Axial high torque damper bearing design method

Abstract

The application discloses a kind of axial high-torque damping bearing design methods, which include inner ring, outer ring, rolling body and conical elastic damping element, corresponding sealing groove is arranged in inner and outer rings, spring steel conical damping element is embedded between two sealing grooves, and has sealing and damping functions.The method steps include: determining the target total damping torque, establishing the mapping model of axial pre-tightening force and damping element geometric parameters based on diaphragm spring mechanics, calculating the inner and outer ring contact friction torque, determining the effective damping torque according to the differential sliding mechanism of double friction pairs, and inversely solving to obtain the optimal parameter combination of damping element taper angle, wall thickness and assembly interference amount.The application can realize quantitative design of damping characteristics, stable damping output in wide temperature range, compact structure, and is suitable for automotive tailgate, precision instrument and other scenes.

Description

Technical Field

[0001] This invention relates to a design method for an axial high torque damping bearing. Background Technology

[0002] In modern mechanical systems, bearings, as key fundamental components supporting rotating shafts, directly determine the vibration and noise levels and service life of the system due to their dynamic characteristics. Traditional miniature deep groove ball bearings (such as the 638 series and 629 series) are typically designed to achieve extremely low coefficients of friction and starting torque, with negligible inherent damping values. However, in specific applications such as automotive tailgate gas spring support systems or precision instrument adjustment knobs, the limited installation space necessitates the use of such miniature bearing structures. In these cases, excessively low internal damping often leads to high-frequency fretting wear or low-frequency wobbling of moving parts during start-up, shutdown, or loading, causing abnormal noises and severely impacting product quality and user experience. Furthermore, the insufficient damping of traditional bearings makes it difficult to achieve the 0.3 Nm required for automotive tailgates, easily generating vibration and noise that is difficult to control precisely, often requiring the addition of additional dampers, increasing cost and complexity.

[0003] In the prior art, in order to avoid the above-mentioned technical defects, the following two technical solutions are usually adopted, but both have significant limitations: (1) External independent damper solution: that is, rubber damping washers, friction plates or hydraulic dampers are connected in series or parallel outside the bearing assembly. This solution not only significantly increases the number of parts and assembly process, resulting in increased system cost, but also often fails to meet the design requirements of lightweight and miniaturization due to the addition of additional axial dimensions. In addition, the cumulative error introduced by the assembly of multiple parts will also reduce the stability of damping output; (2) High viscosity grease filling solution: that is, to increase fluid shear resistance by filling with high viscosity silicone grease or damping grease. However, this solution is significantly affected by temperature and has obvious "viscosity-temperature characteristics" problem. The viscosity of grease increases sharply at low temperature, resulting in excessive starting torque, and the viscosity decreases at high temperature, resulting in damping failure. In addition, grease is prone to oil separation or loss during long-term service, resulting in damping characteristics decaying over time, and the performance consistency throughout the entire life cycle cannot be guaranteed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a design method for axial high torque damping bearings. It replaces traditional dust covers with tapered elastic damping elements, generates stable axial preload through elastic deformation, and constructs a controllable friction damping mechanism inside the bearing to achieve integrated sealing and damping. Furthermore, it establishes a mapping model between damping torque and geometric parameters to achieve precise quantitative reverse design of damping characteristics, thereby improving the bearing's wide-temperature-range operating stability and service life.

[0005] To achieve the above objectives, this invention provides a design method for an axial high-torque damping bearing. The damping bearing includes an inner ring and an outer ring, with rolling elements disposed between the inner and outer rings. A first sealing groove is provided along the edge of the inner ring, and a second sealing groove is provided along the edge of the outer ring. A damping element is disposed between the first and second sealing grooves. The damping element is an elastic annular member with a conical structure, made of spring steel. The outer edge of the damping element is disposed in the second sealing groove, and the inner edge of the damping element is disposed in the first sealing groove. The depth ξ1 of the bottom of the first sealing groove is set to 0.95~1.2mm. The first sealing groove includes a first locking edge and a first stop edge for contacting the inner edge of the damping element. The first stop edge is vertically disposed at the bottom of the first sealing groove, and the first sealing groove and the first locking edge are transitioned by a 5°~15° bevel. The second sealing groove is aligned with the first sealing groove, and the depth ξ2 of the second sealing groove is set to 0.95~1.2mm. The second sealing groove includes a second locking edge and a second stop edge, both of which are perpendicular to the bottom of the second sealing groove. The geometric parameters of the damping element include a cone angle α, a wall thickness t, and a truncated cone height H in its natural state. The minor diameter of the inner edge of the damping element is r. in The inner edge width of the damping element is b1, and the mid-diameter of the inner edge of the damping element is r. in-middle The minor diameter of the outer edge of the damping element is R. out The outer edge width of the damping element is b2, and the mid-diameter of the outer edge of the damping element is r. out-middle The design method includes the following steps: Step 1, determine the target total damping torque M of the bearing. total Based on the configuration of symmetrically arranged damping structures at both ends of the bearing, the target effective damping torque M of the single-sided damping structure is calculated. eff =M total / 2; Step 2: Based on the mechanical principles of diaphragm springs, establish the axial preload F of the conical elastic damping element. a The mechanical mapping model of its geometric parameters, the formula for calculating the axial preload is: In the formula, E is the elastic modulus of the damping element material, and μ is the Poisson's ratio of the tapered damping element material. K1 represents the elastic deformation of the tapered damping element, and K1 is a magnitude coefficient, K1=1.

[0006] Step 3: Calculate the inner ring friction torque M at the contact point between the tapered elastic damping element and the inner ring sealing groove. in The outer ring friction torque M at the contact point with the outer ring sealing groove out ; Average normal contact pressure at the inner ring contact point: Inner ring friction torque: M in =F n-in ×μ×r in-middle ; Average normal contact pressure at the outer ring contact point: Outer ring friction torque: M out =F n-out ×f×r out-middle In the formula, f is the coefficient of friction of the contact surface; Step 4: Based on the differential sliding mechanism of the double friction pair, determine the effective damping torque of the single-sided damping structure as the smaller value of the friction torques of the inner and outer rings: M eff =min(M) in M out Combining the symmetrical damping structure at both ends of the bearing, the total damping torque of the bearing is obtained: M total =2M eff ; Step 5: Based on the target effective damping torque, solve in reverse the process to obtain the optimal parameter combination of the cone angle α, wall thickness t, and corresponding elastic deformation δ of the tapered elastic damping element, thus completing the parametric design of the damping bearing.

[0007] As a further feature of this method, step 5 is followed by a contact stress verification step: the stress distribution in the contact area between the damping element and the sealing groove is analyzed by finite element simulation to optimize the smooth transition profile of the contact surface.

[0008] As a further feature of this method, step 5 is followed by a damping torque consistency verification step, which corrects the friction coefficient and mechanical model parameters by testing the damping torque of multiple batches of samples.

[0009] The beneficial effects of this configuration are as follows: With this configuration, the damping element is installed between the first and second sealing grooves. The elastic deformation generated by axial pressing creates an axial preload, which in turn generates Coulomb friction damping on the contact mating surface. The damping output is provided by the elastic preload of the tapered damping element and the friction of the contact surface, which is different from the traditional fluid shear damping scheme that relies on high-viscosity grease. This design avoids the viscosity-temperature characteristics of grease in principle, minimizing the impact of ambient temperature fluctuations on the damping torque. It maintains stable damping output over a wide temperature range of -40℃ to 120℃, solving the industry pain points of drastic increase in starting torque at low temperatures and damping failure at high temperatures. Simultaneously, it avoids the damping torque attenuation problem caused by grease separation and loss during long-term service, ensuring no significant degradation in damping performance throughout the bearing's entire service life, greatly improving the product's service reliability and performance durability. Furthermore, a precise mapping model between the geometric parameters of the tapered damping element and the axial preload has been established. Combined with contact mechanics calculations of the inner and outer ring double friction pairs, the optimal combination of geometric parameters of the damping element can be directly obtained from the target damping torque through reverse engineering, significantly shortening the product development cycle and reducing material and time costs associated with multiple rounds of trial production. At the same time, the quantitative model ensures the accuracy of the damping torque design, allowing for precise matching of customized damping requirements for different application scenarios. The design limits the effective damping torque on one side to the smaller value of the contact friction torque between the inner and outer rings, ensuring that only one friction pair acts as the main damping surface during bearing rotation, thus avoiding abnormal conditions such as simultaneous slippage or jamming of both friction pairs. This design makes the damping torque output more linear, significantly reducing torque fluctuations and impacts during start-up, shutdown, and speed changes, eliminating the potential for shaking and abnormal noises in moving parts, and improving the smoothness and usability of the mechanism. Simultaneously, combined with the symmetrical damping structure at both ends of the bearing, the damping output at both ends is symmetrical and balanced, resulting in more uniform axial force on the bearing and avoiding uneven wear. Finite element simulation analysis of the stress distribution in the contact area and optimization of the smooth transition profile of the contact surface effectively improve the pressure distribution at the contact interface between the damping element and the sealing groove, eliminating stress concentration at the contact edges. This design avoids early failures such as fretting wear and fatigue spalling caused by excessive edge stress, significantly reduces the wear rate of damping elements and sealing grooves, and extends the overall service life of the bearing. This design eliminates the need for additional damping elements, achieving high damping output without significantly increasing the axial dimension of the bearing. It perfectly fits the compact installation space requirements of miniature bearings, meeting the design trends of lightweight and miniaturized equipment. Simultaneously, it reduces the number of system components and assembly steps, lowers material and labor assembly costs, reduces the cumulative error of multi-component assembly, and further improves the stability of the damping output. Attached Figure Description

[0010] Figure 1 This is a schematic cross-sectional view of the damping bearing in an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of the outer ring of the damping bearing in an embodiment of the present invention. Figure 3 This is a schematic cross-sectional view of the inner ring of the damping bearing in an embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of the damping element of the damping bearing in an embodiment of the present invention; Figure 5 The axial displacement cloud diagram is used for simulation analysis and verification in the embodiments of the present invention; Figure 6 This is a line graph showing the friction torque data at the inner and outer ring grooves in an embodiment of the present invention. Detailed Implementation

[0011] The present invention will be further described in detail below with reference to specific embodiments. This embodiment takes a miniature deep groove ball high damping bearing for use in the support system of automobile tailgate hinge as the design object, with a target total damping torque of 0.3 Nm, and is adapted to the installation space of a miniature bearing with a nominal size of 9 mm inner diameter and 26 mm outer diameter.

[0012] The high-damping bearing designed in this embodiment includes an inner ring 1, an outer ring 2, rolling steel balls 3, a cage, and two sets of tapered elastic damping elements 4 symmetrically arranged at both ends of the bearing axially. The inner ring 1 has a first sealing groove 11 along its two end faces, and the outer ring 2 has a second sealing groove 21 along its two end faces. The inner edge of the tapered elastic damping element 4 is embedded in the first sealing groove 11, and the outer edge is embedded in the second sealing groove 21. The bottom depth ξ1 of the first sealing groove 11 is 1.0 mm, which is within the range of 0.95~1.2 mm; the side of the first sealing groove 11 near the inner ring 1 raceway is the first stop edge 112, which is perpendicular to the bottom of the first sealing groove 11 and serves as the contact friction edge of the inner edge of the damping element 4; the side of the first sealing groove 11 near the end face of the inner ring is the first locking edge 111, which is connected to the first sealing groove 11 by a 10° bevel, which is within the range of 5°~15° and is used for guidance during the press-fitting of the damping element. The second sealing groove 21 is axially aligned with the first sealing groove 11. The bottom depth ξ2 of the second sealing groove 21 is 1.0 mm, which is within the range of 0.95~1.2 mm. The side of the second sealing groove 21 near the raceway of the outer ring 2 is the second stop edge 212, and the side near the end face of the outer ring 2 is the second locking edge 211. Both the second stop edge 212 and the second locking edge 211 are perpendicular to the bottom of the second sealing groove 21. The second locking edge 211 serves as the contact friction edge of the outer edge of the damping element 4. The groove formed by the two vertical edges locks the outer edge of the damping element in an axial position, preventing axial movement during service.

[0013] The conical elastic damping element is made of 65Mn spring steel by stamping and is an elastic ring-shaped component with a conical angle structure; in this embodiment, the inner minor diameter r of the damping element is... in =10mm, inner edge contact width b1=0.3mm, inner edge contact ring middle diameter r in-middle =10.15mm; Large diameter R of the outer edge of the damping element out =24mm, outer edge contact width b2=0.3mm, outer edge contact ring middle diameter r out-middle =23.85mm; the damping element material has an elastic modulus E=206GPa, a Poisson's ratio μ=0.3, and a friction coefficient f=0.15 for the steel contact surface at room temperature.

[0014] The axial high torque damping bearing design method of this embodiment specifically includes the following steps: Step 1, Determine the design objective: Based on the damping requirements of the car tailgate hinge, set the target total damping torque M of the bearing. total =0.3 Nm. Since the damping structures are symmetrically arranged at both ends of the bearing axially, the target effective damping torque of the single-sided damping structure is: M eff =M total / 2=0.15Nm Step 2: Based on the mechanical principles of diaphragm springs, establish the axial preload F of the conical elastic damping element. a The mechanical mapping model with geometric parameters gives the formula for calculating axial preload: Where the magnitude coefficient K1=1, t is the wall thickness of the damping element, δ is the elastic deformation of the damping element after assembly, and H is the truncated cone height of the damping element in its natural state.

[0015] In this embodiment, the damping element wall thickness t=0.25mm and the natural state truncated cone height H=1.3mm are initially selected. The target effective damping torque is used as a constraint, and the torque formula is substituted into the formula for reverse iteration solution.

[0016] Step 3: Calculate the frictional torque at the contact points between the tapered elastic damping element and the inner and outer ring sealing grooves, respectively. First, calculate the average normal contact pressure at the inner ring contact point: Frictional torque at the inner ring contact point: M in =F n-in ×μ×r in-middle Next, calculate the average normal contact pressure at the outer ring contact point: Frictional torque at the outer ring contact point: M out=F n-out ×f×r out-middle Substituting the dimensional parameters of this embodiment, and combining the axial preload formula and the friction torque formula, a reverse solution is performed with a target effective damping torque of 0.15 Nm on one side. The first iteration yields an elastic deformation of δ = 0.22 mm, from which the following can be calculated: Axial preload F_a≈2876N; Inner ring contact average normal pressure F n-in ≈148.2MPa, inner ring friction torque M in ≈0.106 Nm; Outer ring contact average normal pressure F n-out ≈62.8MPa, outer ring friction torque M out ≈0.169Nm.

[0017] Step 4: Based on the differential sliding mechanism of the double friction pair, when the single-sided damping structure is working, the inner friction pair with smaller friction torque is the effective work friction pair. Therefore, the effective damping torque on one side is taken as the smaller of the two values: M eff =min(M) in M out ) The corresponding total damping torque is 0.212 Nm, which does not reach the target value of 0.3 Nm, and the parameters need to be adjusted for further iteration.

[0018] Adjust the damping element wall thickness to t=0.3mm, keep the truncated cone height H=1.3mm constant, and solve in reverse to obtain the elastic deformation δ=0.25mm. Recalculate to get: Axial preload F a ≈4983N; Inner ring friction torque M in ≈0.184 Nm; outer ring friction torque M out ≈0.293 Nm; Single-sided effective damping moment M eff =0.184 Nm, corresponding to the total damping torque M total =2×0.184=0.368Nm, which exceeds the target value.

[0019] Continue fine-tuning the parameters to finally determine the optimal parameter combination: damping element wall thickness t=0.27mm, elastic deformation δ=0.23mm, natural truncated cone height H=1.3mm, corresponding cone angle α≈8.5°.

[0020] Substituting into the calculation, we get: Axial preload F a ≈4072N; Inner ring friction torque M in≈0.151Nm; outer ring friction torque M out ≈0.240 Nm; Single-sided effective damping moment M eff =0.151Nm, total bearing damping torque M total =0.302Nm, the deviation from the target of 0.3Nm is only 0.67%, which meets the design accuracy requirements.

[0021] Step 5: Confirm that the above parameter combination meets the target damping torque requirement, and finally determine the optimal design parameters of the tapered elastic damping element: wall thickness 0.27mm, cone angle 8.5°, corresponding elastic deformation of 0.23mm for assembly interference, and complete the parametric design of the damping bearing.

[0022] Furthermore, after solving for the parameters in step 5, the contact stress verification step is performed: A contact analysis model between the damping element and the sealing groove was established using finite element simulation software, and the stress distribution in the contact area was simulated and calculated. The maximum contact stress at the initial right-angle contact edge was approximately 1180 MPa, posing a risk of edge stress concentration. Based on this, a smooth transition optimization was performed on the contact edge of the damping element, setting a contact optimization fillet radius of R0.1 mm. After optimization, the maximum contact stress was reduced to 860 MPa, which is lower than the allowable contact stress of 65Mn spring steel. This effectively eliminated edge stress concentration, avoiding fretting wear and fatigue spalling, and improving the service life of the bearing.

[0023] Furthermore, after completing parameter optimization, a damping torque consistency verification step is performed: Twenty samples were manufactured according to the final design parameters, and damping torque tests were conducted at room temperature. The average damping torque of the samples was measured to be 0.298 Nm, with maximum deviations of +7.8% and -6.5%, both within the preset ±10% deviation range. Based on the measured data, the friction coefficient in the mechanical model was corrected to 0.147. After correction, the deviation between the calculated and measured values ​​was reduced to within ±3%, further improving the consistency of damping torque in mass production.

[0024] The high-damping bearing designed in this embodiment has an axial total dimension that is basically the same as that of a standard deep groove ball bearing of the same specification, without the need for additional axial installation space. When tested in a temperature range of -40℃ to 120℃, the damping torque fluctuation is less than 5%, which is far superior to the traditional grease damping solution. The damping attenuation rate is less than 8% over the whole life cycle, which can stably meet the usage requirements of scenarios such as automobile tailgates.

[0025] The above examples are merely one preferred embodiment of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included within the protection scope of the present invention.

Claims

1. A design method for an axially high torque damping bearing, characterized in that: The damping bearing includes an inner ring and an outer ring, with rolling elements disposed between them. A first sealing groove is provided along the edge of the inner ring, and a second sealing groove is provided along the edge of the outer ring. A damping element is disposed between the first and second sealing grooves. The damping element is an elastic annular member with a conical structure, made of spring steel. The outer edge of the damping element is disposed in the second sealing groove, and the inner edge is disposed in the first sealing groove. The depth ξ1 of the bottom of the first sealing groove is set to 0.95~1.2mm. The first sealing groove includes a first locking edge and a... A first stop edge contacts the inner edge of the damping element. The first stop edge is vertically disposed at the bottom of the first sealing groove, and the first sealing groove and the first locking edge are transitioned by a 5°~15° bevel. The second sealing groove is aligned with the first sealing groove, and the depth ξ2 of the second sealing groove is set to 0.95~1.2mm. The second sealing groove includes a second locking edge and a second stop edge, both of which are perpendicular to the bottom of the second sealing groove. The geometric parameters of the damping element include the cone angle α, the wall thickness t, and the height H of the truncated cone in its natural state. The minor diameter of the inner edge of the damping element is r. in The inner edge width of the damping element is b1, and the mid-diameter of the inner edge of the damping element is r. in-middle The minor diameter of the outer edge of the damping element is R. out The outer edge width of the damping element is b2, and the mid-diameter of the outer edge of the damping element is r. out-middle The design method includes the following steps: Step 1, determine the target total damping torque M of the bearing. total Based on the configuration of symmetrically arranged damping structures at both ends of the bearing, the target effective damping torque M of the single-sided damping structure is calculated. eff =M total / 2; Step 2: Based on the mechanical principles of diaphragm springs, establish the axial preload F of the conical elastic damping element. a The mechanical mapping model of its geometric parameters, the formula for calculating the axial preload is: In the formula, E is the elastic modulus of the damping element material, and μ is the Poisson's ratio of the tapered damping element material. K1 represents the elastic deformation of the tapered damping element, and K1 is a magnitude coefficient, K1=1; Step 3: Calculate the inner ring friction torque M at the contact point between the tapered elastic damping element and the inner ring sealing groove. in The outer ring friction torque M at the contact point with the outer ring sealing groove out ; Average normal contact pressure at the inner ring contact point: Inner ring friction torque: M in =F n-in ×μ×r in-middle ; Average normal contact pressure at the outer ring contact point: Outer ring friction torque: M out =F n-out ×f×r out-middle In the formula, f is the coefficient of friction of the contact surface; Step 4: Based on the differential sliding mechanism of the double friction pair, determine the effective damping torque of the single-sided damping structure as the smaller value of the friction torques of the inner and outer rings: M eff =min(M) in M out Combining the symmetrical damping structure at both ends of the bearing, the total damping torque of the bearing is obtained: M total =2M eff ; Step 5: Based on the target effective damping torque, solve in reverse the process to obtain the optimal parameter combination of the cone angle α, wall thickness t, and corresponding elastic deformation δ of the tapered elastic damping element, thus completing the parametric design of the damping bearing.

2. The axial high torque damping bearing design method according to claim 1, characterized in that: Step 5 is followed by a contact stress verification step: the stress distribution in the contact area between the damping element and the sealing groove is analyzed by finite element simulation to optimize the smooth transition profile of the contact surface.

3. The axial high torque damping bearing design method according to claim 1, characterized in that: Step 5 is followed by a damping torque consistency verification step, which involves testing the damping torque of multiple batches of samples to correct the friction coefficient and mechanical model parameters.

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