JP2592683Y2 - Trailer eddy current speed reducer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current speed reducer for a trailer towed by a tractor.

[0002]

2. Description of the Related Art When braking a tractor for towing a trailer, a friction brake for a wheel of the trailer is applied in advance by a hand brake provided in a driver's seat of the tractor in order to prevent a jump knife phenomenon peculiar to the trailer. I have to. However, if the friction brake is frequently applied on a long downhill road, for example, there is a problem that the braking ability is reduced due to overheating.

To solve this problem, Japanese Utility Model Laid-Open No. 5-54130 discloses a trailer provided with an eddy current reduction device on the axle. That is, a stator having a pair of left and right electromagnets is disposed in the middle inner space of the axle case of the trailer, and a braking disk facing the electromagnets is connected to the inner ends of the left and right axles. However, the configuration of the eddy current type reduction gear of the above-mentioned trailer is complicated and large to fix the stator having the electromagnet inside the axle case. (B) It is necessary to provide a means for externally cooling the braking disk. (C) When the number of revolutions of the braking disk is the same as that of the wheels, sufficient braking force cannot be obtained, and it is necessary to provide a speed increasing device such as a hub reduction. −
For reasons such as-, it is not possible to attach it to the existing axle case, it will be expensive.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an eddy current type reduction gear of a trailer which can be constituted by an axle case of a rear wheel of a general vehicle and a differential gear. It is in.

[0005]

In order to achieve the above-mentioned object, according to the present invention, a gearbox of a differential gear is mounted on an intermediate portion of an axle case through an annular mounting plate to a cylindrical portion in a longitudinal direction. Coupling, rotatably supporting the both end shafts of the carrier coaxially with the axle in the gear box, shaft-supporting the intermediate bevel gear meshing with the bevel gears coupled to the left and right axles to the carrier, and axle to the crown gear coupled to the carrier. The guide frame connected to the gear box projects into the inside of the brake drum connected to the output shaft, and the guide frame supports a magnet support cylinder movable to the braking position and the non-braking position. A large number of magnets are connected to the magnet support cylinder at equal intervals in the circumferential direction so that the polarities facing the brake drum are alternately different in the circumferential direction.

[0006]

The differential is connected to the existing axle case via an annular mounting plate, and the eddy current type reduction gear of the trailer is connected to the output shaft of the differential. The rotation of the wheels is accelerated by the differential and transmitted to the brake drum via the output shaft.

During braking, when a braking drum rotating at a higher speed than a wheel crosses a magnetic field, the braking drum receives a braking torque based on an eddy current generated in the braking drum and transmits a braking force to the wheels. The brake drum is opened to the outside of the axle case and is cooled by the outside air, so that the overheating does not lower the braking capacity.

[0008]

FIG. 1 is a plan view showing the left half of the axle of a trailer provided with an eddy current type reduction gear according to the present invention, and FIG. 2 is a side sectional view showing the mounted state of the eddy current type reduction gear. . According to the present invention, the axle case 51 is formed by welding a pair of upper and lower divided bodies. That is, if the divided body of the lower half is described, both ends of the elongated plate are formed into a semi-cylindrical shape,
The central portion is extruded downward into a semi-cylindrical shape orthogonal to the semi-cylindrical shapes at both ends, and the cross section of the extruded portion is formed in a groove shape to form a portion for housing the differential device B. By welding a pair of upper and lower divided bodies, a short cylindrical portion 36 in the front-rear direction is formed at the center of the axle case 51. The front edge of the cylindrical portion 36 is reinforced by welding a reinforcing ring 36a made of a thick plate, and the rear edge of the cylindrical portion 36 is connected to a bowl-shaped lid plate 37. Axle case 51
The small-diameter portions supporting the bearings 53 at both ends are integrally formed by welding another short cylindrical body.

A hub 54 is rotatably supported at an end of the axle case 51 by a pair of bearings 53. Although not shown, the wheels are connected to the brake drum 55 of the friction brake.
Together with the flange 53a of the hub 54 by bolts. The friction brake is a back plate 5 that covers the braking drum 55.
7 is connected to the axle case 51. When the camshaft 56 supported by the back plate 57 is rotated remotely from the driver's seat of the tractor, a pair of brake shoes (not shown) is opened, and the lining of the brake shoes is moved inside the brake drum 55. It is pressed against the peripheral surface to generate a braking force. Hub 54 is bolted to flange 52a at the outer end of axle 52.

The inner end of the axle 52 is connected to the bevel gear 45 of the differential B.
Will be combined. The differential device B attaches the gear box 31 to the reinforcing ring 36 a at the front end of the cylindrical portion 36 of the axle case 51.
Are connected via As shown in FIG. 2, the mounting plate 34 has a peripheral flat plate portion 34a connected to a reinforcing ring 36a by a bolt 33, and the gear box 31 has an end flange 31a connected to the mounting plate 3a.
4 is connected to the flat plate portion 34b by the bolt 32.

The shafts at both ends of the carrier 47 are supported by the gear box 31 by bearings 46. Carrier 47 is left and right axle 5
An intermediate bevel gear 50 that meshes with the bevel gear 45 at the inner end of the shaft 2 is supported by a shaft orthogonal to the axle 52. Carrier 47
Is connected to the bevel gear 41 of the output shaft 2.
To be engaged. The output shaft 2 has a bearing sleeve 5 (FIG. 2) whose outer end or front end is connected to a gear box 31 by bearings 3 and 4.
, And the inner end is supported by a bearing on the intermediate wall of the gear box 31.

As shown in FIG. 2, an eddy current type speed reducer A includes a braking drum 27 made of a conductor connected to the front end of the output shaft 2.
And the guide frame 10 connected to the gear box 31. The guide frame 10 is made of a non-magnetic material as a whole.
The outer peripheral wall portion 10a protruding outward from 7 is made of a magnetic material. A mounting flange 21 is spline-fitted to the front end of the output shaft 2 and fastened by a nut 22. A boss 24 is fastened to the mounting flange 21 with a plurality of bolts 23 and nuts. Brake drum 2 with cooling fin 26
7 has one end connected to the outer ends of a plurality of spokes 25 projecting radially outward from the boss 24.

A mounting plate 6 is connected to the bearing cylinder 5 of the gear box 31 by a plurality of bolts 7, and a cylindrical guide frame 10 and a plurality of actuators 8 are connected to the outer peripheral side of the mounting plate 6. The guide frame 10 has an inner space with a rectangular cross section, and the guide frame 1
A number of openings are provided in a portion of the outer peripheral wall facing the inner peripheral surface of the braking drum 27, and the ferromagnetic plates 14 are coupled to the openings at regular intervals in the circumferential direction. On the other hand, a magnet support tube 12 made of a magnetic material is accommodated in the inner space of the guide frame 10 so as to be slidable in the axial direction, and is connected to a rod 9 projecting from the actuator 8 into the guide frame 10.

Each ferromagnetic plate 14 is provided on the outer peripheral surface of the magnet support cylinder 12.
Are coupled to each other. The polarities of the magnets 13 facing the braking drum 27 are alternately arranged in the circumferential direction. The actuator 8 has a piston fitted inside the cylinder, and has end chambers defined at both ends. The rod 9 is connected to the piston.

In FIG. 2, when pressurized air is supplied to the left end chamber of the actuator 8 and the right end chamber is opened to the atmosphere, the magnet support cylinder 12 retreats rightward from the inside of the brake drum 27, No magnetic field is applied to the braking drum 27. At this time, the magnet 13 of the magnet support tube 12 faces the outer peripheral wall portion 10a made of a magnetic material. Such an eddy current type reduction gear A
Is disclosed in, for example, Japanese Patent Application No. 2-112026, and will not be described further. The eddy current type speed reducer A is not limited to the type shown in the figure, and may be of a type that switches between a braking position and a non-braking position when, for example, the magnet support cylinder is rotated in relation to the arrangement pitch of the magnets.

Next, the operation of the eddy current type speed reducer according to the present invention will be described. Normally, the magnet support cylinder 12 is withdrawn from the braking drum 27 by the actuator 8, and the magnet 13 does not exert a magnetic field on the braking drum 27. When the trailer is towed, the rotation of the left and right wheels is controlled by the axle 52, bevel gear 45, intermediate bevel gear 50, carrier 47, crown gear 4
2, transmitted to the output shaft 2 via the bevel gear 41. When the trailer runs straight, the intermediate bevel gear 50 does not rotate, and the crown gear 42 rotates at the same speed as the axle 52. When the trailer turns, the intermediate bevel gear 50 rotates to allow the left and right axles 52 to rotate. The braking drum 27 coupled to the output shaft 2 rotates at an increased speed at the gear ratio of the crown gear 42 and the bevel gear 41, but does not receive a braking force because the magnet 13 does not apply a magnetic field to the braking drum 27.

At the time of braking, when the magnet support cylinder 12 is moved into the inside of the braking drum 27 by the actuator 8 as shown in FIG.
To apply a magnetic field. Brake drum 2 that rotates faster than wheels
When 7 crosses the magnetic field, an eddy current is generated inside the braking drum 27 and the braking drum 27 receives a braking torque. The braking torque received by the braking drum 27 is determined by the differential device B, the axle 52
Is transmitted to the wheels.

The brake drum 27 is open toward the front of the trailer, and receives an airflow from the front as the trailer travels. The heat generated in the braking drum 27 by the eddy current during braking is efficiently cooled by the air flow via the cooling fins 26. The airflow also flows into the inside of the guide frame 10 through the space between the spokes 25, and flows out rearward through an opening (not shown) provided on the mounting plate 6 that also serves as a weight reduction.

In the embodiment shown in FIG. 3, by replacing the mounting plate 34, the gear box 31 is mounted so that the output shaft 2 is inclined upward and forward, and copes with a load below the floor of the trailer or a flying stone from the road surface. it can. For this reason, the mounting plate 34 has a first flat plate portion 34a which is joined to the peripheral portion of the cylindrical portion 36 of the axle case 51 by being overlapped therewith, and the gear box 31 of the differential device B is provided inside the peripheral portion. Are formed, and the second flat plate portions 34b are inclined with respect to the first flat plate portions 34a.

The differential device B and the eddy current type speed reducer A are arranged so that the output shaft 2 is directed rearward of the trailer.
1 may be arranged on the rear side.

[0021]

Since the braking torque transmitted to the wheels by the differential device is smaller than the driving torque transmitted to the wheels in a normal vehicle, the differential device of the small vehicle is connected to the axle case of the existing large vehicle. By connecting the eddy current type speed reducer of the trailer to the output shaft of the differential device, a sufficient braking force can be obtained and the manufacturing cost can be reduced.

The rotation of the wheels is accelerated by the differential device and transmitted to the braking drum of the output shaft, so that an efficient braking force based on the eddy current is obtained.

Since the braking drum is opened to the outside of the axle case, it is excellent in cooling performance and can prevent a decrease in braking ability due to overheating.

By using the eddy current type speed reducer of the trailer, the frequency of using the friction brake of the tractor or the trailer is reduced, and the replacement time of the brake lining can be extended.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of an eddy current type reduction gear of a trailer according to the present invention.

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

FIG. 3 is a side sectional view of an eddy current type speed reducer of a trailer according to a partially modified embodiment of the present invention.

[Explanation of symbols]

2: Output shaft 10: Guide frame 12: Magnet support cylinder 13:
Magnet 27: Brake drum 31: Gear box 34: Mounting plate 36: Cylindrical part 42: Crown gear 45: Bevel gear 47: Carrier 50: Middle bevel gear 51: Axle case 52: Axle

Claims (2)

(57) [Scope of request for utility model registration] 1. A gear box of a differential gear is connected to a longitudinal cylindrical portion provided at an intermediate portion of an axle case via an annular mounting plate, and both end shaft portions of the carrier are rotated coaxially with the axle on the gear box. The intermediate bevel gear meshed with the bevel gear connected to the left and right axle is supported on the carrier, and the crown gear connected to the carrier is meshed with the bevel gear of the output shaft orthogonal to the axle, and the braking is connected to the output shaft. The guide frame connected to the gear box projects into the drum, the guide frame supports a magnet support cylinder that can be moved to a braking position and a non-braking position, and a large number of magnets are arranged on the magnet support cylinder at equal intervals in the circumferential direction. An eddy current type reduction gear for a trailer, characterized in that polarities opposite to each other are alternately different in a circumferential direction. 2. The mounting plate according to claim 1, wherein said mounting plate has a first flat plate portion joined to an end portion of a cylindrical portion of said axle case and joined to an end portion of a gear box of a differential gear inside said end portion. A second flat plate portion for overlapping and connecting the flanges;
The eddy current type reduction gear for a trailer according to claim 1, wherein the flat plate portion is inclined with respect to the first flat plate portion.