Eccentric drive bearing structure for a vibrating screen and method of operation thereof

Abstract

This invention belongs to the field of engineering components technology, specifically relating to bearings, and particularly to the structure and working method of an eccentric transmission bearing for a vibrating screen. One type of eccentric transmission bearing structure for a vibrating screen includes a screen disc, an eccentric transmission assembly, a support frame, and a drive motor. The eccentric transmission assembly includes an eccentric shaft and a bearing assembly, with the bearing assembly sleeved on the outer wall of the eccentric shaft. The outer wall of the eccentric shaft and the inner ring of the bearing assembly are fitted with a clearance fit. The outer ring of the bearing assembly is fixedly installed in a bearing mounting bracket on the screen disc. Through the clearance fit between the inner ring of the bearing assembly and the outer wall of the eccentric shaft, the impact load generated by the vibration of the screen disc is prevented from being transmitted to the fixed area of ​​the bearing assembly, changing the load distribution within the bearing, weakening the damage to the bearing from instantaneous impacts, and significantly improving the service life of the eccentric transmission bearing and the overall operational stability of the machine.

Description

Technical Field

[0001] This invention belongs to the field of engineering components technology, specifically relating to bearings, and more particularly to the structure and working method of an eccentric transmission bearing for a vibrating screen. Background Technology

[0002] Vibrating screens are core equipment for material screening and grading. Their core working principle is to convert the circular rotation of the motor into high-frequency reciprocating vibration of the screen disc. In the power transmission structure of a vibrating screen, the eccentric disc is a key transmission component connecting the motor and the screen disc. Bearings must be installed on the outer side of its rotating shaft for rotational support and transmission limit. The assembly stability and force uniformity of the bearings directly determine the overall operational stability and service life of the vibrating screen.

[0003] In related technologies, the bearing assembly structure of the eccentric disc in a vibrating screen generally employs an interference fit or wedge locking method for a fixed connection between the bearing inner ring and the eccentric disc shaft. This assembly structure can achieve rigid fixation between the bearing inner ring and the shaft, ensuring synchronous rotation without relative motion and meeting the basic requirements of conventional transmission assembly. However, during actual operation of the vibrating screen, this rigid connection structure has the following drawbacks: When a vibrating screen is in operation, the screen disc continuously vibrates at high frequency, generating periodic, high-intensity impact loads. These impact loads are directly transmitted to a fixed area of ​​the bearing structure via the eccentric disc shaft, making load dispersion impossible. Under long-term operation, localized areas of the bearing will be subjected to repeated concentrated impacts, compression, and friction, easily leading to problems such as localized raceway wear, rolling element fatigue damage, and localized stress concentration cracking, significantly shortening the bearing's normal service life. Simultaneously, localized bearing failure directly results in decreased eccentric disc transmission accuracy, screen vibration deviation, and screen body swaying, severely impacting vibrating screening operations.

[0004] Therefore, how to solve the problem of localized concentrated impact loads caused by screen vibration, uneven bearing stress, and severe local fatigue damage is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute information related to the technology. Summary of the Invention

[0006] This disclosure provides at least one embodiment of an eccentric transmission bearing structure for a vibrating screen and its working method.

[0007] In a first aspect, embodiments of this disclosure provide an eccentric transmission bearing structure for a vibrating screen, including a screen disc, an eccentric transmission assembly, a support frame, and a drive motor; the eccentric transmission assembly includes an eccentric rotating shaft and a bearing assembly, the bearing assembly being sleeved on the outer wall of the eccentric rotating shaft; the outer wall of the eccentric rotating shaft and the inner ring of the bearing assembly are assembled with a clearance fit; the outer ring of the bearing assembly is fixedly installed in a bearing mounting bracket on the screen disc.

[0008] In one optional embodiment, the assembly clearance between the outer wall of the eccentric shaft and the inner ring of the bearing is 0.02mm-0.025mm.

[0009] In one optional embodiment, a set of bearing assemblies is fitted at each end of the eccentric shaft, and the two sets of bearing assemblies are symmetrically arranged at both ends of the eccentric transmission assembly.

[0010] In one alternative embodiment, the inner ring of the bearing forms an arc surface towards the axis, and the gap space between the arc surface and the outer wall of the eccentric shaft forms a buffer oil film layer.

[0011] In one optional embodiment, the eccentric transmission assembly includes an active eccentric roller assembly and a driven eccentric roller assembly. The active eccentric roller assembly is driven by a drive motor via belt transmission. The active eccentric roller assembly and the driven eccentric roller assembly rotate synchronously in conjunction with the belt. The rotating shafts of the active eccentric roller assembly and the driven eccentric roller assembly and the corresponding bearing inner rings are all fitted with clearance.

[0012] In one optional embodiment, eccentric wheels are provided on the outer sides of both the active eccentric roller assembly and the driven eccentric roller assembly. The eccentric wheels are rigidly connected to the screen disc, and the excitation force generated by the rotation of the eccentric wheels is directly transmitted to the screen disc to drive the screen disc to vibrate up and down.

[0013] In one optional embodiment, multiple sets of shock-absorbing springs are mounted on the bottom of the screen tray, with the lower ends of the shock-absorbing springs abutting against the support frame. The screen tray achieves flexible vibration isolation connection with the support frame through the shock-absorbing springs.

[0014] In one optional embodiment, the inner wall of the bearing inner ring and the outer wall of the eccentric shaft are both provided with a smooth and wear-resistant coating to reduce frictional loss when the eccentric shaft and the bearing inner ring rotate relative to each other in the circumferential direction.

[0015] In one alternative embodiment, a sealing end cap is provided on the outer side of the bearing assembly to block the gap between the eccentric shaft and the inner ring of the bearing.

[0016] In one alternative embodiment, the screen is multi-layered, and the discharge ports of the screens are oriented differently.

[0017] Secondly, this disclosure also provides a method for operating an eccentric transmission bearing structure for a vibrating screen, the method comprising: S1. Start the drive motor. The drive motor drives the active eccentric roller assembly to rotate. The active eccentric roller assembly rotates synchronously with the driven eccentric roller assembly. The eccentric shaft rotates synchronously with the eccentric wheel. S2. In the initial stage of equipment startup, the eccentric shaft is subjected to rotational torque and circumferential relative sliding occurs due to the gap between the eccentric shaft and the inner ring of the bearing. S3. The rotation of the eccentric wheel generates a periodic excitation force, which drives the screen disc to vibrate up and down at high frequency. The alternating impact load generated by the vibration of the screen disc is transmitted to the inner ring of the bearing through the eccentric shaft. S4. Relying on the tiny gap of 0.02mm-0.025mm, the eccentric shaft continuously rotates slowly relative to the inner ring of the bearing, distributing the alternating impact load evenly to the entire raceway of the inner ring of the bearing, thus avoiding the long-term concentrated action of the impact load on a single local area of ​​the bearing. S5. The lubricating grease in the gap between the eccentric shaft and the inner ring of the bearing forms a buffer oil film, which absorbs the kinetic energy of the instantaneous vibration of the screen plate and weakens the instantaneous contact stress of the bearing rolling pair. S6. The shock-absorbing springs at the bottom of the screen disc continuously absorb the vibration energy of the screen body, blocking the transmission of vibration to the support frame, so that the equipment can continuously and stably complete the material screening operation.

[0018] The beneficial effects of this invention are that it provides an eccentric drive bearing structure and its working method for vibrating screens. By changing the eccentric shaft and the bearing inner ring to a clearance fit, the two can generate circumferential relative sliding during equipment operation, so that the impact load is evenly distributed on the entire circumference of the bearing inner ring raceway, eliminating fixed-point cyclic stress concentration, avoiding premature local bearing failure, and extending the bearing service life. The bearing inner ring is designed with an arc surface structure, which, together with the small gap between the eccentric shaft and the inner ring, can store lubricating grease, forming a continuous buffer oil film during operation. The instantaneous impact kinetic energy generated by the high-frequency up-and-down vibration of the screen disc can be effectively absorbed and buffered by the oil film, reducing the instantaneous contact stress between the bearing rolling elements and the raceway, further reducing the damage to the bearing caused by impact and friction, and improving the smoothness of bearing operation.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A perspective view of the eccentric transmission bearing structure for a vibrating screen provided in an embodiment of this disclosure; Figure 2 A cross-sectional perspective view of a bearing provided in an embodiment of this disclosure; Figure 3 A cross-sectional front view of the eccentric shaft and bearing provided in an embodiment of this disclosure.

[0023] In the picture: 1. Screen plate; 10. Feed port; 2. Eccentric drive assembly; 21. Eccentric shaft; 22. Bearing assembly; 23. Arc surface; 24. Driven eccentric roller assembly; 25. Driven eccentric roller assembly; 26. Sealing end cover; 3. Support frame; 30. Shock-absorbing springs; 4. Drive motor; Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless explicitly stated otherwise. The terms “comprising,” “including,” and “having” are inclusive, and the method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] like Figures 1 to 3 As shown, at least one embodiment provides an eccentric transmission bearing structure for a vibrating screen, including a screen plate 1, an eccentric transmission assembly 2, a support frame 3, and a drive motor 4; wherein the eccentric transmission assembly 2 includes an eccentric rotating shaft 21 and a bearing assembly 22, which is the core improvement part of the present invention.

[0029] like Figure 1 The support frame 3 serves as the load-bearing foundation for the entire machine. It is constructed from welded steel sections into an integrated frame structure, resulting in high overall rigidity. Multiple mounting positions are evenly distributed on the upper surface of the support frame 3 for assembling damping springs 30. The frame as a whole remains stationary and primarily bears all static loads and part of the dynamic loads of the screen disc 1, the eccentric transmission assembly 2, and the materials. It also works in conjunction with the damping springs 30 to achieve vibration isolation.

[0030] In this embodiment, the screen disc 1 is configured as a multi-layer structure, with each layer of screen disc 1 independently completing material screening. Each layer of screen disc 1 is equipped with a corresponding discharge port 10, and the different discharge ports 10 have different orientations, which can realize the separate discharge of materials of different particle sizes and different types, meeting the needs of multi-stage screening. The uppermost screen disc 1 has bearing mounting brackets integrally formed on both sides for fixing the bearing assembly 22. The side wall of the screen disc 1 is rigidly connected to the eccentric wheel in the eccentric transmission assembly 2, receiving the excitation force transmitted by the eccentric wheel to realize the overall up and down vibration. The drive motor 4 is fixedly installed on the mounting bracket on the rear side of the screen disc 1, serving as the sole power source for the entire machine. A pulley is installed at the end of the output shaft of the drive motor 4, which forms a belt drive cooperation with the active eccentric roller assembly 24 through the transmission belt, transmitting the rotational kinetic energy to the eccentric transmission assembly 2, providing power input for the entire excitation mechanism.

[0031] Continue to refer to the appendix Figure 1 The eccentric transmission assembly 2 is divided into two groups: a driving eccentric roller assembly 24 and a driven eccentric roller assembly 25. These two assemblies are arranged parallel to each other on the upper end of the screen disk 1, with pulleys mounted on the same side. They rotate synchronously and in phase via a transmission belt. The driving eccentric roller assembly 24 is driven by a drive motor 4, which in turn drives the driven eccentric roller assembly 25 to operate in coordination. The two assemblies have identical structures, each including an eccentric shaft 21, a bearing assembly 22, and an eccentric wheel. Eccentric wheels are fixedly mounted on the outer sides of both the driving eccentric roller assembly 24 and the driven eccentric roller assembly 25, and the eccentric wheels are rigidly fitted to the screen disk 1. When the eccentric wheels rotate circumferentially with the eccentric shaft 21, they generate periodic excitation force, directly driving the screen disk 1 to complete high-frequency reciprocating vibration.

[0032] like Figure 1 and Figure 3 Each eccentric shaft 21 has a set of bearing assemblies 22 symmetrically assembled at both ends. A clearance fit is used between the outer wall of the eccentric shaft 21 and the inner ring of the bearing assembly 22. In this embodiment, the single-sided assembly clearance is limited to 0.02mm-0.025mm. Figure 3 The 'a' in the figure represents the assembly clearance mentioned above. This clearance value was determined through multiple working condition tests. It can ensure that the eccentric shaft 21 and the inner ring of the bearing can have stable circumferential relative sliding to achieve load distribution. It can also avoid the problem of excessive clearance causing radial movement of the shaft and a decrease in vibration accuracy.

[0033] like Figure 2 The inner wall of the bearing inner ring is machined with an arc surface 23 facing the shaft center. The gap between the arc surface 23 and the outer wall of the eccentric shaft 21 forms an independent oil reservoir. After the equipment is filled with lubricating grease, a stable buffer oil film layer can be formed in this area to absorb instantaneous vibration impact. The inner wall of the bearing inner ring and the outer wall of the eccentric shaft 21 are both coated with a high-hardness, smooth, and wear-resistant coating, which effectively reduces the coefficient of friction when the eccentric shaft 21 and the bearing inner ring rotate circumferentially, reduces friction loss, and improves the service life of the components.

[0034] Continue to refer to the appendix Figure 3 The bearing assembly 22 is fitted with a sealing end cap 26 on its outer side, which completely seals the gap between the eccentric shaft 21 and the inner ring of the bearing. This seal provides protection, preventing leakage of lubricating grease from the gap and blocking dust and solid particles from entering the clearance, thus preventing impurities from causing rotational jamming or abnormal wear. The outer ring of the bearing assembly 22 is fixed inside the bearing mounting bracket of the screen disc 1, ensuring no relative movement between the outer ring and the screen disc 1, and allowing for stable transmission of vibration loads.

[0035] At least one disclosed embodiment provides a method for operating an eccentric transmission bearing structure for a vibrating screen, the method comprising: S1. Start the drive motor 4. The drive motor 4 drives the active eccentric roller assembly 24 to rotate. The active eccentric roller assembly 24 is linked with the driven eccentric roller assembly 25 to rotate synchronously. The eccentric shaft 21 rotates synchronously with the eccentric wheel. S2. In the initial stage of equipment startup, the eccentric shaft 21 is subjected to rotational torque and undergoes circumferential relative sliding due to the gap between the eccentric shaft 21 and the inner ring of the bearing. S3. The rotation of the eccentric wheel generates a periodic excitation force, which drives the screen plate 1 to vibrate up and down at high frequency. The alternating impact load generated by the vibration of the screen plate 1 is transmitted to the inner ring of the bearing through the eccentric rotating shaft 21. S4. The eccentric shaft 21 continuously rotates slowly relative to the inner ring of the bearing, distributing the alternating impact load evenly to the entire raceway of the inner ring of the bearing, thus avoiding the long-term concentrated action of the impact load on a single local area of ​​the bearing. S5. The lubricating grease in the gap between the eccentric shaft 21 and the inner ring of the bearing forms a buffer oil film, which absorbs the instantaneous vibration impact kinetic energy of the screen plate 1 and weakens the instantaneous contact stress of the bearing rolling pair. S6. The bottom damping spring 30 of the screen plate 1 continuously absorbs the vibration energy of the screen body and blocks the transmission of vibration to the support frame 3, so that the equipment can continuously and stably complete the material screening operation.

[0036] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as a second element, component, region, layer, or segment.

[0038] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An eccentric transmission bearing structure for a vibrating screen, comprising a screen disc (1), an eccentric transmission assembly (2), a support frame (3), and a drive motor (4); the eccentric transmission assembly (2) comprises an eccentric rotating shaft (21) and a bearing assembly (22), the bearing assembly (22) being sleeved on the outer wall of the eccentric rotating shaft (21); characterized in that, The outer wall of the eccentric rotating shaft (21) and the inner ring of the bearing assembly (22) are assembled with a clearance fit; the outer ring of the bearing assembly (22) is fixedly installed in the bearing mounting support on the screen plate (1).

2. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, The assembly clearance between the outer wall of the eccentric shaft (21) and the inner ring of the bearing is 0.02mm-0.025mm.

3. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, Both ends of the eccentric shaft (21) are equipped with a set of bearing assemblies (22), and the two sets of bearing assemblies (22) are symmetrically arranged at both ends of the eccentric transmission assembly (2).

4. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, The inner ring of the bearing forms an arc surface (23) towards the axis, and the gap space between the arc surface (23) and the outer wall of the eccentric shaft (21) forms a buffer oil film layer.

5. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, The eccentric transmission assembly (2) includes an active eccentric roller assembly (24) and a driven eccentric roller assembly (25). The active eccentric roller assembly (24) is driven by a drive motor (4) through belt transmission. The active eccentric roller assembly (24) and the driven eccentric roller assembly (25) rotate synchronously in conjunction with the belt. The rotating shafts of the active eccentric roller assembly (24) and the driven eccentric roller assembly (25) and the corresponding bearing inner rings are all fitted with clearance.

6. The eccentric transmission bearing structure for a vibrating screen as described in claim 5, characterized in that, Both the active eccentric roller assembly (24) and the driven eccentric roller assembly (25) are equipped with eccentric wheels on their outer sides. The eccentric wheels are rigidly connected to the screen plate (1). The excitation force generated by the rotation of the eccentric wheels is directly transmitted to the screen plate (1) to drive the screen plate (1) to vibrate up and down.

7. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, The bottom of the screen (1) is equipped with multiple sets of shock-absorbing springs (30), the lower end of the shock-absorbing springs (30) abuts against the support frame (3), and the screen (1) achieves flexible vibration isolation connection with the support frame (3) through the shock-absorbing springs (30).

8. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, The inner wall of the bearing inner ring and the outer wall of the eccentric shaft (21) are both provided with a smooth and wear-resistant coating to reduce frictional loss when the eccentric shaft (21) rotates relative to the bearing inner ring in the circumferential direction.

9. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, A sealing end cap (26) is provided on the outside of the bearing assembly (22), and the sealing end cap (26) seals the gap between the eccentric shaft (21) and the inner ring of the bearing.

10. The eccentric transmission bearing structure for a vibrating screen as described in claim 1, characterized in that, The screen (1) is multi-layered, and the discharge port (10) of the screen (1) faces different directions.

11. A working method for an eccentric transmission bearing structure used in a vibrating screen, characterized in that, The working method of the vibrating screen using the eccentric transmission bearing structure as described in any one of claims 1-10 includes: S1. Start the drive motor (4). The drive motor (4) drives the active eccentric roller assembly (24) to rotate. The active eccentric roller assembly (24) rotates synchronously with the driven eccentric roller assembly (25). The eccentric shaft (21) rotates synchronously with the eccentric wheel. S2. In the initial stage of equipment startup, the eccentric shaft (21) is subjected to rotational torque and undergoes circumferential relative sliding due to the gap between the eccentric shaft (21) and the inner ring of the bearing. S3. The eccentric wheel rotation generates a periodic excitation force that drives the screen plate (1) to vibrate up and down at high frequency. The alternating impact load generated by the vibration of the screen plate (1) is transmitted to the inner ring of the bearing through the eccentric rotating shaft (21). S4. The eccentric shaft (21) continuously rotates slowly relative to the inner ring of the bearing, distributing the alternating impact load evenly to the entire raceway of the inner ring of the bearing, thus avoiding the long-term concentrated action of the impact load on a single local area of ​​the bearing. S5. The eccentric shaft (21) and the lubricating grease in the gap between the bearing inner ring form a buffer oil film, which absorbs the instantaneous vibration impact energy of the screen plate (1) and weakens the instantaneous contact stress of the bearing rolling pair. S6. The bottom damping spring (30) of the screen plate (1) continuously absorbs the vibration energy of the screen body and blocks the vibration from being transmitted to the support frame (3), so that the equipment can continuously and stably complete the material screening operation.

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