JPH11235006A - Eddy-current speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a brake drum to be jointed to a support arm without causing the good conductor of the brake drum to receive a bad effect by heat. SOLUTION: An eddy-current speed reducer is made up of a wheel 9 connected to a rotating shaft 4, a support arm 12 which connects a brake drum 13 to the wheel 9, and a magnet 20 provided on a non-rotating part of a vehicle at the position facing the brake drum 13. The end part of the supporting arm 12 is solidly formed with the brake drum 13, while its base end part is fit into the cylindrical part of the circumferential edge part of the wheel 9. Then, the base end part and end part of the support arm 12 are jointed to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current deceleration device in which a braking drum is joined to a rotating shaft via a support arm without interfering with a good conductor provided on the braking drum for improving the flow of eddy current. It concerns the device.

[0002]

2. Description of the Related Art For example, as disclosed in Japanese Utility Model Laid-Open No. 4-28782, a braking drum which is a rotating magnetic resistor (a metal material attracted to a magnet) and a permanent drum which can be separated from and connected to the braking drum. In a permanent magnet type eddy current reduction device including a magnet, a support arm is formed integrally with a wheel joined to a rotating shaft, and a braking drum is welded to the support arm. In order to increase the braking capability of the eddy current reduction device, for example, in the eddy current reduction device disclosed in Japanese Patent Application No. 9-56849 filed by the present applicant, a good conductor such as copper is joined to the end of the braking drum. You. To join a good conductor such as copper to the end of the braking drum, brazing or spraying (plasma spraying, arc spraying,
Plasma Tungsten Arc (PTA)) has been attempted, but the conventional method requires positioning the brake drum at two locations in the radial direction and the axial direction with respect to the support arm during bonding, which is very troublesome. .

[0003] In order to join the support arm after joining a good annular conductor to the end of the braking drum, welding, friction welding, or the like can be considered from the viewpoint of joining strength. When the good annular conductor bonded to the end of the conductor melts and flows out, and the good conductor is divided in the circumferential direction, the braking torque decreases. In addition, the good conductor is oxidized before the surface treatment, and the durability is significantly impaired. When joining while protecting the good conductor joined to the end of the braking drum, the joining temperature cannot be increased sufficiently, so that the joining strength decreases. If the supporting arm is directly joined to the good conductor joined to the end of the braking drum, the difference between the coefficients of thermal expansion of the braking drum and the good conductor causes the joint between the supporting arm and the braking drum to be heated by the heat during braking of the eddy current reduction device. It may be damaged.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an eddy current reduction device capable of joining a braking drum to a support arm without a bad conductor of the braking drum being adversely affected by heat. To provide.

[0005]

SUMMARY OF THE INVENTION To solve the above problems, the present invention comprises a wheel connected to a rotating shaft, a radial support arm connecting a braking drum to the wheel, and a non-rotating portion of the vehicle. An eddy current reduction device comprising a magnet disposed at a position facing the braking drum, wherein a tip end of the support arm is formed integrally with the brake drum, and a base end of the support arm is formed on a periphery of the wheel. Into the cylindrical part of the part,
The distal end and the proximal end of the support arm are joined to each other.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the brake drum is joined to the support arm so as to reduce the number of jigs required for joining the support arm and to prevent the good conductor of the brake drum from being affected by heat. For this reason, the support arm is divided into a base end and a tip end, and the tip end is formed integrally with the brake drum, and the base end is slidably fitted into a cylindrical portion provided on the periphery of the wheel. The proximal end and the distal end of the support arm are joined to each other by butt welding.

[0007]

1 is a front sectional view of an eddy current reduction device to which the present invention is applied, and FIG. 2 is a side sectional view of the same. The eddy current reduction device couples the braking drum 13 to the rotating shaft 4. For this reason, the spline hole 5a is formed in the output rotary shaft 4 supported by the bearing 3 on the end wall of the gear box 2 of the transmission and protruding from the end wall.
The mounting flange 5 having the above is fitted and fastened by a nut 6 so as not to come off. An end wall of the brake drum 7 of the parking brake and a flange portion 9a integral with the wheel 9 supporting the brake drum 13 of the eddy current reduction device are overlapped on the mounting flange 5, and a plurality of bolts 10 and nuts 10a are provided.
Is concluded.

The brake drum 13 is made of a material having a high magnetic permeability such as iron. The base end of the brake drum 13 is connected to a number of support arms (spokes) 12 extending radially from the wheel 9 as described later. You. A large number of cooling fins 13a are integrally provided on the outer peripheral wall of the braking drum 13 at equal intervals in the circumferential direction. At both ends of the braking drum 13, the braking drum 13
A copper ring 35 as a good conductor for improving the flow of the eddy current and improving the braking ability is previously connected. As shown in FIG. 3, preferably, the copper ring 35 has an L-shaped cross section,
a is coupled to the inner peripheral surface 13c of the braking drum 13.

A guide cylinder 18 having an inner space 23 having a box-shaped cross section is coaxially arranged inside the braking drum 13. The immobile guide cylinder 18 made of a non-magnetic material is fixed by bolts 32 and 33 to a frame plate 31 externally fitted and fixed to the protruding wall 2 a of the gear box 2. The guide cylinder 18 has an outer peripheral wall 18a and an inner peripheral wall 18b.
May be configured by joining an annular end wall plate to both ends of the
The illustrated guide tube 18 has a large number of a left-half cylindrical portion made of a magnetic material such as iron and a right-half inverted L-shaped cylindrical portion made of a non-magnetic material such as aluminum. And are connected by bolts 14 of.

A large number of openings are provided in the outer peripheral wall portion 18a of the guide cylinder 18 facing the inner peripheral surface 13c of the braking drum 13 at equal intervals in the circumferential direction, and a ferromagnetic plate (pole piece) 2 is provided in each opening.
1 is fitted and fixed. In practice, the ferromagnetic plate 21 is cast when the outer peripheral wall 18a is cast from aluminum.

A plurality of actuators (not shown) are supported on the frame plate 31 having the reinforcing ribs 31a at equal intervals in the circumferential direction. The actuator has a piston fitted into the cylinder to define a pair of fluid pressure chambers, and a magnet support cylinder 19 is connected to an end of a rod 17 projecting from the piston into the inner space of the guide cylinder 18. The magnet support tube 19 is supported by the inner space 23 of the guide tube 18 so as to be movable in the axial direction. Magnets 20 facing each ferromagnetic plate 21 are coupled to the outer peripheral wall of the magnet support cylinder 19 so that the polarities are alternately different in the circumferential direction.

At the time of braking, as shown in FIG. 1, the magnet supporting cylinder 19 is moved by the rod 17 of the actuator to the braking drum 13 as shown in FIG.
Is protruded into the inside of. The rotating braking drum 13 is a magnet 2
0 to the inner peripheral surface 13 of the braking drum 13 through the ferromagnetic plate 21
When crossing the magnetic field reaching c, an eddy current is generated in the braking drum 13, and the braking drum 13 generates a braking torque. The braking drum 13 generates heat due to the eddy current, and is cooled by the outside air directly or via the cooling fin 13a. At this time, as shown in FIG. 2, a magnetic circuit 40 is formed between the magnet support cylinder 19 and the braking drum 13. When the brake drum 13 thermally expands, the support arm 12 moves radially outward from the boss 53 (FIG. 3) of the wheel 9 to absorb the deformation of the brake drum 13. At the time of non-braking, if the magnet support cylinder 19 is moved leftward in FIG. 1 by the actuator and is withdrawn from the braking drum 13, the magnet 20 does not apply a magnetic field to the braking drum 13, and the braking drum 13 does not generate a braking torque. .

As shown in FIG. 3, the present invention relates to a brake drum 1.
In order to simplify the coupling of the brake drum 13 to the support arm 12 without the good conductors 3 being adversely affected by heat, the support arm 1
2 is formed integrally with the brake drum 13 and the base end 12a of the support arm 12 is formed integrally with the wheel 9;
The distal end portion 12b and the proximal end portion 12a of the support arm 12 are joined to each other.

As shown in FIG. 4, the wheel 9 is provided with a plurality of bosses 53 projecting radially or radially outward at equal intervals in the circumferential direction, and the cylindrical portion 41 is formed on the boss 53. A shaft portion 43 and a small-diameter shaft portion 43a formed on the base end portion 12a of the support arm 12 are slidably fitted into the cylindrical portion 41, and a spring 42 wound around the small-diameter shaft portion 43a is fixed to the bottom of the cylindrical portion 41. The spring 4 is interposed between the shaft 43 and the step of the shaft 43a.
2, the base end portion 12a of the support arm 12 is urged radially outward. In order to prevent muddy water from entering the cylindrical portion 41,
An O-ring 44 is provided between the shaft 43 and the open end of the cylindrical portion 41.
Is attached. On the other hand, the tip 12b of the support arm 12 is formed integrally with the braking drum 13 by casting or the like.

As shown in FIG. 3, the base end 12a engaged with the cylindrical portion 41 of the boss 53 of the wheel 9 as described above.
And the tip portion 12b integrally connected to the braking drum 13 are butted against each other. A positioning pin 48 urged radially outward by a spring 50 is fitted into a pin hole 49 orthogonal to the abutting surface of the base end portion 12a and the distal end portion 12b. The proximal end 12a and the distal end 12 of the support arm 12 are
Since b is stably connected, the welding operation is greatly simplified, and the two are welded (brazed) as represented by a weld bead 46.

In the above-described embodiment, the magnet support cylinder is reciprocated in the axial direction with respect to the braking drum, so that the magnet is positioned between the braking position where the magnet faces the ferromagnetic plate and the non-braking position where the magnet does not face the ferromagnetic plate. Although the switching type eddy current reduction device has been described, the present invention is not limited to this.
No. 1 for the braking drum as disclosed in
By rotating two magnet support cylinders, a braking position in which two magnets having the same polarity face a common ferromagnetic plate and a braking position in which two magnets having different polarities
An eddy current reduction device of a type in which two magnets are switched to a non-braking position facing a common ferromagnetic plate, and a magnet support cylinder which is immovable inside a braking drum as disclosed in JP-A-4-12659. A magnet support cylinder is disposed, and one of the magnet support cylinders is rotated so that the magnets having the same polarity of both magnet support cylinders entirely face the common ferromagnetic plate, and a braking position where both magnets are supported. The present invention is also applicable to an eddy current reduction device of a type in which a pair of magnets having different cylinder polarities is switched to a non-braking position in which the common ferromagnetic plate and the entire magnet face each other.

The present invention can be applied to not only a permanent magnet type eddy current reduction device but also an electromagnet type eddy current reduction device as disclosed in Japanese Patent Application Laid-Open No. 63-274359.

[0018]

As described above, the present invention provides a wheel connected to a rotating shaft, a radial support arm connecting a brake drum to the wheel, and a non-rotating portion of a vehicle at a position facing the brake drum. In the eddy current reduction device including the magnets provided, the distal end of the support arm is formed integrally with the braking drum, and the base end of the support arm is inserted into a cylindrical portion of a peripheral portion of the wheel. Since the distal end portion and the proximal end portion of the support arm are joined to each other, only one positioning point is required for welding the brake drum to the support arm, especially for a brake drum having a good conductor connected to the inner peripheral surface and / or the end surface. If you apply,
Since the support arm is joined to a portion of the braking drum remote from the good conductor, the adverse effect of heat on the good conductor is suppressed, and the good conductor can be continuously provided in the circumferential direction, so that the braking ability is enhanced.

The number of steps for setting up the jig is small, the alignment when brazing is easy, the joining is simple and reliable, and the braking ability is improved because the good conductor is continuous in the circumferential direction.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an eddy current type speed reducer according to the present invention.

FIG. 2 is a side sectional view of the eddy current type speed reducer.

FIG. 3 is an enlarged front sectional view showing a main part of the eddy current type reduction gear transmission.

FIG. 4 is an enlarged side sectional view showing a main part of the eddy current type speed reducer.

[Explanation of symbols]

2: gear box 4: rotating shaft 5: mounting flange 9a: flange portion 9: wheel 12: support arm 12a: base end portion 12b: distal end portion 13: braking drum 13c: inner peripheral surface 18: guide cylinder 18a: outer peripheral wall portion 18b: inner peripheral wall portion 19: magnet support cylinder 20: magnet 21: ferromagnetic plate 3
5: Copper ring 41: Cylindrical part 42: Spring 43: Shaft part 4
4: O-ring 45, 46: welding bead 48: positioning pin 49: pin hole 50: spring 53: boss

Claims (2)

[Claims] 1. A vortex comprising a wheel connected to a rotating shaft, a radial support arm connecting a braking drum to the wheel, and a magnet disposed at a position of the non-rotating portion of the vehicle opposite to the braking drum. In the current reduction device, the distal end of the support arm is formed integrally with the braking drum, and the proximal end of the support arm is inserted into the cylindrical portion of the peripheral portion of the wheel, and the distal end and the proximal end of the support arm are inserted. An eddy current reduction device, wherein the eddy current reduction device and the first portion are joined to each other. 2. The eddy current reduction device according to claim 1, wherein a good conductor for improving the flow of the eddy current is continuously provided annularly at an end of the braking drum.