US3797759A

US3797759A - Crusher adjusting system

Info

Publication number: US3797759A
Application number: US00241312A
Authority: US
Inventors: F Scaffidi; D Davis; U Sawant
Original assignee: Rexnord Inc
Current assignee: Metso Minerals Milwaukee Inc
Priority date: 1972-04-05
Filing date: 1972-04-05
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19
Also published as: BR7302381D0

Abstract

This is a cone crusher and method of adjusting it under load by partially unclamping the bowl to an extent such that the bowl may be rotated but with some clamping pressure maintained so that the threads stay in full contact thereby avoiding any damage to the threads from the crushing blows.

Description

United States Patent 1191 Davis et al.

[ Mar. 19, 1974 CRUSHER ADJUSTING SYSTEM 3,133,708 5/1964 Bond et a1. 241/290 31142.449 7/1964 Balmer 1. 241/286 [751 Inventors Memmmee Falls; 3.396.915 8/1968 Allen 241/290 Ulhas sawallt, Sussex; Fmllcls 3,397,846 8 1968 Archer 241/286 a d West Allis, all of 3,539,118 11/1970 Kueneman 241 207 [73] Assigneei Renard Inc Milwaukee Wis 3,542,301 11/1970 Tnfonov et a]. 1. 241 207 22 Filed: Apr. 5, 1972 Primary Examiner-Granville Y. Custer, Jr. 21 A L N 241,312 Assistant Examiner-Howard N. Goldberg 1 pp D Attorney, Agent, or FirmHoward T. Markey [52] US. Cl 241/30, 241/37, 22 21110220876 [57] ABSTRACT [51] Int. Cl. 1302c 25/00, B026 2/00 This is a cone r sher and method of adjusting i1 [58] Field 61 Search 241/286, 290, 37, 207, under load y Partially unclamping the bowl to an 241 /3() tent such that the bowl may be rotated but with some clamping pressure maintained so that the threads stay [56] References Cit d in full contact thereby avoiding any damage to the UNITED STATES PATENTS threads from the crushing blows.

3.009.660 l 1/1961 Symons et a1 241/290 18 Claims, 2 Drawing Figures 1 {/5 6 i [/Z I \\1'\I l 1-! fizz l X/ Z? I a" o 1 I I I I 1 a [44 l I I [/4 1 1|] 4% I 1 Z CRUSIIIER ADJUSTING SYSTEM SUMMARY OF THE INVENTION This invention is concerned with adjusting a cone crusher under load without damaging the bowl threads.

Crushers for many years have had the bowl screwthreaded into the adjustment ring which is held by a spring or pneumatic release on the main frame. From time .to time the bowl needs adjusting, either to change the size of the crushing cavity or to compensate for wear on the bowl liner and mantle. Rotation of the bowl, either one way'or the other, will cause it to turn either up or down. When crushing quite hard and abrasive material the bowl may require adjustment quite frequently to compensate for wear, for example once every eight hours. Adjustment normally requires the crusher to be shut down while the bowl is being rotated to avoid damage to the threads between the bowl and adjustment ring. Shutting down the crusher results in lost production, requires the use of labor and is generally expensive and inefficient. I

A primary object of this invention is to adjust a crusher under load, meaning while material is going through it and being crushed, so that it doesnt have to be shut down.

Another object is a method of adjusting a crusher under load that avoids any damage to the bowl threads.

Another object is a system of the above type applicable to a so-called pressure-on clamping system.

Another object is a system of the above type which requires no modification in the structure of the crusher BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partly in section, of a conventional cone crusher; and i FIG. 2 is a shematic of a hydraulic circuit the FIG. I apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a portion of a conventional crusher is shown with a so-called pressure-on clamping system and includes a generally circumferential main frame 200 having an outstanding flange 202 at or near its upper end supporting an adjustment ring 204 which has screw threads 206 in mesh with corresponding threads on the bowl 208. The bowl overhangs and opposes a crushing head 210 which is mounted for gyration in the main frame.

usable with A adjustment ring 204 or support mounts a rotary cap 212 including an upwardly directed side wall 214 upon which a cover 216 may be welded or otherwise secured. The cover 216 may mount a plurality of piston and cylinder assemblies 218, only one of which has been shown in FIG. l, but it will be understood that a plurality may be disposed about the crusher or top cap. Inside the wall 214 is an upstanding bar 220 positioned between a pair of spaced ears 222 extending outwardly from the bowl. The cars and bar provide a lock between the top cap 212 and bowl so that they rotate together.

The so-called pressure-on bowl clamping arrangement disclosed provides an upthrust to the bowl such that the play or clearance'in the threads is always at the bottom of the bowl threads during crushing and so that the threads are always in flrm contact.

In FIG. 1, each of the assemblies 218, which preferably are generally equally spaced around the periphery of the. crusher, are connected together by individual hoses or any suitable fluid connection so that they are in series or in parallel. The particular type of fluid connection is not important. The system may be air, hydraulic, or otherwise, however, hydraulic is preferred. A suitable arrangement of what is referred to as a socalled pressure-on" clamping system is shown and described in US. Pat. No. 3,133,708 issued May 19, 1964 and FIG. I herein is intended to generally depict that system.

With the bowl unclamped or unlocked, one or more hydraulic rams 223 are constructed to rotate the bowl.

All of the above is intended to illustrate a conventional cone crusher and to lay background for the method, controls and cricuits described hereinafter.

As shown and described in Us. Pat. No. 3,133,708, it is known to release all of the clamping upthrust on the bowl so that it is free to rotate. But the crusher must be stopped first so that crushing blows will not be applied to a loose bowl. In the present arrangement, only a part but not all of the upthrust is released with a partial upthrust remaining so that thread clearance is not eliminated. This is to say that a certain amount of the upthrust is first relieved, a sufficient amount so that the bowl may be rotated. But sufficient upthrust remains to overcome the weight of the bowl and its appurtenances so that thread clearance is still eliminated. The clear ance in the threads will still be in the bottom of the threads, which is the same as during full clamping, rather than in the top, which is the condition during complete unclamping. This can be accomplished in a number of ways and in a number of varying clamping systems.

In FIG. 2 a hydraulic circuit is shown in which a pump 224 of any suitable design, driven by a motor 225, draws hydraulic oil from a sump 226 through a filter 228 and discharged it under pressure through a supply line 230 to a directional control valve 232. The supply line 230 may be connected to a conventional overload relief valve 234 which will return oil to the sump at a predetermined overload relief pressure.

The bowl rotating rams, as in FIG. 1, are indicated at 223, only one being shown but at least two are normally used, each double acting and, for purposes of description and illustration, it may be assumed that the rams are apart on opposite sides of the bowl and directed so that they rotate the bowl in the same direction, either clockwise or counterclockwise when viewed from above. A line 236 from control valve 232 will cause the rams to extend while a line 238 will cause them to retract. A separate line 240 is connected to line 236 so that at the same time that the rams are extending, thereby rotating the bowl, oil will be supplied to a pilot valve 242, which, at a given pressure, will relieve the pressure in the hydraulic lock posts 218.

The pump 224 may be of a type that has a number of pistons in it and the line 230 from the pump is connected to most of the pistons. A separate line 244 from the pump may be connected, for example, to one piston and then to a directional control valve 246 to make up for leakage in the lock posts 218. One additional piston may be connected by a line 248 to a directional control valve 250 which operates a selector valve 252. Line 244, after passing through the directional control valve 246, is connected by a line 254 to a supply line 256 which after going through control valve 252 flows to the hydraulic lock posts 218. An accumulator 258 is connected to line 256 beyond valve 252. A pressure sensitive electrical switch 260 responds to the pressure in line 256 and, in turn, starts or stops the motor 225 by an electrical lead 262. An unloading valve 264 senses the pressure in line 244 by a connection 266 so that at a given pressure it will relieve the pressure in line 168 from the selector valve 232 by a connection 270 which, in turn, returns the hydraulic fluid to the tank. A check valve 272 in line 268 prevents the reverse flow of the fluid from line 244. A pressure reducing valve 274 may be set to start and stop the flow of fluid from the hydraulic lock posts 218 at a set point with flow therefrom going through valve 242 to the tank.

A partial unclamp takes place as follows. The lock posts 218 have been initially fully pressured so that the bowl is lifted and clamped. This is done by manual or remote operation of directional control valve 246 so that pressure is supplied through line 230, line 268 and also through line 244 through valve 246, through line 254, line 256, through valve 252 to the lock posts 218. The accumulator 258 will hold the pressure at a certain level and will, to a degree, compensate for lock post leakage. When the bowl is to be adjusted, some of the pressure must be initially relieved in the lock posts 218. The operator first manually or remotely operates valve 250 so that valve 252 will shift, blocking line 256 and therby isolating pressure-sensitive switch 260. Then the operator will shift valve 232 to pressurize the rams 223 causing them to extend. This pressurizes line 240 to open valve 242 causing oil to drain to the tank from the lock posts 218. At a certain point, valve 274 will shift closing the line to the tank and stopping the pressure drain at a certain lower pressure level in the lock posts. Valve 274 is adjustable, and can be preset to whatever pressure is desired. That pressure can be set so that the hydraulic lock posts still lift the bowl and its attached mechanism so that thread clearance is eliminated but without sufficient upthrust or clamping force to prevent the bowl from being rotated. The rams 220 then extend, rotating the bowl. At the end of a ram excursion, valve 232 may be manually or remotely or automatically reversed which, through line 238 will pressurize the rod side of the rams causing them to retract. During ram retraction, the pressure in the lock posts 218 stays the same.

It may well be that under certain circumstances the bowl may tend to creep, either up or down. To prevent such creep, a positive lock of the type shown in FIG. 5 of US. Pat. No. 3,133,708, issued May 19, 1964 and assigned to the present assignee, may be tied into the hydraulic circuit. Or a lock of the type in US. Pat. No. 3,142,449, issued July 28, 1964 and assigned to the present assignee, may be used.

The rams may be cycled any number of times, de pending upon the amount of adjustment desired. This causes the bowl to rotate down which will draw the pistons in the hydraulic lock posts down somewhat which would otherwise tend to build up pressure. This, however, will be relieved each time the rams are extended since this will build up pressure in line 240 opening valve 242 and bleeding off through valve 274 any pressure buildup until valve 274 again closes at its preset pressure.

At the end of adjustment, directional control vavle 232 is centered which immobilizes the rams. Directional control valve 250 should be shifted back to its blocking position which will allow valve 252 to open. Then directional control valve 246 controlling the lock posts is actuated to pressurize line 254 which causes high pressure oil from the pump 224 to be supplied through lines 230 and 244 to line 254. Thus the lock posts 218 will be fully pressurized. Valve 242 will be closed since the pressure will be relieved from line 240. As the pressure builds up in the lock posts at a certain point valve 264 is opened by the pressure in line 266 which causes the oil supply through lines 230 and 268 to be returned to the sump through line 270. Thereafter, only the oil in line 244 will continue to build up pressure in line 254 and in the lock posts. At a set pressure, pressure-sensitive electrical switch 260 will shut down the motor 224 driving the pump which represents the fully pressurized condition for the lock posts.

Any pressure-on system will leak and the pressure sensitive switch 260 will detect this even though the accumulator 258 lengthens the leakage cycle. At some point switch 260 will start the motor 224 to drive the pump 222, but this will only affect line 244, which may be connected to only one piston in the pump since line 266 will keep valve 264 open. Thus the four pistons connected to supply line 230 will merely cycle oil back to the tank. It will be understood that the directional control valve 246, which controls the hydraulic lock posts 218, will be left in the on position when the crusher is operating normally and the lock posts are fully pressurized.

The above may be referred to as partial unclamp. On occasion it is desireable to fully unclamp the bowl, for example when the mantle and liner are sufficiently worn and need replacing. To rotate the bowl back out by use of the rams 223 would be far too slow and it is customary to wrap a cable around the bowl and rotate it rapidly by pulling the cable with an overhead crane or a tractor or the like. There are other circumstances where it may be desired to fully unclamp the bowl and rotate it rapidly, either up or down. In this event, directional control valve 246 controlling the hydraulic lock posts is shifted so that all pressure is relieved through the sump connection 276. This will completely relieve all locking or clamping pressure on the bowl and it will rotate freely.

A jacking circuit may also be provided if, on occasion, it is desirable to jack up the bowl and adjustment ring so that the cavity itself may be cleared if it has become plugged due to tramp iron, large pieces of wood, power failure, or what-have-you. It will be understood that a plurality of jacks may be positioned about the crusher, connected in series, or parallel if desired, with suitable valving connections to an automatically operated pump or a hand pump, none of which has been shown here for purposes of simplicity. Such an arrangement is conventional and may be of the type shown in US. Pat. No. 3,140,835, issued July 14, 1964 and assigned to the present assignee.

The general type of ram arrangement for rotating the bowl has been referred to hereinabove generally as the typeshown in U.S. Pat. No. 3,009,660, issued Nov. 21, 1961 and also US. Pat. No. 3,325,108, issued June 13, 1967. The ram rotating arrangement for the bowl could as well be of the type shown in US. Pat. No. 3,396,915, issued Aug. 13, 1968.

A single ram, one on each side of the bowl, approximately 180 apart has been referred to as the bowl rotating arrangement. But dual rams might be used so that the bowl could be rotated either up or down without separate adjustment of the rams to reverse their direction of thrust. Double or dual rams normally include four rams, in pairs of two each, on opposite sides of the bowl about 180 apart, such as shown in US. Pat. No. 3,570,774, issued Mar. 16, 1971 and US. Pat. No. 3,396,915, issued Aug. 13, 1968.

We claim:

1. An apparatus for adjusting the size of the crushing cavity in a cone crusher while the crusher is in operation in which the crusher has a generally circumferential mainframe with a bowl mounted for adjustment in the main frame opposite acrushing head mounted for gyration within the main frame and a bowl clamping means for applying a hydraulic thrust to the bowl to clamp it in the main frame including means for applying a full hydraulic clamping thrust to the bowl during normal operation of the crusher, means for partially relieving the clamping hydraulic thrust when the bowl is to be rotated for adjustment to an extent such that the bowl may be rotated but sufficient clamping hydraulic thrust will be maintained so that the bowl will be in full contact with the frame, and means for reapplying the full bowl clamping hydraulic thrust by building the hydraulic pressure back up at the conclusion of bowl rotatron.

2. The structure of claim 1 further characterized by and including hydraulic power means on the crusher for adjusting the bowl and means for automatically relieving the full bowl clamping thrust at the beginning of excursion of the power means.

3. The structure of claim 1 further characterized by and including hydraulic rams on the crusher for adjusting the bowl, means for automatically releasing the full hydraulic clamping thrust on the bowl at the beginning of excursion of the rams, and means for automatically stopping the decrease in bowl clamping pressure at a pre-selected lower pressure.

4. The structure of claim 3 further characterized by and including automatic means compensating for leakage in the bowl clamping hydraulicpressure during full clamping thrust.

5. The structure of claim 11 further characterized in that the bowl is mounted for adjustment in the main frame by screw threads and adjustment thereof takes place by rotating the bowl, the hydraulic clamping thrust being directed upwardly to remove thread clearance between the bowl and main frame.

6. In a cone crusher, a generally circumferential main frame, a bowl mounted for adjustment in the main frame and disposed opposite a crushing head mounted for gyration within the main frame, a bowl clamping system for applying a releasable thrust to the bowl to clamp it in the main frame, including means for applying a full hydraulic clamping thrust to the bowl during normal operation of the crusher, and means for partially relieving the clamping thrust so that the bowl may be adjusted while the crusher is still in operation but at the same time sufficient clamping thrust is maintained so, that the bowl is fully supported in the main frame.

7. The structure of claim 6 further characterized by and including hydraulic rams on the crusher for adjusting the bowl, means for automatically releasing the full hydraulic clamping thrust on the bowl at the beginning of excursion of the rams, and means for automatically stopping the decrease in bowl clamping pressure at a pre-selected lower pressure.

8. The structure of claim 7 further characterized by and including automatic means compensating for leakage in the bowl clamping hydraulic pressure during full clamping thrust.

9. The structure of claim 6 further characterized in that the bowl is mounted for adjustment in the main frame by screw threads and adjustment thereof takes place by rotating the bowl, the hydraulic clamping thrust being directed upwardly to remove thread clearancebetween the bowl and main frame.

10. The structure of claim 5 further characterized by and including at least one hydraulic ram on the crusher for rotating the bowl, means responsive to the ram being pressurized for automatically relieving the full hydraulic upthrust, means for automatically stopping the decrease in bowl clamping pressure at a point where the bowl may be rotated by the ram but is still in full contact with the main frame, and means for automatically holding the bowl against slippage during the retraction stroke of the ram.

111. The structure of claim 5 further characterized by and including means for relieving any buildup in the hydraulic clamping pressure during bowl adjustment due to the bowl movement against the bowl clamping means so that the bowl clamping pressure stays at a level that will allow adjustment of the bowl.

12. The structure of claim 5 further characterized by and including a hydraulic ram on the crusher for rotating the bowl, automatic means compensating for leakage in the bowl clamping hydraulic pressure during full clamping thrust, and means for isolating the automatic leakage compensating means during adjustment of the crusher.

13. The structure of claim 3 further characterized by and including means for adjusting the preselected lower pressure.

14. The structure of claim 9 further characterized by and including at least one hydraulic ram on the crusher for rotating the bowl, means responsive to the ram being pressurized for automatically relieving the full hydraulic upthrust, means for automatically stopping the decrease in bowl clamping pressure at a point where the bowl may be rotated by the ram but is still in full contact with the main frame, and means for automatically holding the bowl against slippage during the retraction stroke of the ram.

15. The structure of claim 9 further characterized by and including means for relieving any buildup in the hydraulic clamping pressure during bowl adjustment due to the bowl movement against the bowl clamping means so that the bowl clamping pressure stays at a level that will allow adjustment of the bowl.

16. The structure of claim 9 further characterized by and including a hydraulic ram on the crusher for rotatframe with a bowl mounted thereon for adjustment, including the steps of applying a selected full hydraulic clamping pressure between the main frame and bowl to clamp the bowl in position during crushing, and partially but not fully relieving the clamping hydraulic pressure when the bowl is to be adjusted while continuing the crusher operation of the crusher.

Claims

1. An apparatus for adjusting the size of the crushing cavity in a cone crusher while the crusher is in operation in which the crusher has a generally circumferential main frame with a bowl mounted for adjustment in the main frame opposite a crushing head mountEd for gyration within the main frame and a bowl clamping means for applying a hydraulic thrust to the bowl to clamp it in the main frame including means for applying a full hydraulic clamping thrust to the bowl during normal operation of the crusher, means for partially relieving the clamping hydraulic thrust when the bowl is to be rotated for adjustment to an extent such that the bowl may be rotated but sufficient clamping hydraulic thrust will be maintained so that the bowl will be in full contact with the frame, and means for reapplying the full bowl clamping hydraulic thrust by building the hydraulic pressure back up at the conclusion of bowl rotation.

4. The structure of claim 3 further characterized by and including automatic means compensating for leakage in the bowl clamping hydraulic pressure during full clamping thrust.

5. The structure of claim 1 further characterized in that the bowl is mounted for adjustment in the main frame by screw threads and adjustment thereof takes place by rotating the bowl, the hydraulic clamping thrust being directed upwardly to remove thread clearance between the bowl and main frame.

6. In a cone crusher, a generally circumferential main frame, a bowl mounted for adjustment in the main frame and disposed opposite a crushing head mounted for gyration within the main frame, a bowl clamping system for applying a releasable thrust to the bowl to clamp it in the main frame, including means for applying a full hydraulic clamping thrust to the bowl during normal operation of the crusher, and means for partially relieving the clamping thrust so that the bowl may be adjusted while the crusher is still in operation but at the same time sufficient clamping thrust is maintained so that the bowl is fully supported in the main frame.

9. The structure of claim 6 further characterized in that the bowl is mounted for adjustment in the main frame by screw threads and adjustment thereof takes place by rotating the bowl, the hydraulic clamping thrust being directed upwardly to remove thread clearance between the bowl and main frame.

11. The structure of claim 5 further characterized by and including means for relieving any buildup in the hydraulic clamping pressure during bowl adjustment due to the bowl movement against the bowl clamping means so that the bowl clamping pressure stays at a level that will allow aDjustment of the bowl.

16. The structure of claim 9 further characterized by and including a hydraulic ram on the crusher for rotating the bowl, automatic means compensating for leakage in the bowl clamping hydraulic pressure during full clamping thrust, and means for isolating the automatic leakage compensating means during adjustment of the crusher.

17. The structure of claim 7 further characterized by and including means for adjusting the preselected lower pressure.

18. A method of adjusting a crusher having a main frame with a bowl mounted thereon for adjustment, including the steps of applying a selected full hydraulic clamping pressure between the main frame and bowl to clamp the bowl in position during crushing, and partially but not fully relieving the clamping hydraulic pressure when the bowl is to be adjusted while continuing the crusher operation of the crusher.