JPS5943650B2 - Brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake device, and particularly to a brake device suitable as a safety brake for hoists and the like.

This type of braking device detects the falling speed of the load as centrifugal force, rotates the brake shoe using a centrifugal unit, and moves the brake shoe in the axial direction, moving the brake wheel attached to the shaft to be braked between the brake shoe and the brake disc. Recently, a brake device has been proposed that brakes the rotation of a shaft to be braked by clamping the shaft to the shaft.

However, in such a brake device, when the brake shoe comes into contact with the brake wheel, the frictional force of the sliding surface causes it to rotate further and press against the brake wheel, resulting in excessive braking force and a large impact force on the braked shaft. This has caused damage to the product.

An object of the present invention is to provide a brake device that can prevent braking force from becoming excessive, generate appropriate braking force, and adjust braking force according to each model, each capacity, etc. It is in.

In order to achieve this object, the present invention prevents a first braking member such as a brake shoe from advancing beyond a predetermined position in the axial direction by a stopper provided on a brake stationary part such as a gear case, and The braking force is excessive when the second braking member is clamped between the first braking member and a stationary member such as a brake disc without the brake member pressing against the second braking member such as a brake wheel. Furthermore, a support member such as a brake case that supports the first brake member is attached to the brake stationary part so as to be adjustable in the rotational force direction, and the amount of axial movement of the first brake member is adjusted. It is characterized by being made possible.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a longitudinal sectional side view of a hoist to which a brake device according to the present invention is applied.

In this figure, 1 is a main body frame, and a driving electric motor 2 is attached to one end surface of the main body frame.

A main brake 3 is attached to the outer end surface of the electric drive machine 2, and the motor shaft 2A extended toward this end surface is braked to a stop by this main brake 3 when the electric motor 2 is deenergized. There is.

- The motor shaft 2A passes through the center of the main body frame 1 and extends outside the other end surface of the main body frame 1.

A gear case 4 is attached to the other end surface of the main body frame 1, and a reduction gear 5 housed in the gear case 4 is connected to the motor shaft 2.
The rotation of the person is decelerated and increased, and the final stage gear 5A rotates the suspended load rope drum 6 within the main body frame 1.

The motor shaft 2A extends to the outer end of the gear case 4, and is braked by a safety brake 7 according to the present invention at the outer end of the gear case 4.

Fig. 2 is an enlarged detailed sectional view of the safety brake 7, Fig. 3 is a sectional view taken along line A-A in Fig. 2, Figs. 4 and 5 are front views of the centrifugal unit, and Fig. 4 is a non-operating one. The state and FIG. 5 respectively show the operating state.

A straight tooth spline 2B is formed on an extension of the motor shaft 2A, and a brake wheel 8 is attached thereto so as to be non-rotatable and movable in the axial direction with respect to the shaft.

A centrifugal piece support 9 is fixed to the end of the extension of the motor shaft 2A, and a notch 9A is formed on the outer periphery of the centrifugal piece support 9.
9B and 9C are formed at equal intervals, and centrifugal pieces 10A,
10B, IDC is located.

Each centrifugal piece 10A to 10C is a support pin 11A. 11B, 1
1C, and is pressed against the bottoms of the notches 9A to 9C by extending the ring springs 12A and 12B to the outside of the support pins 11A to 11C on both sides of the centrifugal piece support 9.

13 is a brake case, and the gear case 1 is held by a case retainer 16 fixed to the end face of the gear case 14 with a screw 15.
4 so that its rotational position can be adjusted.

Reference numeral 17 denotes an annular brake disc, which is supported non-rotatably and movably in the axial direction relative to the gear case 14, and is elastically retractable by a disc spring 18.

19 is a cylindrical brake shoe with a bottom, and the cylindrical portion 19
The outer peripheral surface of A is fitted with the brake case 13 through the threaded portion 19B, so that it is supported concentrically with the two motor shafts.

The open end flange 19C of the brake shoe 19 extends radially outward, and the brake wheel 8 is interposed between the flange 19C and the brake disc 17.

Further, a protrusion 19D that protrudes from external force is formed on the outer periphery of the open end flange 19C of the brake shoe 19, and
Corresponding to this protrusion 19D, a protrusion 14A that protrudes inward is formed on the inner periphery of the gear case 14, and when the brake shoe 19 rotates, these protrusions 19D and 14
A collide with each other to prevent the brake shoe 19 from rotating any further.

The inner peripheral surface of the cylindrical portion 19A of the brake shoe 19 is the centrifugal piece 1.
The centrifugal pieces 10A to 10C face the outer circumferential surfaces of the centrifugal pieces 10A to 10C, and when the centrifugal pieces 10A to 10C fly out due to overrotation of the motor shaft 2A in the hoist's load-unloading direction, they come into frictional contact with each other and press the brake shoe 19. They are designed to rotate in the same direction.

The characteristics of the threaded portion 19B are set so that the brake shoe 19 advances toward the brake wheel 8 due to this rotation.

Reference numeral 20 denotes an annular rubber seal having an angular cross-section, and is attached by fitting an inwardly protruding portion 20A at one end of its outer periphery into an annular groove 13A at the end of the brake case 13, and its inner periphery is attached to the cylindrical portion of the brake disc 19. 19A, and seals the gap between the threaded portion of the brake case 13 and the brake disc 19.

The inner diameter of this rubber seal 20 is the same as that of the brake shoe 19.
The inner periphery of the rubber seal 20 is expanded when it is installed, and the elastic force caused by this deformation is much smaller than the rotational force of the brake shoe 19 when the load accelerates and falls. Although it is small, it is adjusted so that it is larger than the rotational force of the brake shoe 19 due to vibration during normal operation.

In the above configuration, the hoist normally rotates the drum 6 using the drive motor 2 and the main brake 3 to hoist, lower, and stop the suspended load.

If the main brake 3 fails and loses braking force during such cargo handling work, especially during a braking stop, the suspended load will reversely drive the hoist due to its own weight and fall.

When the suspended load begins to fall in this way, the motor shaft 2A
When the rotation speed increases and reaches the planned critical rotation speed,
As shown in FIG.
2A and 12B against the external force, and comes into contact with the inner circumferential surface of the cylindrical portion 19A of the brake shoe 19.

As a result, the brake shoe 19 is attached to the centrifugal pieces 10A to 10.
C, it rotates, and moves in the axial direction, that is, in the direction of the brake wheel 8, by the action of the threaded portion 19B.

When the brake shoe 19 moves and clamps the brake wheel 8 with the brake disc 17, a frictional force is generated on the clamping surface and the motor shaft 2A is braked.

At the same time, the brake shoe 19 is dragged and rotated by the frictional force between the flange 19C and the brake wheel 8, so the rotation of the brake shoe 19 rapidly accelerates and presses the brake wheel 8. The disc spring 18 is deflected in accordance with the amount of axial movement of the brake shoe 19, and the reaction force of this deflection becomes a force that presses the brake wheel 8, so that the braked shaft 2A is strongly braked.

Here, if the brake wheel 8 is pressed too much, the braking force becomes larger than necessary, and as described above, a large torsional force is generated on the braked shaft 2A, which may result in damage to the braked shaft 2A-.

In contrast, in this embodiment, a protrusion 19D is formed on the outer circumference of the flange 19C of the brake shoe 19 (which protrudes against external force), and a protrusion 19D is formed on the inner circumference of the gear case 14 corresponding to the protrusion 19D. Since the protruding portion 14A is formed to protrude inwardly, when the brake shoe 19 rotates a predetermined amount, the protruding portions 19D and 14A collide with each other.
The brake shoe 19 does not rotate any further.

That is, the brake shoe 19 does not move further in the axial direction and the brake wheel 8 is not pressed, so that it is possible to prevent excessive braking force from being applied to the braked shaft 2A.

However, just like this, both protrusions 19D.

14A and collide them to form brake shoe 1.
If you just stop the rotation of 9, the stopping position is fixed, so you can only obtain a constant braking force determined by this stopping position.If the required braking force is different for each capacity like a hoist, the required braking force will be different for each capacity. However, there is an inconvenience in that a brake device must be designed accordingly.

Therefore, in this embodiment, the brake shoe 1 is
9 to the gear case 14 in which the stopper protrusion 14A is formed.
Install it so that its rotational position can be adjusted.

With this configuration, the brake case 13 can be assembled by freely adjusting its position in the rotational direction based on the stop position of the brake shoe 19 in the rotational force direction. Adjust the axial movement reference position and move the brake shoe 19.
It becomes possible to adjust the axial stop position of the

That is, since the amount of deflection of the disc spring 18 can be freely set, the necessary braking force corresponding to each capacity of the hoist can be obtained with the same brake device.

As described above, according to the present invention, it is possible to prevent excessive braking force from being applied to the braked shaft, thereby preventing the risk of damage to the shaft and improving safety. The device allows you to set each braking force according to each model, each capacity, etc.

Moreover, the dimensional tolerance of each part can be adjusted by adjusting the mounting position of the supporting member such as the brake case, so there is no need to improve the processing accuracy of each part, and the manufacturing thereof is facilitated.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view of a hoist to which a brake device according to the present invention is applied, FIG. 2 is a vertical side view of a safety brake according to an embodiment of the present invention, and FIG. 4 is a front view showing a non-operating state of the centrifugal unit in the safety brake shown in FIG. 2, and FIG. 5 is a front view showing the centrifugal unit in an operating state. 2A...Electric motor shaft, 8...Brake wheel, 10A-10C...Centrifugal piece, 13...
... Brake case, 14 ... Gear case, 14A ... Stopper protrusion, 15 ...
...Screw, 16...Case holder, 17...
...Brake disc, 19...Brake shoe, 19B...Threaded portion, 19D...Protrusion for stopper.

Claims (1)

[Claims] 1. A braked shaft, a movable member that rotates together with the braked shaft, and when the rotational speed reaches a predetermined number of rotations or more, the movable member pops out in the outer circumferential direction due to the centrifugal force. a first braking member that engages with and rotates the movable member; a support member that supports the first braking member so as to move in the axial force direction when the first braking member rotates; a second braking member mounted so as to be able to rotate and move in the axial direction therewith, the first braking member being pressed against the second braking member by the axial movement thereof; In the brake device, the rotation of the braked shaft is braked by clamping a second brake member between the first brake member and a stationary member,
A stopper for stopping the axial movement of the first braking member at a predetermined position is provided on the brake stationary part, and the support member is attached to the brake stationary part so as to be adjustable in the rotational force direction, A brake device characterized in that the amount of axial movement of a braking member can be adjusted.