US2773680A - Agitators - Google Patents

Description

i. V. ZOZULlN Dec, 133., 195% AGITATORS 2 Sheets-Sheet 1 Filed March 28, 1955 INVENTORY IGOR V. ZOZULM! Z, a w 1%,

ATTORNEY I i. V. ZOZULIN Dec. 11, 1956 AGITATORS Filed March 28, 1955 2 Sheets-Sheet 2 I IV VENTQR 160%? v. ZOZULIA! United States Patent AGITATORS Igor V. Zozulin, Vancouver, British Columbia, Canada, assignor to Tormag Transmissions Limited, Vancouver, British Columbia, Canada Application March 28, 1955, Serial No. 497,080

3 Claims. (Cl. 259-108) My invention relates to improvements in agitators which are particularly adapted for use in dairy tanks and other situations where fluid food products are processed.

The objects of the invention are to provide a structure whereby the agitator assembly may be removed for cleansing purposes without the need for tools and whereby no contact can take place between the fluid in the tank and any part of the driving mechanism for said agitator assembly, irrespective of the head pressure of the fluid in the tank, and also to provide means whereby no fluid may enter the driving mechanism even though fluid may be admitted to the tank before the agitator assembly has been replaced upon the driving mechanism.

The invention contemplates the use of a permanent magnetic coupling and a suitable reduction gear between the drive motor and the agitator, and the provision of means for fully lubricating the drive mechanism in an oil bath, and means for dispersing lubricating oil from the surface of the magnetic coupling immediately followign the starting of the motor. Further objects are to provide a thrust against the diaphragm of the magnetic coupling which automatically compensates as pressure develops in the reduction gear housing, to maintain the air gap on both sides of the diaphragm at a constant irrespective of the presence or absence of end play in the drive motor shaft. A still further object is to provide a sealed housing for the driving mechanism of so few parts that only two stationary gaskets are required in the entire structure to render said housing oil and air pressure tight. Another object is to provide a simple means for varying the air gap between the rotors to vary the driven rotor speed by means outside of the sealed portion of the housing. It is also an object to provide an assembly whereby, if necessary, the drive motor may be removed and replaced while the tank to which it is connected is charged with fluid.

Referring to the accompanying drawings:

Figure 1 is' a vertical sectional view of the invention taken on the line 1-1 of Figure 2.

Figure 2 is a sectional view, part in elevation, taken on the line 22 of Figure 1.

Figure 3 is a sectional view of a modification showing a means for increasing the air gap in the coupling to vary the drive of the coupling.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1 indicates the bottom wall of a tank in which fluid is to be agitated and 2 is a sleeve which is welded into said wall to support the agitator device. A short distance above the inner surface of the tank wall the sleeve 2 is provided with a cover 3 having an inner or final drive shaft sleeve 4 extending upwardly therethrough. A bearing cup 7 is provided at the upper end of the shaft sleeve 4 and a conical flange 8 is fitted below the bearing cup to form a stationary base for an inner rotating air bell 9.

The bell 9 is fitted with a cap 11 having a hub 12 2,773,680 Patented Dec. 11, 1956 which is fitted in the inner race of a bearing 14. The bearing is carried in the cup 7 and the hell 9 is capable of being removed from the shaft sleeve 4 by unscrewing it, then raising it vertically. An outer air bell 15 having a cover plate 16 is supported upon the bell 9 and said cover plate is provided about its periphery with internally projecting lugs 17 which are adapted to enter bayonet slots 18 formed in the periphery of the cap 11. The outer air bell is given a slight turn so that the lugs 17 are retained in their corresponding slots 18 and come to rest against a stop pin 19 provided in the cap 11, thus providing a driving connection between the inner and outer air bells. The air bell 15 extends downwardly into close proximity with the wall 1 of the tank as shown in Figure 1 and is fitted with two or more suitably pitched impellers 21. Obviously when the device is at rest the outer air bell and its impellers may be freely removed for washing purposes by simply disconnecting the lugs 17 from the bayonet slots 18 and lifting said air bell.

A final drive shaft 24 is housed in the shaft sleeve 4 which is socketed at its base as at 25. The upper end of the final drive shaft 24 is non-rotatably connected by a threaded member 26 to the hub 12 by any appropriate means. The lower end of the sleeve 2 and the final drive shaft sleeve 4 is provided with a flange which forms a cover 29 for a transmission housing 39. The connection between the flange 29 and the housing 30 is rendered leak tight by a single O-ring gasket 31. The transmission housing is fitted with a step bearing 32 in its base and supports a member 33 in which an upper bearing 34 is mounted. These two bearings journal a vertical shaft 35 upon which a worm gear 36 is secured. The upper end of the shaft 35 is provided with a concentric stub 38 which extends into the socket 25 at the base of the final drive shaft 24 where it is secured by a pin 39. Meshing with the worm gear 35 is a worm 40 mounted upon a horizontal shaft 42 which is journalled in ball bearings 43 and 44. The space surrounding the bearings 43 and 44 forms an oil chamber 45. The housing 30 ends at its right end in a bell 46 in which an oil return ring member 48 is provided. The upper part of this member is cut away as in Figure 2 to form an oil collector 48A and is apertured as at 49 to communicate with an annular horizontal recess 50 which is in communication with the interspace between the races of the ball bearing 44. The normal oil level in oil chamber 45 would be at the height of the shaft 42 and oil may flow in rest periods through the bearing 44 into the bell 46. As the agitator is started oil in the bell 46 will be thrown tangentially of the rotor 52 and in the direction of the chamber 45 by the screw thread 57 and will be carried into the oil collector 48A from whence it will flow through the aperture 49 into the recess where it will be urged again towards and through the bearing 44 into the chamber 45.

Fitted upon the inner end of the horizontal shaft 42 is a magnetic rotor 52 having a hub 53 which is provided with an external oil lead screw thread 54 for the purpose of urging oil collected behind the upper part of the member 48 through the bearing 44 back into the oil chamber 45. The magnetic rotor is fitted with one or more annular rows of permanent magnets 56 and the periphery of the said rotor is provided with a screw thread 57 which serves to urge oil in contact with the rotor longitudinally of the bell 46 towards the oil return ring member 48. The face of the bell 46 is surrounded by an O-ring gasket 58, which gasket and the bell are entirely covered by a diaphragm 59 held in place by screws 60 passing through a flange 61 of a housing ring 62. Mounted upon the flange 63 of the housing ring 62 is a motor 64 having a drive shaft 65 which is fitted with a rotor 66 having a bimetallic ring 68 opposed to the row of magnets 56. The bimetallic ring 68 is of conventional form consisting of a disk of copper or material of high electrical conductivity backed by a plate of strongly magnetic. permeability such as mildsteel.

. thrust ring 72 having contactwith the face of the .dia-

phragrn in close proximity to-the bimetallicringfit to .resist the air pressure within ,the transmission housing 130. If it isintended to provide for, an extensive range of speed of the magneticrotorSZand its connected parts, including the-impellers .21, a wide'flanged ring 75, see Figure 3, is substituted for the ring 62. The motor drive shaft76 is non-rotativelyfitted with along sleeve 77 carrying a spider coupling '78 having longitudinally projecting studs79 which. engage-the flangegtl of a rotor 81. The rotor 81 is fitted with a bimetallic ring 83 and is mountedon a fixed bushing84 which has sliding movement upon the sleeve 77 and is held against rotation with the motor shaft by the studs 79. The free end of the sleeve 77 carriesthe inner race of a ball hearing 8S'and its outer race carries a thrust ring 86 which bears upon the diaphragm 87. The bell ring 46, the O-ring gasket 58 and the diaphragm 59 form the second joint in the transmission housing. 30. Since there are no glanded shafts or other openings of any kind within the exposed diaphragm area it will be obvious that any changes or removal of parts of the drivingmechanism located ouside the diaphragm may be made without affecting any pressure or other condition within the trans- 5 mission housing, irrespective of the tank containing fluid or otherwise. The motor end of the bushing 84 is fitted with a ball bearing 88 carrying a thrust collarflfl which is normally urged against the pressure thrust of air within the transmission by a spring 91. This collar is adapted to be forced endwise as required by a conically pointed adjusting screw 92 having a hand wheel E 3 by which it is rotated manually from a convenient position outside of the flanged ring.

In operation, the torque of. the motor is transmitted through the magnetic and bimetallic rotors to the;impeller 21 in the usual way. .The static head of fluid in .the tank will cause fluid to enter. the outer air bell 15 which of course will be of such volumetric capacity as to keep the level of the liquid below the air bell 9. The air pressure thus developed inthe bell 15 will be trans- ,mitted through the inner sleeve 4,;the transmission housing 30 and the rotor bell 46 ontothe diaphragm 59 tending to force said diaphragm towards the bimetallic ring 68, but this force will be counteracted by the thrust ring 72,,thus maintainingthe air gaps between the'rotors .52 and 66. Since norleakage of air, can. pass thediaphragm 59 and since the housing of the, driving parts is sealed, no fluid canpass into the inner sleeve 4 and as no pressure canexist in the housing 30, .other than that engendered by the head of fluid in the tank 1 and no .oil can be drawn up into said inner, sleeve when said pressure is relieved. During rest periods some oil may seep through the bearing 44 into the rotor bell 46, but this will be removed and returned to the oil chamber 45 immediately following the starting of the drive motor, thereby preventing any sustained hydraulic friction due to oil contacting the outer surfaces of the magnetic rotor 42. When it is desired to reduce the speed of rotation of the magnetic rotor 52 the screw 92 is rotated to engage the thrust collar 9ltand compress the spring 91, thus moving the bimetallic rotor 81 away from the face of the magnetic rotor 52 and increasing the total air gap therebetween. The above movement reduces the torque developed and obviously increases the slip between the rotors.

What I claim as my invention is:

1. In a fluid agitating device including a vertical shaft operatively connected to an impeller and adapted for upward extension through the base of a tank, said shaft being operatively connected through a horizontal shaft to a magnetic ,couplinghaving a pair of opposed rotors separated by adiaPhragmv from a driven shaft fitted to one of said rotors, said horizontal shaft and part of the driven shaft being in a housing. sealed at one end by the diaphragm and sealed adjacent thevertical shaft by an air locksubject to pressure developed by static fluid in the tank andan annular, thrust ring carried by .the driven shaft and applied to aface oft-hediaphragm for supporting the diaphragm against the pressure developed within the housing, a springsurrounding the driven shaft, said spring bearing against a housing part and urging the annular thrust ring against the diaphragm and exerting a thrust on one of said rotorstowards said. diaphragm.

2. In a fluid agitating device as claimed in claim 1, wherein the thrust ring is freely mounted in a bearing surrounding the driven shaft and the spring pressure is exerted on the bearing throughasleeve surrounding the driven shaft.

3. In a fiuid agitating device including a vertical shaft operatively connected to animpeller and adapted for upward extension through the base of a tank,said shaft being operatively connected through a horizontal shaft to a magnetic coupling having a pair of opposed rotors separated by a diaphragm from adriven shaft fitted to one of said rot0rs, said horizontal shaft being in a housing sealed at one ,endbythe diaphragm and sealed adjacent the vertical shaft by an air lock subject to pressure developed by a static fluid in the tank and anannular thrust ring carried by the driven shaft, and applied to a face of the diaphragm by a spring buttressed from a housing wall for supporting the diaphragm against the pressure developed within the housing by static fluid within the tank, and manually operable means for corn pressing the spring and for moving one of the rotors axially with respect to the other to vary the speed of the driven of the two rotors.

ReferencesgCited in the file of this,v patent UNITED STATES PATENTS 2,373,609 Stahl Apr. 10,- 1945 2,633,339 Okulitch et al. Mar. 31, 1953 FOREIGN, PATENTS 699,580 Great Britain .-NOV. 11, 1953

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