Inclined plane pressing type force transmission vibration isolator for torsion and radial vibration

Abstract

A driving shaft is connected to the rear end of a driving shaft connecting piece, four internal spline grooves are evenly formed in the inner circumference of the driving shaft connecting piece, four splines are arranged on a part of the outer circumference of a driven shaft, the number of the internal spline grooves is equal to that of the splines, and the positions of the internal spline grooves and the splines correspond to each other. The end cover is connected to the front end of the driving shaft connecting piece, the part, without the spline, of the driven shaft extends out of the end cover, the thrust ball bearing is arranged on the inner side of the front end of the shaft connecting piece, a rolling ball at the front end of the thrust ball bearing makes contact with the rear end of the driven shaft, and the sizes of the inner spline groove and the spline are evenly and gradually increased from back to front. The three side slopes of each spline are each provided with a semi-cylindrical groove with the front portion closed and the rear portion closed, all the semi-cylindrical grooves are equal in depth, and embedded cylinders are embedded into the semi-cylindrical grooves. According to the inclined plane pressing type force transmission vibration isolator for torsion and radial vibration, a metal-rubber composite structure is adopted to achieve collaborative isolation of the radial vibration and the torsion vibration. The method is suitable for vibration control of various mechanical systems.

Description

Technical Field

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

[0002] Torsional and radial vibrations are widespread in vehicles, ships, and propellers. Due to uneven mass distribution in the shaft system or environmental factors, torsional and radial vibrations can occur during torque transmission. These vibrations not only affect ride comfort but can also lead to safety accidents such as crankshaft wear and breakage in severe cases, causing significant losses to production and daily life. Currently, torsional vibration isolation generally relies on additional damping mechanisms (such as viscous shock absorbers), but due to stiffness limitations, the torque transmission efficiency is not high.

[0003] For force-transmitting vibration isolators that transmit torsional and radial vibrations, the following issues need to be addressed during operation:

[0004] 1. The propulsion shaft system must achieve torsional vibration isolation while ensuring torque. Simultaneously, radial vibration isolation must also be achieved.

[0005] 2. Achieve vibration isolation while transmitting axial thrust.

[0006] 3. A holistic structure is needed to solve the clamping problem of the mechanism, achieving stable contact, continuous torque transmission, and continuous thrust transmission. Summary of the Invention

[0007] Purpose of the invention

[0008] To address the problems of isolating radial vibration and transmitting axial thrust in existing technologies, this invention provides a slope-pressed force-transmitting vibration isolator for torsional and radial vibration.

[0009] Technical solution

[0010] A slope-clamped force transmission vibration isolator for torsional and radial vibration includes a driven shaft, an end cover, a drive shaft connector, a drive shaft, and an embedded cylinder. The drive shaft is connected to the rear end of the drive shaft connector. The inner circumference of the shaft connector has four internal spline grooves evenly distributed. The outer circumference of the driven shaft is partially provided with four splines. The number of internal spline grooves and splines are equal and their positions correspond. The end cover is connected to the front end of the drive shaft connector. The unsplined portion of the driven shaft extends out of the end cover. A thrust ball bearing is provided on the inner side of the front end of the shaft connector. The balls at the front end of the thrust ball bearing contact the rear end of the driven shaft. The internal spline grooves and splines gradually increase in size from back to front. Each spline has three side slopes with closed semi-cylindrical grooves. All semi-cylindrical grooves are of equal depth and embedded cylinders are embedded in the semi-cylindrical grooves.

[0011] Furthermore, the embedded cylinder is composed of a hollow cylinder and a rubber cylinder, the hollow cylinder and the rubber cylinder being of equal length, with the rubber cylinder located inside the hollow cylinder and filling the hollow cylinder.

[0012] Furthermore, the inner diameter of the semi-cylindrical groove is 1.05 times the overall diameter of the embedded cylinder.

[0013] Furthermore, the length of the inner spline groove is longer than the length of the spline.

[0014] Furthermore, the hollow cylinder is made of structural steel with a wall thickness of 0.2-0.5 mm, and the rubber cylinder is made of rubber.

[0015] Advantages and effects

[0016] This invention relates to a slope-pressurized force-transmitting vibration isolator for torsional and radial vibrations, employing a metal-rubber composite structure to achieve coordinated isolation of radial and torsional vibrations. Under static conditions, the hollow steel cylinder bears the torque and maintains positioning accuracy, avoiding transmission lag caused by the rubber. Under dynamic conditions, the rubber cylinder efficiently dissipates vibration energy through viscoelastic deformation, significantly reducing the transmission rate of mid-to-high frequency vibrations. By adjusting the wall thickness of the hollow cylinder and the hardness of the rubber, the system's natural frequency can be adjusted to adapt to vibration isolation requirements under different operating conditions. The split design of the thrust ball bearing isolates axial thrust from radial / torsional vibration paths, and the slope-mounted self-locking preload mechanism enhances dynamic stability. The internal spline keyway supports quick component replacement, achieving stiffness matching under different operating conditions, extending equipment fatigue life while ensuring transmission accuracy, and is suitable for vibration control of various mechanical systems. Attached Figure Description

[0017] 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.

[0018] Figure 1 A three-dimensional schematic diagram of the front side of an inclined plane compression type force transmission vibration isolator for torsional and radial vibration;

[0019] Figure 2 A three-dimensional schematic diagram of the rear side of an inclined plane compression type force transmission vibration isolator for torsional and radial vibration;

[0020] Figure 3 A schematic diagram of the axial half-section of an inclined plane compression type force transmission vibration isolator for torsional and radial vibration.

[0021] Figure 4 This is a schematic diagram of the three-dimensional structure of the driven shaft;

[0022] Figure 5 This is a schematic diagram of the axial half-section of the drive shaft connector;

[0023] Figure 6This is a three-dimensional schematic diagram of the front side of the drive shaft connector;

[0024] Figure 7 A three-dimensional structural diagram of a driven shaft with an embedded cylinder installed;

[0025] Figure 8 A three-dimensional schematic diagram of the internal structure of a slope-pressed force-transmitting vibration isolator without end caps for torsional and radial vibrations.

[0026] Figure 9 A radial half-section diagram of the internal structure of an inclined plane clamping force transmission vibration isolator without end caps for torsional and radial vibrations.

[0027] Figure 10 The graph shows the relationship between the wall thickness of a hollow cylinder and the characteristic frequency of a torsional vibration system.

[0028] Figure 11 The graph shows the relationship between the wall thickness of the hollow cylinder and the characteristic frequency of the radial vibration system.

[0029] Figure 12 The graph shows the relationship between torsional vibration isolation ratio and hollow cylinder wall thickness.

[0030] Figure 13 This is a graph showing the relationship between radial vibration isolation ratio and hollow cylinder wall thickness.

[0031] Explanation of reference numerals in the attached drawings: 1. Driven shaft, 2. End cover, 3. Hollow cylinder, 4. Rubber cylinder, 5. Drive shaft connector, 6. Thrust ball bearing, 7. Drive shaft, 8. Spline, 9. Semi-cylindrical groove, 10. Internal spline groove. Detailed Implementation

[0032] like Figures 1-9As shown, a slope-pressed force-transmitting vibration isolator for torsional and radial vibration is characterized by comprising a driven shaft 1, an end cap 2, a drive shaft connector 5, a drive shaft 7, and an embedded cylinder. The drive shaft 7 is bolted to the rear end of the drive shaft connector 5. The inner circumference of the shaft connector 5 has four internal spline grooves 10 evenly distributed. The outer circumference of the driven shaft 1 is partially provided with four splines 8. The number of internal spline grooves 10 and splines 8 are equal and their positions correspond. The end cap 2 is bolted to the front end of the drive shaft connector 5. The driven shaft... The portion without spline 8 extends out to the end cap 2. A thrust ball bearing 6 is interference-fitted to the inner front end of the shaft connector 5. The balls at the front end of the thrust ball bearing 6 contact the rear end of the driven shaft 1. The inner spline groove 10 and spline 8 gradually increase in size from back to front. Each spline 8 has three beveled sides with closed semi-cylindrical grooves 9. All semi-cylindrical grooves 9 are of equal depth. Embedded cylinders are embedded in the semi-cylindrical grooves 9, meaning all embedded cylinders gradually move away from the center line of each spline 8 from back to front. The embedded cylinder is composed of a hollow cylinder 3 and a rubber cylinder 4, which are of equal length. The rubber cylinder 4 is located inside the hollow cylinder 3 and fills the interior of the hollow cylinder 3. The inner diameter of the semi-cylindrical groove 9 is 1.05 times the overall diameter of the embedded cylinder, ensuring a certain amount of rolling space for the cylinder. The length of the internal spline groove 10 is slightly longer than the length of the spline 8. Threaded holes are provided at both ends of the drive shaft 7 coupling for connecting the end cover 2 and the drive shaft 7. The hole in the end cover 2 is slightly larger than the shaft diameter of the driven shaft 1 and slightly smaller than the driven shaft 1 collar, applying positive pressure to the driven shaft 1 during installation. A through threaded hole is also provided on the end cover 2 for connection with the drive shaft connector 5. For the embedded cylinder, the rubber cylinder 4 is inserted into the hollow cylinder 3 and fixed using an interference fit.

[0033] During installation, the drive shaft coupling 5 and thrust ball bearing 6 are first selected. To fully utilize the characteristic that the thrust ball bearing 6 can only bear axial loads, it is chosen to transmit axial thrust during installation. Furthermore, the rolling characteristic of the steel balls in the thrust ball bearing 6 avoids direct transmission of radial and torsional vibrations, allowing the vibration isolation mechanism to function effectively. (The thrust ball bearing consists of three parts: a housing ring, a shaft ring, and a steel ball cage assembly. The steel ball cage contains steel balls; this invention does not use a shaft ring, only a housing ring.) The bearing bore of the drive shaft coupling 7 is slightly smaller than that of the thrust ball bearing 6, and the bore depth should be lower than the steel balls and higher than the cage. During installation, the thrust ball bearing 6 is connected to the drive shaft coupling 7 via an interference fit, ensuring that the steel balls can rotate freely and contact the bottom surface of the driven shaft 1.

[0034] Then, hollow cylinder 3 and rubber cylinder 4 are taken. Adhesive is applied to the surface of rubber cylinder 4. Since the size of rubber cylinder 4 is slightly larger than that of hollow cylinder 3, the rubber cylinder 4 is connected to hollow cylinder 3 by an interference fit due to the size difference. Regarding material selection, hollow cylinder 3 is made of structural steel. The structural steel parameters used in this patent are based on the average mechanical properties of common low-carbon structural steels in international standards (such as ASTM A36, EN S235JR, or Chinese Q235 steel), with a wall thickness of 0.2-0.5 mm. Rubber cylinder 4 is made of rubber, preferably silicone rubber or EPDM rubber. Structural steel has high rigidity and can withstand large torques. The hollow structure can ensure torque transmission while isolating vibrations. During the vibration process, the hollow structure undergoes slight deformation, which absorbs vibrations. For the rubber cylinder 4 filled in the hollow cylinder 3, the rubber filling increases the system mass and reduces the resonant frequency. Simultaneously, rubber has a high damping ratio, with a loss coefficient typically between 0.1 and 0.3, enabling it to convert vibrational energy into heat through viscoelastic deformation, significantly reducing vibration transmission rate. Furthermore, the viscoelasticity of rubber allows it to effectively dissipate energy over a wide frequency range, especially showing a more significant suppression effect on mid-to-high frequency vibrations, while also reducing the risk of low-frequency resonance. The composite structure of the hollow cylinder 3 and the rubber cylinder 4 is achieved through "metal bearing + rubber tuning." First, high static stiffness: when transmitting torque statically, the metal primarily transmits torque, avoiding transmission lag caused by the creep of rubber alone. Second, low dynamic stiffness: under dynamic operating conditions, the deformation of the hollow cylinder 3 and the rubber absorbs high-frequency vibrations, thereby protecting the driven shaft 1 and downstream equipment. Simultaneously, it possesses durability: the rubber cylinder 4 absorbs a large amount of vibrational energy, reducing the fatigue stress of the hollow cylindrical metal structure and extending its service life.

[0035] After completing the installation according to the requirement of a single key paired with three hollow cylinders 3 and rubber cylinders 4, it is fitted with the semi-cylindrical grooves 9 of each key on the driven shaft 1. This is a clearance fit. Before installation into the drive shaft 7 coupling, it can be temporarily secured using rubber bands or by hand. The semi-cylindrical grooves are designed for easy disassembly and future replacement with different models of hollow cylinders 3 and rubber cylinders 4 according to different working conditions. Then, the internal spline grooves 10 of each corresponding drive shaft 7 coupling are fitted.

[0036] After installation, it can be observed that the upper end face of the spline 8 of the driven shaft 1 is slightly higher than the upper end face of the coupling of the drive shaft 7, and the lower end face of the spline of the driven shaft 1 does not contact the spherical surface of the thrust ball bearing 6. At this time, if no additional axial static pressure is applied, the hollow cylinder 3 of each spline 8 is in contact with the semi-cylindrical groove 9 and the arc surface of the inner spline groove 10 of the driven shaft 1. Afterwards, since the spline 8 of the driven shaft 1 still extends beyond the drive shaft connector 5, and the length of the end cover 2 is slightly shorter than the distance from the driven shaft 1 collar to the upper end face of the drive shaft connector 5 at this time, the driven shaft 1 will be pressed tightly when connected to the drive shaft connector 5 through the threaded hole of the end cover 2. In this device, the spline of the driven shaft 1 serves as the conical inner ring, the inner spline groove 10 of the drive shaft connector 5 serves as the outer ring circular raceway, and the hollow cylinders 3 are arranged between the two. The projection lines on the surfaces of all hollow cylinders 3 converge at the same point on the axis of the driven shaft 1. Due to the presence of the contact angle, the hollow cylinders 3 will bear a certain thrust. However, the contact angle of this device is small, and it mainly serves to clamp the hollow cylinders 3. The main thrust is borne by the thrust ball bearing 6.

[0037] In operation, the drive shaft 7 transmits torque, torsional vibration, and radial vibration to the drive shaft connector 5 via the flange. Since the driven shaft 1 can slide on the thrust ball bearing 6, vibration and torque need to be transmitted to the driven shaft 1 and downstream equipment via the hollow cylinder 3 and the rubber cylinder 4. The rigidity of the hollow cylinder 3 ensures torque transmission and axial positioning, while the rubber cylinder 4, made of rubber, absorbs most of the axial and radial vibration energy. The inclined clamping mechanism further ensures the stability of the assembled body after installation, continuous torque transmission in operation, and guarantees coaxiality and good alignment. When the torque is transmitted to the driven shaft 1, it generates thrust. The thrust is transmitted along the driven shaft 1, with a small portion transmitted by the hollow cylinder 3 and the majority transmitted from the bottom surface of the driven shaft 1 through the thrust ball bearing 6 to the drive shaft 7 connector, and then to the drive shaft 7, thus achieving thrust transmission.

[0038] To address different working conditions, hollow cylinders with varying wall thicknesses can be selected, along with corresponding rubber cylinders (4). For example, structural steel can be used as the material for these hollow cylinders. Figure 10 and Figure 11 As shown, for the isolation of radial and torsional vibrations, it can be observed that as the wall thickness of the hollow cylinder 3 increases, the system characteristic frequencies of torsional and radial vibrations gradually increase.

[0039] Through the Figure 12 and Figure 13 Data observation shows that when the excitation frequency / natural frequency > Under certain conditions, the vibration transmissibility is less than zero, and the vibration isolator begins to function. The higher the excitation frequency / natural frequency ratio, the better the vibration isolation effect. When selecting spring plate 2, mirror spring plate 6, and hollow cylindrical roller 3, the excitation frequency band shown in the figure can be observed. 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 ratio. 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: an excessively small natural frequency requires a very small spring stiffness k, which makes 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 hollow cylinder 3 with a wall thickness of 0.2mm and its corresponding rubber cylinder 4 are selected, its characteristic frequency is approximately 10.8Hz. The vibration isolator works when the excitation frequency is higher than 15Hz, making it suitable for operating conditions of 30-55Hz. For radial vibration isolation, the diagram uses structural steel as an example. When the thickness of the hollow cylindrical roller 3 is 0.2mm, it is suitable for operating conditions of 60-80Hz. For the same operating condition, since the characteristics of radial and torsional vibrations are different, the hollow cylinder 3 bearing torsion and the hollow cylinder bearing radial vibration can use different wall thicknesses, and corresponding rubber cylinders 4 can be selected. This is because when the wall thickness of the hollow cylinder 3 is changed, the outer diameter does not change, and the spline groove of its drive shaft connector 5 and the semi-cylindrical groove on the spline of the driven shaft 1 can be matched, thereby achieving the purpose of adapting to different operating conditions.

[0040] 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 slope-pressed force-transmitting vibration isolator for torsional and radial vibrations, characterized in that: The assembly includes a driven shaft (1), an end cap (2), a drive shaft connector (5), a drive shaft (7), and an embedded cylinder. The drive shaft (7) is connected to the rear end of the drive shaft connector (5). The inner circumference of the shaft connector (5) is evenly distributed with four internal spline grooves (10). The outer circumference of the driven shaft (1) is partially provided with four splines (8). The number of internal spline grooves (10) and splines (8) are equal and their positions correspond. The end cap (2) is connected to the front end of the drive shaft connector (5). (1) The part without spline (8) extends out of the end cap (2). A thrust ball bearing (6) is provided on the inner side of the front end of the shaft connector (5). The ball at the front end of the thrust ball bearing (6) contacts the rear end of the driven shaft (1). The inner spline groove (10) and spline (8) gradually increase in size from back to front. Each spline (8) has three side slopes with closed semi-cylindrical grooves (9). All semi-cylindrical grooves (9) are of equal depth. Embedded cylinders are embedded in the semi-cylindrical grooves (9).

2. The inclined plane compression type force transmission vibration isolator for torsional and radial vibration according to claim 1, characterized in that: The embedded cylinder is composed of a hollow cylinder (3) and a rubber cylinder (4). The hollow cylinder (3) and the rubber cylinder (4) are of equal length. The rubber cylinder (4) is located inside the hollow cylinder (3) and fills the hollow cylinder (3).

3. The inclined plane compression type force transmission vibration isolator for torsional and radial vibration according to claim 1 or 2, characterized in that: The inner diameter of the semi-cylindrical groove (9) is 1.05 times the overall diameter of the embedded cylinder.

4. The inclined plane compression type force transmission vibration isolator for torsional and radial vibration according to claim 1, characterized in that: The length of the inner spline groove (10) is longer than the length of the spline (8).

5. The inclined plane compression type force transmission vibration isolator for torsional and radial vibration according to claim 2, characterized in that: The hollow cylinder (3) is made of structural steel with a wall thickness of 0.2-0.5 mm, and the rubber cylinder (4) is made of rubber.

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