US2485466A - Centrifugal separator - Google Patents

Description

Oct. 18, 1949. J. E. THoL-L I CENTRIFUGAL sEPARAToR Filed NOV. 20, 1945 Patented ct. 18, 19.491

ican Tool & Machine Co., Boston,

Mass., a corporation of Massachusetts Application November zo, 1945, serial No. 629,745

This invention relates to centrifugal separators, and. is more especially concerned with that type of centrifugal in which the basket is suspended.

Such machines are used very widely in the sugar industry, as well as in others, more especially in connection with the extracting, washing, and refining operations. Usually the load accumulated at the end of a centrifuging step is discharged through the bottom of the basket by forcing a scraper or plow radially into the collection of solid material on the wall of the basket, and then traversing the scraper in a direction parallel to said wall while the basket is revolved slowly. The flexible mounting or support for suspended centrifugals introduces difficulties in performing this unloading operation. That is, the fact that the basket is suspended from overhead means that it is not well supported against the laterally directed pressure of they-scraper or plow which dislodges the material. The result is that this unloading operation produces considerable strain on the entire supporting mechanism for the basket and also tends to create violent oscillating or vibratory movements of the latter.

The present invention is especially concerned with the foregoing considerations, and it aims to devise a thoroughly practical solution for the problem presented by them.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a vertical, sectional View, with some parts in elevation, illustrating portions of the basket of a centrifugal separator and a means provided by this invention for supporting the basket rmly in its centered position during the unloading operation;

Fig. 2 is a vertical, sectional view showing the parts provided by this invention on a larger scale; and

Fig. 3 is a section on the line' 3-3, Fig. 2.

Referring rst to Fig. 1, the construction there shown comprises a basket 2 suspended by a central vertical shaft 3 in any suitable manner such as that shown, for example, in Patent No. 2,018,-

474, dated October 22, 1935, and assigned to the f assignee of the present invention. The basket is enclosed in the usual casing or curb 4, and provision is made for the discharge of the solid 4 Claims. (Cl. 210-63) 2 materials through the bottom of the basket and the casing.

According to the present invention a hollow shaft or bushing 5 is secured centrally in the hub 6 which is fastened to the bottom of the shaft 3 by means o f bolts, such as those shown at I-'I, these boltspreferably also securing the part 5 in its centered position with reference to the axis of the shaft 3.` The lower end of thisl hollow shaft is internally tapered to receive a bearing cap 8 adapted to fit into said taper and fastened to the upper end of a plunger I0 which is supported for vertical sliding movement in a guide-- way formed in the outer free end I2 of a bracket f I2. This bracket is bolted to a stationary portion of the machine frame and is made of approximately V-shaped section, with its edge uppermost where it will better shed the solids discharged frorn the basket.

For the purpose of operating the plunger Il! to move the bearing cap up and down into cooperative relationship with the hollow shaft 5,4 a toggle mechanism is provided comprising upper and lower links I3 and I4, pivoted together at I5, and an additional link I6 which connects said pivot I5 with a pivot pin I1 supported in a head or fitting IB into which an operating rod 2li is screw-threaded. The upper of the two toggle links is pivoted at 2I to the plunger I0, while its companion lower link I4 is pivoted to the head 22 of a fitting having a screw-threaded shank 23 which projects downwardly through a bushing 24 threaded into the lower end of the head I2 of the bracket. This bushing is locked in position by a nut 25, and the stem 23 is secured rigidly to the bushing by a nut and a. check nut, both of which are shown at 2E. Inside the bushing is a compression spring 21, encircling the stem 23, and abutting at its lower end against the bottom of a counter-bore in the bushing 24 and at its upper end against a flange formed on the head 22.

It will thus be observed that if the operating rod 20 is forced inwardly, the toggle will be straightened against the pressure of the spring 21 and thus will force the cap 8 firmly, but yieldingly, into the tapered seat formed for it in the bottom of the shaft 5. In this position the bearing cap and its supporting structure hold the lower end of the basket shaft 3 firmly centered and support it securely against the laterally directed thrust of the unloading scraper or plow.

Preferably the cap 8 is mounted on ball bearings so that very little friction is oiiered by this centering structure to the rotative movements of pull on the rod 20 breaks the toggle, moving the links into the dotted line positions shown vin Fig. 2 and lowering the bearing cap 8 out of contact with its cooperating member 5. The mounting of the plunger and its toggle operating mechanism provide for ample adjustment of the position of the bearing cap 8 when in contact` with the shaft 5.

Thus the invention provides a rm centering bearing for the lower end of the basket shaft, operable during unloading to cooperate with the upper bearing to support the basket `firmly for rotation around its own axis. At the same time this center bearing can quickly be moved downward out of its operative position when it is no longer needed.

A bar or web 28 integral with, or rigidly secured to, the arm I2 serves both as a guide and a support for the operating rod 20 at a point kadjacent to the toggle mechanism.

While I have herein shown and describedv a preferred embodiment of my invention, it will be l evident that this disclosure has been made rather by Way of explanation than limitation, and that the invention may be embodied in `other forms without departing from the spirit 'or scope thereof.

Having thus described my invention, what I desire to claim as new is:

1. In a centrifugal separator of the suspended basket type, the combination with a shaft mounted in a xed central position in the bottom of the basket, of a basket shaft centering bearing engageable with said shaft for rotation therewith and adapted for disengagement therefrom, an upright plunger supporting said bearing below said basket, a bracket mounted rigidly below said basket and provided with a guideway in which said plunger is supported for vertical movement to carry said bearing into and out of engagement with said shaft, a toggle mechanism supported in said bracket and connected with said plunger i to move it up and down by the straightening and collapsing movements of the toggle, and an operating element connected with said toggle to actuate it.

2. A centrifugal separator according to preceding claim 1, including a construction in which a spring backs up one end of said toggle mechanism so that the straightening movement of the toggle takes place against the pressure of said spring. l

3. A centrifugal separator according to preceding claim 1, including a construction in which said bearing structure includes a cap mounted on the upper end of said plunger with an antifriction bearing interposed between the plunger and the bearing cap where it supports the cap for rotation with said basket.

4. In a centrifugal separator of the suspended basket type, the combination with a shaft mounted in a fixed central position in the bottom of the basket, of a basket shaft centering bearing engageable with said shaft for rotation therewith and adapted for disengagement therefrom, a bracket mounted rigidly below said basket, guide supporting means supported by said bracket and supporting said bearingr below the basket in fixed axial' alignment with said shaft for axial movement into engagement with lsaid shaft and for disengagement therefrom, including mechanism operable to move said supporting means vertically to carry said bearing into and out of engagement with said shaft; said 'mechanism including a toggle and means operable to straighten and coilapse said toggle, Awhereby when said toggle is straightened it will move said bearing into 'position to engage and center said shaft and will lower the bearing out of engagement with said shaft when the toggle is collapsed. y

JOI-1N E. THOLL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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