A fixture for testing the efficiency of planetary roller screw pairs

Abstract

This invention discloses a fixture for testing the efficiency of planetary roller screw pairs, relating to the field of mechanical product performance testing technology. It includes a screw shaft with a screw pair nut mounted on it. A nut clamping device is held on the outer side of the screw pair nut, and the nut clamping device is fixedly connected to a motor shaft connection assembly. The end of the screw shaft is fixedly connected to the screw clamping device, and the screw clamping device is fixedly connected to a hydraulic cylinder thrust end adapter. The nut clamping device includes a left clamping sleeve, which, when connected to a right clamping sleeve, forms a clamping cavity. The end face of the clamping cavity abuts against the end of the screw pair nut, and the inner peripheral wall of the clamping cavity has a clearance fit with the outer peripheral wall of the screw pair nut. This invention has a simple structure, strong versatility, and is easy to assemble. By simply changing the external dimensions of the nut clamping device and the screw clamping device, it can be applied to the clamping requirements for efficiency testing of various types of planetary roller screws.

Description

Technical Field

[0001] This invention relates to the field of mechanical product performance testing technology, and in particular to a fixture for testing the efficiency of planetary roller screw pairs. Background Technology

[0002] Planetary roller screw pairs are mechanical transmission devices that can convert rotary motion into linear motion. They are commonly used in military fields such as aerospace and weaponry, as well as in linear actuators of mechanical equipment in civilian fields such as CNC machine tools and medical devices.

[0003] The efficiency of a planetary roller screw is a key performance indicator. The efficiency of a planetary roller screw typically ranges from 70% to 90%, mainly depending on factors such as friction of the threaded pair, load magnitude and direction, rotational speed, and lubrication. Screw efficiency is usually measured by dividing the input power by the output power. Torque and speed sensors can be used to measure the input power, and the output power can be calculated based on the load force and linear velocity sensor. Finally, the efficiency value is obtained by dividing the output power by the input power.

[0004] When conducting efficiency tests, it is important to consider not only the efficiency of the lead screw itself, but also the significant impact of the test platform and its fixtures on the test results. Therefore, designing a stable and precise fixture is of great importance.

[0005] Meanwhile, due to the diverse shapes and structures of planetary roller screw pairs, testing various types and models of planetary roller screws using a single fixture presents problems such as complex fixture structures and inconvenient installation. Summary of the Invention

[0006] The purpose of this invention is to provide a fixture for testing the efficiency of planetary roller screw pairs, which solves the problem mentioned in the background art that testing multiple types and models of planetary roller screws with a single fixture results in complex fixture structures and inconvenient installation.

[0007] The present invention adopts the following technical solutions:

[0008] The present invention provides a fixture for testing the efficiency of planetary roller screw pairs, comprising a screw shaft, a screw pair nut threadedly connected to the screw shaft, a nut clamping device clamping the outer side of the screw pair nut, the nut clamping device being fixedly connected to a motor shaft connecting assembly, the end of the screw shaft being fixedly connected to the screw clamping device, and the screw clamping device being fixedly connected to a hydraulic cylinder thrust end adapter.

[0009] The nut clamping device includes a left clamping sleeve and a right clamping sleeve. The left clamping sleeve and the right clamping sleeve are connected by a bolt assembly. After the left clamping sleeve and the right clamping sleeve are connected, they form a clamping cavity for clamping the lead screw nut. The inner end face of the clamping cavity is pressed against the end of the lead screw nut, and the inner peripheral wall of the clamping cavity is clearance-fitted with the outer peripheral wall of the lead screw nut.

[0010] Furthermore, a docking shaft is provided at the end of the left clamping sleeve away from the right clamping sleeve, and the docking shaft is connected to the motor shaft connection assembly; the motor shaft connection assembly includes a locking nut, which is threaded onto the docking shaft, and a connector is tightly clamped between the locking nut and the left clamping sleeve, and the connector is sleeved on the docking shaft, and the connector is fixedly connected to the motor torque end adapter by a bolt assembly.

[0011] Furthermore, a docking cavity is provided at the center of the motor torque end adapter shaft, and a second keyway is provided on the inner wall of the docking cavity; a first keyway is provided on the docking shaft, the docking shaft is inserted into the docking cavity, and the first keyway and the second keyway are connected and engaged by a key.

[0012] Furthermore, the lead screw clamping device includes a flange seat, which is fixedly connected to the hydraulic cylinder thrust end adapter. A connecting joint is provided at the center of the flange seat, and a lead screw clamping cavity is provided inside the connecting joint.

[0013] The right clamping sleeve is provided with a through hole, and the lead screw shaft passes through the through hole of the right clamping sleeve and is embedded in the lead screw clamping cavity.

[0014] Furthermore, the lead screw shaft has an internal threaded hole at its end, and the coupling has a locking hole. The locking hole is coaxially arranged with the lead screw clamping cavity, and a screw is installed in the locking hole. The screw is threadedly connected to the internal threaded hole.

[0015] Furthermore, the lead screw shaft has a first anti-rotation surface at its end and a second anti-rotation surface on the inner side of the lead screw clamping cavity, with the first anti-rotation surface and the second anti-rotation surface being embedded together.

[0016] Furthermore, the motor shaft connecting assembly, the nut clamping device, the lead screw pair nut, the lead screw shaft, the lead screw clamping device, and the hydraulic cylinder thrust end adapter are all coaxially mounted.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0018] This invention provides a fixture for testing the efficiency of planetary roller screw pairs. It features a simple structure, convenient manufacturing, easy operation, and strong versatility, allowing for rapid disassembly and assembly during efficiency testing. This fixture only requires modification of the external dimensions of the nut clamping device and the screw clamping device to meet the efficiency testing needs of common types of planetary roller screws, including standard and reverse types. Furthermore, this fixture eliminates the need for specific structural processing of the test object during use, avoiding damage or destruction. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the fixture structure for testing the efficiency of planetary roller screw pairs according to the present invention;

[0021] Figure 2 This is a cross-sectional view of the planetary roller screw pair efficiency testing fixture of the present invention.

[0022] Figure 3 This is a schematic diagram of the nut clamping device in the planetary roller screw pair efficiency testing fixture of the present invention.

[0023] Figure 4 This is a schematic diagram of the motor torque end adapter structure in the planetary roller screw pair efficiency testing fixture of the present invention.

[0024] Figure 5 This is a cross-sectional view of the screw clamping device in the planetary roller screw pair efficiency testing fixture of the present invention.

[0025] Figure 6 This is a right view of the screw clamping device in the planetary roller screw pair efficiency testing fixture of the present invention.

[0026] Figure 7 This is a schematic diagram of the screw clamping device in the planetary roller screw pair efficiency testing fixture of the present invention.

[0027] Figure 8 This is a schematic diagram of the end structure of the lead screw shaft in the planetary roller screw pair efficiency testing fixture of the present invention;

[0028] Figure 9 This is a schematic diagram of the hydraulic cylinder thrust end adapter structure in the planetary roller screw pair efficiency testing fixture of the present invention.

[0029] Explanation of reference numerals in the attached drawings: 1. Nut clamping device; 1-1. Left clamping sleeve; 1-2. Right clamping sleeve; 1-3. Connecting shaft; 1-4. First keyway; 1-5. Clamping cavity; 2. Screw clamping device; 2-1. Flange seat; 2-2. Connecting joint; 2-3. Screw clamping cavity; 2-4. Locking hole; 2-5. Screw; 2-6. Second anti-rotation surface; 3. Screw pair nut; 4. Screw shaft; 4-1. Internal threaded hole; 4-2. First anti-rotation surface; 5. Motor shaft connecting assembly; 5-1. Connector; 5-2. Locking nut; 5-3. Motor torque end adapter; 5-4. Connecting cavity; 5-5. Key; 5-6. Second keyway; 6. Hydraulic cylinder thrust end adapter. Detailed Implementation

[0030] To make the technical problems, technical solutions, and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0031] like Figure 1 and Figure 2 As shown, this embodiment discloses a fixture for testing the efficiency of planetary roller screw pairs, including a screw shaft 4, a screw pair nut 3 threadedly connected to the screw shaft 4, a nut clamping device 1 clamping the outer side of the screw pair nut 3, and the nut clamping device 1 being fixedly connected to a motor shaft connecting assembly 5. The end of the screw shaft 4 is fixedly connected to the screw clamping device 2. The screw clamping device 2 is fixedly connected to a hydraulic cylinder thrust end adapter 6. The nut clamping device 1 and the screw clamping device 2 can be designed in various sizes and specifications according to different models of planetary roller screws.

[0032] like Figures 2 to 4 As shown, the nut clamping device 1 includes a left clamping sleeve 1-1 and a right clamping sleeve 1-2, which are connected by a bolt assembly. After connection, the left clamping sleeve 1-1 and the right clamping sleeve 1-2 form a clamping cavity 1-5 for clamping the lead screw nut 3. The inner end face of the clamping cavity 1-5 abuts against the end of the lead screw nut 3, increasing static friction during testing and preventing relative movement during operation. Simultaneously, the inner peripheral wall of the clamping cavity 1-5 and the outer peripheral wall of the lead screw nut 3 have a clearance fit, ensuring the structural integrity of the lead screw nut 3. Both the left clamping sleeve 1-1 and the right clamping sleeve 1-2 are provided with positioning steps that mate with the external structure of the lead screw nut 3, ensuring good concentricity of the assembled fixture and guaranteeing the accuracy of the test results.

[0033] A docking shaft 1-3 is provided at the end of the left clamping sleeve 1-1 away from the right clamping sleeve 1-2. The docking shaft 1-3 is connected to the motor shaft connecting assembly 5. The motor shaft connecting assembly 5 includes a locking nut 5-2, which is threaded onto the docking shaft 1-3. A connector 5-1 is tightly clamped between the locking nut 5-2 and the left clamping sleeve 1-1, and the connector 5-1 is sleeved on the docking shaft 1-3. The connector 5-1 is fixedly connected to the motor torque end adapter 5-3 by a bolt assembly, thereby preventing axial movement of the nut clamping device 1.

[0034] The motor torque adapter 5-3 has a mating cavity 5-4 at its shaft center, and a second keyway 5-6 is provided on the inner wall of the mating cavity 5-4. The mating shaft 1-3 has a first keyway 1-4. The mating shaft 1-3 is inserted into the mating cavity 5-4, and the first keyway 1-4 and the second keyway 5-6 are connected by a key 5-5 to prevent circumferential rotation of the mating shaft 1-3. During mating, first, the key 5-5 is placed into the first keyway 1-4 on the mating shaft 1-3. Then, the mating shaft 1-3 and the key 5-5 are placed together into the mating cavity 5-4, and the key 5-5 is inserted into the second keyway 5-6. The coordinated use of the first keyway 1-4, the second keyway 5-6, and the key 5-5 effectively prevents circumferential rotation.

[0035] like Figure 2 and Figures 5 to 8 As shown, the lead screw clamping device 2 includes a flange seat 2-1, which is fixedly connected to the hydraulic cylinder thrust end adapter 6. A mating joint 2-2 is provided at the center of the flange seat 2-1, and a lead screw clamping cavity 2-3 is provided inside the mating joint 2-2. The right clamping sleeve 1-2 is provided with a through hole, and the lead screw shaft 4 passes through the through hole of the right clamping sleeve 1-2 and is engaged with the lead screw clamping cavity 2-3.

[0036] The lead screw shaft 4 has an internal threaded hole 4-1 at the end of the lead screw, and a locking hole 2-4 is provided in the connector 2-2. The locking hole 2-4 is coaxially arranged with the lead screw clamping cavity 2-3. A screw 2-5 is provided in the locking hole 2-4, and the screw 2-5 is threadedly connected to the internal threaded hole 4-1, thereby axially fixing the lead screw shaft 4 and the lead screw clamping device 2 together.

[0037] like Figure 7 and Figure 8 As shown, the lead screw shaft 4 has a first anti-rotation surface 4-2 at the end of the lead screw shaft 4, and a second anti-rotation surface 2-6 on the inner side of the lead screw clamping cavity 2-3. The first anti-rotation surface 4-2 and the second anti-rotation surface 2-6 are embedded and fitted together to prevent the lead screw shaft 4 from rotating circumferentially.

[0038] In this embodiment, the motor shaft connecting assembly 5, the nut clamping device 1, the lead screw pair nut 3, the lead screw shaft 4, the lead screw clamping device 2, and the hydraulic cylinder thrust end adapter 6 are all coaxially mounted. It should be noted that the hydraulic cylinder thrust end adapter 6 can be replaced with adapters for electric cylinders, vibrators, etc., depending on the type of experimental platform drive device.

[0039] like Figures 1 to 9 As shown, the assembly process of the present invention is as follows:

[0040] First, place the lead screw nut 3 between the left clamping sleeve 1-1 and the right clamping sleeve 1-2, with the lead screw shaft 4 passing through the through hole of the right clamping sleeve 1-2. The lead screw nut 3 is then wrapped around the left clamping sleeve 1-1 and the right clamping sleeve 1-2. The left clamping sleeve 1-1 and the right clamping sleeve 1-2 are then fixedly connected together using screws. When tightening the screws, they should be tightened gradually along the diagonal direction to prevent the lead screw nut 3 from slipping between itself and the fixture during the test.

[0041] Next, insert connector 5-1 and locking nut 5-2 onto mating shaft 1-3 in sequence, and tighten locking nut 5-2 onto mating shaft 1-3. Insert mating shaft 1-3 into mating cavity 5-4, ensuring that the first keyway 1-4, second keyway 5-6, and key 5-5 are keyed together. Finally, secure connector 5-1 to motor torque adapter 5-3 using bolts.

[0042] Next, insert the end of the lead screw shaft 4 into the lead screw clamping cavity 2-3 of the connector 2-2, so that the first anti-rotation surface 4-2 and the second anti-rotation surface 2-6 are engaged. Then, insert the screw 2-5 from the locking hole 2-4 and screw it into the internal thread hole 4-1 of the lead screw shaft 4 to tighten it.

[0043] After assembly, carefully observe whether there is any sign of wobbling between the various structures of the device. If wobbling is found, readjust the tightening torque of each bolt to ensure the overall structure is stable and secure. After ensuring proper assembly, install the entire device onto the test bench. Rotate the motor torque adapter 5-3 axially and move the hydraulic cylinder thrust adapter 6 left and right. Before starting the formal test, it is necessary to ensure the runout of the entire testing fixture to determine the overall coaxiality. A dial indicator can be used, resting against the outer surface of the left clamping sleeve 1-1 or the right clamping sleeve 1-2, and the nut clamping device 1 can be manually rotated to observe whether the runout of the dial indicator is within the test standard range.

[0044] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A fixture for testing the efficiency of a planetary roller screw pair, comprising a screw shaft (4), wherein a screw pair nut (3) is threadedly connected to the screw shaft (4), characterized in that: The outer side of the lead screw nut (3) is clamped with a nut clamping device (1), the nut clamping device (1) is fixedly connected to the motor shaft connection assembly (5), the end of the lead screw shaft (4) is fixedly connected to the lead screw clamping device (2), and the lead screw clamping device (2) is fixedly connected to the hydraulic cylinder thrust end adapter (6). The nut clamping device (1) includes a left clamping sleeve (1-1) and a right clamping sleeve (1-2). The left clamping sleeve (1-1) and the right clamping sleeve (1-2) are connected by a bolt assembly. After the left clamping sleeve (1-1) and the right clamping sleeve (1-2) are connected, they form a clamping cavity (1-5) for clamping the lead screw nut (3). The inner end face of the clamping cavity (1-5) is pressed against the end of the lead screw nut (3). The inner peripheral wall of the clamping cavity (1-5) is clearance-fitted with the outer peripheral wall of the lead screw nut (3). The motor shaft connecting assembly (5), the nut clamping device (1), the lead screw pair nut (3), the lead screw shaft (4), the lead screw clamping device (2), and the hydraulic cylinder thrust end adapter (6) are all coaxially mounted. The lead screw clamping device (2) includes a flange seat (2-1), which is fixedly connected to the hydraulic cylinder thrust end adapter (6). A connecting joint (2-2) is provided at the center of the flange seat (2-1), and a lead screw clamping cavity (2-3) is provided inside the connecting joint (2-2). The right clamping sleeve (1-2) is provided with a through hole, and the lead screw shaft (4) passes through the through hole of the right clamping sleeve (1-2) and is embedded in the lead screw clamping cavity (2-3); The lead screw shaft (4) has an internal threaded hole (4-1) at its end, and a locking hole (2-4) is provided in the connector (2-2). The locking hole (2-4) is coaxially arranged with the lead screw clamping cavity (2-3). A screw (2-5) is provided in the locking hole (2-4), and the screw (2-5) is threadedly connected to the internal threaded hole (4-1). The lead screw shaft (4) has a first anti-rotation surface (4-2) at its end, and a second anti-rotation surface (2-6) is provided on the inner side of the lead screw clamping cavity (2-3). The first anti-rotation surface (4-2) and the second anti-rotation surface (2-6) are embedded in each other. The nut clamping device (1) and the screw clamping device (2) are designed with various sizes and specifications according to different models of planetary roller screws.

2. The fixture for testing the efficiency of planetary roller screw pairs according to claim 1, characterized in that: The left clamping sleeve (1-1) is provided with a docking shaft (1-3) at the end away from the right clamping sleeve (1-2), and the docking shaft (1-3) is connected to the motor shaft connecting assembly (5); The motor shaft connection assembly (5) includes a locking nut (5-2), which is threaded onto the docking shaft (1-3). The locking nut (5-2) and the left clamping sleeve (1-1) tightly clamp the connector (5-1), and the connector (5-1) is sleeved on the docking shaft (1-3). The connector (5-1) is fixedly connected to the motor torque end adapter (5-3) by a bolt assembly.

3. The fixture for testing the efficiency of planetary roller screw pairs according to claim 2, characterized in that: The motor torque end adapter (5-3) has a docking cavity (5-4) at the shaft center, and a second keyway (5-6) is provided on the inner wall of the docking cavity (5-4). The docking shaft (1-3) is provided with a first keyway (1-4), the docking shaft (1-3) is inserted into the docking cavity (5-4), and the first keyway (1-4) and the second keyway (5-6) are connected and engaged by a key (5-5).

Images