Friction and wear test bench for spiral raceway

Abstract

The invention discloses a spiral raceway friction and wear test bench, which comprises a base, a friction and wear test assembly and a friction and wear test device, the two countershaft aligning assemblies are used for supporting the two ends of the testing lead screw and can adjust the vertical height of the testing lead screw, so that a spiral line groove of the testing lead screw is meshed with the nut machining part with the balls, and pre-tightening force is applied to the testing lead screw and the nut machining part; the driving servo motor is used for providing power for rotation of the test lead screw; and the friction wear test assembly comprises a sliding unit fixed on the base, a detection unit, a linear motor and a nut seat which are fixed on the sliding unit, a nut processing piece and a raceway connector which are fixed at the upper end of the nut seat, and an external raceway fixed on the raceway connector. According to the invention, the abrasion loss and friction torque of the ball screw can be measured in the actual meshing process of the ball screw, and the load condition of the ball screw can be simulated.

Description

Technical Field

[0001] This invention belongs to the field of ball screw pair testing, specifically a spiral raceway friction and wear test bench. Background Technology

[0002] As the high-end equipment manufacturing industry iterates and upgrades towards high speed, precision, functional integration, and green energy conservation, the characteristics of ball screw pairs, as core components of precision transmission, have received widespread attention. The lack of experimental data on ball screw pair wear has adversely affected the research on the mechanical model of ball screw pairs. Wear is a crucial performance parameter of ball screw pairs, directly affecting positioning accuracy, service life, energy loss, temperature changes (excessive temperature rise will lead to lubricant deterioration, accelerated wear, and even burning of the working surface), as well as changes in noise and vibration. Therefore, accurate measurement of wear is essential for ball screw pairs.

[0003] Existing friction testing benches (CN204556253U, CN119437969A) are mainly used to simulate the friction and wear processes of materials under actual working conditions to evaluate their friction performance and wear resistance. Their basic working principle includes the following aspects: Loading system: Provides the load required for the test and can be adjusted to simulate different working conditions. The load can be constant or dynamically changing to simulate complex working environments. Friction pair system: Consists of two relatively moving specimens, one fixed and the other moving. Common friction pair forms include ball-disc, pin-disc, and ring-disc. Existing friction testing benches have two major problems: 1) The use of only three common friction pair systems cannot simulate the movement of balls along the raceway in a ball screw pair; 2) The wear morphology of the contact surface cannot be observed with a full-size nut. Summary of the Invention

[0004] The purpose of this invention is to provide a spiral raceway friction and wear test bench to simulate the actual meshing process of a ball screw, measure its wear and friction torque, and simulate the load conditions of the ball screw.

[0005] The technical solution to achieve the purpose of this invention is as follows:

[0006] A spiral raceway friction and wear test bench includes:

[0007] The base is used to support the friction and wear testing components;

[0008] Two self-aligning assemblies are used to support both ends of the test screw, which can adjust the vertical height of the test screw so that the helical groove of the test screw engages with the ball-bearing nut and applies a preload to the test screw and the nut.

[0009] Drive the servo motor to provide power for the rotation of the test lead screw;

[0010] The friction and wear testing assembly includes a sliding unit fixed on a base, a detection unit, a linear motor, and a nut seat fixed on the sliding unit, a nut machining part and a raceway connector fixed on the upper end of the nut seat, and an external raceway fixed on the raceway connector.

[0011] The sliding unit can slide along a direction parallel to the generatrix of the test screw. The detection unit is used to detect the sliding position of the sliding unit to determine the zero point position of the detection unit. The upper surface of the nut machining part and the raceway connector assembly is U-shaped and has a spiral groove for placing the ball. The external raceway is used to make the ball return to the starting point after rolling one revolution. The linear motor is used to provide resistance for the sliding unit.

[0012] The significant advantages of this invention compared to existing technologies are:

[0013] (1) The spiral raceway friction and wear test bench abandons the traditional full-size nut as the test piece. Instead, it uses a machined part evolved from a quarter-size nut as the test piece. Under the condition of the ball moving along the raceway in the simulated ball screw pair, the friction scratches on the surface of the test piece can be observed. The test piece designed in this test can directly observe the surface, thereby eliminating the influence of secondary processing on surface roughness.

[0014] (2) A rotary motor drives the lead screw, while a linear motor restricts the movement of the nut. The resistance received by the nut during its movement is adjusted by setting the power of the linear motor, thereby simulating the load conditions under the actual operation of a ball screw.

[0015] (3) The drive wheel is driven to rotate by the servo motor. The drive wheel drives and adjusts the driven wheel connected to the lower end of the lead screw shaft by the synchronous belt to rotate, thereby adjusting the height of the lead screw shaft so that the lead screw nut can be smoothly engaged, ensuring smooth movement and reliable operation in the friction and wear test, and thus ensuring the reliability of the friction and wear test.

[0016] (4) By arranging the three bolts used to install the nut test bench in the T-slot and fixing the bolts on the sliding unit, the position of the three bolts in the T-slot is moved to adjust the installation angle of the nut seat, thereby adjusting the angle between the nut seat and the test screw, ensuring the concentricity of the nut screw engagement, and also facilitating the installation arrangement. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the test bench.

[0018] Figure 2-a This is a schematic diagram of the friction and wear test assembly.

[0019] Figure 2-bThis is a longitudinal sectional view of the friction and wear test assembly.

[0020] Figure 2-c This is a schematic diagram of the nutless experimental platform.

[0021] Figure 2-d This is a top view of the displacement sensor assembly.

[0022] Figure 3-a This is a schematic diagram of the shaft self-aligning assembly.

[0023] Figure 3-b This is a schematic diagram of the axis self-aligning assembly without a moving platform.

[0024] Figure 4 This is a schematic diagram of the simulated structure of the ball raceway.

[0025] In the diagram: 100 Friction and Wear Test Component, 101 Test Component Base Plate, 102 Test Component Guide Rail, 103 Test Component Slider, 104 Slide Plate, 105 Nut Seat, 106 Nut Machining Part, 107 Locating Pin, 108 H-Type Clamping Block, 109 Test Screw, 110 External Raceway, 111 Displacement Sensor, 112 Displacement Sensor Feedback Unit, 113 Displacement Sensor Base, 114 Linear Motor Stator, 115 Torque Sensor, 116 Linear Motor Mover, 117 Adjusting Bolt, 118 Fixing Bolt, 119 Ball Bearing, 120 Displacement Sensor Bolt Seat, 121 Raceway Connector

[0026] 200 Shaft self-aligning assembly, 201 Lead screw bearing housing, 202 Moving platform, 203 Test lead screw bearing, 204 Adjusting lead screw, 205 Adjusting lead screw bearing, 206 Self-aligning assembly slider, 207 Self-aligning assembly guide rail, 208 Bearing housing, 209 Base plate, 210 Synchronous pulley, 211 Synchronous belt, 212 Adjusting servo motor, 213 Motor plate, 214 Adjusting nut, 215 Flat plate, 300 Base, 400 Drive servo motor, 401 Coupling Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1-4The technical solution of this invention is: a spiral raceway friction and wear test bench, including a friction and wear test assembly 100, two shaft alignment assemblies 200, and a base 300; the friction and wear test assembly 100 is mounted on the shaft alignment assemblies 200 and the base 300; the two shaft alignment assemblies 200 are both mounted on the base 300, and a drive servo motor 400 is connected to the test screw 109 in the friction and wear test assembly 100, while the test screw 109 is mounted on the screw bearing seats 201 of the two shaft alignment assemblies 200.

[0029] Combination Figure 2-a and Figure 2-b The friction and wear test assembly 100 includes a test assembly base plate 101, a test assembly guide rail 102, a test assembly slider 103, a slide plate 104, a nut seat 105, a nut machining part 106, a positioning pin 107, an H-type clamping block 108, a test lead screw 109, an external raceway 110, a displacement sensor 111, a displacement sensor feedback unit 112, a displacement sensor base 113, a linear motor stator 114, a torque sensor 115, a linear motor mover 116, an adjusting bolt 117, a ball bearing 119, a displacement sensor bolt seat 120, and a raceway connector 121. The test assembly base plate 101 is fixed to the base 300. Two test assembly guide rails 102 are arranged parallel above it, and are bolted to the base plate 101. Each guide rail 102 has a test assembly slider 103. Slide plates 104 are bolted to the two sliders 103, and move linearly back and forth along the guide rails 102 as the sliders 103 move. Nut seats 105 are bolted to the slide plates 104. The bottom of the nut seats 105 has a T-slot for mounting bolts, saving space. (See reference.) Figure 2-aThe nut seat 105 has T-slots on both the front and side, where two bolts can slide. However, the bolt hole positions on the slide plate 104 are fixed, so the spacing between the two bolts is also fixed. The vertical movement of the two bolts of a fixed length on the nut seat 105 is equivalent to determining the hypotenuse of a right triangle, which can adjust the angle of the nut seat 105 on the horizontal plane of the slide plate 104. This is equivalent to adjusting the angle between the nut seat 105 and the test screw 109, improving the alignment accuracy and coaxiality of the nut machining part 106. The linear motor stator 114 is fixed to the test assembly base plate 101 by bolts. Since the structure of the linear motor is not the focus of this patent, the focus is on the specific arrangement and application of the linear motor mover 116 and the linear motor stator 114. The linear motor mover 116 is fixed to the slide plate 104 by fixing bolts. The linear motor mover 116 is located on the upper side of the linear motor stator 114, and the length of the linear motor stator 114 after being laid out is the same as that of the test assembly base plate 101. Therefore, when the slide plate 104 moves on the base plate 101 of the test assembly, the linear motor mover 116 fixed on the slide plate 104 will be subjected to the magnetic force of the linear motor stator 114 along the direction of the test assembly guide rail 102, and the magnetic force will serve as the resistance for the friction and wear test. The nut seat 105 is fixed to the slide plate 104 by bolts. Figure 4 As shown, the upper surface of the combination of the nut component 106 and the raceway connectors 121 on both sides is U-shaped. The combination of the nut component 106 and the raceway connectors 121 is embedded in the U-shaped track of the nut seat 105. The nut component 106 has a light hole in the middle. The position of the nut component 106 in the nut seat 105 along the generatrix of the test screw 109 is determined by the positioning pin 107 to ensure strength and meshing accuracy. The combined end face of the nut component 106 and the raceway connectors 121 is clamped by H-type clamping blocks 108. The H-type clamping blocks 108 are connected to the nut seat 105 by bolts, and the nut component 106 is clamped between the two H-type clamping blocks 108. The H-type clamping blocks 108 are widened at the bolt connection to strengthen the structure and prevent breakage.

[0030] Combination Figure 1 The test lead screw 109 is mounted on two lead screw bearing seats 201, parallel to the test assembly guide rail 102. Figure 4As shown, to simulate the principle of a ball screw—that is, to achieve efficient conversion between rotary and linear motion through the continuous rolling of the balls—the balls 119 must form a closed-loop rolling path. When the servo motor 400 drives the test screw 109 to rotate, the balls 119 roll along the track within the helical grooves of the test screw 109 and the nut machining part 106. In the outer circulation of the balls 119, the balls 119 first pass through the raceway in the raceway connector 121, and then return to the starting point through the external pipe 110. Its characteristic is that the balls 119 only need to roll one revolution to return to the starting point. The adjacent raceways of the nut machining part 106 are not connected, resulting in a simple structure, strong versatility, and a relatively large radial dimension. The external raceway 110 is fixed to the raceway connector 121 through a cylindrical slot, ensuring pipe alignment accuracy and facilitating installation. The test screw 109 is supported on two screw bearing seats 201 at its left and right ends, respectively. The screw bearing seats 201 restrict the movement of the test screw 109 along its generatrix direction via shaft shoulders. The ball screw converts the rotational motion into linear motion, ultimately causing the slide plate 104, with the nut component 106 fixed to it, to move along the generatrix direction of the test screw 109, i.e., the direction of the test assembly guide rail 102. The linear motor mentioned in this embodiment also provides resistance to the slide plate 104 in this direction. The drive servo motor 400 is connected to the test screw 109 via a coupling 401, providing power for the rotation of the test screw 109. Figure 2-a The test screw 109 is equipped with a torque sensor 115, which can measure the magnitude of the ball screw meshing force. Combined with... Figure 2-d The displacement sensor 111 is placed on the displacement sensor bolt seat 120, which is fixed to the displacement sensor base 113 by an adjusting bolt 117 and a nut. The displacement sensor base 113 is bolted to the test assembly base plate 101. The displacement sensor base 113 has a T-slot, inside which is placed the square nut of the adjusting bolt 117. The adjusting bolt 117 can move back and forth along the direction of the slot to easily adjust the position of the displacement sensor 111. The displacement sensor feedback unit 112 is bolted to the slide plate 104. When the displacement sensor feedback unit 112 and the displacement sensor 111 coincide, the displacement sensor 111 emits a signal, indicating that the slide plate 104 with the displacement sensor feedback unit 112 has moved to the set position.

[0031] Combination Figure 3-a and Figure 3-bThe self-aligning assembly 200 includes a lead screw bearing seat 201, a moving platform 202, a test lead screw bearing 203, an adjusting lead screw 204, an adjusting lead screw bearing 205, a self-aligning assembly slider 206, a self-aligning assembly guide rail 207, a bearing seat 208, a base plate 209, a synchronous pulley 210, a synchronous belt 211, an adjusting servo motor 212, a motor plate 213, an adjusting nut 214, and a flat plate 215. The synchronous pulley 210, synchronous belt 211, adjusting servo motor 212, and motor plate 213 constitute a drive unit. The adjusting servo motor 212 is fixed on the motor plate 213, and the motor plate 213 is fixed on the base plate 209. The base plate 209 is fixed to the base 300. A linear module of the lead screw guide rail is fixed on the motor plate 213. The linear module includes the adjusting lead screw bearing 205, the self-aligning assembly guide rail 207, and the bearing seat 208. Figure 1 As shown, the shaft alignment assembly 200 is mainly used to adjust the vertical height of the test lead screw 109. Adjusting the servo motor 212 drives the active synchronous pulley 210 to rotate, as... Figure 3-a As shown, the driving synchronous pulley 210 transmits rotational motion to the driven synchronous pulley 210 via the synchronous belt 211. The lower end of the adjusting screw 204 is connected to the driven synchronous pulley 210 and rotates as the synchronous pulley 210 rotates. Figure 3-a As shown, the upper and lower ends of the adjusting screw 204 are mounted on the bearing seat 208 via adjusting screw bearings 205. The bearing seat 208 is fixed to the plate 215 by bolts, and the bearing seat 208 restricts the up and down movement of the adjusting screw 204, maintaining only rotation. Two self-aligning component guide rails 207 are arranged parallel to each other on both sides of the plate 215. The self-aligning component guide rails 207 are fixed to the plate 215 by bolts. Each self-aligning component guide rail 207 has a self-aligning component slider 206. The two self-aligning component sliders 206 are fixed to the moving platform 202 by bolts. The moving platform 202 moves linearly as the self-aligning component sliders 206 move back and forth on the self-aligning component guide rails 207. A lead screw bearing seat 201 is fixed on the moving platform 202 of the linear module. An adjusting nut 214 engages with an adjusting lead screw 204, and the lead screw bearing seat 201 is connected to the adjusting nut 214. As the adjusting lead screw 204 rotates, it drives the adjusting nut 214 to move up and down. Finally, the moving platform 202 adjusts the height of the lead screw bearing seat 201 to ensure that the nut machining part 106 and the test lead screw 109 of the testing mechanism are on the same axis. A certain preload is applied to the nut machining part 106 and the test lead screw 109 to help ensure smooth movement. Ribs are added to the moving platform 202 to increase strength.

[0032] The working process of this friction and wear test bench is as follows: First, the sliding plate 104 is moved to the zero point, that is, the position where the displacement sensor feedback unit 112 and the displacement sensor 111 coincide. Then, a layer of balls 119 is placed in the helical groove of the nut machining part 106 of the test mechanism. Then, the height of the test screw 109 is continuously lowered by adjusting the rotation of the servo motor 212. During this period, the rotation of the test screw 109 is adjusted so that the helical groove of the test screw 109 is just engaged with the nut machining part 106 with balls 119. The external raceway 110 containing balls 119 is inserted into the raceway connector 121. Finally, the drive servo motor 400 and the linear motor mover 116 are started. The servo motor 400 drives the test screw 109 to rotate, resisting the resistance of the slide plate 104 driven by the linear motor mover 116. At this time, the nut workpiece 106 and the test screw 109 mesh and rotate relative to each other. The driving torque can be measured by the torque sensor 115. Since the number of rotations of the servo motor 400 can be controlled, and the distance the slide plate 104 moves is fixed for one rotation of the servo motor 400, the servo motor 400 is set to rotate three times clockwise and then three times counterclockwise, repeating continuously. Finally, after the test is completed, the nut workpiece 106 can be removed to observe its surface roughness.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A spiral raceway friction and wear test bench, characterized in that, include: The base is used to support the friction and wear testing components; Two self-aligning assemblies are used to support both ends of the test screw, which can adjust the vertical height of the test screw so that the helical groove of the test screw engages with the ball-bearing nut and applies a preload to the test screw and the nut. Drive the servo motor to provide power for the rotation of the test lead screw; The friction and wear testing assembly includes a sliding unit fixed on a base, a detection unit, a linear motor, and a nut seat fixed on the sliding unit, a nut machining part and a raceway connector fixed on the upper end of the nut seat, and an external raceway fixed on the raceway connector. The sliding unit can slide along a direction parallel to the generatrix of the test screw. The detection unit is used to detect the sliding position of the sliding unit to determine the zero point position of the detection unit. The upper surface of the nut machining part and the raceway connector assembly is U-shaped and has a spiral groove for placing the ball. The external raceway is used to make the ball return to the starting point after rolling one revolution. The linear motor is used to provide resistance for the sliding unit.

2. The spiral raceway friction and wear test bench according to claim 1, characterized in that, The sliding unit includes a test component base plate, a test component guide rail, a test component slider, and a sliding plate; The test component base plate is fixed on the base. Two test component guide rails are arranged in parallel on the test component base plate. Each test component guide rail has a test component slider. The slide plate is fixed on the two test component sliders and is used to fix the nut seat.

3. The spiral raceway friction and wear test bench according to claim 2, characterized in that, The detection unit includes a displacement sensor, a displacement sensor feedback unit, a displacement sensor base, an adjusting bolt, and a displacement sensor bolt seat. The displacement sensor is mounted on the displacement sensor bolt seat, which is movable on the displacement sensor base and fixed to the displacement sensor base by the adjusting bolt. The displacement sensor feedback unit is fixed to the slide plate.

4. The spiral raceway friction and wear test bench according to claim 2, characterized in that, The stator of the linear motor is fixed to the base plate of the test assembly, and the mover of the linear motor is fixed to the slide plate.

5. The spiral raceway friction and wear test bench according to claim 1, characterized in that, The nut seat has T-slots on the front and sides, and bolts are installed in the T-slots. The bolts are fixed to the sliding unit to adjust the installation angle of the nut seat, thereby adjusting the angle between the nut seat and the test screw.

6. The spiral raceway friction and wear test bench according to claim 1, characterized in that, The nut component is positioned on the nut seat by a locating pin. The combined end face of the nut component and the raceway connector is provided with a clamping block, which is fixed on the nut seat.

7. The spiral raceway friction and wear test bench according to claim 1, characterized in that, The axis alignment assembly includes a lead screw bearing housing, a moving platform, an adjusting lead screw, an adjusting nut, a drive unit, and a linear module. The drive unit drives the adjusting lead screw to rotate, and the adjusting nut cooperates with the adjusting lead screw and fixes the moving platform. The linear module supports the adjusting lead screw and guides the upgrading movement of the moving platform. The lead screw bearing housing is fixed on the moving platform to support the test lead screw.

8. The spiral raceway friction and wear test bench according to claim 1, characterized in that, The drive unit includes a synchronous pulley, a synchronous belt, an adjusting servo motor, and a motor plate. The adjusting servo motor is fixed on the motor plate and drives the active synchronous pulley to rotate. The active synchronous pulley transmits the rotational motion to another driven synchronous pulley through the synchronous belt. The lower end of the adjusting screw is connected to the driven synchronous pulley.

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