A centrifugal disengagement type overrunning clutch disengagement rotation speed calculation method
By establishing the torque balance equation for the eccentric roller at the critical disengagement position and introducing the friction torque term, the disengagement speed under engagement and overrunning states is calculated, overcoming the limitations of existing technology in calculating disengagement speed and improving engine starting reliability and clutch life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AECC HUNAN AVIATION POWERPLANT RES INST
- Filing Date
- 2026-02-04
- Publication Date
- 2026-06-12
Smart Images
Figure CN122197294A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of transmission systems for aero-engines and auxiliary power units, specifically to a method for calculating the disengagement speed of a centrifugal disengagement overrunning clutch. Background Technology
[0002] Aircraft engines require a starter motor mounted on their accessory drive system for starting. The starter motor must rotate the gas generator rotor to a certain proportional speed before the engine can achieve self-sustaining starting and enter a stable operating state; otherwise, the engine may fail to start due to overheating. After a successful start, a centrifugal disengagement overrunning clutch is typically used to disconnect the starter motor torque to protect the starter motor and optimize system operation.
[0003] When designing the disengagement speed of a centrifugal disengagement overrunning clutch, it is necessary to ensure that the full-speed overrunning speed of the clutch in the overrunning state is greater than its disengagement speed. This is to prevent the eccentric roller from being unable to effectively disengage the inner ring during operation, which would cause sliding friction and increased wear. On the other hand, it is necessary to ensure that during engine starting, the maximum speed at which the starter motor rotates to the clutch is less than the disengagement speed of the clutch in the engaged state. This is to prevent the clutch from disengaging prematurely under high speed and light load, which would cause the starter motor to be unable to rotate the rotor to a sufficient speed, leading to overheating and starting failure.
[0004] However, existing methods for calculating the disengagement speed of centrifugal overrunning clutches can only estimate the disengagement speed in the overrunning state without torque transmission. These methods use a simple torque balance model to ignore the influence of frictional torque, obtaining the critical speed required for the centrifugal force of the eccentric roller to overcome the spring force and gravity. This calculation process fails to consider the influence of the normal contact force between the eccentric roller and the inner ring during torque transmission in the engaged state and the resulting frictional torque on the critical disengagement condition. This prevents designers from fully assessing the actual disengagement boundary of the clutch during engine start-up, increasing the risk of insufficient redundancy or overly conservative design in the accessory drive system, and hindering further improvements in the reliability of aero-engine start-up. Summary of the Invention
[0005] In view of this, the present invention provides a method for calculating the disengagement speed of a centrifugal disengagement overrunning clutch, in order to solve the problem that the existing methods for calculating the disengagement speed of an overrunning clutch cannot calculate the overrunning clutch in the engaged state, resulting in a large deviation between the theoretical disengagement state and the actual disengagement boundary during the engine starting stage.
[0006] In a first aspect, the present invention provides a method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch, comprising the following steps:
[0007] Establish the torque balance equation of the eccentric roller in the overrunning clutch when it is in the critical disengagement position. The torque balance equation shall include at least the first torque term generated by the gravity of the eccentric roller, the second torque term generated by the centrifugal force of the eccentric roller, and the third torque term generated by the elastic element acting on the eccentric roller. Based on the real-time operating speed of the overrunning clutch, the real-time centrifugal force equation of the eccentric roller in the overrunning clutch is established. The first disengagement speed of the overrunning clutch in the engaged state and the second disengagement speed in the overrunning state are calculated based on the torque balance equation and the real-time centrifugal force equation. Specifically, when calculating the first disengagement speed, the torque balance equation includes a fourth torque term generated by the friction between the eccentric roller and the inner ring, and when calculating the second disengagement speed, the torque balance equation does not include the fourth torque term.
[0008] A method for calculating the disengagement speed of a centrifugal overrunning clutch is developed. This method establishes a mechanical model of the eccentric roller under critical disengagement conditions and selectively introduces a fourth torque term generated by friction into the torque balance equation. This allows for effective calculation of the disengagement speed of the centrifugal overrunning clutch under both engagement and overrunning operating states. It overcomes the limitation of existing technologies that can only calculate the disengagement speed under overrunning conditions, enabling designers to simultaneously obtain complete disengagement speed data for both the torque-transmitting starting phase and the normal operating phase without torque transmission. This provides a more comprehensive calculation basis for the design of aero-engine accessory transmission systems. This ensures that the clutch's full-speed overrunning speed is higher than the disengagement speed under overrunning conditions, preventing slippage wear between the eccentric roller and the inner ring due to ineffective disengagement. Simultaneously, it ensures that the maximum speed at which the starter motor rotates the clutch during engine startup is lower than the disengagement speed under engagement conditions, preventing premature clutch disengagement during startup that could prevent the gas generator rotor from reaching its self-sustaining speed. This effectively improves engine starting reliability and clutch lifespan, enhancing the engineering applicability and design accuracy of the disengagement speed calculation.
[0009] In one alternative implementation, in the step of the torque balance equation for the eccentric roller in the clutch when it is in the critical disengagement position, the equilibrium point of the torque balance equation is set as the contact point between the eccentric roller and the outer ring.
[0010] By setting the equilibrium point as the contact point between the eccentric roller and the outer ring, the line of action of the contact force between the eccentric roller and the inner and outer rings can be made to pass exactly through the equilibrium point. This eliminates the torque generated by these contact forces in the torque balance equation, simplifying the analysis and establishment process of the torque balance equation.
[0011] In one alternative implementation, the formula for calculating the first disengagement speed based on the torque balance equation and the real-time centrifugal force equation is as follows:
[0012] Where, n j Let m be the initial disengagement speed, m be the mass of a single eccentric roller, g be the acceleration due to gravity, and L be the initial disengagement speed. G F is the lever arm of gravity from the eccentric roller's weight to the equilibrium point. T L is the elastic force provided to the elastic element within the overrunning clutch. T The elastic force provided to the elastic element is the elastic lever arm from the equilibrium point, μ is the coefficient of friction between the eccentric roller and the inner ring of the overrunning clutch, N i L is the normal contact force between the eccentric roller and the inner ring. f R is the frictional lever arm from the frictional force between the eccentric roller and the inner ring of the overrunning clutch to the equilibrium point. c L is the distance from the center of gravity of the eccentric roller to the rotation center of the overrunning clutch. L The centrifugal force arm of the eccentric roller is the centrifugal force from the equilibrium point.
[0013] By taking gravity, spring force, centrifugal force, and frictional torque as the resistance terms for disengagement, the disengagement speed of the overrunning clutch in the torque-transmitting engagement state can be accurately calculated, solving the problem that existing technologies cannot effectively calculate the disengagement speed in the engagement state.
[0014] In one alternative implementation, the normal contact force N i The calculation formula is:
[0015] Where T is the torque transmitted by the overrunning clutch, V is the inner wedge angle of the overrunning clutch, and N is the number of eccentric rollers in the overrunning clutch. This is the value of the outer radius of the inner ring of the overrunning clutch after deformation has stabilized.
[0016] The value of the outer radius of the inner ring of the overrunning clutch after deformation has stabilized is used as the actual outer radius of the inner ring to calculate the normal contact force. This can truly reflect the actual contact geometry between the inner ring and the eccentric roller in the engaged state of the overrunning clutch, eliminate the calculation error caused by ignoring structural deformation, and improve the calculation accuracy of the normal contact force and the first disengagement speed.
[0017] In one alternative implementation, To account for the effective contact radius of the inner ring when transmitting torque after elastic deformation caused by actual working load, i.e., the actual outer radius of the inner ring of the overrunning clutch after radial elastic deformation and reaching a stable state under the normal contact force of the eccentric rollers, this design allows the calculation model to incorporate the elastic deformation effect of the inner ring under working conditions. This more closely reflects the actual working condition of the clutch, further improving the accuracy and reliability of the disengagement speed calculation results.
[0018] In one alternative implementation, the formula for calculating the second disengagement speed based on the torque balance equation and the real-time centrifugal force equation is as follows:
[0019] Where, n c This is the second disengagement speed.
[0020] In one alternative implementation, the real-time centrifugal force equation is:
[0021] Among them, F L is the real-time centrifugal force, and n is the real-time operating speed of the overrunning clutch.
[0022] In one optional implementation, after calculating the first disengagement speed of the overrunning clutch in the engaged state and the second disengagement speed in the overrunning state based on the torque balance equation and the real-time centrifugal force equation, the method further includes: comparing the first disengagement speed with the highest speed at which the starter motor drives the clutch during engine starting, and comparing the second disengagement speed with the clutch's full-speed overrunning speed, to verify whether the first disengagement speed and the second disengagement speed of the overrunning clutch meet the design requirements of the engine transmission system.
[0023] By comparing the theoretically calculated disengagement speed with the actual operating parameters of the engine transmission system, it is possible to directly verify whether the design of the disengagement speed of the overrunning clutch is reasonable, and to determine whether the clutch will disengage too early during the starting phase or fail to disengage in time during the overrunning phase. This provides designers with a means of parameter verification, guides the adjustment and optimization of structural parameters such as the stiffness of the elastic element and the mass of the eccentric roller, and ensures the success rate of engine starting and the reliability of clutch operation.
[0024] In one alternative implementation, the critical disengagement position of the eccentric roller is when the support point of the eccentric roller is at the maximum of the gravitational lever arm in the overrunning clutch, and the torque generated by the gravity of the eccentric roller is at its maximum value.
[0025] Since the gravitational torque on the eccentric rollers varies at different positions on the inner ring of the overrunning clutch, using the position with the maximum gravitational torque as the calculation benchmark for the critical disengagement position ensures that the calculated first and second disengagement speeds are the maximum values of the required disengagement speeds among all eccentric rollers. This guarantees that the eccentric rollers at any position can disengage at that speed, avoiding the risk of some eccentric rollers failing to disengage due to improper selection of positions.
[0026] In one optional implementation, the method further includes establishing a three-dimensional kinematic model of the overrunning clutch using a multibody dynamics simulation method, using the first disengagement speed and the second disengagement speed as simulation input conditions, and verifying the consistency between the disengagement action of the eccentric roller at the corresponding speed and the theoretical calculation results. The three-dimensional kinematic model includes at least the actual geometry and contact relationship of the eccentric roller, inner ring, outer ring, elastic element and cage.
[0027] By using multibody dynamics simulation to conduct virtual experiments to verify the theoretical calculation results, it is possible to predict the actual disengagement behavior of the eccentric roller before manufacturing the physical prototype of the overrunning clutch, verify the accuracy of the torque balance equation and speed calculation formula, discover nonlinear factors or contact dynamic effects that may be ignored in the theoretical model, provide simulation data support for the effectiveness of the calculation method, and reduce R&D costs and experimental risks. Attached Figure Description
[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0029] Figure 1 This is a schematic diagram of the structure of a centrifugal disengagement overrunning clutch provided in an embodiment of the present invention.
[0030] Figure 2 for Figure 1 A schematic diagram of the forces acting on the eccentric roller at point a.
[0031] Figure 3 for Figure 1 A schematic diagram of the forces acting on the eccentric roller at point b.
[0032] Figure 4 for Figure 1 A schematic diagram of the forces acting on the eccentric roller at point c.
[0033] Figure 5 for Figure 1 A schematic diagram of the forces acting on the eccentric roller at point d.
[0034] Explanation of reference numerals in the attached figures: 1. Inner ring; 2. Outer ring; 3. Eccentric roller; 4. Elastic element; 5. Cage. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0036] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.
[0037] According to an embodiment of the present invention, in one aspect, a method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch is provided, wherein, as Figure 1 As shown, the centrifugal disengagement overrunning clutch consists of components such as an inner ring 1, an outer ring 2, eccentric rollers 3, elastic elements 4, a cage 5, and bearings. The inner ring 1 and outer ring 2 are arranged coaxially, forming an annular space between them. Multiple eccentric rollers 3 are evenly distributed within the annular space between the inner ring 1 and outer ring 2 under the action of the cage 5, ensuring uniform load distribution on the overrunning clutch. The outer contour surface of each eccentric roller 3 simultaneously contacts the inner surface of the outer ring 2 and the outer surface of the inner ring 1. The cage 5 accommodates and constrains the eccentric rollers 3, ensuring that the multiple eccentric rollers 3 are evenly separated and positioned circumferentially by the cage 5, thereby guaranteeing uniform force distribution on all parts of the clutch under load. Each eccentric roller 3 is equipped with an elastic element 4, typically a spring, which applies a preload force to the eccentric roller 3 in the direction of clutch disengagement.
[0038] The method for calculating the disengagement speed of a centrifugal disengagement overrunning clutch includes the following steps: First, the force state of the eccentric roller 3 in the overrunning clutch at the critical disengagement position is analyzed, and a torque balance equation is established with respect to the eccentric roller 3. The torque balance equation includes at least a first torque term generated by the gravity of the eccentric roller 3, a second torque term generated by the centrifugal force of the eccentric roller 3, and a third torque term generated by the elastic element 4 acting on the eccentric roller 3. The torque balance equation describes the balance between the torque that causes the roller to disengage and the torque that prevents it from disengaging at the critical disengagement moment.
[0039] Secondly, a dynamic correlation equation is established. To incorporate the rotational speed variable into the calculation, an equation describing the quantitative relationship between centrifugal force and rotational speed needs to be established, namely, the real-time centrifugal force equation. The real-time centrifugal force equation expresses the centrifugal force acting on the eccentric roller 3 as a function of the current real-time operating speed of the overrunning clutch, the mass of the eccentric roller 3, and the distance from its center of mass to the rotational axis of the clutch. This allows the abstract centrifugal force to be characterized using specific, measurable rotational speed parameters.
[0040] Then, the disengagement speed is calculated. By combining the torque balance equation and the real-time centrifugal force equation established above, and through mathematical derivation and solution, the first disengagement speed of the overrunning clutch in the engaged state and the second disengagement speed in the overrunning state are calculated.
[0041] When calculating the first disengagement speed of the clutch in the engaged state, transmitting torque, an additional fourth torque term is added to the torque balance equation, consisting of the frictional force generated by the relative motion tendency between the eccentric roller 3 and the inner ring 1 of the clutch. When calculating the second disengagement speed of the clutch in the overrunning state, where there is a speed difference between the inner and outer rings 2 and torque is basically not transmitted, the influence of this frictional force is not considered; that is, the fourth torque term is not included in the torque balance equation at this time. Through the construction of targeted torque balance equations, the first disengagement speed and the second disengagement speed of the overrunning clutch in the engaged state and the overrunning state can be accurately characterized, respectively.
[0042] The method for calculating the disengagement speed of a centrifugal disengagement overrunning clutch establishes a mechanical model of the eccentric roller 3 in the critical disengagement state. By selectively introducing a fourth torque term generated by friction into the torque balance equation, it achieves effective calculation of the disengagement speed of the centrifugal disengagement overrunning clutch under two different operating states: engagement and overrunning. This overcomes the limitation of existing technologies that can only calculate the disengagement speed in the overrunning state. It allows designers to obtain complete disengagement speed data of the clutch in both the torque-transmitting starting phase and the normal operating phase when no torque is transmitted, providing a more comprehensive calculation basis for the design of aero-engine accessory transmission systems. This ensures that the clutch's full-speed overrunning speed is higher than the disengagement speed in the overrunning state, avoiding sliding wear between the eccentric roller 3 and the inner ring 1 due to ineffective disengagement. At the same time, it ensures that the maximum speed at which the starter motor rotates the clutch during engine start-up is lower than the disengagement speed in the engagement state, preventing the clutch from disengaging too early during the starting phase and causing the gas generator rotor to fail to reach its self-sustaining speed. This effectively improves the reliability of engine start-up and the service life of the clutch, enhancing the engineering applicability and design accuracy of the disengagement speed calculation.
[0043] In this embodiment, in the step of the torque balance equation when the eccentric roller 3 in the clutch is in the critical disengagement position, the equilibrium point of the torque balance equation is set at the point where the support point of the eccentric roller is at the maximum gravity lever arm in the overrunning clutch, that is, where the torque generated by the gravity of the eccentric roller is at its maximum value.
[0044] By setting the equilibrium point as the contact point between the eccentric roller 3 and the outer ring 2, the line of action of the contact force between the eccentric roller 3 and the inner ring 1 and the outer ring 2 can be made to pass through the equilibrium point. This eliminates the torque generated by these contact forces in the torque balance equation, simplifying the analysis and establishment process of the torque balance equation.
[0045] Specifically, such as Figures 2 to 5 As shown, the torque of the eccentric roller 3 under gravity load varies depending on its position. Point A in the figure is the contact point between the eccentric roller 3 and the inner ring 1; point B is the contact point between the eccentric roller 3 and the outer ring 2; point O... G Point F is the center of gravity of eccentric roller 3; G For the weight of eccentric roller 3; F L F is the centrifugal force of the eccentric roller 3. T The elastic force exerted on the eccentric roller 3; F f The frictional force between the eccentric roller 3 and the inner ring 1; L G L is the gravity lever arm of eccentric roller 3; L L is the centrifugal force lever arm of eccentric roller 3; T L is the lever arm of the elastic force acting on the eccentric roller 3. f The frictional lever arm between the eccentric roller 3 and the inner ring 1; The contact forces of the inner and outer rings 2 pass through the line AB, therefore no torque is generated. Thus, the torque balance equation at the critical disengagement of the eccentric roller 3 is:
[0046]
[0047]
[0048]
[0049]
[0050]
[0051] Among them, M G M represents the gravitational torque of the eccentric roller 3 about point B, i.e., the first torque term; L M represents the centrifugal torque of the eccentric roller 3 about point B, i.e., the second torque term; T M is the spring torque of the eccentric roller 3 around point B, i.e., the third torque term; f is the frictional torque of eccentric roller 3 about point B, i.e., the fourth torque term; μ is the coefficient of friction between eccentric roller 3 and inner ring 1; N i This is the normal contact force between the eccentric roller 3 and the inner ring 1.
[0052] The disengagement speed should be the speed at which all eccentric rollers 3 disengage. Therefore, in this embodiment, the critical disengagement position of the eccentric rollers 3 is when the support point of the eccentric rollers 3 is on the outer ring 2 in the overrunning clutch, at which point the torque generated by the gravity of the eccentric rollers 3 is at its maximum value. Figure 1 The state of the eccentric roller 3 at point d is calculated.
[0053] Since the gravitational torque on the eccentric roller 3 is different at different positions of the inner ring 1 of the overrunning clutch, the position with the largest gravitational torque is used as the calculation benchmark for the critical disengagement position. This ensures that the calculated first disengagement speed and second disengagement speed are the maximum values of the required disengagement speeds among all eccentric rollers 3. This guarantees that the eccentric roller 3 at any position can disengage at this speed, avoiding the risk that some eccentric rollers 3 cannot disengage due to improper selection of positions.
[0054] In this embodiment, the formula for calculating the first disengagement speed based on the torque balance equation and the real-time centrifugal force equation is as follows:
[0055] Where, n j Let m be the initial disengagement speed, m be the mass of a single eccentric roller 3, g be the acceleration due to gravity, and L be the initial disengagement speed. G For the eccentric roller, the lever arm of gravity from the point of equilibrium is F. T The elastic force provided by the elastic element 4 within the overrunning clutch, L T The elastic force provided by the elastic element 4 to the equilibrium point is the elastic lever arm, μ is the coefficient of friction between the eccentric roller 3 and the inner ring 1 of the overrunning clutch, N i L is the normal contact force between the eccentric roller 3 and the inner ring 1. f R is the frictional lever arm from the frictional force between the eccentric roller 3 and the inner ring 1 of the overrunning clutch to the equilibrium point. c L is the distance from the center of gravity of the eccentric roller 3 to the rotation center of the overrunning clutch. L The centrifugal force arm of the eccentric roller 3 from the centrifugal force to the equilibrium point.
[0056] By combining gravity, spring force, centrifugal force, and frictional torque as resistance factors for disengagement, the disengagement speed of the overrunning clutch in the torque-transmitting engagement state can be accurately calculated, solving the problem that existing technologies cannot effectively calculate the disengagement speed in the engagement state.
[0057] In the formula for the first disengagement speed, the normal contact force N i The calculation formula is:
[0058] Where T is the torque transmitted by the overrunning clutch, V is the inner wedge angle of the overrunning clutch, and N is the number of eccentric rollers 3 in the overrunning clutch. This is the value of the outer radius of the inner ring 1 of the overrunning clutch after deformation has stabilized.
[0059] The value of the outer radius of the inner ring 1 of the overrunning clutch after deformation has stabilized is used as the actual outer radius of the inner ring 1 to calculate the normal contact force. This can truly reflect the actual contact geometry between the inner ring 1 and the eccentric roller 3 when the overrunning clutch is engaged, eliminate the calculation error caused by ignoring structural deformation, and improve the calculation accuracy of the normal contact force and the first disengagement speed.
[0060] Furthermore, To account for the effective contact radius of the inner ring 1 when transmitting torque after elastic deformation caused by actual working load, i.e., the actual outer radius of the inner ring 1 of the overrunning clutch after radial elastic deformation and reaching a stable state under the normal contact force of the eccentric roller 3, the calculation model can incorporate the elastic deformation effect of the inner ring 1 under working conditions. This allows the model to more closely approximate the actual working conditions of the clutch, further improving the accuracy and reliability of the disengagement speed calculation results.
[0061] In this embodiment, the formula for calculating the second disengagement speed based on the torque balance equation and the real-time centrifugal force equation is as follows:
[0062] Where, n c This is the second disengagement speed.
[0063] In one embodiment, the real-time centrifugal force equation is:
[0064] Among them, F L is the real-time centrifugal force, and n is the real-time operating speed of the overrunning clutch.
[0065] In one embodiment, after calculating the first disengagement speed of the overrunning clutch in the engaged state and the second disengagement speed in the overrunning state based on the torque balance equation and the real-time centrifugal force equation, the method further includes: comparing the first disengagement speed with the highest speed at which the starter motor drives the clutch during engine starting, and comparing the second disengagement speed with the clutch's full-speed overrunning speed, to verify whether the first disengagement speed and the second disengagement speed of the overrunning clutch meet the design requirements of the engine transmission system.
[0066] By comparing the theoretically calculated disengagement speed with the actual working parameters of the engine transmission system, it is possible to directly verify whether the design of the disengagement speed of the overrunning clutch is reasonable, and to determine whether the clutch will disengage too early during the starting phase or fail to disengage in time during the overrunning phase. This provides designers with a means of parameter verification, guides the adjustment and optimization of structural parameters such as the stiffness of the elastic element 4 and the mass of the eccentric roller 3, and ensures the success rate of engine starting and the reliability of clutch operation.
[0067] In one embodiment, the method further includes establishing a three-dimensional kinematic model of the overrunning clutch using a multibody dynamics simulation method, taking the first disengagement speed and the second disengagement speed as simulation input conditions, and verifying the consistency between the disengagement action of the eccentric roller 3 at the corresponding speed and the theoretical calculation results. The three-dimensional kinematic model includes at least the actual geometry and contact relationship of the eccentric roller 3, the inner ring 1, the outer ring 2, the elastic element 4, and the cage 5.
[0068] By using multibody dynamics simulation to conduct virtual experiments to verify the theoretical calculation results, the actual disengagement behavior of the eccentric roller 3 can be predicted before the manufacturing of the physical prototype of the overrunning clutch. This verifies the accuracy of the torque balance equation and the speed calculation formula, and identifies nonlinear factors or contact dynamic effects that may be neglected in the theoretical model. Simulation data support is provided to support the effectiveness of the calculation method, thereby reducing R&D costs and experimental risks.
[0069] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch, characterized in that, Includes the following steps: Establish the torque balance equation of the eccentric roller (3) in the overrunning clutch when it is in the critical disengagement position. The torque balance equation includes at least a first torque term generated by the gravity of the eccentric roller (3), a second torque term generated by the centrifugal force of the eccentric roller (3), and a third torque term generated by the elastic element (4) acting on the eccentric roller (3). Based on the real-time operating speed of the overrunning clutch, the real-time centrifugal force equation of the eccentric roller (3) in the overrunning clutch is established. The first disengagement speed of the overrunning clutch in the engaged state and the second disengagement speed in the overrunning state are calculated based on the torque balance equation and the real-time centrifugal force equation. When calculating the first disengagement speed, the torque balance equation includes a fourth torque term generated by the friction between the eccentric roller (3) and the inner ring (1), and when calculating the second disengagement speed, the torque balance equation does not include the fourth torque term.
2. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to claim 1, characterized in that, In the step of the torque balance equation of the eccentric roller (3) in the clutch when it is in the critical disengagement position, the balance point of the torque balance equation is set as the contact point between the eccentric roller (3) and the outer ring (2).
3. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to claim 2, characterized in that, The formula for calculating the first disengagement speed based on the torque balance equation and the real-time centrifugal force equation is as follows: Where, n j Let m be the first disengagement speed, m be the mass of a single eccentric roller (3), g be the acceleration due to gravity, and L be the acceleration due to gravity. G For the gravitational lever arm of the eccentric roller (3) from the equilibrium point, F T The elastic force provided by L to the elastic element (4) within the overrunning clutch T The elastic force provided by the elastic element (4) to the equilibrium point is the elastic lever arm, μ is the coefficient of friction between the eccentric roller (3) and the inner ring (1) of the overrunning clutch, and N i L is the normal contact force between the eccentric roller (3) and the inner ring (1). f R is the frictional lever arm from the frictional force between the eccentric roller (3) and the inner ring (1) of the overrunning clutch to the equilibrium point. c L is the distance from the center of gravity of the eccentric roller (3) to the rotation center of the overrunning clutch. L The centrifugal force arm of the eccentric roller (3) to the equilibrium point.
4. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to claim 3, characterized in that, The normal contact force N i The calculation formula is: Where T is the torque transmitted by the overrunning clutch, V is the inner wedge angle of the overrunning clutch, and N is the number of eccentric rollers (3) in the overrunning clutch. The value of the outer radius of the inner ring (1) of the overrunning clutch after deformation has stabilized.
5. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to claim 4, characterized in that, The effective contact radius of the inner ring (1) when transmitting torque is considered after the inner ring (1) undergoes elastic deformation due to actual working load.
6. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to claim 3, characterized in that, The formula for calculating the second disengagement speed based on the torque balance equation and the real-time centrifugal force equation is as follows: Where, n c This is the second disengagement speed.
7. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to any one of claims 3 to 6, characterized in that, The real-time centrifugal force equation is: Among them, F L is the real-time centrifugal force, and n is the real-time operating speed of the overrunning clutch.
8. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to any one of claims 1 to 6, characterized in that, After calculating the first disengagement speed of the overrunning clutch in the engaged state and the second disengagement speed in the overrunning state based on the torque balance equation and the real-time centrifugal force equation, the method further includes: comparing the first disengagement speed with the highest speed at which the starter motor drives the clutch during engine starting, and comparing the second disengagement speed with the clutch's full-speed overrunning speed, to verify whether the first disengagement speed and the second disengagement speed of the overrunning clutch meet the design requirements of the engine transmission system.
9. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to any one of claims 1 to 6, characterized in that, The critical disengagement position of the eccentric roller (3) is when the support point of the eccentric roller (3) is at the maximum position of the gravity lever arm in the overrunning clutch, and the torque generated by the gravity of the eccentric roller (3) is at its maximum value.
10. The method for calculating the disengagement speed of a centrifugal disengagement type overrunning clutch according to any one of claims 1 to 6, characterized in that, It also includes establishing a three-dimensional kinematic model of the overrunning clutch using a multibody dynamics simulation method, taking the first disengagement speed and the second disengagement speed as simulation input conditions, and verifying the consistency between the disengagement action of the eccentric roller (3) at the corresponding speed and the theoretical calculation results. The three-dimensional kinematic model includes at least the actual geometric shape and contact relationship of the eccentric roller (3), inner ring (1), outer ring (2), elastic element (4) and cage (5).