JPS592076Y2 - Hydraulic balance type worm gear jack - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulically balanced worm gear jack that combines the advantages of a hydraulic jack and a worm gear jack by integrating them into one body.

Conventionally, hydraulic jacks and worm gear jacks have been used for jack-up and jack-down devices, respectively, but hydraulic jacks can be considerably more compact for the same capacity than worm gear jacks.

(2) Compared to a worm gear jack, the efficiency is several orders of magnitude better (usually 70 to 80%), so the drive source can be made smaller.

■ Compared to worm gear jacks, the operating speed can be easily increased and it can be used more frequently.

It has the advantages of ■ It is difficult to synchronize.

■ Due to the hydraulic lock, there is a danger in the unlikely event of an accident.

It has the following disadvantages.

On the other hand, worm gear jacks: ■ Can be easily synchronized and its accuracy is accurate.

■ Easy self-locking and high reliability during work.

However, on the other hand, the efficiency is low (usually 15 = 20%) because it takes advantage of the self-locking feature, and the driving source is therefore large.

■ The amount of heat generated becomes extremely large, and the frequency of use, operating speed,
Stroke etc. are also limited.

■ Sufficient care must be taken during the initial jerking operation of the sliding parts.

Some movement and slippage was observed.

The present invention is a jack that combines these jacks to take advantage of their respective strengths and compensate for their shortcomings.

To explain the drawings in detail, FIG. 1 shows a longitudinal section of an embodiment of the present invention, and a main body 1 has a worm 2 built therein.

A worm wheel 3 that meshes with the worm 2 is supported via a bearing 4, and is further enclosed and supported by a bearing cover 6 via a bearing 5.

A screw rod 7 that is screwed through the center of the worm wheel 3 at right angles is regulated from rotating by a key 8 that penetrates the main body 1 and the bearing cover 6 and is embedded in the bearing cover 6, and a piston 9 is fitted to the lower end. Then, the piston nut 10 is screwed and tightened.

Thus, the piston 9 slides in an oil-tight manner within the cylinder 11 fixedly suspended from the main body 1 via the packing 12.

As a jack up or jack down device,
As shown in FIGS. 2 and 3, several worm gear jacks according to the present invention are used in parallel communication through a conduit 14.

Note that 15 is a pump and 16 is a switching valve.

When in use, the switching valve 16 is switched to apply hydraulic pressure to the cylinder 11.
By feeding the worm wheel 3 into the main body 1 and balancing the load and hydraulic pressure, the worm wheel 3 is rotated in a state close to no load, and the worm 2 is rotated via an electric motor (not shown) connected from the outside of the main body 1 to perform jacking up and jacking down. Performs synchronized operation.

If the load fluctuates, use the proportional pilot relief valve shown in Figure 3.

In other words, there is a load measuring device 17 between the 7 screw rods and the load.
This measured value is received by the proportional electromagnetic pilot relief valve 18, and this pilot pressure is sent to the relief valve 19.
The balance between the load and the hydraulic jack output is achieved by applying the

With the above configuration and operation, the present invention can: (1) significantly reduce the size of the driving source;

For example, load 180 TON, speed 1300 mm/m
When driving four 1N (7) jacks, a conventional worm gear jack requires an input of about 765 to 1020 KW, assuming its efficiency is 15 to 20%, but according to the implementation of the present invention, For hydraulic drive source, 235 KW at 65% efficiency, for worm gear jack drive source, approximately.
Since it is said to be 60 to 70 KW, a total of 300 KW would be sufficient, which is about 200 KW.

■ Safety devices work double.

That is, in addition to the hydraulic lock, the worm wheel also acts as a safety nut to ensure self-locking.

■ While the worm wheel provides highly accurate synchronization, there is no load on the worm wheel itself during operation, so the amount of heat generated at the threaded surface with the screw rod is small.
You can increase the frequency of use.

■ In the conventional large worm gear jack,
The worm, worm wheel, and bearing account for a large amount of weight, but according to this method, no load is applied to the worm wheel as described above, so the worm, worm wheel, and bearing can be made extremely small. Costs can also be reduced by using a hydraulic system.

■ Space can be drastically reduced.

This is a hydraulically balanced worm gear jack that has the following features.

[Brief explanation of drawings]

FIG. 1 shows a longitudinal section of an embodiment of the present invention, FIG. 2 shows a hydraulic circuit diagram for jacking up and jacking down operations, and FIG. 3 shows a hydraulic circuit diagram when the load varies. 20 indicates a relief valve.

Claims (1)

[Scope of utility model registration request] A hydraulically balanced worm gear jack, characterized in that a piston is provided at the end of the screw rod of the worm gear jack, and a cylinder containing the piston and sliding in an oil-tight manner is integrally connected to the worm gear jack body.