Patent Application
20240269683
Roller crushers are used for the comminution of material, e.g. ores. The comminution of material happens in-between two rollers, which together defines a crushing gap, where material to be crushed is introduced. The rollers are installed in a machine frame via bearing housings. Each roller may be provided with one, two or more independent bearing housings. During comminution of material large forces are constantly applied on the material and in return the rollers crushing the material. To assure the roller crusher is not damaged by these forces, one of the rollers is installed in fixed bearing housings, i.e. bearing housings which are fixed in relation to the machine frame, and the other roller is installed in movable bearing housings, i.e. bearing housings which may move in relation to the machine frame. Consequently, the roller crusher comprises a movable roller and a fixed roller. Thus, when a large load is applied on the rollers, the movable roller may move away from the fixed roller, which in return widens the crushing gap and lessens the load. However, to assure the movable roller returns to its optimal crushing position, and delivers a sufficient crushing pressure during operation, the floating roller is biased towards the fixed roller via a hydraulic system. The hydraulic system biases the movable roller by delivering a force to the movable bearing housings of the movable roller. However, since the movable bearing housings are independent from each other the movement of the moveable roller may lead to skewing, i.e. the two rollers become unparallel. Skewing may for example happen if a feed of material is unevenly distributed when entering the crushing gap or if material having varying properties, such as moisture content, enters the crusher or if a tamp event occurs.
Skewing of the floating roller may compromise seals, and in some cases where flanges are installed on one of the rollers, skewing may lead to unwanted contact between the roller and the flanges. Thus, making it hard to use flanged rollers if skewing is an issue.
It is an object of the present invention to provide a solution for preventing or at least reducing skewing in rollers crusher which is furthermore flexible and easily adaptable to a wide variety of roller crushers.
According to a first aspect, this and other objects are achieved by a hydraulic system for a roller crusher comprising a machine frame, a fixed roll supported by one or more fixed bearing housings, a movable roll supported by a first movable bearing housing and a second movable bearing housing, wherein the one or more fixed bearing housings are fixed relative to the machine frame, wherein the first movable bearing housing and the second movable bearing housing are movable relative to the machine frame, and wherein the fixed roll and the movable roll defines a crushing gap for receiving material to be comminuted, the hydraulic system comprising:
Consequently, a hydraulic system is provided where movement of the first main piston and the second main piston are synchronized via the operational coupling to the first crossing cylinder and the second crossing cylinder, respectively. The movement of the synchronizing pistons is synchronized by the first rebound chamber being fluidly connected to the second compression chamber, and the second rebound chamber being fluidly connected to the first compression chamber, thus when the volume of the first rebound chamber is compressed, e.g. when the first synchronizing piston moves along the first axis, fluid is transferred to the second compression chamber which expands the volume of the second compression chamber, and thus moving the second synchronizing in sync with the first synchronizing piston. Furthermore, since the main pistons are operationally coupled to the synchronizing pistons the movement of these are also synchronized. Synchronizing the movement between the pistons assures that when the hydraulic system is connected to a roller crusher, movement of the movable bearing housings is synchronized, thus avoiding skewing of the roller. Furthermore, only the main cylinders need to contribute to the crushing force exerted along the first axis and the second axis, while the synchronizing cylinders need only to synchronize movement of the different pistons, this further simplifies hydraulic wiring needed for the hydraulic system.
The first synchronizing hydraulic chamber and the second synchronizing hydraulic chamber are preferably formed with the same dimensions, thus leading to the volume of the first compression chamber and the first rebound chamber matching that of the second compression chamber and the second rebound chamber, respectively.
In the context of this disclosure when components are described as operationally coupled it is to be understood as when the components are operated they are coupled together.
In the context of this disclosure when components are described as connected it is not to only be interpreted as a direct connection between the components, the connection may also be an indirect connection achieved via intermediate components.
In an embodiment the first main hydraulic chamber is hollow and defines a first inner compartment, wherein the second main hydraulic chamber is hollow and defines a second inner compartment, and wherein the first crossing cylinder is arranged in the first inner compartment and the second crossing cylinder is arranged in the second inner compartment.
Consequently, a very space efficient set-up between the main cylinders and the synchronizing cylinders is achieved. Furthermore, arranging the synchronizing cylinders at least partly within the main cylinders may further facilitate an operational coupling between the synchronizing cylinders and the main cylinders.
In an embodiment the first main hydraulic chamber occupies 60-90% of a first cylinder area and the second main hydraulic chamber occupies 60-90% of a second cylinder area, wherein the first cylinder area is a cross-sectional area of the first hydraulic chamber and the first inner compartment in a plane perpendicular to the first axis and the second cylinder area is a cross-sectional area of the second hydraulic chamber and the second inner compartment in a plane perpendicular to the second axis.
The applicant has found that by having the main hydraulic chambers occupying 60-90% of the cylinder areas, the hydraulic chambers do not need an increase in diameter in comparison to the conventional hydraulic systems currently installed on roller crushers in order to deliver a sufficient force to the roller crusher. Thus, facilitating the retrofitting of the hydraulic system, and minimizing the changes needed in a manufacturing facility for manufacturing hydraulic systems and roller crushers with a hydraulic system according to the invention.
In an embodiment the fluid connection between the first compression chamber and the second rebound chamber forms a first closed fluid circuit and the fluid connection between the first rebound chamber and the second compression chamber forms a second closed fluid circuit.
Consequently, the synchronization of movement of the piston may be achieved autonomous without the need for external control, as the operation of the crossing cylinders will always be synchronized. This also further simplifies the hydraulic wiring needed in the system. In some cases, relieve valves may be connected to the first closed fluid circuit and the second closed fluid circuit to have a failsafe.
In an embodiment the hydraulic system comprises one or more hydraulic accumulators in fluid connection with the first main hydraulic chamber and/or the second main hydraulic chamber.
Hydraulic accumulators may help in providing additional force to the main cylinder and/or stabilizing the force delivered by the main cylinders.
In an embodiment the first synchronizing piston and the first synchronizing piston element are integrally connected, and the second synchronizing piston and the second synchronizing piston element are integrally connected.
Consequently, it is assured that the piston elements do not move relative to the synchronizing pistons, thus assuring the movement of the synchronizing pistons are synchronized when fluid is moved between the rebound chambers and the compression chambers. Alternatively, the piston elements may be provided as seals on the synchronizing pistons. Providing the piston elements as seals may case manufacturing of the synchronizing pistons, as seals may be added on a wide variety of pistons. Furthermore, seals are cheap and easily replaceable in case of wear and tear.
In an embodiment the first crossing cylinder is engaged with the first main cylinder to prevent movement of the first crossing cylinder relative to the first main cylinder in a first plane perpendicular to the first axis, and/or the second crossing cylinder is engaged with the second main cylinder to prevent movement of the second crossing cylinder relative to the second main cylinder in a second plane perpendicular to the second axis.
During operation of a roller crusher large forces are present which may lead to vibrations or lateral forces, such forces may move the cylinders relative to each other, thus potentially impacting the synchronization of the movement between the main pistons. Consequently, by preventing movement of the crossing cylinders relative to the main cylinders, these negative effects may be eliminated or at least reduced.
In an embodiment the first main piston is connected with the first synchronizing piston and/or the second main piston is connected with the second synchronizing piston.
Consequently, allowing the main cylinders to be operationally coupled with the crossing cylinders. By connecting the main pistons together with the synchronizing pistons, it is assured that movement of the main pistons is always synchronized by the crossing cylinders. The connection between the main pistons and the synchronizing piston may be achieved by bolting or a locking engagement, e.g. a male-female connection.
In an embodiment the first main piston is integrally connected with the first synchronizing piston and/or the second main piston is integrally connected with the second synchronizing piston.
An integral connection may assure the main cylinders and the synchronizing cylinder are operationally coupled. An integral connection may be achieved by forming the main pistons together with the synchronizing pistons, or by welding and the main pistons together with the synchronizing pistons.
In an embodiment the first main piston is configured to deliver the force along the first axis onto the first synchronizing piston and/or the second main piston is configured to deliver the force along the second axis onto the second synchronizing piston.
Thus, allowing the main cylinders and the synchronizing cylinder to be operationally coupled without forming a connection locking between the main pistons and the synchronizing pistons. Not locking the main pistons together with the synchronizing pistons may case the assembling and disassembling of the hydraulic system, which may prove especially advantageous when mounting the hydraulic system on a roller crusher.
According to a second aspect of the invention a roller crusher for comminution of material is provided, the roller crusher comprising:
The different aspects of the present invention can be implemented in different ways described above and in the following, each yielding one or more of the benefits and advantages described in connection with at least one of the aspects described above, and each having one or more preferred embodiments corresponding to the preferred embodiments described in connection with at least one of the aspects described above and/or disclosed in the dependent claims.
Furthermore, it will be appreciated that embodiments described in connection with one of the aspects described herein may equally be applied to the other aspects.
The above and/or additional objects, features and advantages of the present invention, will be further elucidated by the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings, wherein:
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and to convey the scope of the invention to the skilled person.
Referring initially to
Referring to
The hydraulic system 1 further comprises a first crossing cylinder 12 and a second crossing cylinder 14 connected to the first movable bearing housing 241 and the second movable bearing housing 242, respectively. In the shown embodiment, the first crossing cylinder 12 and the second crossing cylinder 14 are directly connected to the first movable bearing housing 241 and the second movable bearing housing 242, respectively. Alternatively, the first crossing cylinder 12 and/or the second crossing cylinder may be indirectly connected to the first movable bearing housing 241 and/or the second movable bearing housing 242, respectively. The indirect connection may be achieved via shims or the main pistons 111 and 131. The first crossing cylinder 12 comprises a first synchronizing hydraulic chamber 121 and a first synchronizing piston 122. The second crossing cylinder 14 comprises a second synchronizing hydraulic chamber 141 and a second synchronizing piston 142. The first synchronizing piston 122 and the second synchronizing piston 142 are movable along the first axis A1 and the second axis A2, respectively. The first synchronizing piston 122 abuts the first movable bearing housing 241, thus forming a connection between the first crossing cylinder 12 and the first movable bearing housing 241. The first synchronizing piston 122 being for exerting a force along the first axis A1 resulting in a force on the first movable bearing housing 241. The second synchronizing piston 142 abuts the second movable bearing housing 242, thus forming a connection between the second crossing cylinder 14 and the second movable bearing housing 242. The second synchronizing piston 142 being for exerting a force along the second axis A2 resulting in a force on the second movable bearing housing 242. The first synchronizing piston 122 and the second synchronizing piston 142 are operationally coupled to the first main piston 111 and the second main piston 131, respectively. In the shown embodiment the operational coupling is achieved by the main pistons 111 and 131 being configured to deliver a force along the first axis A1 and second axis A2 onto the synchronizing pistons 122 and 142. In the shown embodiment this is achieved by the first main pistons 111 and the second main piston 131 directly abutting the first synchronizing piston 122 and the second synchronizing piston 142, respectively. Alternatively, shims or similar may be placed in-between the main pistons 111 and 131 and the synchronizing pistons 122 and 142. The operational coupling may alternatively be achieved by connecting the main pistons 111 and 131 to the synchronizing pistons 122 and 142 via bolting or welding. The operational coupling facilitates that the movement of the main pistons 111 and 131 is synchronized with the movement of the movement of the synchronizing pistons 122 and 142, e.g. when high loads generated by material in the crushing gap 26 the operation coupling assures the main pistons 111 and 131 moves in sync with the synchronizing pistons 122 and 142. The first synchronizing piston 122 and the second synchronizing piston 142 extends into the first synchronizing hydraulic chamber 121 and the second synchronizing hydraulic chamber 121, respectively. The first synchronizing piston 122 and the second synchronizing piston 142 comprises a first synchronizing piston element 123 and the second synchronizing piston element 143, respectively. The first synchronizing piston element 123 separates the first synchronizing hydraulic chamber 121 into a first compression chamber 124 and a first rebound chamber 125. The second main piston 143 element separates the second synchronizing hydraulic chamber 141 into a second compression chamber 144 and a second rebound chamber 145. Thus, when the first synchronizing piston 122 moves along the first axis A1, the first synchronizing piston element 123 also moves along the first axis A1. The movement of the first synchronizing piston element 123 along the first axis A1 changes the volumes of the first compression chamber 124 and the first rebound chamber 125. When the second synchronizing piston 142 moves along the second axis A2, the second synchronizing piston element 143 also moves along the second axis A2. The movement of the second synchronizing piston element 143 along the second axis A2 changes the volumes of the second compression chamber 144 and the second rebound chamber 145.
The first crossing cylinder 12 and the second crossing cylinder 14 are in the shown embodiment structured identically. However, the first crossing cylinder 12 and the second crossing cylinder 14 may differ structurally from each other.
The first compression chamber 124 is fluidly connected to the second rebound chamber 145 via a first synchronizing hydraulic line 17. The first rebound chamber 125 is fluidly connected to the second compression chamber 144 via a second synchronizing hydraulic line 18. The fluid connections between the compression chambers 124 and 144 and the rebound chambers 125 and 145 synchronize the movement of the first synchronizing piston 122 and the second synchronizing piston 142. The movements of the first synchronizing piston 122 and the second synchronizing piston 142 are synchronized by the fluid connections between the compression chambers 124 and 144 and the rebound chambers 125 and 145 keeping the volume ratio between the volume of the first rebound chamber 125 and the second compression chamber 144 and the volume of the second rebound chamber 145 and the first compression chamber 124 constant. This constant volume ratio assures that the first synchronizing piston 122 and the second synchronizing piston 142 moves in sync with each other. Thus, when the first compression chamber 124 is compressed, due to the first synchronizing piston 122 moving, fluid is transferred from the first compression chamber 124 to the second rebound chamber 145, thus expanding the second rebound chamber 145 and leading to a compression of the second compression chamber 144, which results in the second synchronizing piston 142 moving in sync with the first synchronizing piston 122. Consequently, the fluid connection between the compression chambers 124 and 144 and the rebound chambers 125 and 145 assures that the synchronizing pistons 122 and 142 move in sync with each other. In the shown embodiment, the first fluid connection 17 between the first compression chamber 124 and the second rebound chamber 145 form a first closed fluid circuit and the second fluid connection 18 between the first rebound chamber 125 and the second compression chamber 144 form a second closed fluid circuit.
Referring to
Referring to
Although some embodiments have been described and shown in detail, the invention is not restricted to them, but may also be embodied in other ways within the scope of the subject matter defined in the following claims. In particular, it is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention.
In device claims enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims or described in different embodiments does not indicate that a combination of these measures cannot be used to advantage.
It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2150814-8 | Jun 2021 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/034446 | 6/22/2022 | WO |
