Torsion and radial vibration force transmission vibration isolator

Abstract

The torsion and radial vibration force transmission vibration isolator comprises a driving shaft connecting shaft piece, a driven shaft, a driving shaft, a front end cover and an elastic connecting piece, the driving shaft connecting shaft piece is connected to the front end of the driving shaft, internal spline grooves are evenly formed in the inner circumference of the driving shaft connecting shaft piece, and a spline is arranged on one part of the periphery of the driven shaft; the front end cover is connected to the front end of the driving shaft connecting shaft piece, the part, without the splines, of the driven shaft extends out of the front end cover, a thrust ball bearing is arranged on the inner side of the front end of the driving shaft, and a rolling ball at the front end of the thrust ball bearing makes contact with the rear end of the driven shaft. And an elastic connecting piece is arranged between each internal spline groove and the spline. The torsional vibration isolation device can transmit torque and isolate torsional vibration, installation is convenient and fast, active adaptation of vibration isolation frequency can be achieved by adjusting and replacing the thicknesses of the springs and the cylindrical rollers with different rigidities, and the vibration isolation requirements of torsional vibration and radial vibration are met.

Description

Technical Field

[0001] This invention belongs to the field of vibration control of motor drive shafts, and relates to a force-transmitting vibration isolator for torsional and radial vibrations. Background Technology

[0002] Torsional vibration is widespread in industrial fields such as automobiles and ships. For example, ship propellers under periodic pulsating loads can induce torsional vibration in the drive shaft, while automobile engine crankshafts also generate torsional vibration under periodic forces. This type of vibration not only transmits to the vehicle or ship hull through the structure, reducing ride comfort, but can also lead to serious accidents such as crankshaft wear or even breakage due to resonance. Currently, traditional solutions often employ damping energy dissipation principles (such as rubber-viscose dampers) to suppress resonant amplitude. However, such methods alter the system's natural frequency, potentially worsening vibration isolation effects in other frequency bands, and cannot fundamentally prevent the transmission of vibration to the foundation.

[0003] Existing patented technologies, such as the Chinese invention patents "Torsion Vibration Attenuation Device" (application number: CN201180075606.6) and "Torsion Vibration Damper" (application number: CN201310057232.6), mainly design dampers that combine with clutches to address the torsional vibration of automotive transmission systems. However, their application scenarios are limited, and they lack versatility. Furthermore, during engine start-up and acceleration, the shaft system needs to pass through a resonance zone, and traditional dampers struggle to handle ultra-low frequency vibrations.

[0004] Existing technologies have significant shortcomings in addressing the combined vibration isolation requirements of radial and torsional vibrations. For example, Chinese patents such as "Sliding Beam and Spring Combination Nonlinear Ultra-Low Frequency Vibration Isolator" (application number: CN201210145254.3) and "Disc-Shaped Rubber Quasi-Zero Stiffness Vibration Isolator" (application number: CN201310330360.3) propose quasi-zero stiffness vibration isolation schemes for vertical translational vibrations, but do not address vibration isolation designs for torsional vibrations. Furthermore, existing shaft vibration isolators mostly employ single-function structures, making it impossible to adapt to multiple operating conditions through the adjustment of flexible elements. This results in a limited vibration isolation frequency range and makes it difficult to simultaneously meet the requirements of lightweight design and functional integration.

[0005] Based on the aforementioned technical bottlenecks, there is an urgent need for a shaft isolator that can simultaneously suppress torsional and radial vibrations and support dynamic adjustment of flexible elements. Summary of the Invention

[0006] Purpose of the invention

[0007] To address the problem that existing shaft vibration isolators cannot simultaneously isolate torsional and radial vibrations, this invention provides a force-transmitting vibration isolator for torsional and radial vibrations, which can have elastic elements to achieve vibration isolation effects under different working conditions.

[0008] Technical solution

[0009] A force-transmitting vibration isolator for torsional and radial vibration includes a drive shaft coupling, a driven shaft, a drive shaft, a front end cover, and a spring-loaded connector. The drive shaft coupling is connected to the front end of the drive shaft. The inner circumference of the drive shaft coupling is evenly distributed with internal spline grooves. A portion of the outer circumference of the driven shaft is provided with splines. The number of internal spline grooves and splines are equal and their positions correspond. The front end cover is connected to the front end of the drive shaft coupling. The portion of the driven shaft without splines extends out of the front end cover. A thrust ball bearing is provided on the inner side of the front end of the drive shaft. The balls at the front end of the thrust ball bearing contact the rear end of the driven shaft. A spring-loaded connector is provided between each internal spline groove and spline.

[0010] Furthermore, the number of internal spline slots and splines is greater than or equal to 4.

[0011] Furthermore, the elastic connector includes a side plate, a cylindrical roller, an H-shaped plate, a spring, and a limiting plate. The lower end of the H-shape of the H-shaped plate covers the spline, and the upper end of the H-shape of the H-shaped plate is a recessed arc groove. The cylindrical roller is located in the recessed arc groove and contacts the inner spline groove. Springs are abutted on both the left and right sides of the H-shape of the H-shaped plate, and the other end of each spring abuts on the side plate. The side plate contacts the inner wall of the inner spline groove. The rear end of the H-shaped plate is closed, and the front end of the H-shaped plate is not closed. The limiting plate is fixed to the front end of the H-shaped plate.

[0012] Furthermore, the cylindrical roller is hollow.

[0013] Furthermore, the number of springs between the H-shaped plate and each side plate is greater than or equal to 2, and one end of the spring is fixed to the H-shaped plate and / or fixed to the side plate.

[0014] Furthermore, the side plate is L-shaped, and the bent end of the side plate is axially fixed to the drive shaft connecting member.

[0015] Furthermore, the cylindrical roller contacts the bottom of the recessed arc groove.

[0016] Furthermore, the front end of the drive shaft has multiple fixing slots, and the rear end of the side plate is inserted into the fixing slots.

[0017] Furthermore, the spring is in its normal state, free from compression and stretching.

[0018] Advantages and effects

[0019] This invention, through a spline structure combined with a spring-loaded connector, can transmit torque and isolate torsional vibration. By adjusting and replacing springs of different stiffnesses and cylindrical roller thicknesses, the vibration isolation frequency can be adapted to different working conditions, thus meeting the needs for isolating torsional and radial vibrations. The thrust ball bearing enables force transmission. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the descriptions below.

[0021] Figure 1 A three-dimensional schematic diagram of the front side of a force-transmitting vibration isolator for torsional and radial vibrations;

[0022] Figure 2 A three-dimensional schematic diagram of the rear side of a force-transmitting vibration isolator for torsional and radial vibration.

[0023] Figure 3 A schematic diagram of the axial half-section of a force-transmitting vibration isolator for torsional and radial vibrations;

[0024] Figure 4 A schematic diagram of the radial half-section of a force-transmitting vibration isolator for torsional and radial vibrations;

[0025] Figure 5 This is a schematic diagram of the three-dimensional structure of the elastic connector;

[0026] Figure 6 A three-dimensional structural diagram showing a driven shaft with a spring-loaded connecting member installed.

[0027] Figure 7 A three-dimensional schematic diagram of the installation position of the limit plate (the left side of the diagram shows the structure without the limit plate installed);

[0028] Figure 8 This is a three-dimensional schematic diagram of the front side of the vibration isolator (without the front and rear end covers);

[0029] Figure 9 A three-dimensional structural diagram of a drive shaft equipped with a thrust ball bearing;

[0030] Figure 10 This is an enlarged planar schematic diagram of a portion of the elastic connector structure;

[0031] Figure 11 A radial cross-sectional view of a force-transmitting vibration isolator for torsional and radial vibrations of a six-bonded spline;

[0032] Figure 12 A radial cross-sectional view of a force-transmitting vibration isolator for torsional and radial vibrations of an eight-key spline.

[0033] Figure 13 The simulation results of spring stiffness versus system characteristic frequency are shown in the figure.

[0034] Figure 14 The simulation results of spring stiffness and vibration isolation rate are shown in the figure.

[0035] Figure 15 The simulation results of the relationship between the thickness of the cylindrical roller 3 and the system characteristic frequency are shown in the figure.

[0036] Figure 16 The simulation results for the thickness and vibration isolation rate of cylindrical roller 3 are shown in the figure.

[0037] Explanation of reference numerals in the attached drawings: 1. Drive shaft connecting member, 2. Side plate, 3. Cylindrical roller, 4. H-shaped plate, 5. Driven shaft, 6. Spring, 7. Drive shaft, 8. Limiting plate, 9. Thrust ball bearing, 10. Front end cover, 11. Inner spline groove, 12. Spline, 13. Fixing groove. Detailed Implementation

[0038] Example 1

[0039] like Figures 1-10 As shown, a force-transmitting vibration isolator for torsional and radial vibration includes a drive shaft coupling 1, a driven shaft 5, a drive shaft 7, a front end cover 10, and a spring-loaded connector. The drive shaft coupling 1 is connected to the front end of the drive shaft 7 by screws. The inner circumference of the drive shaft coupling 1 is evenly distributed with internal spline grooves 11. A portion of the outer circumference of the driven shaft 5 is provided with splines 12. The number of internal spline grooves 11 and splines 12 is equal to 4 and their positions correspond. The front end cover 10 is connected to the front end of the drive shaft coupling 1 by screws. The portion of the driven shaft 5 without splines 12 extends out of the front end cover 10. A thrust ball bearing 9 is interference-fitted on the inner side of the front end of the drive shaft 7. The balls at the front end of the thrust ball bearing 9 contact the rear end of the driven shaft 5. A spring-loaded connector is provided between each internal spline groove 11 and spline 12.

[0040] The elastic connector includes a side plate 2, a cylindrical roller 3, an H-shaped plate 4, a spring 6, and a limiting plate 8. The lower end of the H-shape of the H-shaped plate 4 covers the spline 12, and the upper end of the H-shape of the H-shaped plate 4 is a recessed arc groove. The cylindrical roller 3 is located in the recessed arc groove and contacts the inner spline groove 11. The cylindrical roller 3 is hollow, allowing for appropriate compression deformation. The cylindrical roller 3 contacts the bottom of the recessed arc groove, reducing the contact area and facilitating rotation. Springs 6 are abutted on both sides of the H-shape of the H-shaped plate 4, and the other end of each spring 6 abuts against the side plate 2. The side plate 2 contacts the inner wall of the inner spline groove 11. The rear end of the H-shaped plate 4 is closed, while the front end is open. The limiting plate 8 is fixed to the front end of the H-shaped plate 4 with screws. The number of springs 6 between the H-shaped plate 4 and each side plate 2 is greater than or equal to 2 for greater stability. One end of each spring 6 is welded to the H-shaped plate 4 and / or welded to the side plate 2. The side plate 2 is L-shaped, and the bent end of the side plate 2 is axially fixed to the drive shaft coupling 1 by screws. The front end of the drive shaft 7 has multiple fixing slots 13, and the rear end of the side plate 2 is inserted into the fixing slots 13. Preferably, the springs 6 are in their normal state without compression or tension, but a moderate amount of compression is also acceptable.

[0041] Example 2

[0042] like Figure 11As shown, the number of internal spline grooves 11 and splines 12 are 6 each, and the positions of other structures are adaptively changed but the structures are the same.

[0043] Example 3

[0044] like Figure 12 As shown, the number of internal spline grooves 11 and splines 12 are 8 each, and the positions of other structures are adaptively changed but the structures are the same.

[0045] For larger journals, the number of spline keys can also be changed as the journal size increases; six-key and eight-key designs use similar structures. Increasing the number of keys increases the contact area, resulting in a more uniform load distribution and reducing stress concentration on individual keys, thus significantly improving overall torque transmission capability. Multi-key structures provide more continuous engagement, reduce torque fluctuations during single-key switching, improve transmission smoothness, and enhance alignment and installation accuracy.

[0046] For the propulsion shaft, since the transmission of torque generates thrust, the propulsion shaft is required to transmit the thrust to the machine body. At the same time, due to the vibration of the motor and shaft, the vibration isolation of torsional and radial vibrations will be transmitted to the driven shaft 5 through the drive shaft 7. When designing the propulsion shaft vibration isolator, the design principle is to isolate torsional and radial vibrations while ensuring the transmission of torque and thrust.

[0047] The drive shaft coupling 1 and drive shaft 7 serve as power components, the thrust ball bearing 9 serves as a thrust-bearing component, the circumferentially distributed elastic connecting parts serve as vibration isolation components, and the driven shaft 5 serves as an output component.

[0048] To achieve vibration isolation, the vibration isolation component consists of multiple sub-units arranged circumferentially. In installation, springs 6 can be welded to both side plate 2 and H-shaped plate 4 simultaneously, or only one spring 6 can be welded. Then, hollow cylindrical rollers 3 are installed in the upper arc groove of the H-shaped plate 4. Since the arc is a superior arc, the secant line of the arc-shaped end is smaller than the outer diameter of the hollow cylindrical roller 3, thus ensuring radial limitation of the hollow cylindrical roller 3. A limiting plate 8 ensures axial limitation. The strength of the side plate 2 and springs, as well as the wall thickness of the cylindrical roller 3, can be adjusted for different transmission conditions. The elastic connector, composed of side plate 2, spring 6, cylindrical roller 3, and H-shaped plate 4, is assembled with the splines 12 of the driven shaft 5 through the square groove at the lower end of the H-shaped plate 4, arranged circumferentially. Finally, the driven shaft 5 and the elastic connector are inserted into the drive shaft coupling 1, and secured with screws through the flange of the drive shaft 7 and the screw holes on the rear end face of the drive shaft coupling 1. To secure the side plate 2, the size of the drive shaft coupling 1 must be larger than the key of the driven shaft 5. Positioning holes are provided between the side plate 2 and the drive shaft coupling 1. Thanks to the size difference, an L-shaped wrench can be used to install hex bolts at the front and rear ends of the drive shaft coupling 1. For a single spring-loaded connector, both the upper and lower side plates 2 need to be fixed to the drive shaft coupling 1, and the spring-loaded connectors at each key position are fixed sequentially. The front cover 10 is connected to the drive shaft coupling 1 to ensure the sealing of the vibration isolator's interior and the axial positioning of the driven shaft 5. The end face of the inlet is radially positioned with the thrust ball bearing 9 installed in the drive shaft 7. The drive shaft coupling 1 is connected via the flange of the drive shaft 7. When selecting the spring 6, it remains at its natural length and in a relaxed state when installed in the drive shaft coupling 1. As for the cylindrical roller 3, it is kept in a compressed state during installation. Since the radial vibration deformation is very small, the cylindrical roller 3 will keep in contact with the inner spline groove 11 of the drive shaft connecting part 1 during the actual vibration isolation process.

[0049] When the propulsion shaft is working, the drive shaft 7 of the power component transmits torque and vibration to the elastic connector through the drive shaft coupling 1. During the torsion process, the side plate 2 is highly efficient in static torsion because the static stiffness and dynamic stiffness of the spring 6 are basically the same. When the dynamic excitation frequency is much higher than the system's natural frequency, high-frequency vibration is significantly suppressed. Using two sets of side plates 2 and spring 6, the spring 6 can be stretched and compressed during the torsion process, thus achieving the function of isolating torsional vibration when the torsion is in forward and reverse rotation. At the same time, the cylindrical roller 3 can slide at a certain angle on the arc surface in the inner spline groove 11, which can perform radial limiting. When excessive relative torsion occurs, it will lock up, extending the spring life. For radial vibration, the cylindrical rollers 3, due to their axisymmetric structure, experience more uniform force distribution. The hollow structure provides greater deflection or deformation space, increasing elasticity. In terms of dynamic characteristics, the hollow structure has less mass and a lower natural frequency, making it more suitable for isolating high-frequency vibrations. In this example, the diagonally distributed cylindrical rollers 3 can achieve radial vibration isolation through their compression or elongation, as well as the elongation and compression of the spring 6. Simultaneously, the rotational motion of the driven shaft 5 generates thrust, which is transmitted through the shaft end face to the thrust ball bearing 9, and then from the thrust ball bearing 9 to the machine body, achieving power output. For the thrust ball bearing 9, only its seat ring and ball cage are used; the original shaft ring on the other side is discarded, allowing the balls to directly contact the shaft end face. Due to the rolling of the balls, the torsion and radial vibration of the driving shaft 7 are not directly transmitted to the driven shaft 5, but only axial force is transmitted, achieving the thrust function. The specific design requirements for the thrust ball bearing 9 are that the outer diameter should be smaller than the narrowest diameter of the drive shaft coupling 1, but slightly larger than the bottom bearing groove of the drive shaft coupling 1 to achieve an interference fit, while the inner diameter should be slightly larger than the bearing groove positioning block. The thrust ball bearing 9 is then installed using a bearing press-fitting device.

[0050] For different operating conditions and different torsional frequencies, the natural frequency of the system can be increased or decreased by replacing the springs with springs of different stiffness to prevent resonance. Figure 13 As shown, with the increase of spring stiffness, the characteristic frequency of the entire system increases, but the rate of increase of the characteristic frequency decreases. The vibration isolation rate distribution is as follows: Figure 14 As shown. Different radial vibration frequencies can be achieved by replacing cylindrical rollers 3 with rollers of different thicknesses, such as... Figure 15 As shown, with the spring stiffness remaining constant, the characteristic frequency of the entire system increases with the increase of thickness t. The rate of increase in characteristic frequency is accelerating with the increase of thickness t of the cylindrical roller 3. The vibration isolation rate is as follows: Figure 16 The distribution is shown.

[0051] Through the Figure 14 and Figure 16 Data observation shows that when the excitation frequency / natural frequency > Under certain conditions, the vibration transmissibility is less than zero, and the force-transmitting vibration isolators for torsional and radial vibrations begin to function. The higher the excitation frequency / natural frequency ratio, the better the vibration isolation effect. When selecting side plate 2, mirror spring plate 6, and hollow cylindrical roller 3, the excitation frequency band shown in the figure can be used. Therefore, to obtain a good vibration isolation effect, the natural frequency of the vibration isolation device and shaft system should be much smaller than the excitation frequency to increase the excitation frequency / natural frequency value. In practice, the excitation frequency / natural frequency ratio is often taken as 2.5 to 5, and should not be too large. This is because: a too small natural frequency requires a very small spring stiffness k, which will make it difficult for the spring to support the weight of the machine, leading to stability problems. Moreover, when the excitation frequency / natural frequency ratio rises to a certain value, the decreasing trend of the vibration transmissibility TA tends to level off, and the vibration isolation effect tends to level off. Specific implementation schemes can be selected according to the diagram. For example, for torsional vibration isolation, when a spring with a stiffness of 250 N / mm is selected, its characteristic frequency is approximately 16.3 Hz. The vibration isolator works when the excitation frequency is higher than 23 Hz, and it is more suitable for operating conditions of 35–60 Hz. For radial vibration isolation, the diagram uses structural steel as an example. When the thickness of the hollow cylindrical roller 3 is 0.2 mm, it is more suitable for operating conditions of 150–170 Hz.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A force-transmitting vibration isolator for torsional and radial vibrations, characterized in that: The device includes a drive shaft coupling (1), a driven shaft (5), a drive shaft (7), a front end cover (10), and a spring-loaded connector. The drive shaft coupling (1) is connected to the front end of the drive shaft (7). The inner circumference of the drive shaft coupling (1) is evenly distributed with internal spline grooves (11). A portion of the outer circumference of the driven shaft (5) is provided with splines (12). The number of internal spline grooves (11) and splines (12) are equal and their positions correspond. The front end cover (10) is connected to the front end of the drive shaft coupling (1). The portion of the driven shaft (5) without splines (12) extends out of the front end cover (10). A thrust ball bearing (9) is provided on the inner side of the front end of the drive shaft (7). The balls at the front end of the thrust ball bearing (9) are in contact with the rear end of the driven shaft (5). A spring-loaded connector is provided between each internal spline groove (11) and spline (12).

2. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 1, characterized in that: The number of internal spline grooves (11) and splines (12) is greater than or equal to 4.

3. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 1, characterized in that: The elastic connector includes a side plate (2), a cylindrical roller (3), an H-shaped plate (4), a spring (6), and a limiting plate (8). The lower end of the H-shaped plate (4) covers the spline (12), and the upper end of the H-shaped plate (4) is a recessed arc groove. The cylindrical roller (3) is located in the recessed arc groove and contacts the inner spline groove (11). The left and right sides of the H-shaped plate (4) are supported by springs (6), and the other end of each spring (6) is supported by the side plate (2). The side plate (2) contacts the inner wall of the inner spline groove (11). The rear end of the H-shaped plate (4) is closed, and the front end of the H-shaped plate (4) is not closed. The limiting plate (8) is fixed to the front end of the H-shaped plate (4).

4. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 3, characterized in that: The cylindrical roller (3) is hollow.

5. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 3, characterized in that: The number of springs (6) between the H-shaped plate (4) and each side plate (2) is greater than or equal to 2, and one end of the spring (6) is fixed to the H-shaped plate (4) and / or fixed to the side plate (2).

6. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 3, characterized in that: The side plate (2) is L-shaped, and the bent end of the side plate (2) is axially fixed to the drive shaft connecting member (1).

7. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 3, characterized in that: The cylindrical roller (3) contacts the bottom of the recessed arc groove.

8. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 3, characterized in that: The front end of the drive shaft (7) is provided with multiple fixing slots (13), and the rear end of the side plate (2) is inserted into the fixing slots (13).

9. The force-transmitting vibration isolator for torsional and radial vibrations according to claim 3 or 5, characterized in that: The spring (6) is in its normal state, free from compression and stretching.

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