamic torque decreases as the opposing area between the rotor and the permanent magnets decreases,
The state returns to the state of brake leaf F in Fig. 3 again.

Therefore, if a small braking force is required, it is sufficient to adjust the advance and retreat of the magnets so that the opposing area between the permanent magnet and the rotor is at an intermediate position between full-face contact and full-face separation. This can be controlled by incorporating various position sensors (not shown) and controlling the drive of the motor. In the above embodiment, a configuration in which a pole piece is attached to the magnetic pole face of the magnet is shown, but the pole piece is not an essential member for achieving the present invention.

The results of the tl control 1 to lux tests are shown in FIG.

In other words, these are the results of measuring the braking 1-lux at each vehicle speed in case A when the rare earth magnet is applied to the entire surface, case B when it is applied to 374 surfaces, and case when it is applied to 1/2 surface.

Further, the permanent magnet can be moved back and forth by using the screw force exerted by the screw ball and the nut l, but is not limited to this, and other mechanisms can be used.

Effects of the Invention The present invention is constructed as described above, and the braking force generated can be increased or decreased by one herk by changing the corresponding area between the rotor and the permanent magnet, so the braking force can be easily controlled and applied to a wide range of decelerations.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a speed reduction device according to the present invention in a braking state, Fig. 2 is a side view taken along line A-A in Fig. 1, Fig. 3 is a longitudinal cross-sectional view in a non-braking state, and Fig. 4 is The right side view of Fig. 1 is an explanatory diagram showing the outline of the drive system for advancing and retracting the support ring having a group of permanent magnets, and Fig. 5 shows the relationship between vehicle speed and braking torque of the reduction gear using rare earth magnets. This is a graph showing. 1...Rotating shaft 2...Cooling fins 3...
・Rotor 4...Bearing box cylinder 5...Support part (A6...Guide rail 7...Support ring
8...Slide saddle 9...Pole piece 10
...Permanent magnet 11...Cylinder 12...
・Cover plate 13...To oak 1 14...Threaded rod 15...Bearing 16...Gear 17.
... Bearing 18 ... Intermediate gear 19 ...
Motor 20... Drive gear Applicant: Sumitomo Metal Industries, Ltd. Sumitomo Special Kinku Co., Ltd.

Claims (1)

[Claims] 1. A rotor is fitted to one end of a rotating shaft, and a support ring having a plurality of permanent magnets surrounding it so that the polarities of adjacent magnets are opposite to each other is attached to the rotor in the axial direction of the rotating shaft. An eddy current reduction gear whose length can be freely moved back and forth from the position where the pole face completely faces the rotor to the position where it completely separates from the rotor with the required gap.