A double-mass vibrating grate and a method for determining its parameters

Abstract

The present invention relates to a dual-mass vibrating grate and a method for determining its parameters, and relates to the technical field of mechanical vibration equipment, including an outer mass and an inner mass, the outer mass includes a hinge, a grate body and an outer frame of a driving unit, a power source is arranged on the inner mass, the inner mass and the outer mass are connected by a main vibration spring, the grate body includes a first horizontal section, an inclined section and a second horizontal section, one end of the first horizontal section is connected to a hinge, the hinge is arranged on a fixed basic structure, the other end of the first horizontal section is connected to the inclined section, the inclined section is at a preset inclination angle with the horizontal direction, the end of the inclined section is connected to the second horizontal section, the bottom of the second horizontal section is connected to another fixed basic structure through a vibration isolation spring, and the upper part of the second horizontal section is connected to the outer frame of the driving unit. According to the principle of vibration utilization, the present invention reduces the starting time and starting current, protects the motor, improves the working efficiency, prolongs the service life, and reduces energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical vibration equipment, and in particular to a dual-mass vibration grate and a method for determining its parameters. Background Art

[0002] In the actual engineering of metallurgy, coal mining, mining, etc., screening materials is a very important link. Impurities are removed through screening equipment to ensure the quality and purity of the materials. For example, in the mining process, the mined ore is unloaded through a dumper, but there are many impurities in the ore. Placing a grate under the dumper can screen the unloaded ore, providing higher purity ore for subsequent processes, achieving the purpose of screening and dropping.

[0003] In actual working conditions, it will be affected by many factors, such as the influence of weather. A humid environment will cause sticking and blocking of materials on the grate. The emergence of vibrating grates can solve these problems. The exciting force generated by the eccentric body driven by the motor can make the materials adhering to the grate fall normally. At present, vibrating grates play an important role in on-site operations in many engineering fields. However, the existing vibrating grates have the following problems: 1. The starting time is long, which makes the motor easy to burn out and the working efficiency is low. 2. The current is large during operation, which exceeds the rated current of the motor, causing the motor to burn out, reducing the service life of the motor and affecting the progress of the process. 3. The traditional vibrating grate adopts a single-mass structure, and the equipment has low working efficiency, low production capacity, energy consumption, and poor process effect. Summary of the invention

[0004] In response to the technical problems raised above, a dual-mass vibrating grate and a method for determining its parameters are provided.

[0005] The technical means adopted by the present invention are as follows:

[0006] A double-mass vibrating grate comprises an outer mass and an inner mass, wherein the outer mass comprises a hinge, a grate body and an outer frame of a driving unit, a power source is arranged on the inner mass, and the inner mass and the outer mass are connected by a main vibration spring, the grate body comprises a first horizontal section, an inclined section and a second horizontal section, one end of the first horizontal section is connected to a hinge, and the hinge is arranged on a fixed basic structure, the other end of the first horizontal section is connected to the inclined section, and the inclined section is inclined at a preset angle to the horizontal direction, the end of the inclined section is connected to the second horizontal section, the bottom of the second horizontal section is connected to another fixed basic structure through a vibration isolation spring, and the top of the second horizontal section is connected to the outer frame of the driving unit.

[0007] Furthermore, the power source is arranged at the center of mass of the inner mass body, and the power source is a vibrator. A plurality of main vibration springs are arranged circumferentially of the vibrator, and the main vibration springs have stiffness in both horizontal and vertical directions.

[0008] Furthermore, the outer frame of the vibration exciter is welded from thick steel plates, and the outer frame of the driving unit is provided with a plurality of reinforcing ribs.

[0009] Furthermore, the outer frame of the driving part is connected to the second horizontal section of the grating body through a flange structure.

[0010] Furthermore, the exciter is a vibration source used to drive the operation of the equipment. It is composed of an induction motor and an eccentric rotor. The exciter is driven by the induction motor. The eccentric rotor rotates around the center of the rotation axis. The whole exciter rotates counterclockwise and generates exciting forces in the vertical and horizontal directions respectively.

[0011] Furthermore, a plurality of openings are provided on the grate, and the aperture sizes vary based on the distribution positions.

[0012] Furthermore, the double-mass vibrating grate is used in the unloading process of the car tipper, and is arranged below the car tipper and above the silo.

[0013] The present invention also discloses a method for determining parameters of the dual-mass vibrating grate, comprising the following steps:

[0014] Step 1, establish the dynamic model and system motion differential equation;

[0015] Establishing the coordinate system: The vibrator rotates around the central axis Rotation, is the rotation angle of the eccentric rotor; the swing angle of the outer mass body around the hinge is , the exciter is installed at the mass center of the endomass. The rotation center of the exciter is coaxial with the mass center of the endomass, so the swing of the endomass is ignored. The degrees of freedom of the entire vibration system are: Direction displacement, The displacement in the direction , , the swing angle of the exoplasm , and the rotation phase angle of the exciter ;

[0016] In the coordinate system In the figure, the coordinates of the eccentric rotor of the vibrator are It can be expressed as

[0017]

[0018] Endosomal displacement It can be expressed as

[0019]

[0020] Eccentric rotor in moving coordinate system The coordinates in can be expressed as

[0021]

[0022] The kinetic energy of the system when working is expressed as follows

[0023]

[0024] The spring connection point is at The coordinates in are

[0025]

[0026]

[0027]

[0028] When the system is working, the spring connection point is The coordinates in can be expressed as

[0029]

[0030] The potential energy of the system when working is expressed as follows

[0031]

[0032] in

[0033]

[0034] The energy dissipation function of the system is expressed as follows

[0035]

[0036] in

[0037]

[0038] The Lagrangian equations of the system are as follows

[0039]

[0040] in

[0041]

[0042] The differential equation of motion for the system is given by

[0043]

[0044] in

[0045]

[0046]

[0047]

[0048] In the formula, —moment of inertia of the ectoplasm; —Switch angle of the grate; —The main vibration spring is Stiffness coefficient in direction; —The main vibration spring is Stiffness coefficient in direction; —Vibration isolation spring Stiffness coefficient in direction; —The main vibration spring is Damping coefficient in direction; —The main vibration spring is Damping coefficient in direction; —Vibration isolation spring Damping coefficient in direction; —Eccentric rotor mass; —Endoplasmic mass; —Eccentric radius of the vibrator; —The vertical distance from the connection point between the spring connected below the inner mass body and the outer mass body to the connection point between the vibration isolation spring and the outer mass body; —The horizontal distance from the connection point between the spring connected to the right side of the endoplasmic body and the endoplasmic body to the center of mass of the endoplasmic body; —The horizontal distance from the connection point between the spring on the right side of the endoplasmic body and the exoplasmic body to the center of mass of the endoplasmic body; —The vertical distance from the connection point between the spring connected to the endomass above the endomass to the center of mass of the endomass; —The vertical distance from the connection point between the spring connected to the outer mass body above the inner mass body to the center of mass of the inner mass body;

[0049] Step 2, determining the response of the vibration system;

[0050] Let the exciter speed be ,but

[0051] Using the transfer function method, the system response is as follows:

[0052]

[0053]

[0054]

[0055] in

[0056]

[0057]

[0058]

[0059]

[0060] Compared with the prior art, the present invention has the following advantages:

[0061] 1. The main vibration spring is used to connect the inner mass body and the outer mass body of the present invention, so as to realize the flexible separation of the exciter and the grate body. The system working point is set to work near resonance, so as to prevent the motor from starting too long and the current from being too large for a long time, and protect the motor from damage. The dual-mass vibrating grate starts and stops quickly, does not burn the power source (such as induction motor, etc.), and has a long equipment life.

[0062] 2. The power source is arranged on the inner mass body. Under the energy buffering and high damping effect of the main vibration spring between the two mass bodies, the negative impact of the heavy load or impact load on the outer mass body on the power source on the inner mass body is significantly alleviated or even completely isolated, thereby achieving the purpose of protecting the power source.

[0063] 3. The exciter is arranged on the outer frame of the exciter. The equipment as a whole forms a double-mass structure. After the equipment is turned on, the exciter generates an exciting force in the horizontal and vertical directions respectively, thereby driving the grate body to realize the swing vibration around the hinge axis, so as to achieve the function of screening materials. Due to the energy buffering and high damping effect of the main vibration spring between the outer mass body and the inner mass body, the reaction force of the hinge connection of the outer mass body (grate body) on the power source (such as an induction motor, etc.) is significantly reduced and alleviated, achieving the purpose of protecting the power source.

[0064] 4. Compared with the conventional single-mass vibrating grate of the same type, the double-mass vibrating grate of the present invention has a system operating point set at near-resonance operation, and can use the resonance effect to achieve energy saving, generally saving about 40%-60%.

[0065] 5. The double-mass vibrating grate of the present invention adopts a flange connection at the connection point between the outer frame of the driving part and the grate body, making installation, disassembly and maintenance more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0067] Figure 1 It is a schematic diagram of the structure of the present invention.

[0068] In the figure: 1. hinge; 2. grating body; 3. outer frame of driving part; 4. main vibration spring; 5. inner mass body; 6. basic structure; 7. vibration isolation spring; 8. exciter. DETAILED DESCRIPTION

[0069] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0070] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0072] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0073] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0074] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0075] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0076] like Figure 1As shown, a double-mass vibrating grate comprises an outer mass and an inner mass 5, the outer mass comprises a hinge 1, a grate body 2 and an outer frame 3 of a driving unit, a power source is arranged on the inner mass, the inner mass and the outer mass are connected by a main vibration spring, the grate comprises a first horizontal section, an inclined section and a second horizontal section, one end of the first horizontal section is connected to a hinge, the hinge is arranged on a fixed basic structure 6, the other end of the first horizontal section is connected to the inclined section, the inclined section is inclined at a preset angle to the horizontal direction, the end of the inclined section is connected to the second horizontal section, the bottom of the second horizontal section is connected to another fixed basic structure through a vibration isolation spring 7, and the top of the second horizontal section is connected to the outer frame of the driving unit.

[0077] As an optional embodiment, there are two hinges 1, which are installed on the foundation 6 and connected to the grate body 2 through an axis. The grate body 2 is the main component in contact with the material. The outer frame 3 of the driving unit is connected to the grate body 2 with bolts through a flange structure, and the overall arrangement is symmetrical. The exciter 8 is composed of an eccentric rotor driven by a motor and is arranged on the side plate of the inner mass body 5. The exciter is positioned by aligning the rotation center of the motor with the center of mass of the inner mass body. There are eight main vibration springs 4, and the inner mass body 5 is connected to the outer frame 3 of the driving unit through the main vibration springs 4. There are four vibration isolation springs 7, the upper part of the vibration isolation spring 7 is connected to the grate body 2, and the lower part is installed on the foundation 6, so that the entire structure forms a double mass system of inner and outer mass bodies.

[0078] As the vibrator rotates counterclockwise, it gives power to the equipment. Excitation force is generated in both horizontal and vertical directions, driving the inner mass body to perform elliptical motion, and the outer mass body to swing slightly around the hinge, achieving the purpose of vibration screening and solving the problems of sticking and blocking materials.

[0079] Furthermore, the power source is arranged at the center of mass of the inner mass body, and the power source is a vibrator 8. A plurality of main vibration springs 4 are arranged around the vibrator, and the main vibration springs have stiffness in both horizontal and vertical directions.

[0080] Furthermore, the outer frame of the vibration exciter is welded from thick steel plates, and the outer frame of the driving unit is provided with a plurality of reinforcing ribs.

[0081] Furthermore, the outer frame of the driving part is connected to the second horizontal section of the grating body through a flange structure.

[0082] Furthermore, the exciter is a vibration source used to drive the operation of the equipment. It is composed of an induction motor and an eccentric rotor. The exciter is driven by the induction motor. The eccentric rotor rotates around the center of the rotation axis. The whole exciter rotates counterclockwise and generates exciting forces in the vertical and horizontal directions respectively.

[0083] Furthermore, a plurality of openings are provided on the grate, and the aperture sizes vary based on the distribution positions.

[0084] Furthermore, the double-mass vibrating grate is used in the unloading process of the car tipper, and is arranged below the car tipper and above the silo.

[0085] The present invention also discloses a method for determining parameters of the dual-mass vibrating grate, comprising the following steps:

[0086] Step 1, establish the dynamic model and system motion differential equation;

[0087] Establishing the coordinate system: The vibrator rotates around the central axis Rotation, is the rotation angle of the eccentric rotor; the swing angle of the outer mass body around the hinge is , the exciter is installed at the mass center of the endomass. The rotation center of the exciter is coaxial with the mass center of the endomass, so the swing of the endomass is ignored. The degrees of freedom of the entire vibration system are: Direction displacement, The displacement in the direction , , the swing angle of the exoplasm , and the rotation phase angle of the exciter ;

[0088] In the coordinate system In the figure, the coordinates of the eccentric rotor of the vibrator are It can be expressed as

[0089]

[0090] Endosomal displacement It can be expressed as

[0091]

[0092] Eccentric rotor in moving coordinate system The coordinates in can be expressed as

[0093]

[0094] The kinetic energy of the system when working is expressed as follows

[0095]

[0096] The spring connection point is at The coordinates in are

[0097]

[0098]

[0099]

[0100] When the system is working, the spring connection point is The coordinates in can be expressed as

[0101]

[0102] The potential energy of the system when working is expressed as follows

[0103]

[0104] in

[0105]

[0106] The energy dissipation function of the system is expressed as follows

[0107]

[0108] in

[0109]

[0110] The Lagrangian equations of the system are as follows

[0111]

[0112] in

[0113]

[0114] The differential equation of motion for the system is given by

[0115]

[0116] in

[0117]

[0118]

[0119]

[0120] In the formula, —moment of inertia of the ectoplasm; —Switch angle of the grate; —The main vibration spring is Stiffness coefficient in direction; —The main vibration spring is Stiffness coefficient in direction; —Vibration isolation spring Stiffness coefficient in direction; —The main vibration spring is Damping coefficient in direction; —The main vibration spring is Damping coefficient in direction; —Vibration isolation spring Damping coefficient in direction; —Eccentric rotor mass; —Endoplasmic mass; —Eccentric radius of the vibrator; —The vertical distance from the connection point between the spring connected below the inner mass body and the outer mass body to the connection point between the vibration isolation spring and the outer mass body; —The horizontal distance from the connection point between the spring connected to the right side of the endoplasmic body and the endoplasmic body to the center of mass of the endoplasmic body; —The horizontal distance from the connection point between the spring on the right side of the endoplasmic body and the exoplasmic body to the center of mass of the endoplasmic body; —The vertical distance from the connection point between the spring connected to the endomass above the endomass to the center of mass of the endomass; —The vertical distance from the connection point between the spring connected to the outer mass body above the inner mass body to the center of mass of the inner mass body;

[0121] Step 2, determining the response of the vibration system;

[0122] Let the exciter speed be ,but

[0123] Using the transfer function method, the system response is as follows:

[0124]

[0125]

[0126]

[0127] in

[0128]

[0129]

[0130]

[0131]

[0132] Based on the above embodiments, the present invention has the following effects: according to the vibration utilization technology, the exciter can be operated quickly to transmit power to the grate, thereby improving the working efficiency and preventing the motor from being burned out. The vibrating grate quickly passes through the resonance area, so that the current quickly drops below the rated current of the motor, thereby increasing the service life of the motor. The stability of the spring is also guaranteed, and the heating problem caused by the increase in spring temperature is avoided.

[0133] The dual-mass design uses springs to connect two masses, forming a sub-resonant system, compared to a single-mass structure. The dual-mass system can achieve the same working efficiency with less power. This can save energy and extend the service life of the equipment.

[0134] By using the resonance principle and applying it to the equipment, the stability of the frequency and amplitude of the equipment during operation is ensured, and the rapid increase of vibration when passing through the resonance area is avoided, which increases the service life of the spring and the grating body.

[0135] In terms of structural design, the outer frame of the driving part and the grating body are connected in the form of a flange, which makes installation and disassembly more convenient and easy to maintain.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining parameters of a dual-mass vibrating grate, characterized in that: The double-mass vibrating grate comprises an outer mass and an inner mass, the outer mass comprises a hinge, a grate body and an outer frame of a driving unit, a power source is arranged on the inner mass, the inner mass and the outer mass are connected by a main vibration spring, the grate comprises a first horizontal section, an inclined section and a second horizontal section, one end of the first horizontal section is connected to a hinge, the hinge is arranged on a fixed basic structure, the other end of the first horizontal section is connected to the inclined section, the inclined section is inclined at a preset angle to the horizontal direction, the end of the inclined section is connected to the second horizontal section, the bottom of the second horizontal section is connected to another fixed basic structure through a vibration isolation spring, and the top of the second horizontal section is connected to the outer frame of the driving unit; The parameter determination method comprises the following steps: Step 1, establish the dynamic model and system motion differential equation; Establishing the coordinate system: The vibrator rotates around the central axis Rotation, is the rotation angle of the eccentric rotor; the swing angle of the outer mass body around the hinge is , the exciter is installed at the mass center of the endomass. The rotation center of the exciter is coaxial with the mass center of the endomass, so the swing of the endomass is ignored. The degrees of freedom of the entire vibration system are: Direction displacement, The displacement in the direction , , the swing angle of the exoplasm , and the rotation phase angle of the exciter ; In the coordinate system In the figure, the coordinates of the eccentric rotor of the vibrator are Expressed as Endosomal displacement Expressed as Eccentric rotor in moving coordinate system The coordinates in are expressed as The kinetic energy of the system when working is expressed as follows The spring connection point is at The coordinates in are When the system is working, the spring connection point is The coordinates in are expressed as The potential energy of the system when working is expressed as follows in The energy dissipation function of the system is expressed as follows in The Lagrangian equation of the system is as follows in The differential equation of motion for the system is given by in In the formula, —moment of inertia of the ectoplasm; —Switch angle of the grate; —The main vibration spring is Stiffness coefficient in direction; —The main vibration spring is Stiffness coefficient in direction; —Vibration isolation spring Stiffness coefficient in direction; —The main vibration spring is Damping coefficient in direction; —The main vibration spring is Damping coefficient in direction; —Vibration isolation spring Damping coefficient in direction; —Eccentric rotor mass; —Endoplasmic mass; —Eccentric radius of the vibrator; —The vertical distance from the connection point between the spring connected below the inner mass body and the outer mass body to the connection point between the vibration isolation spring and the outer mass body; —The horizontal distance from the connection point between the spring connected to the right side of the endoplasmic body and the endoplasmic body to the center of mass of the endoplasmic body; —The horizontal distance from the connection point between the spring on the right side of the endoplasmic body and the exoplasmic body to the center of mass of the endoplasmic body; —The vertical distance from the connection point between the spring connected to the endomass above the endomass to the center of mass of the endomass; —The vertical distance from the connection point between the spring connected to the outer mass body above the inner mass body to the center of mass of the inner mass body; Step 2, determining the response of the vibration system; Let the exciter speed be ,but Using the transfer function method, the system response is as follows: in 。 2. The method for determining parameters of a dual-mass vibrating grate according to claim 1, characterized in that: The power source is arranged at the mass center of the inner mass body. The power source is a vibrator. A plurality of main vibration springs are arranged around the vibrator. The main vibration springs have rigidity in both horizontal and vertical directions.

3. The method for determining parameters of a dual-mass vibrating grate according to claim 1, characterized in that: The outer frame of the exciter is welded from thick steel plates, and the outer frame of the driving part is provided with a plurality of reinforcing ribs.

4. The method for determining parameters of a dual-mass vibrating grate according to claim 1, characterized in that: The outer frame of the driving part is connected to the second horizontal section of the grating body through a flange structure.

5. The method for determining parameters of a dual-mass vibrating grate according to claim 1, characterized in that: The exciter is a vibration source used to drive the operation of the equipment. It consists of an induction motor and an eccentric rotor. The exciter is driven by the induction motor. The eccentric rotor rotates around the center of the rotation axis. The whole exciter rotates counterclockwise and generates exciting forces in the vertical and horizontal directions respectively.

6. The method for determining parameters of a dual-mass vibrating grate according to claim 1, characterized in that: The grate is provided with a number of openings, and the aperture sizes vary based on the distribution positions.

7. The method for determining parameters of a dual-mass vibrating grate according to claim 1, characterized in that: The double-mass vibrating grate is used in the unloading process of the car tipper, and is arranged below the car tipper and above the silo.

Images