Lead screw reverse drive force detection device

Abstract

The invention relates to the technical field of mechanical transmission part performance detection, in particular to a lead screw reverse drive force detection device. The device comprises a detection platform, a driving assembly, a linear guiding assembly, a measuring assembly, an adjusting assembly, a lead screw mounting assembly and a displacement detection unit. The measuring assembly comprises a pressure sensing unit and a nut mounting unit which are sequentially arranged in the Z direction; the adjusting assembly is arranged on the measuring assembly and located between the pressure sensing unit and the nut mounting unit, and the driving assembly drives the measuring assembly to move in the Z direction to drive the nut to move in the axial direction of the to-be-measured lead screw so as to drive the to-be-measured lead screw to rotate; the pressure sensing unit is used for detecting the axial pressure borne by the nut in the driving process, and the displacement detection unit is used for detecting the displacement of the measuring assembly or the nut in the Z direction. The lead screw reverse driving force detection device realizes specialization and integration of lead screw reverse driving force detection, ensures accuracy and directness of force transmission and measurement in a detection process, and provides accurate axis alignment adjustment capability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical transmission component performance detection, and in particular to a lead screw counter driving force detection device. BACKGROUND

[0002] Lead screw pairs such as ball screws or trapezoidal screws are commonly used transmission elements in precision machinery, and their performance directly affects the precision, efficiency and service life of the entire transmission system. Counter driving force (or "reverse driving force") is one of the key indicators for measuring the performance of a lead screw pair, which reflects the axial force corresponding to the resistance torque that needs to be overcome when the lead screw is not actively rotating, and the lead screw is forced to rotate by driving the nut to move axially along the lead screw. Accurate detection of the counter driving force of the lead screw is crucial for evaluating its transmission efficiency, pre-tightening state, wear condition and quality consistency.

[0003] Currently, in the prior art, there is a lack of a special, simple structure and high detection precision lead screw counter driving force detection device. Some detection methods may rely on complex multi-axis loading and measurement systems, which are costly and cumbersome to operate, and it is difficult to ensure the accurate centering and interference-free relative motion of the nut and the lead screw to be detected during the detection process, thereby affecting the accuracy and reliability of the detection results. Therefore, there is an urgent need for a special device that can conveniently and accurately detect the counter driving force of the lead screw. SUMMARY

[0004] The purpose of the present application is to provide a lead screw counter driving force detection device to solve the technical problems of the prior art, such as the lack of a special, simple structure and high detection precision lead screw counter driving force detection device, and the difficulty in ensuring the accurate centering and interference-free relative motion of the nut and the lead screw to be detected during the detection process.

[0005] In a first aspect, the present application provides a lead screw counter driving force detection device, comprising: a detection platform, a driving assembly, a linear guide assembly, a measurement assembly, an adjustment assembly, a lead screw mounting assembly, and a displacement detection unit; The driving assembly is fixedly installed on the detection platform and is used to provide an axial driving force; The linear guide assembly is fixedly installed on the detection platform, and its guide direction is defined as the Z direction; The measurement assembly is slidably arranged on the linear guide assembly and is connected to the output end of the driving assembly to move in the Z direction under the driving of the driving assembly; the measurement assembly comprises a pressure sensing unit and a nut mounting unit arranged in sequence in the Z direction; the nut mounting unit is used to mount the nut and prevent the nut from rotating during the detection process; The adjustment assembly is arranged on the measurement assembly and located between the pressure sensing unit and the nut mounting unit, and is used to adjust the position of the nut mounting unit in a plane perpendicular to the Z direction; The screw rod mounting assembly is fixedly arranged on the detection platform and located at the distal end of the linear guide assembly along the Z direction, and is used for rotatably mounting the to-be-tested screw rod; The nut mounted on the nut mounting unit is capable of engaging with the to-be-tested screw rod mounted on the screw rod mounting assembly; the driving assembly drives the measuring assembly to move along the Z direction, drives the nut to move along the axial direction of the to-be-tested screw rod, and thus drives the to-be-tested screw rod to rotate; the pressure sensing unit is used for detecting the axial pressure borne by the nut during the driving process, and the displacement detecting unit is used for detecting the displacement of the measuring assembly or the nut along the Z direction.

[0006] In an optional embodiment, the driving assembly comprises an electric cylinder and an electric cylinder seat, the electric cylinder seat is fixed to the detection platform, the electric cylinder is mounted on the electric cylinder seat, and the output shaft of the electric cylinder is arranged along the Z direction and connected with the measuring assembly.

[0007] In an optional embodiment, the linear guide assembly comprises at least one linear guide rail fixed to the detection platform and a sliding block slidingly arranged on the linear guide rail; the measuring assembly is fixedly connected with the sliding block.

[0008] In an optional embodiment, the linear guide assembly comprises two linear guide rails parallel to each other, and the screw rod mounting assembly is arranged between the two linear guide rails; the sliding block is arranged on the two linear guide rails.

[0009] In an optional embodiment, the measuring assembly further comprises a first connecting seat, the first connecting seat is fixedly connected with the sliding block; the first connecting seat has opposite first and second sides, the first side is connected with the output end of the driving assembly, and the second side faces the screw rod mounting assembly; the adjusting assembly is mounted on the second side of the first connecting seat.

[0010] In an optional embodiment, the adjusting assembly is an XY-axis displacement platform, which is used for manually adjusting the positions of components mounted thereon in the X and Y directions; the pressure sensing unit is mounted on the XY-axis displacement platform.

[0011] In an optional embodiment, the pressure sensing unit comprises a pressure sensor and a second connecting seat; the pressure sensor is fixedly mounted on the XY-axis displacement platform and is used for detecting the force borne in the Z direction; the second connecting seat is fixedly mounted on the force sensing end of the pressure sensor.

[0012] In an optional embodiment, the nut mounting unit includes a hollow rod, which is fixedly connected to the second connecting seat; the hollow rod is provided with a threaded portion, and the nut is screwed onto the threaded portion; a cavity is formed inside the hollow rod to allow the end of the lead screw to be tested to extend into it.

[0013] In an optional embodiment, the lead screw mounting assembly includes a lead screw seat to be tested and a bearing; the lead screw seat to be tested is fixed to the testing platform; the bearing is mounted on the lead screw seat to be tested, and the lead screw to be tested is mounted in the bearing.

[0014] In an optional embodiment, the displacement detection unit includes a grating sensor, which is disposed outside the linear guide assembly and parallel to the guiding direction of the linear guide assembly.

[0015] Compared with the prior art, the technical advantages of the lead screw counter-drive force detection device provided by the present invention are as follows: 1. Specialization and integration of lead screw back-drive force detection: By integrating the drive assembly, linear guide assembly, measurement assembly (including pressure sensing unit and nut mounting unit), adjustment assembly, lead screw mounting assembly, and displacement detection unit onto a detection platform, a complete and clearly structured specialized detection device is formed. This device modularly integrates key functions such as driving, guiding, centering adjustment, installation and fixing, and force and displacement detection, enabling lead screw back-drive force detection to be completed on a standardized, dedicated device. This overcomes the problems of cumbersome operation and poor consistency caused by relying on complex temporary tooling or general-purpose equipment.

[0016] 2. Ensuring the accuracy and directness of force transmission and measurement during the detection process: By adopting a series drive method of "drive component - linear guide component - measurement component," and clearly integrating the pressure sensing unit into the measurement component, the axial driving force applied by the drive component can be transmitted to the pressure sensing unit with almost no lateral force interference through the high-precision guidance of the linear guide component, and ultimately act on the nut. This structure ensures that the axial pressure detected by the pressure sensor directly and accurately reflects the axial resultant force that needs to be overcome to drive the nut to move (and thus drive the lead screw to rotate), providing accurate raw force data for calculating the counter-drive force.

[0017] 3. It provides precise shaft alignment adjustment capability, structurally ensuring testing accuracy: By setting up an independent adjustment component and positioning it between the pressure sensing unit and the nut mounting unit, the device is able to precisely adjust the position of the nut mounting unit (and the installed nut) in a plane perpendicular to the direction of movement (Z-axis). This core design allows the operator to precisely align the nut's shaft with the shaft of the lead screw to be tested, already mounted on the lead screw mounting assembly, before testing. This effectively eliminates the problem of misalignment between the nut and the lead screw caused by initial installation errors, avoiding abnormal friction, jamming, or even damage. It fundamentally ensures that the testing is performed under ideal fit conditions, thereby significantly improving the accuracy, reliability, and repeatability of the test results.

[0018] 4. A complete detection data chain has been established: By simultaneously configuring pressure sensing units and displacement detection units, the device can synchronously and in real-time collect key physical quantities during the driving process—axial force and nut displacement. Displacement data can be used to further calculate velocity and acceleration, and combined with real-time force data, it provides a sufficient and necessary data foundation for accurately calculating the lead screw's reaction force using a mechanical model. This force-displacement synchronous detection architecture is the fundamental guarantee for the device to achieve quantitative and high-precision detection.

[0019] 5. Simulates real-world working conditions; the testing principle is direct and effective: The lead screw to be tested is rotatably mounted via the lead screw mounting assembly, and the nut is fixed via the nut mounting unit. During testing, the device simulates the actual reverse transmission condition that may occur in a lead screw pair: "the nut moves axially, driving the lead screw to rotate." The testing principle closely resembles the essence of physics, and the measured reverse driving force data can directly and effectively reflect the performance characteristics of the lead screw pair under reverse transmission conditions, providing intuitive and reliable evaluation results.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Fig. 1 This is a schematic diagram of the overall structure when the nut and the lead screw under test are separated, as provided in an embodiment of the present invention. Fig. 2 This is a schematic diagram of the overall structure of the nut on the lead screw to be tested, provided in an embodiment of the present invention. Fig. 3This is a partial enlarged view of the nut on the lead screw to be tested, as provided in an embodiment of the present invention.

[0023] Icons: 1-Detection platform; 2-Electric cylinder; 3-Electric cylinder base; 4-Linear guide rail; 5-Slider; 6-First connecting seat; 7-XY axis displacement platform; 8-Pressure sensor; 9-Second connecting seat; 10-Hollow rod; 11-Nut; 12-Screw seat to be tested; 13-Bearing; 14-Screw to be tested; 15-Grate sensor. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0029] The specific structure is as follows: Figs. 1 to 3 As shown.

[0030] This embodiment provides a lead screw counterforce detection device, including a detection platform 1, a drive assembly, a linear guide assembly, a measurement assembly, an adjustment assembly, a lead screw mounting assembly, and a displacement detection unit.

[0031] The testing platform 1 provides a stable mounting base for the entire device, which is usually a metal plate or frame structure with sufficient rigidity and flatness.

[0032] The drive assembly provides axial (Z-axis) driving force. In this embodiment, the drive assembly specifically includes an electric cylinder 2 and an electric cylinder mount 3. The electric cylinder mount 3 is fixedly mounted on one end of the detection platform 1 by fasteners such as bolts. The electric cylinder 2 is fixedly mounted on the electric cylinder mount 3, and the central axis of its output shaft (push rod or pull rod) is arranged horizontally along a predefined Z-axis. The electric cylinder 2 can be a servo electric cylinder or a stepper electric cylinder to precisely control the output force, speed, and position.

[0033] The linear guide assembly provides high-precision linear guidance for the movement of the measuring component. In this embodiment, the linear guide assembly includes two parallel linear guide rails 4 fixedly mounted on the detection platform 1. Each linear guide rail 4 is equipped with one or more sliders 5, which can slide precisely along the track of the linear guide rail 4. The two linear guide rails 4 are arranged parallel to the Z-axis. In other possible embodiments, the linear guide assembly may also include only one linear guide rail 4 and a corresponding slider 5, but the dual-rail structure provides better torsional rigidity and motion stability.

[0034] The measuring assembly is slidably mounted on the linear guide assembly. Specifically, the measuring assembly includes a first connecting seat 6, a pressure sensing unit, and a nut mounting unit. The bottom of the first connecting seat 6 is fixedly connected to two sliders 5 by bolts, thereby supporting the entire measuring assembly on the linear guide rail 4 and allowing it to slide along the Z-axis. The left side of the first connecting seat 6 (defined as the first side) is connected to the output shaft end of the electric cylinder 2 to receive driving force. The right side of the first connecting seat 6 (defined as the second side) is used to mount subsequent components.

[0035] The adjustment assembly is mounted on the second side (right side) of the first connecting seat 6 of the measuring assembly. In this embodiment, the adjustment assembly is specifically a manually operated XY-axis displacement platform 7. The XY-axis displacement platform 7 is fixed to the right side of the first connecting seat 6 by bolts. This platform has built-in precision screws and slide mechanisms in the X and Y directions (both perpendicular to the Z direction) that are perpendicular to each other. By rotating the corresponding adjustment knob, the mounting surface on it can be moved slightly and precisely in the XY plane. The adjustment range is typically several millimeters, and the resolution can reach the micrometer level. In another embodiment, the adjustment assembly can also adopt other micro-motion platforms with similar two-dimensional adjustment functions, such as a two-dimensional micro-adjustment stage with a flexible hinge structure.

[0036] The pressure sensing unit is mounted on the adjustment assembly (i.e., the XY-axis displacement platform 7). In this embodiment, the pressure sensing unit specifically includes a pressure sensor 8 and a second connecting seat 9. The pressure sensor 8 (e.g., a strain gauge force sensor) is bolted to the adjustment platform of the XY-axis displacement platform 7, with its sensitive axis aligned with the Z-direction, for accurately measuring pressure (tension and compression) along the Z-direction. The second connecting seat 9 is a transition connector, bolted to the force-sensing end of the pressure sensor 8 (typically the force-measuring rod or mounting surface at the center of the sensor). In other feasible embodiments, the pressure sensing unit may also employ other types of force sensors, such as piezoelectric force sensors, in conjunction with a corresponding mounting structure.

[0037] The nut mounting unit is used to mount the nut 11 to be tested and prevent it from rotating. In this embodiment, the nut mounting unit includes a hollow rod 10. One end of the hollow rod 10 is rigidly connected to the second connecting seat 9 by means of bolts or threads. The other end of the hollow rod 10 or the outer cylindrical surface near the other end is machined with external threads to form a threaded portion. The nut 11 to be tested (whose internal thread matches the lead screw 14 to be tested) is screwed onto the threaded portion and tightened to the bottom with a tool, so that it is in close contact with the end face of the hollow rod 10 or the locking nut, so that the nut 11 does not rotate relative to the hollow rod 10 (i.e., relative to the measuring component) during the testing process. The interior of the hollow rod 10 is axially through, forming a cavity with a diameter larger than the outer diameter of the lead screw 14 to be tested, so that the end of the lead screw 14 to be tested can extend into this cavity. In another embodiment, the nut mounting unit can also use a solid rod with a specific anti-rotation key or clamping device to mount and fix the nut, but the hollow rod 10 solution allows for a longer testing stroke and has better versatility.

[0038] The lead screw mounting assembly is fixedly mounted on the testing platform 1 and located at the far end (i.e., right side) of the linear guide assembly along the Z-direction. In this embodiment, the lead screw mounting assembly includes a lead screw seat 12 to be tested and a bearing 13. The lead screw seat 12 to be tested is fixedly mounted on the testing platform 1 by bolts and is located in the area between the two linear guide rails 4. The bearing 13 is installed in the bearing hole of the lead screw seat 12 to be tested. One end of the lead screw 14 to be tested is mounted and supported in the bearing 13, allowing the lead screw 14 to rotate freely about its axis. Ideally, the axis of the lead screw 14 to be tested should be parallel to the Z-direction.

[0039] The displacement detection unit is used to accurately measure the displacement of the measuring component (i.e., nut 11) along the Z-axis. In this embodiment, the displacement detection unit is specifically a grating sensor 15. The grating sensor 15 can output a high-resolution displacement signal in real time. In other embodiments, the displacement detection unit may also employ other high-precision displacement measuring devices such as a laser interferometer, a magnetic scale, or a combination of a high-precision encoder and a synchronous belt / screw.

[0040] The working principle and testing process of the device are as follows: Installation and Preparation: Insert one end of the lead screw 14 to be tested into the bearing 13 of the lead screw mounting assembly and secure it. Tighten the nut 11 onto the threaded portion of the hollow rod 10 to prevent rotation. Move the assembled measuring assembly to the initial position so that the threaded hole of the nut 11 is aligned with the threaded end of the lead screw 14 to be tested, but not yet engaged.

[0041] Coaxiality adjustment: Manually operate the X and Y axis adjustment knobs of the XY axis displacement platform 7 to finely adjust the position of the pressure sensing unit and the nut mounting unit (i.e., nut 11) in the horizontal plane. Ensure that the axis of nut 11 is well coaxial with the axis of the lead screw 14 to be measured.

[0042] Detection Execution: The control program for electric cylinder 2 is activated, causing the output shaft of electric cylinder 2 to extend slowly and uniformly (or in a preset speed-changing mode), pushing the first connecting seat 6 and the entire measuring assembly to move to the right (towards the lead screw 14 under test) along the linear guide rail 4. Nut 11 moves accordingly and engages with the lead screw 14 under test; continued movement pushes nut 11 along the axial direction of the lead screw 14. Since nut 11 is restricted from rotation by the hollow rod 10, its axial movement forces the lead screw 14 under test to rotate within the bearing 13. During this process, the grating sensor 15 records the change in displacement (S) of nut 11 over time (t) in real time, and the pressure sensor 8 records the axial force (F) required to drive nut 11 to move in real time.

[0043] Data Processing: The collected displacement signals are processed to obtain the velocity (v) and acceleration (a) of the nut 11. Combined with the real-time acquired axial force F, the equivalent axial counter-drive force required to drive the lead screw 14 under test to rotate can be calculated according to mechanical principles, thereby evaluating the reverse transmission performance of the lead screw pair. By analyzing the changes in the counter-drive force throughout the movement process, the uniformity of the lead screw and the presence of any jamming points can be determined.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lead screw counterforce detection device, characterized in that, include: The testing platform (1), drive assembly, linear guide assembly, measuring assembly, adjusting assembly, lead screw mounting assembly, and displacement detection unit; The drive assembly is fixedly mounted on the detection platform (1) and is used to provide axial driving force; The linear guide assembly is fixedly installed on the detection platform (1), and its guiding direction is defined as the Z direction; The measuring component is slidably disposed on the linear guide component and connected to the output end of the drive component to move along the Z direction under the drive of the drive component; the measuring component includes a pressure sensing unit and a nut mounting unit arranged sequentially along the Z direction; the nut mounting unit is used to install the nut (11) and prevent the nut (11) from rotating during the detection process; The adjustment component is disposed on the measuring component and located between the pressure sensing unit and the nut mounting unit, and is used to adjust the position of the nut mounting unit in a plane perpendicular to the Z direction; The lead screw mounting assembly is fixedly mounted on the detection platform (1) and located at the far end of the linear guide assembly along the Z direction, for rotatably mounting the lead screw (14) to be tested. The nut (11) installed on the nut mounting unit can engage with the lead screw (14) to be tested installed on the lead screw mounting assembly; the driving assembly drives the measuring assembly to move along the Z direction, thereby driving the nut (11) to move along the axial direction of the lead screw (14) to be tested, thereby driving the lead screw (14) to be tested to rotate; the pressure sensing unit is used to detect the axial pressure on the nut (11) during the driving process, and the displacement detection unit is used to detect the displacement of the measuring assembly or the nut (11) along the Z direction.

2. The lead screw counterforce detection device according to claim 1, characterized in that, The drive assembly includes an electric cylinder (2) and an electric cylinder base (3). The electric cylinder base (3) is fixed on the detection platform (1). The electric cylinder (2) is mounted on the electric cylinder base (3), and the output shaft of the electric cylinder (2) is arranged along the Z direction and connected to the measuring assembly.

3. The lead screw counterforce detection device according to claim 1, characterized in that, The linear guide assembly includes at least one linear guide rail (4) fixed on the detection platform (1) and a slider (5) slidably disposed on the linear guide rail (4); the measuring assembly is fixedly connected to the slider (5).

4. The lead screw counterforce detection device according to claim 3, characterized in that, The linear guide assembly includes two parallel linear guide rails (4), and the lead screw mounting assembly is disposed between the two linear guide rails (4); the slider (5) is disposed on the two linear guide rails (4).

5. The lead screw counterforce detection device according to claim 3 or 4, characterized in that, The measuring assembly further includes a first connecting seat (6), which is fixedly connected to the slider (5); the first connecting seat (6) has a first side and a second side opposite to each other, wherein the first side is connected to the output end of the driving assembly, and the second side faces the lead screw mounting assembly; the adjusting assembly is installed on the second side of the first connecting seat (6).

6. The lead screw counterforce detection device according to claim 5, characterized in that, The adjustment component is an XY axis displacement platform (7) for manually adjusting the position of the component installed on it in the X and Y directions; the pressure sensing unit is installed on the XY axis displacement platform (7).

7. The lead screw counterforce detection device according to claim 6, characterized in that, The pressure sensing unit includes a pressure sensor (8) and a second connecting seat (9); the pressure sensor (8) is fixedly installed on the XY axis displacement platform (7) and is used to detect the force in the Z direction; the second connecting seat (9) is fixedly installed on the force sensing end of the pressure sensor (8).

8. The lead screw counterforce detection device according to claim 7, characterized in that, The nut mounting unit includes a hollow rod (10), which is fixedly connected to the second connecting seat (9); the hollow rod (10) is provided with a threaded part, and the nut (11) is screwed onto the threaded part; a cavity is formed inside the hollow rod (10) to allow the end of the lead screw (14) to be tested to extend into it.

9. The lead screw counterforce detection device according to claim 1, characterized in that, The lead screw mounting assembly includes a lead screw seat (12) to be tested and a bearing (13); the lead screw seat (12) to be tested is fixed on the testing platform (1); the bearing (13) is installed on the lead screw seat (12) to be tested, and the lead screw (14) to be tested is installed in the bearing (13).

10. The lead screw counterforce detection device according to claim 1, characterized in that, The displacement detection unit includes a grating sensor (15), which is disposed on the outside of the linear guide assembly and parallel to the guiding direction of the linear guide assembly.

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