A design method and system for a bidirectional self-locking planetary roller screw pair

Abstract

The present invention provides a bidirectional self-locking planetary roller screw pair design method and system, the method includes obtaining a digital model to be optimized and determining characteristic parameter information, and then determining a self-locking inequality according to a self-locking requirement; determining numerical information corresponding to each variable in the self-locking inequality according to the characteristic parameter information and substituting the numerical information into the self-locking inequality to respectively determine the numerical range information of the first equivalent friction angle and the second equivalent friction angle, performing a force analysis on the digital model to be optimized and determining a load balance equation group and a transmission efficiency relationship, substituting the characteristic parameter information into the load balance equation and the transmission efficiency relationship, determining the relationship parameters between the first equivalent friction angle, the second equivalent friction angle and the transmission efficiency of the digital model to be optimized; substituting the numerical range information and the relationship parameters into a preset optimization function to determine the friction coefficient and the tooth side angle. The present invention solves the problem in the prior art that there is a lack of a planetary roller screw pair that does not require additional auxiliary components and has high transmission efficiency and can be bidirectionally self-locking.

Description

Technical Field

[0001] The invention relates to the field of transmission devices, and in particular to a design method and system for a bidirectional self-locking planetary roller screw pair. Background Art

[0002] Planetary roller screws are widely used in humanoid robots, aerospace, automobiles, ships and other national defense security and strategic emerging industries due to their advantages of small size, high load, high reliability and long life. Compared with trapezoidal screws, planetary roller screws have several more rollers in the circumference, and the sliding friction transmission of trapezoidal screws is replaced by rolling friction transmission, thereby greatly improving the transmission efficiency. However, the existing planetary roller screws do not have self-locking ability, which to a certain extent restricts the further application of planetary roller screws.

[0003] In the prior art, there is a solution to achieve self-locking by connecting a sliding screw structure in series on the planetary roller screw pair structure. Although this method can achieve self-locking to a certain extent, this method not only greatly reduces the transmission efficiency of the planetary roller screw pair, but also increases the volume and mass of the planetary roller screw pair, which reduces the advantages of the planetary roller screw such as small size, light weight and high efficiency. In addition, there is also a solution to achieve bidirectional self-locking of the planetary roller screw pair by adding an auxiliary structure. The auxiliary structure achieves preload adjustment by adding a wedge-shaped self-locking nut and an adjusting gasket at both ends of the nut. Although this method can achieve bidirectional self-locking of the planetary roller screw pair to a certain extent, this design method makes the structure of the planetary roller screw pair more complicated by adding an additional auxiliary structure.

[0004] In addition, a design method for a bidirectional self-locking planetary roller screw pair is proposed by increasing the friction on the screw-roller side and the roller-nut side. Although the bidirectional self-locking of the planetary roller screw pair can be achieved by increasing the friction on both sides, the transmission efficiency of the planetary roller screw pair is significantly reduced by increasing the friction. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a bidirectional self-locking planetary roller screw pair design method and system, aiming to solve the problem in the prior art of lack of a planetary roller screw pair that does not require additional auxiliary components and has high transmission efficiency and can be bidirectionally self-locking.

[0006] A method for designing a bidirectional self-locking planetary roller screw pair according to an embodiment of the present invention comprises:

[0007] Obtaining a digital model to be optimized, and determining characteristic parameter information according to the digital model to be optimized, wherein the digital model to be optimized is the digital model of the planetary roller screw pair to be optimized, and then determining a self-locking inequality according to a self-locking requirement;

[0008] Determine the numerical information corresponding to each variable in the self-locking inequality by a preset method according to the characteristic parameter information, and substitute the numerical information into the self-locking inequality to respectively determine the numerical range information of the first equivalent friction angle and the second equivalent friction angle, wherein the first equivalent friction angle is the equivalent friction angle between the screw and the roller, and the second equivalent friction angle is the equivalent friction angle between the roller and the nut;

[0009] Performing a force analysis on the digital model to be optimized and determining a load balance equation group of the digital model to be optimized, and determining a transmission efficiency relationship formula of the digital model to be optimized, substituting the characteristic parameter information into the load balance equation and the transmission efficiency relationship formula, and determining a relationship parameter between the first equivalent friction angle, the second equivalent friction angle, and the transmission efficiency of the digital model to be optimized;

[0010] Substituting the numerical range information and the relationship parameter into a preset optimization function to determine the optimal friction coefficient and tooth flank angle corresponding to the first equivalent friction angle and the second equivalent friction angle, so as to adjust the numerical model to be optimized according to the friction coefficient and the tooth flank angle to determine a target numerical model;

[0011] The self-locking inequality is:

[0012]

[0013]

[0014] in, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and are the helix angles of the screw, roller and nut respectively, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β It is the spiral tooth side angle.

[0015] In addition, the bidirectional self-locking planetary roller screw pair design method according to the above embodiment of the present invention may also have the following additional technical features:

[0016] Furthermore, the step of substituting the numerical information into the self-locking inequality to respectively determine the numerical range information of the first equivalent friction angle and the second equivalent friction angle includes:

[0017] Determine the helix angles of the screw rod, the roller and the nut according to a first preset equation group;

[0018] Substituting the helix angle into the self-locking inequality to determine the numerical range information;

[0019] The first preset equation group is:

[0020]

[0021]

[0022] in, , and are the number of heads of the screw, roller and nut respectively, P is the pitch, the pitch of the screw, roller and nut are the same. , and They are the middle diameters of the screw, roller and nut respectively.

[0023] Furthermore, the load balance equation group is:

[0024]

[0025]

[0026] in, K rs and K rn are the Hertzian contact stiffness between the screw and the roller and between the roller and the nut in the point contact form, n t Total number of single roller thread teeth, A s and A n are the effective contact areas of the screw and nut, F n,j-1 and F n,j Roller No. j-1 and j Normal contact force of thread teeth, E is the equivalent elastic modulus, n is the number of built-in rollers in the planetary roller screw pair, F a is the total axial load of the planetary roller screw pair, is the helix angle of the roller, β It is the spiral tooth side angle.

[0027] Furthermore, the transmission efficiency relationship is:

[0028]

[0029]

[0030]

[0031] in, or is the transmission efficiency, P0 is the output power of the planetary roller screw pair, P is the friction loss power of the planetary roller screw pair, Fa is the total axial load of the planetary roller screw pair, oh is the screw speed, Mf0 is the total friction torque of the planetary roller screw pair.

[0032] Further, the total friction torque of the planetary roller screw pair is determined by a second preset equation group according to the characteristic parameter information, and the second preset equation group is:

[0033]

[0034]

[0035]

[0036]

[0037] in, and are the spin-sliding friction torques between the screw and the roller and between the roller and the nut, respectively. and are the major and minor radii of the contact ellipse between the screw and the roller, and are the minimum and maximum values ​​of the major semi-axis of the contact ellipse between the screw and the roller, x is the horizontal axis coordinate of the contact ellipse area, y is the ordinate coordinate of the contact ellipse area, and are the major and minor radii of the contact ellipse between the roller and the nut, and are the minimum and maximum values ​​of the semi-major axis of the contact ellipse between the roller and the nut, respectively.

[0038] Furthermore, the preset optimization function is:

[0039]

[0040] in, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β is the helical tooth flank angle, Fn,j is the normal contact force of the jth thread of the roller, or is the transmission efficiency, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and They are the helix angles of the screw, roller and nut respectively.

[0041] Further, after the step of adjusting the digital model to be optimized according to the friction coefficient and the tooth flank angle to determine the target digital model, the step includes:

[0042] Determine the theoretical transmission efficiency corresponding to the friction coefficient and the tooth flank angle;

[0043] Simulating the target digital model to determine the test transmission efficiency corresponding to the target digital model and to judge whether the target digital model can achieve bidirectional self-locking;

[0044] If the target digital model can achieve bidirectional self-locking, and the ratio of the test transmission efficiency to the theoretical transmission efficiency is within a preset range, the target digital model is output for processing and production.

[0045] Another object of an embodiment of the present invention is to provide a bidirectional self-locking planetary roller screw pair design system, the system comprising:

[0046] A parameter acquisition module is used to acquire a digital model to be optimized, and determine characteristic parameter information according to the digital model to be optimized, wherein the digital model to be optimized is the digital model of the planetary roller screw pair to be optimized, and then determine a self-locking inequality according to a self-locking requirement;

[0047] A self-locking condition module, used to determine the numerical information corresponding to each variable in the self-locking inequality by a preset method according to the characteristic parameter information, and substitute the numerical information into the self-locking inequality to respectively determine the numerical range information of a first equivalent friction angle and a second equivalent friction angle, wherein the first equivalent friction angle is the equivalent friction angle between the screw and the roller, and the second equivalent friction angle is the equivalent friction angle between the roller and the nut;

[0048] a transmission efficiency relationship determination module, used to perform a force analysis on the digital model to be optimized and determine a load balance equation group of the digital model to be optimized, and determine a transmission efficiency relationship formula of the digital model to be optimized, substitute the characteristic parameter information into the load balance equation and the transmission efficiency relationship formula, and determine a relationship parameter between the first equivalent friction angle, the second equivalent friction angle and the transmission efficiency of the digital model to be optimized;

[0049] A target numerical model determination module is used to substitute the numerical range information and the relationship parameters into a preset optimization function to determine the optimal friction coefficient and tooth side angle corresponding to the first equivalent friction angle and the second equivalent friction angle, so as to adjust the numerical model to be optimized according to the friction coefficient and the tooth side angle to determine the target numerical model.

[0050] Another object of an embodiment of the present invention is to provide a storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the steps of the above-mentioned bidirectional self-locking planetary roller screw pair design method are implemented.

[0051] Another object of an embodiment of the present invention is to provide an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned bidirectional self-locking planetary roller screw pair design method when executing the program.

[0052] The present invention obtains the digital model of the screw pair to be optimized, obtains the corresponding parameters according to the digital model, and determines the inequality. After substituting the parameters into the inequality, the corresponding friction equivalent value range under the bidirectional self-locking condition of the screw pair to be optimized is obtained, and then the load balance condition of the screw pair and the transmission efficiency relationship are determined by force analysis of the digital model, and the relationship parameters between the friction equivalent and the load balance and the transmission efficiency are determined, and the relationship parameters and the value range are substituted into the preset optimization function, and then the parameters of the screw pair are optimized to obtain the optimal friction coefficient and spiral tooth side angle, and then the optimization parameters of the screw pair of the model size are determined, so that the bidirectional self-locking function of the screw pair can be realized and the transmission efficiency and load distribution consistency of the screw pair can be guaranteed by adjusting the parameters corresponding to the digital model. With this design method, there is no need to add additional auxiliary components, and the transmission performance of the screw pair is guaranteed. It can be done by adjusting the friction coefficient and the spiral tooth side angle, without modifying other external dimensions of the screw pair, and the compatibility between the screw pair and other components in the existing industry is guaranteed. Therefore, the present invention solves the problem in the prior art that there is a lack of a planetary roller screw pair that does not require additional auxiliary components and has high transmission efficiency and can be bidirectionally self-locking. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A cross-sectional schematic diagram of a bidirectional self-locking planetary roller screw pair in a first embodiment of the present invention;

[0054] Figure 2 A schematic diagram of the structure of a bidirectional self-locking planetary roller screw pair in the first embodiment of the present invention;

[0055] Figure 3 A schematic diagram of the force of the bidirectional self-locking planetary roller screw pair in the first embodiment of the present invention;

[0056] Figure 4Schematic diagram of the self-spinning sliding friction torque of the bidirectional self-locking planetary roller screw pair in the first embodiment of the present invention;

[0057] Figure 5 It is a flow chart of the design method of the bidirectional self-locking planetary roller screw pair in the first embodiment of the present invention;

[0058] Figure 6 It is a structural block diagram of a bidirectional self-locking planetary roller screw pair design system in a second embodiment of the present invention;

[0059] Figure 7 is a schematic structural diagram of an electronic device in a third embodiment of the present invention;

[0060] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0061] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0062] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0064] Embodiment 1

[0065] See also Figure 1-Figure 5 , showing a design method of a bidirectional self-locking planetary roller screw pair and a bidirectional self-locking planetary roller screw pair in a first embodiment of the present invention, the planetary roller screw pair 10 comprises a nut 11, a plurality of rollers 12, a screw rod 13, two inner gear rings 14 and two retaining frames 15;

[0066] The screw rod 13 and the nut 11 are installed coaxially, and multiple rollers 12 are evenly arranged between the screw rod 13 and the nut 11 along the circumferential direction. Two retaining frames 15 are symmetrically installed at the two ends of the inner side of the nut 11 and are clearance-matched with the optical axis sections 121 at both ends of the rollers 12. Two inner gear rings 14 are arranged inside the nut 11 and mesh with the roller teeth 122 at both ends of the rollers 12.

[0067] The method specifically includes steps S01 to S04.

[0068] S01, obtaining a digital model to be optimized, and determining characteristic parameter information according to the digital model to be optimized, wherein the digital model to be optimized is the digital model of the planetary roller screw pair to be optimized, and then determining a self-locking inequality according to a self-locking requirement;

[0069] Specifically, the self-locking inequality is:

[0070]

[0071]

[0072] in, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and are the helix angles of the screw, roller and nut respectively, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β It is the spiral tooth side angle.

[0073] It should be noted that in order to realize the bidirectional self-locking function of the planetary roller screw pair, the condition of thread self-locking needs to be met, that is, the helix angle of the thread is smaller than the equivalent friction angle of the helical pair, that is, the helix angle of the nut 11, roller 12 and screw 13 is smaller than the equivalent friction angle between the screw 13 and the roller 12 and between the roller 12 and the nut 11. Therefore, the corresponding self-locking inequality is constructed, in which the equivalent friction angle depends on the helical tooth side angle and the friction coefficient.

[0074] S02, determining numerical information corresponding to each variable in the self-locking inequality by a preset method according to the characteristic parameter information, and substituting the numerical information into the self-locking inequality to respectively determine numerical range information of a first equivalent friction angle and a second equivalent friction angle, wherein the first equivalent friction angle is an equivalent friction angle between the screw and the roller, and the second equivalent friction angle is an equivalent friction angle between the roller and the nut;

[0075] Specifically, the helix angles of the screw rod, the roller and the nut are determined according to a first preset equation group;

[0076] Substituting the helix angle into the self-locking inequality to determine the numerical range information;

[0077] The first preset equation group is:

[0078]

[0079]

[0080] in, , and are the number of heads of the screw, roller and nut respectively, P is the pitch, the pitch of the screw, roller and nut are the same. , and They are the middle diameters of the screw, roller and nut respectively.

[0081] It should be noted that in order to achieve bidirectional self-locking of the planetary roller screw pair 10, it is necessary to increase the equivalent friction angle of the screw 13-roller 12 side and the roller 12-nut 11 side, or reduce the helix angle of the screw 13, roller 12 and nut 11. Since the helix angle is only related to the number of threads, pitch and middle diameter of the thread, in order not to change the volume and mass of the planetary roller screw pair 10 in the actual design process, the number of threads, pitch and middle diameter values ​​are all fixed. Therefore, in order to achieve bidirectional self-locking of the planetary roller screw pair 10, it is achieved by increasing the equivalent friction angle. According to the above formula, to increase the equivalent friction angle of the screw 13-roller 12 side and the roller 12-nut 11 side, it is necessary to increase the friction coefficient of the screw 13-roller 12 side and the roller 12-nut 11 side or increase the tooth side angle of the screw 13, roller 12 and nut 11. The larger the friction coefficient, the lower the transmission efficiency of the planetary roller screw pair 10; the larger the thread flank angle, the more uneven the load distribution of the planetary roller screw pair 10. Therefore, in order to achieve bidirectional self-locking of the planetary roller screw pair 10, it is necessary to increase the equivalent friction angles of the screw 13-roller 12 side and the roller 12-nut 11 side, while taking into account the transmission efficiency and load distribution uniformity of the planetary roller screw pair 10.

[0082] S03, performing a force analysis on the digital model to be optimized and determining a load balance equation group of the digital model to be optimized, and determining a transmission efficiency relationship formula of the digital model to be optimized, substituting the characteristic parameter information into the load balance equation and the transmission efficiency relationship formula, and determining a relationship parameter between the first equivalent friction angle, the second equivalent friction angle, and the transmission efficiency of the digital model to be optimized;

[0083] Specifically, the load balance equations are:

[0084]

[0085]

[0086] in, K rs and K rn are the Hertzian contact stiffness between the screw and the roller and between the roller and the nut in the point contact form, n t Total number of single roller thread teeth, A s and A n are the effective contact areas of the screw and nut, F n,j-1 and F n,j Roller No. j-1 and j Normal contact force of thread teeth, E is the equivalent elastic modulus, n is the number of built-in rollers in the planetary roller screw pair, F a is the total axial load of the planetary roller screw pair, is the helix angle of the roller, β It is the spiral tooth side angle.

[0087] In addition, the transmission efficiency relationship is:

[0088]

[0089]

[0090]

[0091] in, or is the transmission efficiency, P0 is the output power of the planetary roller screw pair, P is the friction loss power of the planetary roller screw pair, Fa is the total axial load of the planetary roller screw pair, oh is the screw speed, Mf0 is the total friction torque of the planetary roller screw pair.

[0092] Further, the total friction torque of the planetary roller screw pair is determined by a second preset equation group according to the characteristic parameter information, and the second preset equation group is:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] in, and are the spin-sliding friction torques between the screw and the roller and between the roller and the nut, respectively. and are the major and minor radii of the contact ellipse between the screw and the roller, and are the minimum and maximum values ​​of the major semi-axis of the contact ellipse between the screw and the roller, x is the horizontal axis coordinate of the contact ellipse area, y is the ordinate coordinate of the contact ellipse area, and are the major and minor radii of the contact ellipse between the roller and the nut, respectively. and are the minimum and maximum values ​​of the semi-major axis of the contact ellipse between the roller and the nut, respectively.

[0099] Specifically, Mf0 is the total friction torque of the planetary roller screw pair, which includes elastic hysteresis friction torque, spin sliding friction torque and lubricant viscous friction torque. Since the friction torque caused by elastic hysteresis friction torque and lubricant viscous friction torque is very small, only spin sliding friction torque is considered when calculating the total friction torque. By analyzing the data under stress, the load balance and transmission efficiency of the numerical model and the equivalent friction angle, that is, the relationship parameters between the friction coefficient and the helical tooth side angle, are determined.

[0100] S04, substituting the numerical range information and the relationship parameter into a preset optimization function to determine the optimal friction coefficient and tooth flank angle corresponding to the first equivalent friction angle and the second equivalent friction angle, so as to adjust the numerical model to be optimized according to the friction coefficient and the tooth flank angle to determine a target numerical model;

[0101] Specifically, the preset optimization function is:

[0102]

[0103] in, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β is the helical tooth flank angle, F n,j is the normal contact force of the jth thread of the roller, or is the transmission efficiency, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and They are the helix angles of the screw, roller and nut respectively.

[0104] Specifically, by substituting the above-obtained relationship parameters and numerical ranges into the optimization function and iterating, the optimization parameters of the planetary roller screw pair of this model and size can be quickly obtained, so that the optimized planetary roller screw pair can achieve bidirectional self-locking and meet the consistency of load distribution and transmission efficiency.

[0105] In addition, by way of example and not limitation, in some optional embodiments, the step of determining the target digital model by adjusting the digital model to be optimized according to the friction coefficient and the tooth side angle includes: determining the theoretical transmission efficiency corresponding to the friction coefficient and the tooth side angle; simulating the target digital model to determine the test transmission efficiency corresponding to the target digital model and judging whether the target digital model can achieve bidirectional self-locking; if the target digital model can achieve bidirectional self-locking, and the ratio of the test transmission efficiency to the theoretical transmission efficiency is within a preset range, then outputting the target digital model for processing and production. By simulating the optimized target digital model to implement the verification step, it is ensured that the optimized digital model achieves the desired purpose and effect, and avoids systematic errors that occur when optimizing by this method. In addition, if the optimized digital model does not achieve the expected effect, it is necessary to verify the calculation steps in the scheme to ensure that each step and the optimization function are accurate, and after the verification is completed, return to the initial step to re-optimize the parameters.

[0106] In summary, the bidirectional self-locking planetary roller screw pair design method in the above-mentioned embodiment of the present invention obtains the digital model of the screw pair to be optimized, obtains the corresponding parameters according to the digital model, and determines the inequality. After substituting the parameters into the inequality, the corresponding value range of the friction equivalent under the bidirectional self-locking condition of the screw pair to be optimized is obtained, and the load balance condition of the screw pair and the transmission efficiency relationship are determined by force analysis of the digital model, and the relationship parameters between the friction equivalent, load balance and transmission efficiency are determined, and the relationship parameters and the value range are substituted into the preset optimization function, and then the parameters of the screw pair are optimized to obtain the optimal friction coefficient and spiral tooth side angle, and then the optimization parameters of the screw pair of this model and size are determined, so that the bidirectional self-locking function of the screw pair can be realized and the transmission efficiency and load distribution consistency of the screw pair can be ensured by adjusting the parameters corresponding to the digital model. By adopting this design method, there is no need to add additional auxiliary components, and the transmission performance of the screw pair is guaranteed. By adjusting the friction coefficient and the spiral tooth side angle, there is no need to modify other external dimensions of the screw pair, and the compatibility between the screw pair and other existing parts in the industry is guaranteed. Therefore, the present invention solves the problem in the prior art that there is a lack of a planetary roller screw pair that does not require additional auxiliary components and has high transmission efficiency and can be self-locked in both directions.

[0107] Embodiment 2

[0108] See also Figure 6 , which is a structural block diagram of a bidirectional self-locking planetary roller screw pair design system proposed in the second embodiment of the present invention, the bidirectional self-locking planetary roller screw pair design system 200 includes: a parameter acquisition module 21, a self-locking condition module 22, a transmission efficiency relationship determination module 23, and a target digital-analog determination module 24, wherein:

[0109] A parameter acquisition module 21 is used to acquire a digital model to be optimized, and determine characteristic parameter information according to the digital model to be optimized, wherein the digital model to be optimized is the digital model of the planetary roller screw pair to be optimized, and then determine a self-locking inequality according to a self-locking requirement;

[0110] A self-locking condition module 22, used to determine the numerical information corresponding to each variable in the self-locking inequality by a preset method according to the characteristic parameter information, and substitute the numerical information into the self-locking inequality to respectively determine the numerical range information of a first equivalent friction angle and a second equivalent friction angle, wherein the first equivalent friction angle is the equivalent friction angle between the screw and the roller, and the second equivalent friction angle is the equivalent friction angle between the roller and the nut;

[0111] A transmission efficiency relationship determination module 23 is used to perform a force analysis on the digital model to be optimized and determine a load balance equation group of the digital model to be optimized, and determine a transmission efficiency relationship formula of the digital model to be optimized, substitute the characteristic parameter information into the load balance equation and the transmission efficiency relationship formula, and determine a relationship parameter between the first equivalent friction angle, the second equivalent friction angle and the transmission efficiency of the digital model to be optimized;

[0112] The target numerical model determination module 24 is used to substitute the numerical range information and the relationship parameters into a preset optimization function to determine the optimal friction coefficient and tooth side angle corresponding to the first equivalent friction angle and the second equivalent friction angle, so as to adjust the numerical model to be optimized according to the friction coefficient and the tooth side angle to determine the target numerical model.

[0113] The self-locking inequality is:

[0114]

[0115]

[0116] in, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and are the helix angles of the screw, roller and nut respectively, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β It is the spiral tooth side angle.

[0117] Furthermore, the self-locking condition module 22 includes:

[0118] A parameter determination unit, configured to determine the helix angles of the screw rod, the roller and the nut according to a first preset equation group;

[0119] A calculation unit is used to substitute the helix pitch angle into the self-locking inequality to determine the numerical range information.

[0120] The first preset equation group is:

[0121]

[0122]

[0123] in, , and are the number of heads of the screw, roller and nut respectively, P is the pitch, the pitch of the screw, roller and nut are the same. , and They are the middle diameters of the screw, roller and nut respectively.

[0124] Furthermore, the transmission efficiency relationship determination module 23 includes:

[0125] The load balance equations are:

[0126]

[0127]

[0128] in, K rs and K rn are the Hertzian contact stiffness between the screw and the roller and between the roller and the nut in the point contact form, n t Total number of single roller thread teeth, A s and A n are the effective contact areas of the screw and nut, F n,j-1 and F n,j Roller No. j-1 and j Normal contact force of thread teeth, E is the equivalent elastic modulus, n is the number of built-in rollers in the planetary roller screw pair, F a is the total axial load of the planetary roller screw pair, is the helix angle of the roller, β It is the spiral tooth side angle.

[0129] The transmission efficiency relationship is:

[0130]

[0131]

[0132]

[0133] in, or is the transmission efficiency, P0 is the output power of the planetary roller screw pair, P is the friction loss power of the planetary roller screw pair, Fa is the total axial load of the planetary roller screw pair, oh is the screw speed, Mf0 is the total friction torque of the planetary roller screw pair.

[0134] A friction torque determination unit is used to determine the total friction torque of the planetary roller screw pair through a second preset equation group according to the characteristic parameter information, and the second preset equation group is:

[0135]

[0136]

[0137]

[0138]

[0139] in, and are the spin-sliding friction torques between the screw and the roller and between the roller and the nut, respectively. and are the major and minor radii of the contact ellipse between the screw and the roller, and are the minimum and maximum values ​​of the major semi-axis of the contact ellipse between the screw and the roller, x is the horizontal axis coordinate of the contact ellipse area, y is the ordinate coordinate of the contact ellipse area, and are the major and minor radii of the contact ellipse between the roller and the nut, respectively. and are the minimum and maximum values ​​of the semi-major axis of the contact ellipse between the roller and the nut, respectively.

[0140] The preset optimization function is:

[0141]

[0142] in, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β is the helical tooth flank angle, F n,j is the normal contact force of the jth thread of the roller, or is the transmission efficiency, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and They are the helix angles of the screw, roller and nut respectively.

[0143] Furthermore, the bidirectional self-locking planetary roller screw pair design system 200 includes:

[0144] A transmission efficiency determination unit, used to determine a theoretical transmission efficiency corresponding to the friction coefficient and the tooth flank angle;

[0145] A verification unit, used for simulating the target digital model to determine the test transmission efficiency corresponding to the target digital model and to judge whether the target digital model can achieve bidirectional self-locking;

[0146] The output unit is used to output the target digital model for processing and production when the target digital model can achieve bidirectional self-locking and the ratio of the test transmission efficiency to the theoretical transmission efficiency is within a preset range.

[0147] The functions or operation steps implemented when the above modules are executed are substantially the same as those in the above method embodiments, and will not be repeated here.

[0148] Embodiment 3

[0149] Another aspect of the present invention provides an electronic device, see Figure 7 , shown is a schematic diagram of an electronic device in the third embodiment of the present invention, including a memory 20, a processor 40, and a computer program 30 stored in the memory and executable on the processor. When the processor 40 executes the computer program 30, the bidirectional self-locking planetary roller screw pair design method as described above is implemented.

[0150] In some embodiments, the processor 40 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 20, such as executing access restriction programs.

[0151] Among them, the memory 20 includes at least one type of readable storage medium, and the readable storage medium includes a flash memory, a hard disk, a multimedia card, a card-type memory (for example, an SD or DX memory, etc.), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory 20 can be an internal storage unit of an electronic device, such as a hard disk of the electronic device. In other embodiments, the memory 20 can also be an external storage device of an electronic device, such as a plug-in hard disk equipped on the electronic device, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (FlashCard), etc. Further, the memory 20 can also include both an internal storage unit of the electronic device and an external storage device. The memory 20 can not only be used to store application software and various types of data of the electronic device, but also can be used to temporarily store data that has been output or is to be output.

[0152] It should be pointed out that Figure 3 The structure shown does not constitute a limitation on the electronic device. In other embodiments, the electronic device may include fewer or more components than those shown in the figure, or combine certain components, or arrange the components differently.

[0153] The embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned bidirectional self-locking planetary roller screw pair design method.

[0154] Those skilled in the art will appreciate that the logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For purposes of this specification, "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0155] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk case (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0156] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or a combination thereof: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0157] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0158] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A design method for a bidirectional self-locking planetary roller screw pair, characterized in that: The method comprises: Obtaining a digital model to be optimized, and determining characteristic parameter information according to the digital model to be optimized, wherein the digital model to be optimized is the digital model of the planetary roller screw pair to be optimized, and then determining a self-locking inequality according to a self-locking requirement; Determine the numerical information corresponding to each variable in the self-locking inequality by a preset method according to the characteristic parameter information, and substitute the numerical information into the self-locking inequality to respectively determine the numerical range information of the first equivalent friction angle and the second equivalent friction angle, wherein the first equivalent friction angle is the equivalent friction angle between the screw and the roller, and the second equivalent friction angle is the equivalent friction angle between the roller and the nut; Performing a force analysis on the digital model to be optimized and determining a load balance equation group of the digital model to be optimized, and determining a transmission efficiency relationship formula of the digital model to be optimized, substituting the characteristic parameter information into the load balance equation and the transmission efficiency relationship formula, and determining a relationship parameter between the first equivalent friction angle, the second equivalent friction angle, and the transmission efficiency of the digital model to be optimized; Substituting the numerical range information and the relationship parameter into a preset optimization function to determine the optimal friction coefficient and tooth flank angle corresponding to the first equivalent friction angle and the second equivalent friction angle, so as to adjust the numerical model to be optimized according to the friction coefficient and the tooth flank angle to determine a target numerical model; The self-locking inequality is: in, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and are the helix angles of the screw, roller and nut respectively, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β is the spiral tooth flank angle; The load balance equations are: in, K rs and K rn are the Hertzian contact stiffness between the screw and the roller and between the roller and the nut in the point contact form, n t Total number of single roller thread teeth, A s and A n are the effective contact areas of the screw and nut, F n,j-1 and F n,j Roller No. j-1 and j Normal contact force of thread teeth, E is the equivalent elastic modulus, n is the number of built-in rollers in the planetary roller screw pair, F a is the total axial load of the planetary roller screw pair, is the helix angle of the roller, β is the spiral tooth flank angle; The preset optimization function is: in, and are the friction coefficients between the screw and the roller and between the roller and the nut, respectively. β is the helical tooth flank angle, F n,j is the normal contact force of the jth thread of the roller, η is the transmission efficiency, and are the equivalent friction angles between the screw and the roller and between the roller and the nut, respectively. , and They are the helix angles of the screw, roller and nut respectively.

2. The design method of a bidirectional self-locking planetary roller screw pair according to claim 1, characterized in that: The step of substituting the numerical information into the self-locking inequality to respectively determine the numerical range information of the first equivalent friction angle and the second equivalent friction angle comprises: Determine the helix angles of the screw rod, the roller and the nut according to a first preset equation group; Substituting the helix angle into the self-locking inequality to determine the numerical range information; The first preset equation group is: in, , and are the number of heads of the screw, roller and nut respectively, P is the pitch, the pitch of the screw, roller and nut are the same. , and They are the middle diameters of the screw, roller and nut respectively.

3. The design method of a bidirectional self-locking planetary roller screw pair according to claim 1, characterized in that: The transmission efficiency relationship is: in, η is the transmission efficiency, P0 is the output power of the planetary roller screw pair, P is the friction loss power of the planetary roller screw pair, Fa is the total axial load of the planetary roller screw pair, ωs is the screw speed, Mf is the total friction torque of the planetary roller screw pair.

4. The design method of a bidirectional self-locking planetary roller screw pair according to claim 3, characterized in that: The total friction torque of the planetary roller screw pair is determined by a second preset equation group according to the characteristic parameter information, and the second preset equation group is: in, and are the spin-sliding friction torques between the screw and the roller and between the roller and the nut, respectively. and are the major and minor radii of the contact ellipse between the screw and the roller, and are the minimum and maximum values ​​of the major semi-axis of the contact ellipse between the screw and the roller, respectively. x is the horizontal axis coordinate of the contact ellipse area, y is the ordinate coordinate of the contact ellipse area, and are the major and minor radii of the contact ellipse between the roller and the nut, and are the minimum and maximum values ​​of the semi-major axis of the contact ellipse between the roller and the nut, respectively.

5. The design method of a bidirectional self-locking planetary roller screw pair according to claim 1, characterized in that: After the step of adjusting the digital model to be optimized according to the friction coefficient and the tooth flank angle to determine the target digital model, the following steps are included: Determine the theoretical transmission efficiency corresponding to the friction coefficient and the tooth flank angle; Simulating the target digital model to determine the test transmission efficiency corresponding to the target digital model and to judge whether the target digital model can achieve bidirectional self-locking; If the target digital model can achieve bidirectional self-locking, and the ratio of the test transmission efficiency to the theoretical transmission efficiency is within a preset range, the target digital model is output for processing and production.

6. A bidirectional self-locking planetary roller screw pair design system, characterized in that: For implementing the bidirectional self-locking planetary roller screw pair design method according to any one of claims 1 to 5, the system comprises: A parameter acquisition module is used to acquire a digital model to be optimized, and determine characteristic parameter information according to the digital model to be optimized, wherein the digital model to be optimized is the digital model of the planetary roller screw pair to be optimized, and then determine a self-locking inequality according to a self-locking requirement; A self-locking condition module, used to determine the numerical information corresponding to each variable in the self-locking inequality by a preset method according to the characteristic parameter information, and substitute the numerical information into the self-locking inequality to respectively determine the numerical range information of a first equivalent friction angle and a second equivalent friction angle, wherein the first equivalent friction angle is the equivalent friction angle between the screw and the roller, and the second equivalent friction angle is the equivalent friction angle between the roller and the nut; a transmission efficiency relationship determination module, used to perform a force analysis on the digital model to be optimized and determine a load balance equation group of the digital model to be optimized, and determine a transmission efficiency relationship formula of the digital model to be optimized, substitute the characteristic parameter information into the load balance equation and the transmission efficiency relationship formula, and determine a relationship parameter between the first equivalent friction angle, the second equivalent friction angle and the transmission efficiency of the digital model to be optimized; A target numerical model determination module is used to substitute the numerical range information and the relationship parameters into a preset optimization function to determine the optimal friction coefficient and tooth side angle corresponding to the first equivalent friction angle and the second equivalent friction angle, so as to adjust the numerical model to be optimized according to the friction coefficient and the tooth side angle to determine the target numerical model.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the bidirectional self-locking planetary roller screw pair design method as described in any one of claims 1 to 5 are implemented.

8. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for designing a bidirectional self-locking planetary roller screw pair as claimed in any one of claims 1 to 5 is implemented.

Images