JPS6112151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a drive shaft seal device, and particularly to a drive shaft seal device suitable for using a plurality of bellows cores.

[Background of the invention]

A drive shaft sealing device using a conventional shaft sealing bellows for stroke operation will be explained with reference to FIGS. 1 and 2. FIGS. 1 and 2 respectively show the upper and lower portions of a drive shaft sealing device using vertical welded bellows. The welded bellows core 1 is shown in its most extended state. The working cylinder 5 is inserted into the stationary cylinder 6, and both cylinders are arranged concentrically in a vertical shape. A plurality of bellows cores 1 are mounted in series between an operating cylinder 5 and a stationary cylinder 6 via a lower mounting bracket 3 and an upper mounting bracket 2. Bellows core 1 is
It allows relative movement between the working cylinder 5 and the stationary cylinder 6, and serves as a shaft seal between the internal atmosphere 7 and the external atmosphere 8. Slide guides 4, 4A, and 4B are designed so that each part of the bellows core 1 deforms as evenly as possible when the bellows core 1 expands and contracts, especially when it expands rapidly.
has been established. The upper end of the uppermost slide guide 4 is fixed to the stationary cylinder 6 via the upper mounting bracket 2, and the lowermost slide guide 4 is fixed to the lower mounting bracket 3.
It is fixed to the actuating cylinder 5 via. A plurality of slide guides 4A and 4B are installed between these two slide guides 4 and 4, to which intermediate spacers 10 for fixing the ends of the bellows core 1 are fixed on the upper and lower sides. And the slide guides 4A and 4B are
As shown in the lower part of Fig. 1, each stopper 9A,
The locking portions 9B are arranged so as to lock alternately from the inside and outside. The stoppers 9A attached to both ends of the slide guide 4A stop when the bellows core 1 is extended.
It is designed to come into contact with and be locked with the stopper 9 of the slide guide 4 or the stopper 9B of the slide guide 4B.

The slide guides 4, 4A and 4B extend and contract in conjunction with the expansion and contraction of the bellows core 1, and the stoppers 9, 9A, 9B and the intermediate spacer 10 have the function of mechanical stoppers at the upper and lower stroke limits. . In addition, this slide guide 4, 4A,
4B reinforces the bellows core 1, which has poor buckling strength against internal pressure, that is, the pressure of the internal atmosphere 7. In this way, slide guides 4, 4A, 4
Despite the installation of B, the bellows core 1 does not expand evenly during stroke operation, especially during rapid expansion. Therefore, only the part connected to the upper mounting bracket 2 receives the weight of the movable body. It is prone to excessive deformation and breakage at a stroke count much shorter than the design life.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact drive shaft sealing device that can buffer the operation of the bellows core at the end during operation.

[Summary of the invention]

A feature of the present invention is that a buffer spring is provided between the drive shaft and the bellows core, between the stopper of the upper mounting member and the intermediate protrusion of the slide guide adjacent thereto.

[Embodiments of the invention]

An embodiment of the drive shaft sealing device using the bellows of the present invention will be described below with reference to FIGS. 3 and 4.
3 and 4 show the bellows free length at the time of maximum extension (when the operating cylinder 5, which is the drive shaft, is at the maximum upper position) in the state before starting on the compression side. The bellows core 1 allows relative movement between the working cylinder 5 and the stationary cylinder 6 and provides a shaft seal between the internal atmosphere 7 and the external atmosphere 8, as in the conventional example. The upper end of one bellows core 1 is fixed to the actuating cylinder 5 by an upper mounting bracket 2, and the lower end thereof is fixed to an intermediate spacer 10 of the slide guide 4A. The lower end of the other bellows core 1 is fixed to the stationary cylinder 6 by the lower mounting bracket 3, and the upper end thereof is attached to the intermediate spacer 10 of the slide guide 4A.
Further, both ends of the bellows core 1 other than these are respectively attached to the intermediate spacers 10 of the adjacent slide guides 4A and 4B. One slide guide 4 has its upper end fixed to the actuation cylinder 5 via the upper fitting 2. The lower end of the other slide guide 4 is fixed to the stationary cylinder 6 via the lower mounting bracket 3. Slide guides 4, 4A and 4
B expands and contracts at the same time as the bellows core 1 expands and contracts. The stoppers 9, 9A, 9B and the intermediate spacer 10 also operate in the same manner as in the conventional example. In this embodiment, between the stopper 9 of the slide guide 4 attached to the upper mounting bracket 2 and the intermediate spacer 10 of the slide guide 4A adjacent thereto, and between the stopper 9A of the slide guide 4A and the adjacent slide guide A compression spring 11 is disposed between each of the intermediate spacers 10 of 4B. As shown in Fig. 4, no compression spring 11 is installed between the lower slide guides 4A, 4B, 4, and the compression spring 11 is installed a few blocks from the upper bellows core 1, so that it will not be affected by its own weight. Only the parts that undergo uniform compression and are susceptible to excessive deformation during transient periods are included.

As described above, the drive shaft sealing device using the bellows of this embodiment is achieved by installing a spring between the stopper of the slide guide in several blocks of the upper bellows core and the intermediate spacer of the adjacent slide guide. The bellows is braked by providing a damping effect during rapid operation due to the stroke operation, and operates to suppress uneven deformation of the bellows as much as possible. Furthermore, in this embodiment, since the compression spring 11 is used between the upper slide guides as described above, when the bellows core 1 rapidly contracts (when the actuating cylinder 5, which is the drive shaft, rapidly moves downward) ) The impact applied to the bellows core 1 due to the collision between the stopper of the slide guide adjacent to the spacer and the spacer can be suppressed.
That is, when the cylinder 5 rapidly moves downward, the upper slide guides 4, 4A, 4B shown in FIG. Stopper 9 in the diagram
and the intermediate spacer 10, and the stopper 9A and the intermediate spacer 10 are about to collide. However, in this embodiment, since the coil spring 11 is interposed between the collision intervals, this collision cannot occur as a collision between the rigid bodies of the stopper and spacer made of rigid metal. Therefore, the excessive collision caused by the direct collision between the rigid bodies is caused by the spacer 1.
Does not add to 0. Therefore, the end portion of the bellows 1 attached to the spacer 10 will not be damaged. Moreover, the upper slide guides 4, 4 are subjected to rapid acceleration with respect to the upward movement of the cylinder 5.
Since the stoppers 9, 9A and 9A, 9B between A and 4B are pressed together in advance by the coil spring 11, no collision impact occurs.

Furthermore, in this embodiment, the coil springs 11 are provided between several blocks of slide guides at the top where collision is a problem, so that the coil springs 11 are not provided throughout the entire structure from the top to the bottom. Even if the coil spring 11 vibrates during shock during operation and the bellows 1 resonates, the resonance is only partial, and the resonance is stronger than that of the entire bellows 1 compared to when the coil spring 11 is provided between the slide guides of all blocks.
There is little chance of this happening. Therefore, there is little damage to the bellows. Furthermore, in this embodiment, the compression spring 11 is
Since it is arranged in the space inside the bellows core 1 created by the formation of B, the diameter does not increase and the structure is compact.

The above embodiment describes the case where a damper spring is installed that acts on the compression side of the free length of the bellows core, but the same applies if the spring is installed so that it acts on the tension side of the bellows core shown in the conventional example. Of course, it has the following effects.

〔Effect of the invention〕

As described above, the drive shaft sealing device using the bellows of the present invention buffers the operation of the bellows core on the end side and prevents uneven deformation of the bellows core when the bellows core operates rapidly due to the rapid stroke operation of the drive shaft. In addition to being able to buffer the impact force caused by the rapid compression of the bellows core, collisions between rigid slide guides do not occur. Moreover, even if a buffering means using a spring is adopted, resonance of the entire bellows is unlikely to occur due to the presence of the spring, and the integrity of the bellows can be ensured. Further, since the buffer spring is disposed in the space within the bellows core created by providing the stopper, the drive shaft sealing device can be kept compact.

[Brief explanation of the drawing]

1 and 2 show a drive shaft sealing device using a conventional bellows, FIG. 1 is a top sectional view, FIG. 2 is a bottom sectional view, and FIGS. 3 and 4 are a drive shaft sealing device using a bellows according to the present invention. One embodiment of the sealing device is shown, with FIG. 3 being a top sectional view and FIG. 4 being a bottom sectional view. 1... Bellows core, 2... Upper mounting bracket, 3
... Lower mounting bracket, 4, 4A, 4B ... Slide guide, 5 ... Operating cylinder, 6 ... Stationary cylinder, 7 ...
...Internal atmosphere, 8...External atmosphere, 9, 9A, 9
B...stopper, 11...coil spring.

Claims (1)

[Claims] 1 a lower mounting member attached to a stationary cylinder and located inside the stationary cylinder; an upper mounting member attached to a drive shaft that moves up and down in the axial direction within the stationary cylinder and located outside the drive shaft; A plurality of bellows cores are disposed in the axial direction between the shaft and the stationary cylinder and surround the drive shaft, and a first upper stopper and a first lower stopper are provided to connect the drive shaft and the bellows core. a plurality of first slide guides arranged in the axial direction between them and to which one end of the bellows core is attached; and a plurality of first slide guides having a length that vertically overlaps the first lower stopper at the maximum upward movement position of the drive shaft. a second upper stopper for limiting extension of the bellows core; and a second lower stopper for limiting extension of the bellows core, the second lower stopper having a length extending vertically over the first upper stopper at the maximum upward movement position of the drive shaft. a plurality of second slide guides arranged axially between the drive shaft and the bellows core and to which one end of the bellows core is attached; the upper mounting member having a stopper member that limits the extension of the bellows core in contact with the upper stopper of the slide guide located therein; and at least the lowest portion of the first and second slide guides inside the bellows core; A drive shaft sealing device comprising a coil spring provided between an intermediate protrusion provided on an upper slide guide and the stopper member.