A method and device for determining a load spectrum for an accelerated durability test of a ball screw pair

Abstract

The present disclosure relates to a method for determining a load spectrum of an accelerated durability test of a ball screw pair, the method comprising: obtaining a working load spectrum, loading frequency information and accelerated durability load spectrum information of the ball screw pair; obtaining an equivalent axial load force and a working rotational speed parameter according to the working load spectrum, the equivalent axial load force representing a constant load force equivalent to the working load force; obtaining an accelerated durability loading frequency according to the equivalent axial load force, the working rotational speed parameter, the loading frequency information and the accelerated durability load spectrum information, the accelerated durability loading frequency representing a number of times that the ball screw pair bears a test load force in the accelerated durability test; and determining the load spectrum of the accelerated durability test of the ball screw pair according to the accelerated durability loading frequency and the accelerated durability load spectrum information, the load spectrum of the accelerated durability test of the ball screw pair representing a relationship between a test load force and a test rotational speed associated with the ball screw pair in the accelerated durability test and changing with time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precise transmission technology of automobile brake system, and particularly relates to a method and device for determining a load spectrum of an accelerated durability test of a ball screw pair. BACKGROUND

[0002] The ball screw pair is one of the most commonly used transmission elements in the precise transmission unit, is widely used in the fields of numerical control machine tools, equipment manufacturing, automobile transportation and the like, and is a key functional part. The service life of the ball screw pair directly affects the service life of the entire transmission system, and usually needs to be subjected to a durability test. In the related art, the load applied to the ball screw pair is usually a step-shaped constant load, the load form is simple, the service life can be easily estimated, and the requirement for the durability test equipment is low. With the increasing diversification of application scenarios of the ball screw pair, the actual loading condition thereof is more complex, the service life is difficult to estimate by using the traditional method, and new challenges are also posed to the determination of the accelerated durability test spectrum. SUMMARY

[0003] To solve at least one of the above technical problems, the present disclosure provides a method and device for determining a load spectrum of an accelerated durability test of a ball screw pair.

[0004] In one aspect, the present disclosure provides a method for determining a load spectrum of an accelerated durability test of a ball screw pair, the method comprising:

[0005] obtaining a working load spectrum, loading frequency information and accelerated durability load spectrum information of the ball screw pair, the working load spectrum representing a relationship between a working load force associated with the ball screw pair and a working rotational speed changing with time, the working load force being directly or inversely proportional to the time value, the loading frequency information representing a rated number of times of bearing the working load force by the ball screw pair, and the accelerated durability load spectrum information including a test load force;

[0006] obtaining an equivalent axial load force and a working rotational speed parameter according to the working load spectrum, the equivalent axial load force representing an equivalent constant load force of the working load force;

[0007] obtaining an accelerated durability loading frequency according to the equivalent axial load force, the working rotational speed parameter, the loading frequency information and the accelerated durability load spectrum information, the accelerated durability loading frequency representing a number of times of bearing the test load force by the ball screw pair in the accelerated durability test;

[0008] determining a load spectrum of the accelerated durability test of the ball screw pair according to the accelerated durability loading frequency and the accelerated durability load spectrum information, the load spectrum of the accelerated durability test of the ball screw pair representing a relationship between the test load force associated with the ball screw pair and a test rotational speed changing with time in the accelerated durability test.

[0009] In an optional embodiment, the obtaining of the equivalent axial load force and the working rotational speed parameter according to the working load spectrum comprises:

[0010] determining the working load force based on the working load spectrum;

[0011] performing equal-division processing on the working load force to obtain at least two equal-division working load forces;

[0012] performing integral processing on the at least two equal-division working load forces to obtain the equivalent axial load force.

[0013] In an optional embodiment, the obtaining of the equivalent axial load force and the working rotational speed parameter according to the working load spectrum further comprises:

[0014] determining a working rotational speed value and a rotational speed time information based on the working load spectrum, the rotational speed time information representing a time length during which the working rotational speed value is not zero;

[0015] performing integral summation processing on the working rotational speed value to obtain an equivalent working rotational speed, the equivalent working rotational speed representing a constant rotational speed value equivalent to the working rotational speed value;

[0016] determining the equivalent working rotational speed and the rotational speed time information as the working rotational speed parameter.

[0017] In an optional embodiment, the obtaining of the accelerated durability loading times according to the equivalent axial load force, the working rotational speed parameter, the loading times information and the accelerated durability load spectrum information comprises:

[0018] determining an equivalent test load force, an equivalent test rotational speed and a test rotational speed time information according to the accelerated durability load spectrum information, the accelerated durability load spectrum information comprising a test load force, a test rotational speed and a test time information, the equivalent test load force representing a constant load force equivalent to the test load force, the equivalent test rotational speed representing a constant rotational speed value equivalent to the test rotational speed, and the test rotational speed time information representing a time length during which the rotational speed in the test rotational speed time information is not zero;

[0019] obtaining the accelerated durability loading times according to the equivalent axial load force, the working rotational speed parameter, the loading times information, the equivalent test load force, the equivalent test rotational speed and the test rotational speed time information.

[0020] In an optional embodiment, the determining of the equivalent test load force, the equivalent test rotational speed and the test rotational speed time information according to the accelerated durability load spectrum information comprises:

[0021] performing integral calculation processing on the test load force and the test rotational speed to obtain the equivalent test load force and the equivalent test rotational speed;

[0022] performing summation processing on the time length during which the rotational speed in the test time information is not zero to obtain the test rotational speed time information.

[0023] In an optional embodiment, the method for determining the accelerated durability test load spectrum of the ball screw pair according to the accelerated durability load number and the accelerated durability load spectrum information comprises the following steps:

[0024] adjusting the accelerated durability load spectrum information based on the accelerated durability load number to obtain target load spectrum information;

[0025] determining the accelerated durability test load spectrum of the ball screw pair according to the target load spectrum information.

[0026] In a second aspect, the application further provides a device for determining the accelerated durability test load spectrum of a ball screw pair, which comprises:

[0027] a obtaining module, configured to obtain the working load spectrum of the ball screw pair, the load number information and the accelerated durability load spectrum information, wherein the working load spectrum represents the relationship between the working load force and the working rotational speed of the ball screw pair with time, the working load force is directly or inversely proportional to the time value, and the load number information represents the rated number of times that the ball screw pair bears the working load force;

[0028] an equivalent axial load force module, configured to obtain the equivalent axial load force and the working rotational speed parameter according to the working load spectrum and the load number information, wherein the equivalent axial load force represents a constant load force equivalent to the working load force;

[0029] an accelerated durability load number module, configured to obtain the accelerated durability load number according to the equivalent axial load force, the working rotational speed parameter, the load number information and the accelerated durability load spectrum information, wherein the accelerated durability load number represents the number of times that the ball screw pair bears the test load force in the accelerated durability experiment;

[0030] a load spectrum determining module, configured to determine the accelerated durability test load spectrum of the ball screw pair according to the accelerated durability load number and the accelerated durability load spectrum information, wherein the accelerated durability test load spectrum of the ball screw pair represents the relationship between the test load force and the test rotational speed of the ball screw pair with time in the accelerated durability experiment.

[0031] In a third aspect, the application further provides an electronic device, which comprises:

[0032] a processor;

[0033] a memory for storing processor-executable instructions;

[0034] wherein the processor is configured to execute the instructions to implement the method for determining the accelerated durability test load spectrum of the ball screw pair.

[0035] In a fourth aspect, the present application further provides a storage medium, which enables an electronic device to execute the above-mentioned ball screw pair accelerated durability test load spectrum determination method when instructions in the storage medium are executed by a processor of the electronic device.

[0036] In a fifth aspect, the present application further provides a computer program product, which comprises a computer program stored in a readable storage medium, and at least one processor of a computer device reads and executes the computer program from the readable storage medium, so that the device executes the above-mentioned ball screw pair accelerated durability test load spectrum determination method.

[0037] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, but not limiting the present application.

[0038] The implementation of the present application has the following beneficial effects:

[0039] The working load spectrum, loading frequency information and accelerated durability load spectrum information of the ball screw pair are obtained, the working load spectrum represents the relationship between the working load force associated with the ball screw pair and the working rotational speed changing with time, the working load force can be proportional or inversely proportional to the time value, the loading frequency information represents the rated number of times of the ball screw pair bearing the working load force, and the accelerated durability load spectrum information includes the test load force; the equivalent axial load force and the working rotational speed parameter are obtained according to the working load spectrum, the equivalent axial load force represents the equivalent constant load force of the working load force; the accelerated durability loading frequency is obtained according to the equivalent axial load force, the working rotational speed parameter, the loading frequency information and the accelerated durability load spectrum information, the accelerated durability loading frequency represents the number of times of the ball screw pair bearing the test load force in the accelerated durability test; the ball screw pair accelerated durability test load spectrum is determined according to the accelerated durability loading frequency and the accelerated durability load spectrum information, and the ball screw pair accelerated durability test load spectrum represents the relationship between the test load force associated with the ball screw pair and the test rotational speed changing with time in the accelerated durability test.

[0040] The present application realizes the simplified calculation and equivalent conversion of the working load force proportional or inversely proportional to the time value, realizes the analysis and processing of the complex working load force, and completes the calculation of the equivalent axial load under the condition of the complex working load force through the analysis and processing of the working load spectrum.

[0041] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, and the advantages thereof, the accompanying drawings required by the description of the embodiments or the prior art will be briefly described in the following. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings herein are incorporated into the description and constitute a part of the description, show embodiments consistent with the present disclosure, and together with the description serve to explain the principles of the present disclosure, and do not constitute an improper limitation on the present disclosure.

[0043] Figure 1 is a schematic diagram of an implementation environment according to an exemplary embodiment;

[0044] Figure 2 is a flowchart of a method for determining an accelerated durability test load spectrum of a ball screw pair according to an exemplary embodiment;

[0045] Figure 3 is a flowchart of obtaining an equivalent axial load force according to an exemplary embodiment;

[0046] Figure 4 is a flowchart of obtaining a working rotational speed parameter according to an exemplary embodiment;

[0047] Figure 5 is a block diagram of a device for determining an accelerated durability test load spectrum of a ball screw pair according to an exemplary embodiment;

[0048] Figure 6 is a block diagram of an electronic device for determining an accelerated durability test load spectrum of a ball screw pair according to an exemplary embodiment;

[0049] Figure 7 is a schematic diagram of a working load spectrum according to an exemplary embodiment;

[0050] Figure 8 is a schematic diagram of an accelerated durability load spectrum according to an exemplary embodiment;

[0051] Figure 9 is a schematic diagram of a calculation principle of an equivalent axial load according to an exemplary embodiment;

[0052] Figure 10 is a schematic diagram of a stepped load spectrum according to an exemplary embodiment;

[0053] Figure 11 is a schematic diagram of specific parameters of a working load spectrum and an accelerated durability load spectrum according to an exemplary embodiment. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present specification will be described clearly and completely in combination with the drawings in the embodiments of the present specification. Obviously, the described embodiments are only some of the embodiments of the present specification, rather than all the embodiments. Based on the embodiments in the present specification, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0055] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or server including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0056] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numbers in the drawings represent functionally the same or similar elements. Although various aspects of the embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated. The word "exemplary" used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0057] The term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0058] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the specific embodiments below. Those skilled in the art should understand that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, elements, and circuits well known to those skilled in the art are not described in detail in order to highlight the main idea of the present disclosure.

[0059] In the related art, the load applied to the ball screw pair is usually a stepped constant load, the load form is simple, the life estimation is easy to perform, and the requirement for the durability test equipment is low. However, for complex loads, it is difficult to estimate the life of the ball screw pair by using the traditional method, and new challenges are also put forward for determining the accelerated durability test spectrum under complex load conditions.

[0060] In order to realize the life estimation of the ball screw pair under complex load and the formulation of the accelerated durability test method, shorten the durability test time, and reduce the test cost, an embodiment of the present disclosure provides a ball screw pair accelerated durability test load spectrum determination method.

[0061] Please refer to Figure 1 , Figure 1 is a schematic diagram of an application environment according to an exemplary embodiment, as Figure 1 shown, the application environment can include a server 01 and a terminal 02.

[0062] In an optional embodiment, the server 01 can be used for the ball screw pair accelerated durability test load spectrum determination method to perform calculation processing. Specifically, the server 01 can be a stand-alone physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDN), and big data and artificial intelligence platforms, etc. Basic cloud computing services.

[0063] In an optional embodiment, the terminal 02 can combine the ball screw pair accelerated durability test load spectrum determination method of the server 01 to perform calculation processing. Specifically, the terminal 02 can include but is not limited to smart phones, desktop computers, tablet computers, notebook computers, smart speakers, digital assistants, augmented reality (AR) / virtual reality (VR) devices, smart wearable devices, and the like. The operating system running on the electronic device can include but is not limited to Android system, iOS system, Linux system, Windows system, Unix system, etc.

[0064] For example, the working load spectrum, the loading frequency information and the accelerated endurance load spectrum information of the ball screw pair are input on the terminal 02, the server 01 acquires the working load spectrum, the loading frequency information and the accelerated endurance load spectrum information of the ball screw pair on the terminal 02, and then obtains the equivalent axial load force and the working rotational speed parameter according to the working load spectrum, the equivalent axial load force representing a constant load force equivalent to the working load force; obtains the accelerated endurance loading frequency according to the equivalent axial load force, the working rotational speed parameter, the loading frequency information and the accelerated endurance load spectrum information, the accelerated endurance loading frequency representing the number of times of bearing the test load force of the ball screw pair in the accelerated endurance experiment; determines the accelerated endurance test load spectrum of the ball screw pair according to the accelerated endurance loading frequency and the accelerated endurance load spectrum information, the accelerated endurance test load spectrum of the ball screw pair representing the relationship between the test load force and the test rotational speed associated with the ball screw pair and the time change in the accelerated endurance experiment; and finally transmits the accelerated endurance test load spectrum of the ball screw pair to the terminal 02.

[0065] In addition, it should be noted that, Figure 1 The application environment shown is only one application environment provided by the present disclosure, and other application environments can also be included in actual application.

[0066] In the embodiments of the present disclosure, the server 01 and the terminal 02 can be directly or indirectly connected through wired or wireless communication, which is not limited in the present disclosure.

[0067] Figure 2 A flow chart of a ball screw pair accelerated endurance test load spectrum determination method according to an exemplary embodiment is shown in FIG. 2. Figure 2 As shown in FIG. 2, the ball screw pair accelerated endurance test load spectrum determination method comprises the following steps:

[0068] Step S201: Acquire the working load spectrum, the loading frequency information and the accelerated endurance load spectrum information of the ball screw pair, the working load spectrum representing the relationship between the working load force and the working rotational speed associated with the ball screw pair and the time change, the working load force being proportional or inversely proportional to the time value, the loading frequency information representing the rated number of times of bearing the working load force of the ball screw pair, and the accelerated endurance load spectrum information including the test load force.

[0069] In the embodiments of the present disclosure, the working load spectrum and the loading times information of the ball screw pair are determined according to the actual service load of the ball screw pair. Specifically, the working load force and the working speed of the ball screw pair are measured at different time points during the process that the ball screw pair bears the actual service load, so as to determine the relationship between the working load force and the working speed with time, and then the working load spectrum is drawn according to the relationship between the working load force and the working speed with time. In the actual service load of the ball screw pair, the working load force borne by the ball screw pair in a certain time period is not always kept at a constant value, but gradually increases or decreases from a certain working load force value to another working load force value. For the case that the working load force gradually increases in a certain time period, the working load spectrum can be drawn by approximating it as a slope load in which the working load force is proportional to time, and the starting point of the slope load is the minimum working load force value in the time period, and the end point is the maximum working load force value in the time period. For the case that the working load force gradually decreases in a certain time period, the working load spectrum can be drawn by approximating it as a slope load in which the working load force is inversely proportional to time, and the starting point of the slope load is the maximum working load force value in the time period, and the end point is the minimum working load force value in the time period. The accelerated endurance load spectrum information of the ball screw pair is obtained by preliminary setting. The working load spectrum can reflect the relationship between the working load force and the working speed associated with the ball screw pair with time, and the loading times information can reflect the rated number N f1 of times that the ball screw pair bears the working load force. Optionally, as shown in Figure 7 , the working load force borne by the ball screw pair changes with time as follows: in the t1 and t5 stages, the working load force is proportional to the time value; in the t3 and t7 stages, the working load force is inversely proportional to the time value; that is, in the t1, t3, t5 and t7 stages, the load borne by the ball screw pair is a slope load; in the t2 and t6 stages, the working load force remains a constant value F1; in the t4 stage, the working load force remains a constant value F2. Optionally, as shown in Figure 7 , the working speed of the ball screw pair changes with time as follows: in the t1, t3, t5 and t7 stages, the working speed is not zero, and in the t1 and t7 stages, the working speed is a constant value n1; in the t3 and t5 stages, the working speed is a constant value n2; in the t2, t4 and t6 stages, the working speed is zero. Optionally, as shown in Figure 8 , the test load force in the accelerated endurance load spectrum information changes with time as follows: in the t1' stage, the test load force is proportional to the time value; in the t3' stage, the test load force is inversely proportional to the time value; that is, in the t1' and t3' stages, the test load borne by the ball screw pair is a slope load; in the t2' stage, the test load force remains a maximum value F max . Optionally, as shown inFigure 8 As shown in FIG. 2, the test rotating speed of the ball screw pair varies with time as follows: in the t1' and t3' stages, the test rotating speed is not zero, and in the t1' and t3' stages, the test rotating speed is set to a constant value n1'; in the t2' stage, the test rotating speed is zero.

[0070] Step S202: obtaining equivalent axial load force and working rotating speed parameter according to working load spectrum, the equivalent axial load force representing a constant load force equivalent to the working load force.

[0071] In the embodiments of the present disclosure, obtaining equivalent axial load force and working rotating speed parameter according to working load spectrum comprises the following:

[0072] Figure 3 A flowchart for obtaining equivalent axial load force according to an exemplary embodiment is shown in FIG. 2, which comprises the following steps: Figure 3 As shown in FIG. 2, obtaining equivalent axial load force and working rotating speed parameter comprises the following steps:

[0073] Step S301: determining working load force based on working load spectrum.

[0074] In the embodiments of the present disclosure, since the working load spectrum can reflect the relationship between the working load force borne by the ball screw pair and time, the horizontal coordinate is time and the vertical coordinate is working load force in the working load spectrum, so the working load force in a certain time period can be determined.

[0075] Step S302: performing equal-division processing on the working load force to obtain at least two equal-division working load forces.

[0076] In the embodiments of the present disclosure, when the working load force is proportional to or inversely proportional to the time value, the working load is a ramp load force, as shown in FIG. 3. Figure 9 As shown in FIG. 3, p points in the range interval of the ramp load force value are equally divided into p+1 parts, and the minimum point of the ramp load force value is recorded as the 0th equal-division point, i.e., F0=F min The ramp load force value of the ith equal-division point, i.e., the ith equal-division working load force F i is F

[0077]

[0078] (1) In the formula, F min is the minimum value of the ramp load force, and ΔF is the range of the ramp load force, i.e., the maximum value minus the minimum value of the ramp load force.

[0079] Step S303: performing integral processing on the at least two equal-division working load forces to obtain equivalent axial load force.

[0080] In the embodiments of the present disclosure, based on the equivalent axial load calculation formula of the conventional step load, and combined with the differential limit idea, the equivalent axial load force corresponding to the ramp load can be calculated. As shown in Figure 10 For the axial load changing in steps, i.e., the axial load is a constant segmented function of time, the calculation formula of the corresponding equivalent axial load force is

[0081]

[0082] (2) In the formula, n m is the equivalent rotational speed corresponding to the conventional step load, F m is the equivalent axial load force corresponding to the conventional step load, n j is the rotational speed in the jth time segment, F j is the axial load in the jth time segment, q j is the proportion of the jth time segment in the total time length.

[0083] The entire ramp load force is equivalent to p+1 step loads, and the load force values are F O , F1,…, F p , which can be obtained by calculation according to formula (1). Since it is the force value of the equal division point, the time proportion of each constant load in the segment ramp load is Considering that the rotational speed is constant, formula (2) can be simplified to calculate the equivalent axial load corresponding to the ramp load:

[0084]

[0085] (3) In the formula, F m is the equivalent axial load corresponding to the ramp load, which can be further arranged into the following formula by substituting formula (1):

[0086]

[0087] Combined with the series related knowledge of the polynomial, formula (4) can be further written as follows:

[0088]

[0089] When the number of equal division points p tends to infinity, a series of step loads equivalent to the original ramp load can be established, and therefore, the limit of formula (5) with respect to p can be obtained as follows:

[0090]

[0091] The equivalent axial load can be calculated according to formula (6).

[0092] Based on the above, the embodiment of the present disclosure realizes the simplified processing of the work load force proportional to the time value by equally dividing the work load force, and completes the equivalent conversion of the work load force based on the idea of integral and infinite series; by integrating at least two equally divided work load forces, the analysis and processing of the complex work load force are realized, the calculation of the equivalent axial load under the complex work load force is completed, and the application range of the equivalent axial load calculation method of the ball screw pair is effectively expanded.

[0093] Figure 4 is a flow chart for obtaining a work speed parameter according to an exemplary embodiment, as shown in Figure 4 obtaining an equivalent axial load force and a work speed parameter, also includes:

[0094] Step S401: determining a work speed value and a speed time information based on a work load spectrum, the speed time information representing the length of time when the work speed value is not zero.

[0095] In the embodiment of the present disclosure, since the work load spectrum can reflect the relationship between the work speed of the ball screw pair and the change of time, the horizontal coordinate is time and the vertical coordinate is work speed in the work load spectrum, so the work speed value and the corresponding length of time in a certain time period can be determined, and the length of time when the work speed value is not zero is added to obtain the speed time information.

[0096] Step S402: integrating and summing the work speed value to obtain an equivalent work speed, which represents a constant speed value equivalent to the work speed value.

[0097] In the embodiment of the present disclosure, based on the equivalent speed calculation formula of the conventional step load and combined with the idea of differential limit, the equivalent speed corresponding to the ramp load can be calculated. As shown in Figure 10 for the speed with step change, i.e. the speed is a constant piecewise function of time, the calculation formula of the corresponding equivalent speed is

[0098]

[0099] (7) In the formula, n m is the equivalent work speed corresponding to the conventional step load, n j is the work speed in the jth time period, and q j is the proportion of the jth time length to the total time length.

[0100] Since the time proportion corresponding to each constant speed is Considering that the speed is constant, the formula (7) can be simplified, and the equivalent work speed corresponding to the ramp load is calculated as: n m = con , n conTo be constant.

[0101] Step S403: Determine the equivalent working rotational speed and the rotational speed time information as the working rotational speed parameter.

[0102] In the embodiments of the present disclosure, the equivalent working rotational speed and the rotational speed time information obtained through step S402 and step S401 are determined as the working rotational speed parameter.

[0103] Based on the above, the embodiments of the present disclosure realize the extraction of the rotational speed related information in the working load spectrum by determining the working rotational speed value and the rotational speed time information based on the working load spectrum; the calculation of the equivalent working rotational speed is realized by integrating and summing the working rotational speed value, the equivalent transformation of the working rotational speed is completed, the calculation process is simplified, and the subsequent further calculation and analysis processing of the working rotational speed parameter is facilitated.

[0104] Step S203: Obtain the accelerated durability loading times according to the equivalent axial load force, the working rotational speed parameter, the loading times information and the accelerated durability load spectrum information, the accelerated durability loading times representing the times of the ball screw pair bearing the test load force in the accelerated durability experiment.

[0105] In the embodiments of the present disclosure, the accelerated durability loading times are obtained according to the equivalent axial load force, the working rotational speed parameter, the loading times information and the accelerated durability load spectrum information, including the following:

[0106] Step S501: Determine the equivalent test load force, the equivalent test rotational speed and the test rotational speed time information according to the accelerated durability load spectrum information, the accelerated durability load spectrum information including the test load force, the test rotational speed and the test time information, the equivalent test load force representing the constant load force equivalent to the test load force, the equivalent test rotational speed representing the constant rotational speed value equivalent to the test rotational speed, and the test rotational speed time information representing the time length of the rotational speed being not zero in the test rotational speed time information.

[0107] In the embodiments of the present disclosure, the equivalent test load force, the equivalent test rotational speed and the test rotational speed time information are determined according to the accelerated durability load spectrum information, including the following:

[0108] Step S601: Perform integral calculation processing on the test load force and the test rotational speed to obtain the equivalent test load force and the equivalent test rotational speed.

[0109] In the embodiments of the present disclosure, the integral calculation processing on the test load force and the test rotational speed includes: determining the minimum value of the test load force and the range of the test load force according to the test load force in the accelerated durability load spectrum information, and bringing the minimum value of the test load force F min and the range of the test load force ΔF' into formula (6) to obtain the equivalent test load force F mAccording to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined j According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined j According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined j According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined j According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined j According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined m According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined m According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined con According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined con According to the accelerated durability load spectrum information, the test rotating speed n in the jth segment time is determined

[0110] Step S602: The time length with non-zero rotating speed in the test time information is summed to obtain test rotating speed time information.

[0111] In the embodiment of the present disclosure, the time length with non-zero rotating speed in the test time information is all added to obtain the time with non-zero overall rotating speed, and the time with non-zero overall rotating speed is determined as the test rotating speed time information.

[0112] Based on the above, the embodiment of the present disclosure realizes the simplified processing of the test load force proportional to the time value by integrating and processing the test load force and the test rotating speed, completes the equivalent conversion of the test load force, is helpful for the analysis and processing of the complex test load force, and can complete the calculation of the equivalent test load force and the equivalent test rotating speed under the condition of the complex test load force, which is helpful for the further calculation and analysis of the equivalent test load force and the equivalent test rotating speed.

[0113] Step S502: The accelerated durability loading times are obtained according to the equivalent axial load force, the working rotating speed parameter, the loading times information, the equivalent test load force, the equivalent test rotating speed and the test rotating speed time information.

[0114] In the embodiment of the present disclosure, the main failure mode of the ball screw pair is fatigue pitting wear, and the damage equivalent principle is suitable for accelerated durability test. First, the life of the ball screw pair with a survival rate of 90% is calculated according to the ball screw pair life (in revolutions) calculation formula, and the ball screw pair life (in revolutions) calculation formula is as follows:

[0115]

[0116] In formula (8), L is the life with a survival rate of 90%, C a is the rated dynamic load, which is determined by the geometric structure parameters of the ball screw pair.

[0117] Assuming that the damage of the ball screw pair is certain under the equivalent axial load, the damage can be linearly superimposed every time the shaft rotates one revolution, and failure occurs when the damage and equal to 1. The damage equivalence principle considers that the remaining life of the material is the same when the damage is the same. Therefore, the accelerated durability loading times can be determined according to the equal damage before and after the load acceleration, that is,

[0118]

[0119] (9) In the formula, N f1 , N f2 are the loading times information and the accelerated durability loading times respectively, T is the rotation speed time information, that is, the time of the screw rotation under the working load every time the load is loaded, T' is the test rotation speed time information, that is, the time of the screw rotation under the accelerated durability test load every time the load is loaded, n m , n m are the equivalent working rotation speed and the equivalent test rotation speed respectively, and L1 and L2 are the rated life corresponding to the working load and the accelerated test load.

[0120] The accelerated durability loading times can be further calculated according to the formula (8) and the formula (9):

[0121]

[0122] (10) In the formula, F m , F m are the equivalent axial load force and the equivalent test load force respectively.

[0123] Based on the above, the disclosure embodiments realize the calculation of the equivalent test load force and the equivalent test rotation speed by integrating and calculating the test load force and the test rotation speed. Through the analysis and processing of the equivalent axial load force, the working rotation speed parameter, the loading times information, the equivalent test load force, the equivalent test rotation speed and the test rotation speed time information, the calculation and acquisition of the accelerated durability loading times are realized, which helps to improve the efficiency of the accelerated durability test and reduce the test time.

[0124] Step S204: determining the ball screw pair accelerated durability test load spectrum according to the accelerated durability loading times and the accelerated durability load spectrum information, the ball screw pair accelerated durability test load spectrum representing the relationship between the test load force and the test rotation speed associated with the ball screw pair in the accelerated durability test and the change with time.

[0125] In the disclosure embodiments, the ball screw pair accelerated durability test load spectrum is determined according to the accelerated durability loading times and the accelerated durability load spectrum information, including the following:

[0126] Step S701: adjusting the accelerated durability load spectrum information based on the accelerated durability loading times to obtain target load spectrum information.

[0127] In the embodiment of the present disclosure, the accelerated endurance loading number N f2 When the preset requirement is not met, the accelerated endurance load spectrum information is adjusted, the test load force, the test rotating speed and the test time information in the accelerated endurance load spectrum information are re-determined, the calculation process in the step S203 is repeated according to the re-determined accelerated endurance load spectrum information, the accelerated endurance loading number is re-iteratively calculated until the accelerated endurance loading number meets the preset requirement, and the accelerated endurance load spectrum information corresponding to the accelerated endurance loading number meeting the preset requirement is determined as the target load spectrum information. Optionally, the preset requirement can be that the calculated accelerated endurance loading number N f2 is approximately equal to the specified number of times.

[0128] Step S702: determining the accelerated endurance test load spectrum of the ball screw pair according to the target load spectrum information.

[0129] In the embodiment of the present disclosure, the test load force, the test rotating speed and the test time information in the target load spectrum information can be used to determine the relationship between the test load force and the test rotating speed changing with time, and the accelerated endurance test load spectrum of the ball screw pair can be determined according to the relationship between the test load force and the test rotating speed changing with time.

[0130] Based on the above, the embodiment of the present disclosure realizes the acquisition of the target load spectrum information meeting the test requirement through the adjustment and calculation of the accelerated endurance load spectrum information, and the accelerated endurance test load spectrum of the ball screw pair determined according to the target load spectrum information can realize the accelerated endurance test of the ball screw pair under complex load, thereby expanding the application range of the accelerated endurance test method of the ball screw pair.

[0131] In the above embodiment, the present disclosure obtains the corresponding accelerated endurance test load spectrum through the calculation and analysis of the complex load force whose value can be proportional to or inversely proportional to the time value. Compared with other methods for determining the accelerated endurance test load spectrum of the ball screw pair, the present disclosure realizes the simplified processing of the working load force proportional to the time value through the equal division processing of the working load force, realizes the analysis and processing of the complex working load force through the equivalent conversion of the working load force based on the integral and infinite series, completes the calculation of the equivalent axial load under the complex working load force, effectively expands the application range of the equivalent axial load calculation method of the ball screw pair, and reduces the performance requirement of the test equipment; the equivalent test load force and the equivalent test rotating speed are calculated through the integral calculation processing of the test load force and the test rotating speed, which helps to improve the efficiency of the accelerated endurance test.

[0132] In a specific embodiment, the technical solution in the embodiment of the present disclosure is implemented as follows:

[0133] The specific parameters of the working load spectrum and the accelerated durability load spectrum are as follows: Figure 11 As shown in the diagram, the working load spectrum and the accelerated durability load spectrum are illustrated below. Figure 7 and Figure 8 As shown.

[0134] First, calculate the equivalent axial load and equivalent rotational speed corresponding to the working load spectrum:

[0135] Since the working load consists of four ramp loads, the equivalent axial load F for each ramp load should be calculated first. m1 -F m4 With equivalent rotational speed n m1 -n m4 Then, the final equivalent axial load F is calculated according to the conventional stepped load calculation method. m With equivalent rotational speed n m .

[0136] Since the rotational speed is constant under each ramp load, therefore,

[0137]

[0138] Substituting this into equation (7) further, we can obtain the overall equivalent rotational speed n. m :

[0139]

[0140] Due to symmetry, the equivalent axial loads of 0→F1 and F1→0, and F1→F2 and F2→F1 are equal, i.e.

[0141]

[0142] Further, the overall equivalent axial load F is obtained. m :

[0143]

[0144] Secondly, calculate the equivalent axial load and equivalent rotational speed of the accelerated durability load spectrum:

[0145] The accelerated load durability spectrum has two ramp loads, which also need to be calculated separately and equivalent to conventional stepped loads, so as to calculate the corresponding equivalent axial load and equivalent rotational speed.

[0146] Similar to the calculation method for working loads, the equivalent rotational speeds for both ramp loads are:

[0147] n′ m1 =n′ 2m =n′1=2000rpm (15)

[0148] Since the rotational speed is the same under the ramp load, the overall equivalent rotational speed is:

[0149] n′ m = 2000 rpm (16)

[0150] In terms of axial load, 0→F max and F max →0, the equivalent axial loads are equal, and from equation (6), we have:

[0151]

[0152] Further, the overall load has an equivalent axial load of:

[0153] F′ m = F′ m1 = F′ m2 = 6300 N (18)

[0154] Finally, combined with the established accelerated durability model (equation (10)), the loading times N f2 of the accelerated durability load are calculated:

[0155]

[0156] In addition, the ratio of the test time under the accelerated durability load to the test time under the original working load, i.e., the time acceleration ratio, can be further calculated:

[0157]

[0158] where T period and T′ period are the cycle periods of the two loads. The calculation of the acceleration ratio is 3.1, i.e., the time required for the test under the accelerated durability load determined by this method is about 1 / 3 of the original, greatly improving the test efficiency.

[0159] Figure 5 is a ball screw pair accelerated durability test load spectrum determination device block diagram according to an exemplary embodiment. Referring to Figure 5 , the device includes a state acquisition module 801, an equivalent axial load force module 802, an accelerated durability loading times module 803, and a load spectrum determination module 804, wherein,

[0160] The acquisition module 801 is used to acquire the working load spectrum of the ball screw pair, the loading times information, and the accelerated durability load spectrum information. The working load spectrum represents the relationship between the working load force associated with the ball screw pair and the working rotational speed changing with time. The working load force value can be directly proportional or inversely proportional to the time value. The loading times information represents the rated number of times that the ball screw pair bears the working load force. The accelerated durability load spectrum information includes the test load force.

[0161] An equivalent axial load force module 802 is configured to obtain an equivalent axial load force and a work rotational speed parameter according to the work load spectrum and the loading times information, the equivalent axial load force representing a constant load force equivalent to the work load force;

[0162] An accelerated durability loading times module 803 is configured to obtain an accelerated durability loading times according to the equivalent axial load force, the work rotational speed parameter, the loading times information and the accelerated durability load spectrum information, the accelerated durability loading times representing the times of the ball screw pair bearing the test load force in the accelerated durability experiment;

[0163] A load spectrum determination module 804 is configured to determine a ball screw pair accelerated durability test load spectrum according to the accelerated durability loading times and the accelerated durability load spectrum information, the ball screw pair accelerated durability test load spectrum representing the relationship between the test load force and the test rotational speed associated with the ball screw pair in the accelerated durability experiment.

[0164] In an optional embodiment, the equivalent axial load force module 802 comprises:

[0165] A work load force module is configured to determine the work load force based on the work load spectrum;

[0166] An equal division work load force module is configured to perform equal division processing on the work load force to obtain at least two equal division work load forces;

[0167] An equivalent axial load force sub-module is configured to perform integral processing on the at least two equal division work load forces to obtain the equivalent axial load force.

[0168] In an optional embodiment, the equivalent axial load force module 802 further comprises:

[0169] A rotational speed information module is configured to determine a work rotational speed value and rotational speed time information based on the work load spectrum, the rotational speed time information representing the time length during which the work rotational speed value is not zero;

[0170] An equivalent work rotational speed module is configured to perform integral sum processing on the work rotational speed value to obtain an equivalent work rotational speed, the equivalent work rotational speed representing a constant rotational speed value equivalent to the work rotational speed value;

[0171] A work rotational speed parameter module is configured to determine the equivalent work rotational speed and the rotational speed time information as the work rotational speed parameter.

[0172] In an optional embodiment, the accelerated durability loading times module 803 comprises:

[0173] The equivalent test information module is used to determine the equivalent test load force, equivalent test speed, and test speed-time information based on the accelerated durability load spectrum information. The accelerated durability load spectrum information includes test load force, test speed, and test time information. The equivalent test load force represents the equivalent fixed load force, the equivalent test speed represents the equivalent fixed speed value, and the test speed-time information represents the duration during which the speed is not zero in the test speed-time information.

[0174] The Accelerated Durability Loading Cycles submodule is used to obtain the accelerated durability loading cycles based on the equivalent axial load force, operating speed parameters, loading cycle information, equivalent test load force, equivalent test speed, and test speed-time information.

[0175] In an optional embodiment, the above-mentioned equivalent test information module includes:

[0176] The equivalent test submodule is used to perform integral calculations on the test load force and test speed to obtain the equivalent test load force and equivalent test speed.

[0177] The test speed module is used to sum the durations in the test time information where the speed is not zero, and obtain the test speed time information.

[0178] In an optional embodiment, the load spectrum determination module 804 described above includes:

[0179] The target load spectrum information module is used to adjust the accelerated durability load spectrum information based on the number of accelerated durability loading cycles to obtain the target load spectrum information.

[0180] The load spectrum determination submodule is used to determine the load spectrum for accelerated durability testing of the ball screw pair based on the target load spectrum information.

[0181] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0182] In an exemplary embodiment, an electronic device is also provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is used for the instructions to implement the method for determining the load spectrum of a ball screw pair in an accelerated durability test as described in the embodiments of this disclosure.

[0183] Figure 6 This is a block diagram illustrating an electronic device for determining the load spectrum in an accelerated endurance test of a ball screw assembly, according to an exemplary embodiment. The electronic device may be a terminal, and its internal structure diagram may be as follows: Figure 6As shown, the electronic device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for determining the load spectrum of a ball screw pair in accelerated durability testing. The display screen can be a liquid crystal display (LCD) or an e-ink display. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the device's casing, or an external keyboard, touchpad, or mouse.

[0184] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present disclosure and does not constitute a limitation on the electronic device to which the present disclosure is applied. A specific electronic device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0185] In an exemplary embodiment, a storage medium is also provided, which, when the instructions in the storage medium are executed by the processor of an electronic device, enables the electronic device to perform the ball screw pair accelerated endurance test load spectrum determination method in the embodiments of this disclosure.

[0186] In an exemplary embodiment, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute the method for determining the load spectrum of accelerated endurance test for ball screw pairs in embodiments of this disclosure.

[0187] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this disclosure can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAM bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0188] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0189] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for determining the load spectrum of an accelerated endurance test for a ball screw pair, characterized in that, The method includes: The working load spectrum, loading cycle information, and accelerated durability load spectrum information of the ball screw pair are obtained. The working load spectrum characterizes the relationship between the working load force and the working speed associated with the ball screw pair and the change over time. The value of the working load force can be directly or inversely proportional to the time value. The loading cycle information characterizes the rated number of times the ball screw pair bears the working load force. The accelerated durability load spectrum information includes the test load force and the test speed. The equivalent axial load force and operating speed parameters are obtained from the working load spectrum. The equivalent axial load force represents a constant load force equivalent to the working load force. Based on the accelerated durability load spectrum information, the equivalent test load force, equivalent test rotation speed, and test rotation speed-time information are determined. The equivalent test load force represents a constant load force equivalent to the test load force, the equivalent test rotation speed represents a constant rotation speed value equivalent to the test rotation speed, and the test rotation speed-time information represents the duration during which the rotation speed is not zero. The number of accelerated durability loading cycles is calculated using the following formula: Where, N f1 N f2 The loading count information and the accelerated durability loading count are respectively, Fm and Fm' are the equivalent axial load force and the equivalent test load force, respectively, T is the rotational speed-time information, T' is the test rotational speed-time information, and n m 、n' m These are the equivalent operating speed and the equivalent test speed, respectively, and the equivalent operating speed and the speed-time information are the operating speed parameters; Based on the number of accelerated durability loading cycles, the accelerated durability load spectrum information is adjusted to obtain the target load spectrum information; The accelerated endurance test load spectrum of the ball screw pair is determined based on the target load spectrum information. The accelerated endurance test load spectrum of the ball screw pair characterizes the relationship between the test load force and the test speed associated with the ball screw pair and time during the accelerated endurance test.

2. The method according to claim 1, characterized in that, The process of obtaining the equivalent axial load force and operating speed parameters based on the working load spectrum includes: The working load force is determined based on the working load spectrum; The working load force is divided into equal parts to obtain at least two equal working load forces; The equivalent axial load force is obtained by integrating the at least two equally divided working load forces.

3. The method according to claim 1, characterized in that, The step of obtaining the equivalent axial load force and operating speed parameters based on the working load spectrum also includes: The working speed value and speed-time information are determined based on the working load spectrum, wherein the speed-time information represents the duration during which the working speed value is not zero; The operating speed value is integrated and summed to obtain the equivalent operating speed, which represents a constant speed value equivalent to the operating speed value. The equivalent operating speed and the speed-time information are determined as the operating speed parameter.

4. The method according to claim 1, characterized in that, The accelerated durability load spectrum information also includes test time information. The step of determining the equivalent test load force, equivalent test rotation speed, and test rotation speed-time information based on the accelerated durability load spectrum information includes: The equivalent test load force and the equivalent test speed are obtained by performing integral calculation on the test load force and the test speed; The durations during which the rotational speed is not zero in the test time information are summed to obtain the test rotational speed time information.

5. A device for determining the load spectrum of an accelerated endurance test for a ball screw pair, characterized in that, include: The acquisition module is used to acquire the working load spectrum, loading cycle information, and accelerated durability load spectrum information of the ball screw pair. The working load spectrum represents the relationship between the working load force and working speed associated with the ball screw pair and the change over time. The value of the working load force can be directly or inversely proportional to the time value. The loading cycle information represents the rated number of times the ball screw pair bears the working load force. The accelerated durability load spectrum information includes the test load force and the test speed. The equivalent axial load force module is used to obtain the equivalent axial load force and working speed parameters based on the working load spectrum and the loading number information. The equivalent axial load force represents a constant load force equivalent to the working load force. The equivalent test information module is used to determine the equivalent test load force, equivalent test speed, and test speed time information based on the accelerated durability load spectrum information. The equivalent test load force represents a fixed load force equivalent to the test load force, the equivalent test speed represents a fixed speed value equivalent to the test speed, and the test speed time information represents the duration during which the speed is not zero in the test speed time information. The Accelerated Durability Load Count submodule is used to calculate the accelerated durability load count using the following formula: Where, N f1 N f2 The loading count information and the accelerated durability loading count are respectively, Fm and Fm' are the equivalent axial load force and the equivalent test load force, respectively, T is the rotational speed-time information, T' is the test rotational speed-time information, and n m 、n' m These are the equivalent operating speed and the equivalent test speed, respectively, and the equivalent operating speed and the speed-time information are the operating speed parameters; The target load spectrum information module is used to adjust the accelerated durability load spectrum information based on the number of accelerated durability loading cycles to obtain the target load spectrum information. The load spectrum determination submodule is used to determine the accelerated durability test load spectrum of the ball screw pair based on the target load spectrum information.

6. An electronic device, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is used to execute the instructions to implement the method for determining the load spectrum of the ball screw pair accelerated endurance test as described in any one of claims 1 to 4.

7. A storage medium, characterized in that, When the instructions in the storage medium are executed by the processor of the electronic device, the electronic device is able to perform the method for determining the load spectrum of the ball screw pair accelerated endurance test as described in any one of claims 1 to 4.

8. A computer program product, characterized in that, The computer program product includes a computer program stored in a readable storage medium, wherein at least one processor of a computer device reads from and executes the computer program from the readable storage medium, causing the device to perform the method for determining the load spectrum of an accelerated endurance test for a ball screw pair as described in any one of claims 1 to 4.

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