JP2940237B2 - Eddy current type reduction gear - 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 type speed reducer which performs both deceleration braking during vehicle running and braking during parking.

[0002]

2. Description of the Related Art In an eddy current type speed reducer disclosed in Japanese Patent Application Laid-Open No. 3-3179, a brake drum of a speed reducer and a brake drum of a parking brake are provided together at a joint between an output rotary shaft and a propulsion shaft of a transmission. Are combined. Since this reduction gear is disposed in a narrow space at the rear of the transmission, it is subject to various restrictions in size, and the heat generated during deceleration braking is only released from the cooling fins on the outer peripheral wall of the braking drum, and the braking is performed. Since heat radiation from the inner peripheral wall of the drum is hindered by the brake drum of the parking brake, it is hardly expected.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide an eddy-current system in which a speed reducer can also function as a parking brake, expanding the degree of freedom in design and reducing manufacturing costs. It is to provide a reduction gear.

[0004]

In order to achieve the above-mentioned object, according to the present invention, a non-magnetic material having a conical outer peripheral surface is provided on a fixed frame projecting into the inside of a braking drum having an inner peripheral surface. Supports a hollow movable frame consisting of: a large number of ferromagnetic plates arranged at equal circumferential intervals on the outer peripheral wall of the movable frame, and a magnet support cylinder supported in the inner space of the movable frame has a polarity with respect to the ferromagnetic plate. Drive means for coupling a large number of permanent magnets so that the permanent magnets are alternately different in the circumferential direction, and driving the magnet support cylinder to a braking position where the permanent magnets overlap the ferromagnetic plate and a non-braking position where the permanent magnets do not overlap; And a parking brake operation mechanism for moving the movable frame toward and away from the surface.

[0005]

According to the present invention, the inner peripheral surface of the braking drum has a conical shape, and the outer peripheral surface of the movable frame that guides and supports the magnet support tube has a conical shape that can be separated from and attached to the inner peripheral surface of the braking drum. . During parking, when the movable frame is moved in the axial direction and the outer peripheral surface of the movable frame is pressed against the inner peripheral surface of the braking drum, the movable frame works as a parking brake.

[0006] When the movable frame is slightly moved in the axial direction so as to withdraw from the inside of the brake drum while the vehicle is running, a gap is formed between the inner peripheral surface of the brake drum and the outer peripheral surface of the movable frame. When the rotating brake drum crosses the magnetic field from the permanent magnet, an eddy current flows through the brake drum, and the brake drum receives a braking torque.

[0007]

FIG. 1 is a side sectional view showing an upper half of an eddy current type speed reducer according to the present invention, and FIG. 2 is a front sectional view of the speed reducer according to the present invention. The eddy current type speed reducer includes a brake drum 14 connected to the output rotation shaft 3 of a vehicle transmission, a non-magnetic movable frame 21 disposed inside the brake drum 14, and a fixed frame 17 supporting the movable frame 21. And A mounting flange 5 is fitted to the rotating shaft 3 by a spline 4 and a nut 6
Is concluded. A flange 9 integral with the boss 10 of the braking drum 14 is superimposed on the mounting flange 5 and fastened by a plurality of bolts 7 and nuts 8. The end of a braking drum 14 is connected to the tips of a number of spokes 12 extending radially from the boss 10. The braking drum 14 has a conical inner peripheral surface 13 and is provided with a large number of cooling fins 15 arranged at equal circumferential intervals on the outer peripheral wall.

The movable frame 21 is formed by connecting end walls 22 and 23 made of an annular plate to both ends of an outer cylindrical portion 24 and an inner cylindrical portion 25. The outer peripheral surface 24a of the right half of the outer cylindrical portion 24 is braked. The conical surface is parallel to the inner peripheral surface 13 of the drum 14. A large number of ferromagnetic plates (pole pieces) 26 arranged at regular intervals in the circumferential direction are coupled to the outer cylindrical portion 24 having a conical surface. Preferably, a ferromagnetic cylinder 29 is coupled to the left half of the outer cylinder 24. The ferromagnetic cylinder 29 and the ferromagnetic plate 26 are cast when the outer cylinder part 24 is cast.

A magnet support cylinder 27 is supported in the inner space of the movable frame 21 so as to be movable in the axial direction. The outer peripheral surface of the magnet support cylinder 27 is a conical surface parallel to the inner peripheral surface 13 of the braking drum 14,
Also, a number of permanent magnets 28 facing each ferromagnetic plate 26 are coupled. The polarities of the permanent magnets 28 with respect to the ferromagnetic plate 26 are arranged so as to be alternately different in the circumferential direction.

The fixed frame 17 supporting the movable frame 21 is constituted by connecting an outer cylindrical portion 19 and an inner cylindrical portion 20 to an end wall 18 formed of an annular plate. The spline 1 is attached to the outer cylinder 19 of the fixed frame 17.
The outer cylinder part 24 of the movable frame 21 is fitted to the inner cylinder part 20 by the spline 20a by the 9a. The flange 16 integral with the end wall 18 of the fixed frame 17 is fixed to the wall 2 of the transmission.

An actuator 31 as means for driving the magnet support cylinder 27 is connected to the end wall 18. The actuator 31 inserts a piston 33 into a cylinder 32 and
4, 35 are divided. A rod 36 protruding from the piston 33 penetrates the end wall 18 and the end wall 22 and passes through the magnet support cylinder 2.
7.

The movable frame 21 is provided on the inner peripheral surface 13 of the braking drum 14.
The parking brake operation mechanism 40 for moving the vehicle apart is configured as follows. The end wall 18 of the fixed frame 17 supports a lever 38 that can rotate together with the shaft 41, and the tip of the lever 38 is connected to the end wall 22 of the movable frame 21. The rod 37 is connected to a long lever 39 connected to the shaft 41. The rod 37 is remotely operated by a parking lever in the driver's seat.

Next, the operation of the speed reducer according to the present invention will be described. When the parking brake is applied, the rod 37 is pushed and the lever 39 is rotated by operating the parking lever.
The lever 38 rotates clockwise together with the shaft 41, and is pushed by the lever 38 to move the movable frame 21 rightward.
Is pressed against the inner peripheral surface 13 of the braking drum 14. Accordingly, the rotation of the braking drum 14 is prevented, and the movement of the parked vehicle is prevented.

When driving the vehicle, the movable frame 21 is returned to the position shown in the figure by operating the parking lever. Next, when pressurized air is supplied to the chamber 35 of the actuator 31, the magnet support cylinder 27 is moved together with the piston 33 by the inner cylinder 25 of the movable frame 21.
Move to the left along with the brake drum 14
Retire from inside. The permanent magnet 28 faces the ferromagnetic cylinder 29, and a short-circuit magnetic circuit is generated between the ferromagnetic cylinder 29 and the magnet support cylinder 27, and the permanent magnet 28 does not apply a magnetic field to the braking drum 14. Therefore, the rotating braking drum 14 does not receive the braking torque.

To perform deceleration braking during traveling, when the magnet support cylinder 27 is moved to the position shown in the drawing by the actuator 31, the permanent magnets 2 whose polarities are alternately arranged in the circumferential direction are alternately arranged.
8 overlaps the ferromagnetic plate 26 and applies a magnetic field to the braking drum 14. When the rotating brake drum 14 crosses the magnetic field, an eddy current flows through the brake drum 14 and the brake drum 14 receives a braking torque. At this time, a magnetic circuit is generated between the braking drum 14 and the magnet support cylinder 27, as shown by a chain line in FIG.

In the embodiment of FIGS. 3 and 4, instead of moving the magnet support tube 27 in the axial direction, the magnet support tube 27 is rotated to perform deceleration braking and release. Dimensions can be reduced. The magnet support cylinder 27 is the inner cylinder 2 of the movable frame 21.
The arm 54 is supported by the bearing 45 and protrudes from the magnet support cylinder 27 through the slit of the end wall 22. The arm 54 is connected to the rod of the actuator 51. The actuator 51 is formed by inserting a piston 53 into a circumferentially extending cylinder 52 connected to the end wall 22 of the movable frame 21.
The arm 54 is connected to a rod protruding from the arm. Other configurations are the same as those in the embodiment of FIG.

When the parking brake is applied, the lever 38 is rotated together with the lever 39 by operating the parking lever to move the movable frame 21 to the right.
3 and the rotation of the braking drum 14 is prevented.

During traveling, when the magnet support cylinder 27 is rotated by the actuator 51 by half of the arrangement interval p of the permanent magnets 28, the permanent magnets 28 arranged so that the polarities alternately differ in the circumferential direction become two adjacent magnets. A short-circuit magnetic circuit shown by a dashed line in FIG. 4 is generated between the ferromagnetic plate 26 and the magnet support cylinder 27 over the ferromagnetic plate 26, and the permanent magnet 28
No magnetic field. When performing deceleration braking during traveling, the magnet support cylinder 27 is rotated in the reverse direction by the actuator 51 to bring the state shown in FIG.

[0019]

As described above, according to the present invention, the inner peripheral surface of the braking drum of the reduction gear for performing the deceleration braking during traveling is made conical,
Since the outer cylindrical portion or the outer peripheral surface of the movable frame that guides the magnet support cylinder has a conical shape, when the movable frame during parking is moved in the axial direction,
The outer peripheral surface of the movable frame is pressed against the inner peripheral surface of the braking drum,
Generates braking force. Therefore, it is not necessary to separately dispose the reduction gear and the parking brake as in the conventional example, the configuration is simplified, and the production cost can be greatly reduced.

If an opening is provided in the fixed frame that guides the movable frame, the heat of the brake drum during deceleration braking can easily escape from the inner peripheral surface, and heat radiation is improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an upper half of an eddy current type reduction gear according to the present invention.

FIG. 2 is a front sectional view showing a braking state of the speed reducer.

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

FIG. 4 is a front sectional view showing a non-braking state of the speed reducer.

[Explanation of symbols]

3: rotating shaft 13: inner peripheral surface 14: braking drum 1
7: fixed frame 21: movable frame 24: outer cylinder portion 24a: outer peripheral surface 26: ferromagnetic plate 2
7: Magnet support cylinder 28: Permanent magnet 31: Actuator 40: Parking brake operation mechanism

Continuation of the front page (72) Inventor Hayao Isoyama 3-25-1, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Kawasaki Plant of Isuzu Motor Co., Ltd. (56) References JP-A-3-86061 (JP, A) 3-3179 (JP, U) Hikaru Hei 3-60873 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02K 49/10

Claims (1)

(57) [Claims] A hollow movable frame made of a non-magnetic material having a conical outer surface is supported on a fixed frame whose inner peripheral surface protrudes into the inside of a braking drum having a conical shape. A large number of ferromagnetic plates arranged at equal intervals are coupled, and a large number of permanent magnets are coupled to a magnet support cylinder supported in the inner space of the movable frame so that the polarity to the ferromagnetic plate is alternately different in the circumferential direction. A drive means for driving the support cylinder to a braking position where the permanent magnet overlaps the ferromagnetic plate and a non-braking position where the permanent magnet does not overlap; and a parking brake operating mechanism for moving the movable frame to and away from the inner peripheral surface of the braking drum. An eddy current type speed reducer, characterized in that: