JP2508734Y2 - Centrifuge drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Use of the Invention] The present invention relates to a drive device for rotating a rotating body at high speed, such as a centrifuge.

[Background of the invention]

In the conventional centrifuge drive device, as shown in FIG. 4, the vibration caused by the unbalance in the sample 20 is absorbed.
A plurality of thin plates are rolled on the outer circumference of the bearing 4 with a sleeve 6 interposed therebetween, and a laminated oil damper 5 containing oil is provided between the thin plates. In addition, the annular groove 15 on the outer circumference of the oil damper 5
A structure is provided in which oil is flowed to prevent the oil damper 5 from running out of oil.

However, as shown in the detailed view of the vicinity of the bearing 4 shown in FIG. 5, a gap 14 is required between the sleeve 6 and the end of the oil damper 5 and the shaft case 3 in order for the oil damper to move and absorb the vibration. Is. When the vacuum 14 is evacuated, a negative pressure is applied to the annular groove 15, so that oil may be sucked into the clearance 14 and flow into the bearing 4, resulting in excessive oil supply. Further, if an O-ring 25 is provided between the sleeve 6 and the shaft case 3 as shown in FIG. 6, the inflow of oil can be prevented, but due to the frictional force between the O-ring 25 and the sleeve 6,
The horizontal movement of the oil damper 5 may be restricted, and the vibration absorbing effect may be reduced.

[Purpose of device]

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and improve the life and reliability of this type of drive device.

[Outline of device]

The present invention focuses on the fact that the oil leakage from the oil damper is due to the pressure difference during evacuation, and only a maximum of 1 atm is applied, and the oil is sealed by not restricting the movement of the sleeve and the oil damper. The sleeve, shaft case and packing have been devised so that

[Example of device]

An embodiment according to the present invention is shown in FIG. 1, and an enlarged view of part A of FIG. 1 is shown in FIG. Further, FIG. 4 shows a sectional view of the entire drive unit including the rotation chamber.

The rotor 19 in which the sample 20 to be separated is inserted is rotated at high speed by the drive shaft 12 via the rotary shaft 1 in the rotary chamber 18 decompressed by the vacuum pump 22. The air in the space 26 in the drive device 27 passes through the bearing 4, the bearing space 28, and the rotary chamber 18 and is exhausted by the vacuum pump 22. On the outer periphery of the bearing 4, in order to absorb vibration caused by unbalance in the sample 20, a laminated oil damper 5 formed by rolling a plurality of thin plates is provided via a cylindrical sleeve 6 and moves horizontally. This has the effect of damping the vibration. An oil pump is installed around the oil damper 5.
Since the oil is circulated at 24, the oil is always kept between the thin plates of the oil damper 5. The shaft case 3 is provided with a sponge-like foam packing 10.
10 is pressed against the upper end surface of the sleeve 6.

Now, when the vacuum pump 22 is operated to reduce the pressure in the rotary chamber, the bearing chamber 28 also becomes negative pressure, and the air in the void 14 leaks from the gap of the packing 10. However, the oil damper 5
Even if the oil sucked out from the annular groove 15 on the outer periphery of the seal tries to pass through the gap of the packing 10, it will be
It does not leak with a pressure difference of about atmospheric pressure. Further, since the packing 10 is a sponge-like foaming material, the resistance against movement in the shearing direction is small, and does not restrain the movement of the sleeve 6 and the oil damper 5 in the horizontal direction.

The same effect can be obtained by using the lip seal 16 shown in FIG. 3 instead of the sponge-like foam packing 10.

The lip seal 16 presses the tip of the lip lightly against the sleeve 6 to prevent oil from leaking, and since the lip is thin, it does not restrain the movement in the horizontal direction.

[Effect of device]

According to the present invention, since the oil can be sealed without restraining the movement of the oil damper, it is possible to prevent excessive lubrication of the bearing and deterioration of the vibration absorbing performance.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a driving device according to the present invention, FIG. 2 is an enlarged view of part A of FIG. 1, and FIG. 3 is part A of FIG. 1 shown by a modification of FIG. FIG. 4 is an enlarged view, FIG. 4 is a cross-sectional view of the entire drive device including a rotation chamber, and FIGS. In the figure, 1 is a rotary shaft, 3 is a shaft case, 4 is a bearing, 5 is an oil damper, 6 is a sleeve, 10 is packing,
12 is a drive shaft, 14 is empty, 15 is an annular groove, 16 is a lip seal, 18 is a rotation chamber, 19 is a rotor, 20 is a sample, 22 is a vacuum pump, 24 is an oil pump, 25 is an O-ring, 26 is A space, 27 is a drive unit, and 28 is a bearing chamber.

Claims (1)

(57) [Scope of utility model registration request] 1. A centrifuge comprising a rotation chamber for rotating a rotor containing a sample, a drive device for driving the rotor, and a vacuum pump for decompressing the rotation chamber and the inside of the drive device. In the drive device, the drive device supports a drive shaft, a cylindrical sleeve provided on the outer periphery of the bearing, and an oil damper further provided on the outer periphery thereof.
A centrifuge characterized by comprising a sleeve and a shaft case holding the oil damper, and a packing that does not restrain the movement of the bearing, the sleeve, and the oil damper is provided in a gap between the sleeve end surface and the shaft case. Machine drive.