US2216926A

US2216926A - Bearing for crushers

Info

Publication number: US2216926A
Application number: US190934A
Authority: US
Inventors: Edgar B Symons; Oscar C Gruender
Original assignee: Nordberg Manufacturing Co
Current assignee: Nordberg Manufacturing Co
Priority date: 1938-02-17
Filing date: 1938-02-17
Publication date: 1940-10-08
Anticipated expiration: 1957-10-08

Description

Oct. 8, 1940.

E. B. sYMoNs ET AL BEARING FOR CRUSHERS Filed Feb. 1?, 1958 2 Sheets-Sheet l l zeyez'zard 2 429075 ,Sywams' Oscar C aruezeaer 1940- E. B. SYMONS El AL BEARING FOR CRUSI'IERS Filed Feb. 17, 1938 '2 Shoetgu-Sheet 2 a 2am r t IM grammatically in the Patented Oct. 8, 1940 UNITED STATES PATENT OFFICE BEARING FOR CBUSHERS Edgar B. Symons, Hollywood, Calif., and Oscar C.

Gruender, Milwaukee, Wis., assignors to Nordberg Manufacturing 00., Milwaukee, Wis., a

corporation of Wisconsin Application February 17,

8 Claims.

This invention. relates to an improvement in bearing means for gyratory crushers and has for one purpose to provide bearing means which shall have a minimum tendency to burn out orwear under intermittent load.

Another p p se is the provision of improved means for maintaining an efiective actuating contact between the eccentric and the shaft of a gyratory crusher.

Other purposes will appear from time to time in the course of the specification and claims.

The invention is illustrated more or less diaaccompanying drawings, wherein: l V

Figure 1 is a vertical axial section; Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is a diagrammatic horizontal section illustrating the relationship of the crushing cavity to the bearing means for the crusher shaft, parts being shown without load;

Figure 4 is a similar diagrammatic section diagrammatically illustrating the eifect of a crushing load; and i Figure 5 is a'vertical axial section through the shaft and eccentric illustrating the clearance dimensions on a somewhat enlarged scale.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, I generally indicates any suitable base upon which the crusher may be supported. 2 indicates a circumferentially extending main frame having an upwardly and outwardly extending flange 3 upon which seats a ring 4 having an inwardly screw-threaded portion 5. 6 indicates an outwardly screwthreaded bowl support in mesh with the threads on the member 5 whereby the parts may be vertically adjusted in relation to each other. I

hook-shaped lugs 5, U-bolts 3, locking nuts I0 and adjusting shims Ii. The .member 4 is normally held fixed in relation to the main frame 2 by the,

following structure: an upper ring l2, a lower ring I3 are penetrated by securing rods I4 headed as at above the top of the member 4 and provided with nuts or limiting abutments it below the lower ring l3. I! are coiled springs compressed between the rings 12 and I3. II are any suitable guiding members interposed between the members 3 and 4 having downwardly extending portions l9 penetrating the springs II. It will be understood that the normal effect 01' the springs I1 is to hold the ring 4 and thus the upper portion 6 and thebowl I fixed in relation to the main frame 2 while permitting the bowl or bowl liner I to recede when subjected to predetermined excess crushing stresses.

is an eccentric sleeve connected to the main 1938, Serial No. 190,934

frame 2 in any suitable manner as by the spider or connecting portions 2i. 22 is any suitable bearing member or bushing which may for example be, of bronze.

23 is an eccentric sleeve rotating within the bearing 22. 24 is a bushing or bearing of bronze or the like positioned within the eccentric 23 and providing a cavity or aperture 25 in which. is positioned the crusher shaft 26 herein shown as tapered. As will be clear from Figure 1 and from the diagrams, Figures 3 and 4, the inner diameter'of the sleeve 24 or the space 25 is excessively greater than the greater portion 30 is closed by an upper closure plate 3| upon which is supported an upwardly concave spherical bearing member 32 which receives the corresponding downwardly convex spherical bear' ing surface 34 of the crushing head generally indicated as 33. 35 is any suitable crushing mantle which may be held down for example by the top plate 35, the details of which form no part of the present invention. We may provide any suitable meansfor maintaining a constant and adequate supply of oil in the

spaces

25 and 22a and in their communicating passages. We illustrate, for example, an oil inlet passage which may be supplied by oil from any suitable storage and pumping means. 4| is any suitable. oil outlet pipe whereby the constant circulation of oil may be maintained through the machine; The details of the oil passages are not of themselves part of the present invention, but we indicate the main oil passage 42 in the shaiftv 26 which communicates with a passage 43 in the head and extends to the spherical bearing 32, 34. Oil may circulate thence over the gear 21 and pinion 28 and back to the outlet 4|. It will be understood, however, that by any suitable means we maintain a constant and preferably. full supply of oil in the

spaces

22a and 25 and the employsive clearance between the sleeve 24 shaft 26. We fill the space left by these excesan eccentric, owing to the eccentric aperture therein defined by the sleeve 24.

The use and operation of our invention are as follows:

In gyratory crushing, and particularly in crushing with the so-called gyra-tory cone crushers, the problem of maintaining a proper bearing relationship between the crusher shaft and the eccentric has at times been difficult. The bearing problem differs from that of an ordinary rotating shaft because in the first place the load is highly intermittent and irregular. As material to be crushed is dumped into the space between the opposed crushing members I and 35, it is in many instances not uniformly distributed; also the load fluctuates where irregular feed is employed and may differ from instant to instant and from point to point about the circumference of the crushing cavity. We find it advantageous to cope with and take advantage of this intermittent load by employing excess clearances, not only between the shaft 26 and the bearing sleeve 24, but between the eccentric 23 and the bearing sleeve 22. The excessive clearance between the eccentric 23 and the sleeve 22 necessitates excesand the sive clearances with a body of oil which has an effect radically other than that of the normal viscosity of the oil in a bearing having ordinary clearances.

Referring for example to Figure 3, where the bearings and crushing cavity are diagrammatically shown as roughly concentric, the machine may be considered as running empty, the shaft 26 will be centrifugally displaced in its bearing, and the eccentric 23 will be centrifugally displaced in its bearing, taking the positions shown. Owing to the fact that the cavities are filled with oil, there will be a slight clearance at the close side, which has been diagrammatically increased to indicate that the oil prevents any metal to metal contact. When no rock is being fed into the machine, there is nothing to prevent the parts from centrifugally taking the positions in which they are diagrammatically shown in Figure 3.

Referring to Figure 4, when the mantle 35 pinches a rock X against the bowl liner 1 and begins to apply pressure, then the shaft 26 moves within the eccentric and the eccentric 23 moves within the sleeve 22 to the positions inwhich they are shown in Figure 4. However, in taking this position, the eccentric will roll in its hearing as it is driven from the shaft 29 and will climb the film of oil so rapidly that it will not be displaced before the pressure has been released and the eccentric can again start going back. This intermittent rolling of the eccentric builds up a film of oil thicker than is possible in any bearing where viscosity alone is used. We are therefore depending upon displacement of oil rather than upon mere viscosity of oil, and the very action of the eccentric in rolling within its outer bearing tends to thicken the film of oil between it and the bearing 22 at the point of pressure at every move of the eccentric. The mass of oilinvolved is so great that the movement of the eccentric caused by compression against the stone X is ineffective to force the eccentric 23 into a metal to metal contact with the surrounding bearing sleeve 22, and heating and damage to the opposed bearing surfaces is positively prevented. We wish to emphasize that the effect of rolling the eccentric within its bearing against a large body of oil under compression is quite different from the effect obtained by the employment of normal clearances. In the usual hearing, as employed for example with rotating shafts, a very thin film of oil is more or less evenly distributed and the oil reaches the point of high pressure due to its viscosity. We do not rely on viscosity at all but on the hydraulic effect obtained by rolling the eccentric over a very much larger mass or volume of oil, which volume is made possible by the exaggerated clearances between the opposed bearing surfaces.

As to the inner bearing between the shaft 26 and the surrounding sleeve 24, the shaft does not roll as the eccentric does, but its displacement is so rapid and intermittent that, in connection with its increased clearance, the same general effect is obtained and the same avoidance of reliance on mere viscosity.

In considering actual dimensions, they differ from machine to machine, depending upon the size of the machine and the purpose for which it is employed. As a schematic indication, we have illustrated clearances in Figure 5 as follows: between the eccentric 23 and the surrounding bearing sleeve 22 we show an outside theoretical radial clearance of a; of an inch which is uniform from top to bottom of the bearing surfaces. This permits a substantial lateral movement or slippage of the eccentric 23 as it rolls about within its bearing. But this exaggerated movement of eccentric 23 demands compensation in similarly increased clearances between the shaft 26 and its surrounding bearing 24. We illustrate a radial clearance of 3 2' of an inch at the top of the eccentric, increasing to A; l

inch at the bottom. We may express these clearances with the following formula:

Assuming the distance A between the intersecting point of the axes of the eccentric sleeve bearing 22 and shaft 26 and the top of the bearing sleeve 24 equals the distance B which repre sents the length of the bearing sleeve 24, then the total lowermost clearance between the bell mouthed bearing sleeve 24 and the shaft 26 may be arrived at by adding the top clearances indicated in Figure 5, and multiplying it by 2, representing the distance A,'equaling 1; plus the distance B, in this case also equaling 1. The formula is thus A major advantage in our invention is the effect of a larger clearance between the eccentric 23 and the eccentric sleeve bearing 22. This very large clearance and the rapid movement of the eccentric in relation to the eccentric sleeve permits the eccentric and shaft to dance as the intermittent load is applied to the crushing cavity. This large clearance and rapid movement necessitates the employment of a large clearance between the shaft 28 and its surrounding sleeve 24, and in order to get a line contact betweenthe shaft and the surrounding bearing at all positions of the eccentric, the clearance must increase progressively from top to bottom of the shaft. Thus, what we may call a bell mouth effect is necessitated by the relationship between the eccentric 23 and the bearing sleeve in which it moves. The amount of taper or excess clearance necessary depends upon the clearance between and the relative movement of the eccentric 23 and its surrounding sleeve. Therefore, in such large machines as cone crushers having a head with a seven-foot bottom diameter, we have to provide a very substantial bell mouth effect of the inner shaft bearing-or space 25 which permits an effective crushing thrust without springing of the shaft or any tendency to break the shaft, and at the same time allows the shaft to dance from one position to another within its surrounding sleeve while maintaining at all times an effective line contact.

I claim: v

1. In bearing means for gyratory crushers, an eccentric sleeve, an eccentric rotatably mounted within said sleeve and means for rotating it, said eccentric having an eccentric aperture therein, a crushing shaft penetrating said aperture, a crushing head associated with said shaft, supporting means for said crushing head adapted to guide said head for gyratory movement about a center located adjacent the top of said head, the aperture of the eccentric being inclined in relation to theaxis of rotation of said eccentric, the clearance between the eccentric and eccentric sleeve substantially exceeding normal bearing clearances, the clearance between the crusher shaft and the opposed wall of the aperture of the eccentric substantially exceeding normal bearing clearances and increasing progressively downwardly along said shaft, and means for maintaining a substantially continuous volume of -oil throughout the space provided by said excess clearances, whereby a substantial thickness of oil is maintained between the opposed metal parts at all positions of eccentric and shaft.

2. In bearing means forgyratory crushers, an eccentric sleeve, an eccentric rotatably mounted within said sleeve and means for rotating it, said eccentric having an eccentric aperture therein, a crushing shaft penetrating said aperture, a crushing head associated with said shaft, supporting means forsaid crushing head adapted to guide said head for gyratory movement about a center located adjacent the top-of said head, the aperture of the eccentric being inclined in relation to the axis of rotation of said eccentric, the clearance between the eccentric and eccentric sleeve substantially exceeding normal bearing clearances and being substantially uniform from top to bottom of the eccentric, the clearance between the crusher shaft and the opposed wall of the aperture of the eccentric substantiallyexceeding normal bearing clearances and increasing progressively downwardly along said shaft, and means for maintaining a substantially continuous volume of oil throughout the space pro vided by said excess clearances, whereby a substantial thickness of ofl is maintained between the opposed metal parts at all positions of eccentric and shaft. l

3. In a gyratory crusher and bearing means therefor a crushing shaft, a crushing head,

means for constraining-said head to gyratory movement about a center located adJacent the top of the head, and means .for gyratlng said head, including an eccentric sleeve, an eccentricrotatably mountedv within said sleeve and means for rotating it, said eccentric having an eccentric aperture therein into which said crushing shaftpenetrates, said aperture being inclined from the vertical, the clearance between the eccentric and the eccentric sleeve substantially exceeding normal bearing clearances whereby said eccentric sleeve may move laterally in addition to its rotary movement, the clearancebetween the crush-,-

.er shaft and the opposedwall of the aperture of the eccentric substantially exceeding normal bearing clearances, said clearance increasing progressively downwardly along said shaft, whereby at all positions of the eccentric during its lateral movement an effective bearing connection is obtained between the opposed portions 5' of the shaft and eccentric, and means for maintaining a substantially continuous volume of oil throughout the space provided by said excess clearances, whereby a substantial thickness of oil is maintained between the opposed metal parts at all positions of the eccentric and shaft, said volume of oil being sufficient to damp. the movement of the eccentric within the eccentric sleeve, and of the shaft within the eccentric aperture.

4. In bearing means for gyratory crushers, an eccentric sleeve, an eccentric rotatably mounted within said sleeve and means forrotating it, said eccentric having an eccentric aperture therein, a crushing shaft penetrating said aperture, a crushing head associated with said shaft, supporting means for said crushing headadapted to guide said head for gyratory movement about a center located above the top of the eccentric, the aperture of the eccentric being inclined in relation to the. axis of rotation of said eccentric, the clearance between the crusher shaft and the opposed wall of the aperture of the eccentric increasing progressively downwardly along said shaft, and means for maintaining a substantially continuous layer of oil throughout the space provided by the clearance between the crusher shaft and the eccentric, of sufficient depth and volume to respond hydraulically to relative movement of the crusher shaft and eccentric.

5. In bearing means for gyratory crushers, an

eccentric sleeve, an eccentric rotatably mounted center located adjacent the top of said head, the

aperture of the eccentric being inclined in relation to the axis of rotation of said eccentric, the clearance between the eccentric and eccentric sleeve being substantially uniform from top to bottom of the eccentric, the clearance between the crusher shaft and theopposed wall of the aperture of the eccentric increasing progressively 50 downwardly along said shaft, and means for maintaining a substantially continuous volume of oil throughout the space provided by said, clearances, whereby a layer of oil of sufficient depth and volume to respond hydraulically to relative movement of the crusher shaft and eccentric or of eccentric and eccentric sleeve is maintained at all positions of the parts.

6. In a gyratory crusher, a crushing-head, a shaft extending downwardly therefrom, an ec- 00 centrically aperturedlmember surrounding said