The invention generally relates to a gyratory crusher. In particular, but not exclusively, the invention relates to a lubrication system for a gyratory crusher.
Mineral material, such as stone, is retrieved to be processed from the ground either by exploding or by digging. The mineral material may also comprise natural stone, gravel and construction waste. Both mobile and fixed plants are used for processing. The material to be processed is fed with e.g. an excavator or a wheel loader into a feed hopper of the processing plant, from where the material is forwarded to be processed.
In a gyratory crusher, eccentric movement of the main shaft causes the mineral material to be crushed in a crushing chamber between an inner wear part connected to the main shaft and an outer wear part connected to the frame of the crusher. The main shaft, or the head of the crusher, is supported at its bottom by a thrust bearing and an piston.
The thrust bearing receives the crushing forces and needs to be lubricated. The lubricating fluid is conducted to the thrust bearing via a hollow in the piston. Such arrangements are known e.g. from patent publications U.S. Pat. No. 7,922,109 and U.S. Pat. No. 6,328,237.
In case of a tramp release, i.e. in a situation in which uncrushable material ends up in the crushing chamber, the main shaft, or head, rapidly moves downwards causing the thrust bearing to receive a large surface force and friction losses. In such a case the lubrication sufficient in a normal operating situation might prove inadequate.
The objective of the invention is to provide a lubrication system for a gyratory crusher with an piston, a thrust bearing and lubrication thereof mitigating the problems of the prior art.
According to a first aspect of the invention there is provided a lubrication system for a gyratory crusher, comprising
The system may be further configured to in response to the pressure rising in the second space to conduct fluid from the second space to the first space.
The lubrication system may further comprise a first channel connecting the first space with the outside of the piston.
The lubrication system may further comprise second channel formed between the side surface of the piston and the cylinder; and connecting the first space with the second space.
The lubrication system may further comprise a third channel connecting the second channel to a supply of fluid.
The lubrication system may further comprise a fourth channel connecting the second space to the first space.
The lubrication system may further comprise a third space above the thrust bearing inside the cylinder configured to receive fluid from the thrust bearing.
The lubrication system may further comprise a fifth channel connecting the third space to the supply of fluid.
The system may be configured to in response to the pressure rising in the second space to conduct fluid from the second space to the first space via the first channel and the second channel and/or via the fourth channel.
The lubrication system may further comprise further fluid transfer means for additionally supplying fluid to the first space in response to detecting the downward movement of the piston.
The further fluid transfer means may comprise a pump.
According to a second aspect of the invention there is provided a lubrication method for a gyratory crusher, comprising
The method may comprise supplying to and holding fluid in a second space between the cylinder and the piston; and in response to the pressure rising in the second space conducting fluid from the second space to the first space.
The fluid may be supplied to the first space via a first channel, a second channel and a third channel connected to a supply of fluid.
The fluid may be supplied to the second space via the second channel.
The fluid may be supplied from the thrust bearing to a third space above the thrust bearing inside the cylinder.
The fluid may be supplied from third space to the supply of fluid via a fifth channel.
The fluid may be supplied in response to the pressure rising in the second space to the first space via the first channel and the second channel and/or via a fourth channel.
The fluid may be supplied to the first space in response to detecting the downward movement of the piston additionally using further fluid transfer means.
The further fluid transfer means may comprise a pump.
According to a third aspect of the invention there is provided a gyratory crusher comprising a lubrication system of the first aspect.
According to a fourth aspect of the invention there is provided a mineral material processing plant comprising a crusher according to the third aspect.
The mineral material processing plant may comprise a mobile plant.
Different embodiments of the present invention will be illustrated or have been illustrated only in connection with some aspects of the invention. A skilled person appreciates that any embodiment of an aspect of the invention may apply to the same aspect of the invention and other aspects
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
In the following description, like numbers denote like elements. It should be appreciated that the illustrated figures are not entirely in scale, and that the figures mainly serve the purpose of illustrating embodiments of the invention.
The piston 25 has a first diameter d1 and a second diameter d2. The first diameter d1 is larger than the second diameter d2, and the piston is formed in such a way as to have a shoulder 60 between the two diameters, i.e. the cross-section of the piston 25 has a shape reminiscent of the letter T. The shape, i.e. the inner diameter, of the cylinder 20 substantially corresponds to the shape and diameters of the piston.
The piston 25 is hollow and comprises a first space 30 configured for conducting fluid towards and into the thrust bearing 15. The thrust bearing is of the conventional type comprising for example lubrication grooves for spreading the fluid to the surfaces thereof. The piston 25 further comprises a first channel, or duct, 65 configured for conducting fluid into the first space 30, i.e. the first channel 65 connects the first space 30 with the outside of the piston 25. In a further example embodiment, the lubrication system comprises further fluid transfer means, e.g. such as a pump, (not shown) for additionally supplying fluid to the first space (30) in response to detecting a tramp release. The system comprises in an embodiment means for detecting the tramp release e.g. electronic means or a pressure valve. In case of a tramp release, the pressure under the piston 25 rises, i.e. in a pressure volume 90. The pressure is detected by a pressure sensor or a pressure valve 80, which is configured to open when the pressure exceeds a predetermined limit value and the piston 25 moves downwards.
The cylinder 20 and the piston 25 are formed in such a way that a second space 40 is formed between the portion of the piston having the first diameter d1 and the portion of the cylinder 20 having the smaller diameter corresponding to the second diameter d2 of the piston 25. The volume of the second space is variable in accordance with the movement of the piston 25 in the cylinder 20. For example in case of a tramp release as the piston 25 rapidly moves downwards, the volume of the second space 40 decreases rapidly.
A second channel, or duct, 35 is formed between the side surface of the piston 25 and the cylinder 20. In an example embodiment, the second channel 35 is formed as groove in the surface of the piston 25 and/or the cylinder 20. The second channel 35 is connected, i.e. in fluid connection, with the first channel 65 and with the second space 40. The cylinder 20 comprises a third channel, or duct, 45 in fluid connection with the second channel 35. The third channel 45 is in fluid connection with a supply of lubricating fluid (not shown) and is configured to conduct the fluid into the second channel 35 and therethrough into the first space 30 via the first channel 65 and to the second space 40.
In an embodiment, the piston 25 comprises a fourth channel 70 connecting the first space 30 to the second space 40. The fourth channel 70 is configured for conducting fluid from the second space 40 into the first space 30. In a further embodiment, the fourth channel comprises several channels, ducts or holes. In a further example embodiment additional fluid is supplied to the first space (30) in response to detecting a tramp release using further fluid transfer means such as a pump. The tramp release is in an embodiment detected e.g. electronically or mechanically by a pressure valve 80.
A third space 50 is formed above the thrust bearing 15 inside the cylinder 20. The third space is configured for receiving lubricant from the thrust bearing 15 and for conducting the heated lubricant back to the lubricant supply (not shown) to be cooled via a fifth channel, or duct, 55. In a further example embodiment, in addition to or instead of the fifth channel 55, the heated lubricant received from the thrust bearing is conducted further through radial bearings (not shown).
The material to be crushed is in an example embodiment fed to the feeder 410 and therefrom by the conveyor 411 to the crusher 100. The feeder 410 may also be a so-called scalper feeder. The material to be crushed coming from the conveyor is directed to the feed opening 421. In a further example embodiment, the material to be crushed is fed to the feed opening directly, for example by a loader.
The transmission is arranged to rotate the eccentric assembly around the main shaft producing gyratory movement between the inner and the outer crushing parts.
The skilled person appreciates that the mineral material processing plant 400 can, in a further example embodiment, be a stationary mineral material processing plant comprising crushing, screening and conveying units. In a further example embodiment, the mobile processing plant may, instead of tracks depicted in
Without in any way limiting the scope of protection, interpretation or possible applications of the invention, a technical advantage of different embodiments of the invention may be considered to be reduced risk of overheating of the thrust bearing. Further, a technical advantage of different embodiments of the invention may be considered to be lessened wear of the thrust bearing. Still further, a technical advantage of different embodiments of the invention may be considered to be increased lifetime of the crusher. Still further, a technical advantage of different embodiments of the invention may be considered to be increased safety.
The foregoing description provides non-limiting examples of some embodiments of the invention. It is clear to a person skilled in the art that the invention is not restricted to details presented, but that the invention can be implemented in other equivalent means. Some of the features of the above-disclosed embodiments may be used to advantage without the use of other features.
As such, the foregoing description shall be considered as merely illustrative of the principles of the invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.
Filing Document | Filing Date | Country | Kind |
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PCT/FI2015/050604 | 9/14/2015 | WO | 00 |