Vibrating assembly based on cantilever shaft and machining method of vibrating assembly

Abstract

The invention discloses a vibrating assembly based on a cantilever shaft and a machining method of the vibrating assembly, and relates to the technical field of vibrating equipment.The machining method comprises the steps that according to the use working condition and excitation requirements of the vibrating assembly, it is determined that a permanent magnet synchronous motor is adopted for a driving system, and the permanent magnet synchronous motor is composed of a motor stator and a motor rotor; the mass and the eccentric radius of an eccentric block used for generating exciting force are determined based on the exciting requirement; a motor stator is fixedly installed in the shell, and a motor rotor is fixedly connected to one end of a motor rotating shaft; an eccentric block is fixedly installed on a motor rotating shaft, and a first rolling bearing and a second rolling bearing are arranged on the motor rotating shaft on the two axial sides of the eccentric block respectively. According to the invention, the motor rotating shaft cantilever section is actively arranged in structural design instead of a simple avoidance cantilever structure; the eccentric block is arranged between the two sets of bearings, and the motor rotor is located on the outer side of the bearing on one side, so that the position and the range of the cantilever section are definitely defined structurally.

Description

Technical Field

[0001] This invention relates to the field of vibration equipment technology, specifically to a vibratory assembly based on a cantilever shaft and its processing method. Background Technology

[0002] Insertion-type eccentric concrete vibrators with built-in motors need to be inserted into concrete or other materials for vibration operations. Their overall structure is usually slender. The outer diameter of existing concrete vibrators is generally 38mm, 45mm, 50mm, 56mm, etc., while the length of the rod is usually 400-600mm or more. Due to the limitation of the slender structure, the cross-sectional area of ​​the vibrator shell is small. In a limited space, the motor, shaft, eccentric block, bearing and motor lead wire need to be arranged at the same time. This inevitably results in a certain length of outward extension or weak support section of the motor shaft, which creates the objective conditions for forming a cantilever structure. To avoid the motor shaft forming a cantilever structure and causing large deflections during high-speed operation, existing technologies typically increase the number of bearings to provide multi-point support for the shaft. For example, a set of smaller bearings is placed at the end near the motor lead wire to provide support for the motor shaft, and the motor lead wire is led out from the annular area between the outer circumference of the bearing and the housing. At the same time, bearings are placed on both sides of the axial direction of the eccentric block area to support the shaft, so as to minimize the cantilever length of the shaft, or even avoid the existence of cantilever sections in the structural design. The design scheme of using multiple bearings to avoid the cantilever structure has revealed many problems in practical applications. On the one hand, the small-sized bearings used near the motor lead have limited load-bearing capacity and cannot withstand the large radial eccentric force generated by the eccentric block during high-speed operation for a long time. On the other hand, the motor lead passes through a narrow annular space, which is prone to friction with the housing or hole wall under vibration conditions, causing insulation wear and safety hazards. In addition, multiple bearings supporting the same motor shaft at the same time require extremely high coaxiality, which is difficult to guarantee in actual processing and assembly, and can easily lead to unstable shaft operation. It can be seen that the design idea of ​​simply increasing the number of bearings to avoid the shaft cantilever is difficult to balance load-bearing capacity, safety and operational stability in a slender vibratory bar structure. Therefore, this application proposes a vibratory assembly based on a cantilever shaft and its processing method. Summary of the Invention

[0003] The purpose of this invention is to provide a vibratory tamping assembly based on a cantilever shaft and its processing method, so as to solve the problems mentioned in the background art.

[0004] This invention can be achieved through the following technical solution: a method for processing a vibratory tamping assembly based on a cantilever shaft, comprising: S1. Based on the operating conditions and excitation requirements of the vibrating components, the drive system is determined to be a permanent magnet synchronous motor. The permanent magnet synchronous motor consists of a motor stator and a motor rotor. The mass and eccentric radius of the eccentric block used to generate the excitation force are determined based on the excitation requirements. S2. Fix the motor stator inside the housing and fix the motor rotor to one end of the motor shaft; S3. The eccentric block is fixedly installed on the motor shaft, and at least one set of rolling bearing one and at least one set of rolling bearing two are respectively installed on the motor shaft on both sides of the eccentric block, and the outer rings of rolling bearing one and rolling bearing two are fixedly installed in the housing. S4. By limiting the axial position of rolling bearing one and rolling bearing two, the motor rotor is located on the side of rolling bearing one away from the eccentric block, so that the part of the motor shaft covered by the motor rotor forms a cantilever section. S5. Under the centrifugal load generated by the eccentric block, calculate the maximum deflection at the end of the cantilever section and compare the maximum deflection with the working air gap value between the motor rotor and the motor stator. When the maximum deflection is less than the working air gap value, it is determined that the vibrating assembly meets the operating requirements.

[0005] A further technical improvement of the present invention is that, after S5, the equivalent dynamic load borne by rolling bearing one and rolling bearing two is calculated based on the mass of the eccentric block, the eccentric radius and the working speed of the motor shaft, and the calculated lifespan is checked to see if it meets the preset lifespan design requirements.

[0006] A further technical improvement of the present invention is that: rolling bearing one and rolling bearing two are the same cylindrical roller bearings.

[0007] A further technical improvement of the present invention is that, when rolling bearing one and rolling bearing two are installed in the housing, the coaxiality tolerance grade of each bearing mounting hole is controlled to be no less than grade 4.

[0008] A further technical improvement of the present invention is that, in S2, after the motor rotor is fixedly connected to one end of the motor shaft, an outlet space for the motor lead wires to be led out is also provided. The outlet space is located inside the housing and is radially outside the cantilever section and the rolling bearing.

[0009] The present invention also discloses a vibratory assembly based on a cantilever shaft. The vibratory assembly is manufactured by any of the above-mentioned vibratory assembly processing methods and includes a housing, a permanent magnet synchronous motor, a motor shaft, an eccentric block, and rolling bearing one and rolling bearing two. The permanent magnet synchronous motor includes a motor stator and a motor rotor. The motor stator is fixedly installed inside the housing, and the motor rotor is fixedly connected to one end of the motor shaft. The eccentric block is fixedly installed on the motor shaft; Both rolling bearing one and rolling bearing two are mounted on the motor shaft and are located on both sides of the axial direction of the eccentric block. The outer rings of rolling bearing one and rolling bearing two are fixedly mounted in the housing, thereby forming a double support structure for the motor shaft on both sides of the eccentric block. The motor rotor is located on the side of the rolling bearing away from the eccentric block, so that the part of the motor shaft covered by the motor rotor forms a cantilever section.

[0010] A further technical improvement of the present invention is that: a front plug and a rear plug are respectively provided at both axial ends of the housing, and the front plug and the rear plug are fixedly installed on the housing.

[0011] A further technical improvement of the present invention is that: a vibration-damping and insulating sealing plug is provided inside the housing, the vibration-damping and insulating sealing plug is disposed on the side of the motor rotor away from the eccentric block, and the vibration-damping and insulating sealing plug is installed on the housing; The motor stator is electrically connected to a motor lead wire, which passes through a vibration-damping insulating sealing plug and is led out from the housing.

[0012] Compared with the prior art, the present invention has the following beneficial effects: This invention employs an eccentric block with bearings on both sides in its structural arrangement, creating a cantilever section on the side of the motor rotor. This allows for a clear definition of the position and length of the cantilever section without increasing the number of bearings. This structural arrangement enables the stress state and deformation characteristics of the cantilever section to be determined during the design phase, providing a clear structural basis for subsequent analysis and verification of the operational safety of the cantilever section. Furthermore, this invention calculates and verifies the maximum deflection offset of the cantilever section of the rotating shaft in response to the centrifugal load generated by the eccentric block during high-speed operation. It then compares this deflection offset with the working air gap between the motor stator and the motor rotor, thereby determining whether the designed cantilever section meets the usage requirements during the design phase. In this way, the rotating shaft cantilever structure is kept under control in terms of stress and deformation, avoiding problems such as stator-rotor interference caused by excessive offset of the cantilever section. On the other hand, by systematically designing and verifying the support structure and cantilever deformation under the premise of accepting the existence of the rotating shaft cantilever, this invention reduces the reliance on multiple sets of bearings to avoid the cantilever, reduces the number of bearings and the requirements for assembly coaxiality, and at the same time provides structural space for the reasonable arrangement of motor lead wires; while ensuring the compactness of the slender vibrator structure, it improves the stability of the rotating shaft operation and the reliability of the whole machine, and is suitable for high-frequency, high-speed concrete vibration operation environment. Attached Figure Description

[0013] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0014] Figure 1 This is a flowchart of the processing method for the vibratory tamping component in this invention; Figure 2 This is a cross-sectional view of the vibrating assembly in this invention.

[0015] In the diagram: 1. Front plug; 2. Rolling bearing one; 3. Housing; 4. Eccentric block; 5. Motor shaft; 6. Rolling bearing two; 7. Motor stator; 8. Motor rotor; 9. Vibration-proof insulating sealing plug; 10. End cover; 11. Motor lead wire; 12. Rear plug. Detailed Implementation

[0016] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0017] Please see Figure 1 As shown, the present invention provides a method for processing a vibratory tamping assembly based on a cantilever shaft, comprising: S1. Based on the operating conditions and excitation requirements of the vibrating components, the drive system is determined to be a permanent magnet synchronous motor. The permanent magnet synchronous motor consists of a motor stator 7 and a motor rotor 8. The mass and eccentric radius of the eccentric block 4 used to generate the excitation force are determined based on the excitation requirements. Specifically, in step S1, according to the process requirements of concrete vibration construction, the design excitation force of the vibrating assembly is 6000N, and the vibration frequency is 200Hz. Based on the above excitation requirements, it is preliminarily estimated that the maximum motor power required for the vibrating assembly in working condition is 2kW.

[0018] To meet the volume and power density requirements of the cantilevered rotor structure, a permanent magnet synchronous motor is selected as the power source for the drive system. The permanent magnet synchronous motor consists of a stator 7 and a rotor 8. Based on the motor power and structural dimensions, the following structural parameters are determined: a designed motor power of 2kW, a motor length of 66mm, a stator inner diameter Dm = 23mm, a rotor outer diameter dm = 22.1mm, and an air gap t = 0.45mm between the stator and rotor.

[0019] Meanwhile, the structural parameters of the eccentric block 4 used to generate the excitation force are determined according to the excitation requirements. The length of the eccentric block is 86mm, the mass is m=0.285kg, and the eccentric radius is r=0.0136m.

[0020] S2. In step S2, the motor stator 7 is fixedly installed inside the housing 3, and the motor rotor 8 is fixedly connected to one end of the motor shaft 5, so that the motor rotor 8 drives the motor shaft 5 to rotate synchronously.

[0021] In this step, space also needs to be planned for the lead-out of the motor lead 11. This lead-out space is located inside the housing 3 and is radially outside the cantilever section that will be subsequently covered by the motor rotor 8 and the rolling bearing 2.

[0022] S3. The eccentric block 4 is fixedly installed on the motor shaft 5, and rolling bearing 2 and rolling bearing 6 are respectively installed on the motor shaft 5 on both sides of the eccentric block 4, and the outer rings of rolling bearing 2 and rolling bearing 6 are fixedly installed in the housing 3. In this embodiment, rolling bearing 2 and rolling bearing 6 are the same cylindrical roller bearing, specifically model NUP2204E. The diameter of the motor shaft 5 is selected as 20mm.

[0023] In bearing load verification, the formula for calculating the equivalent dynamic load of the bearing is as follows: ; in, ; In the formula, C—the calculated value of the basic rated dynamic load, in N; P—Equivalent dynamic load, N; —Radial load, N; —Axial load, N; —Lifespan factor; — Velocity factor; —Moment load factor; —Impact load factor; —Temperature factor; —Basic radial dynamic load rating of the bearing, N.

[0024] The shaft speed is calculated as follows: ; The angular frequency is: ; The radial load is: ; Axial load is taken as: ; The equivalent dynamic load is: ; Refer to the mechanical design manual for values: =1.23; =0.171; =1.5; =1.2; =1.0; NUP2204E bearing ; Substituting the values, we get: C≈80461.81N; The structure employs two NUP2204E bearings at each end of the eccentric block, with the radial load distributed to each bearing as follows: 80461.81 ÷ 4 ≈ 20115.45 N; Comparing the C of a single bearing with , satisfying C≤ The bearings meet the design requirements. When installing rolling bearing 2 and rolling bearing 6 into housing 3, the coaxiality tolerance grade of each bearing mounting hole shall be controlled to be no less than grade 4.

[0025] S4. By limiting the axial position of rolling bearing 12 and rolling bearing 26, the motor rotor 8 is located on the side of rolling bearing 12 away from the eccentric block 4, so that the part of the motor shaft 5 covered by the motor rotor 8 forms a cantilever section. Specifically, the length of the motor shaft 5 is determined based on the lengths of the motor and the eccentric block, with a shaft diameter of 20mm. The geometric parameters of the cantilever section are as follows: a=57.75mm; b=57.25mm; L=115mm; c=94.5mm.

[0026] S5. Under the centrifugal load generated by the eccentric block 4, calculate the maximum deflection at the end of the cantilever section and compare the maximum deflection with the working air gap value between the motor rotor 8 and the motor stator 7.

[0027] The formula for calculating eccentric load is: ; Substitute specific values: ; The formula for calculating the deflection angle of a cantilever rotor is: ; The formula for calculating the maximum offset is: ; Substituting the values, we get: ; ; The maximum offset of the cantilever rotor is 5.30μm, which is much smaller than the working air gap of 0.45mm between the motor stator 7 and the motor rotor 8. Therefore, the cantilever structure design of the motor shaft 5 meets the operating requirements.

[0028] After S5, based on the mass of eccentric block 4, eccentric radius and working speed of motor shaft 5, calculate the equivalent dynamic load borne by rolling bearing 1 2 and rolling bearing 2 6, and check whether their calculated life meets the preset life design requirements.

[0029] And please see Figure 2 As shown, this embodiment also discloses a vibratory assembly based on a cantilever shaft. The vibratory assembly is manufactured using any of the above-mentioned vibratory assembly manufacturing methods and includes a housing 3, a permanent magnet synchronous motor, a motor shaft 5, an eccentric block 4, and rolling bearing 2 and rolling bearing 6. The permanent magnet synchronous motor includes a motor stator 7 and a motor rotor 8. The motor stator 7 is fixedly installed inside the housing 3, and the motor rotor 8 is fixedly connected to one end of the motor shaft 5 and rotates synchronously with the motor shaft 5.

[0030] Eccentric block 4 is fixedly installed on motor shaft 5 to generate excitation force when motor shaft 5 rotates. Rolling bearing 2 and rolling bearing 6 are both installed on motor shaft 5 and are located on both sides of eccentric block 4 respectively. The outer rings of rolling bearing 2 and rolling bearing 6 are fixedly installed in housing 3, thus forming a double support structure for motor shaft 5 on both sides of eccentric block 4.

[0031] Rolling bearing 2 is located on the side closer to the permanent magnet synchronous motor, and rolling bearing 6 is located on the other side of the eccentric block 4. Through the axial arrangement of rolling bearings 2 and 6, the motor rotor 8 is positioned on the side of rolling bearing 2 away from the eccentric block 4, thus forming a cantilever section of the motor shaft 5 covered by the motor rotor 8. This cantilever section undergoes stress and deformation analysis under the centrifugal load generated by the eccentric block 4 to ensure its operational safety.

[0032] The housing 3 is provided with a front plug 1 and a rear plug 12 at its two axial ends. Both the front plug 1 and the rear plug 12 are fixedly installed on the housing 3 to seal and protect the internal structure of the housing 3, while improving the overall structural strength and sealing performance of the vibrating assembly.

[0033] On the side near the permanent magnet synchronous motor, the housing 3 is provided with an end cover 10. The end cover 10 is used to position the permanent magnet synchronous motor in the axial direction and cooperates with the housing 3 to form a motor mounting cavity.

[0034] On the side of the motor rotor 8 away from the eccentric block 4, a vibration-damping and insulating sealing plug 9 is provided inside the housing 3. The vibration-damping and insulating sealing plug 9 is installed on the housing 3 and is used to dampen, insulate, and seal the motor lead wire 11. The motor stator 7 is electrically connected to the motor lead wire 11. The motor lead wire 11 passes through the vibration-damping and insulating sealing plug 9 and is led out from the housing 3 to realize the power supply connection to the permanent magnet synchronous motor.

[0035] Through the above structural arrangement, within the limited space of the shell 3 of the slender vibratory assembly, it is possible to ensure that the motor shaft 5 is reliably supported under eccentric load, and to provide a reasonable and safe lead-out path for the motor lead wire 11, thereby improving the stability and safety of the vibratory assembly under high-speed operation.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for processing a vibratory tamping assembly based on a cantilever shaft, characterized in that, include: S1. Based on the operating conditions and excitation requirements of the vibrating components, the drive system is determined to be a permanent magnet synchronous motor. The permanent magnet synchronous motor consists of a motor stator (7) and a motor rotor (8). The mass and eccentric radius of the eccentric block (4) used to generate the excitation force are determined based on the excitation requirements. S2. Fix the motor stator (7) inside the housing (3) and fix the motor rotor (8) to one end of the motor shaft (5); S3. The eccentric block (4) is fixedly installed on the motor shaft (5), and at least one set of rolling bearing one (2) and at least one set of rolling bearing two (6) are respectively installed on the motor shaft (5) on both sides of the axial direction of the eccentric block (4), and the outer rings of rolling bearing one (2) and rolling bearing two (6) are fixedly installed in the housing (3). S4. By limiting the axial position of rolling bearing 1 (2) and rolling bearing 2 (6), the motor rotor (8) is located on the side of rolling bearing 1 (2) away from the eccentric block (4), so that the part of the motor shaft (5) covered by the motor rotor (8) forms a cantilever section. S5. Under the centrifugal load generated by the eccentric block (4), calculate the maximum deflection at the end of the cantilever section and compare the maximum deflection with the working air gap value between the motor rotor (8) and the motor stator (7). When the maximum deflection offset is less than the working air gap value, the vibratory tamping assembly is deemed to meet the operating requirements.

2. The method for processing a vibratory assembly based on a cantilever shaft according to claim 1, characterized in that, After S5, based on the mass of the eccentric block (4), the eccentric radius, and the working speed of the motor shaft (5), the equivalent dynamic load borne by the rolling bearing one (2) and the rolling bearing two (6) is calculated, and their calculated lifespan is checked to see if it meets the preset life design requirements.

3. The method for processing a vibratory assembly based on a cantilever shaft according to claim 2, characterized in that, Rolling bearing 1 (2) and rolling bearing 2 (6) are the same cylindrical roller bearings.

4. The method for processing a vibratory assembly based on a cantilever shaft according to claim 3, characterized in that, When rolling bearing 1 (2) and rolling bearing 2 (6) are installed in housing (3), the coaxiality tolerance grade of each bearing mounting hole shall be controlled to be no less than grade 4.

5. The method for processing a vibratory assembly based on a cantilever shaft according to claim 1, characterized in that, In S2, after the motor rotor (8) is fixedly connected to one end of the motor shaft (5), an outlet space is also provided for the motor lead wire (11) to be led out. The lead-out space is located inside the housing (3) and is radially outside the cantilever section and the rolling bearing (2).

6. A vibratory compaction assembly based on a cantilever shaft, characterized in that, The vibratory assembly is manufactured using the vibratory assembly processing method described in any one of claims 1-5, and includes a housing (3), a permanent magnet synchronous motor, a motor shaft (5), an eccentric block (4), and rolling bearing one (2) and rolling bearing two (6). The permanent magnet synchronous motor includes a motor stator (7) and a motor rotor (8). The motor stator (7) is fixedly installed inside the housing (3), and the motor rotor (8) is fixedly connected to one end of the motor shaft (5). The eccentric block (4) is fixedly installed on the motor shaft (5); The first rolling bearing (2) and the second rolling bearing (6) are both installed on the motor shaft (5) and are located on both sides of the axial direction of the eccentric block (4). The outer rings of the first rolling bearing (2) and the second rolling bearing (6) are fixedly installed in the housing (3), thereby forming a double support structure for the motor shaft (5) on both sides of the eccentric block (4). The motor rotor (8) is located on the side of the rolling bearing (2) away from the eccentric block (4), so that the part of the motor shaft (5) covered by the motor rotor (8) constitutes a cantilever section.

7. A vibratory tamping assembly based on a cantilever shaft according to claim 6, characterized in that, The housing (3) has a front plug (1) and a rear plug (12) at its two axial ends, and the front plug (1) and the rear plug (12) are fixedly installed on the housing (3).

8. A vibratory tamping assembly based on a cantilever shaft according to claim 7, characterized in that, The housing (3) is provided with a vibration-damping insulating sealing plug (9), which is located on the side of the motor rotor (8) away from the eccentric block (4) and is installed on the housing (3). The motor stator (7) is electrically connected to a motor lead wire (11), which passes through the anti-vibration insulating sealing plug (9) and is led out from the housing (3).

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