Screw displacement detection device, parallel mechanism

Abstract

The present application discloses a screw displacement detection device and a parallel mechanism to solve the technical problem of low screw control accuracy. In the prior art, the movement mode of the grating scale displacement sensor is different from that of the screw, and the grating scale displacement sensor cannot be simply combined with the screw. To this end, the present application discloses a screw displacement detection device, in which the grating scale tape is fixedly set on the screw; the mounting seat is sleeved on the screw; the grating scale reading head is embedded in the mounting seat; to ensure that when the screw rotates, the mounting seat rotates with the screw, and the grating scale tape moves linearly with the screw relative to the grating scale reading head, thereby realizing the detection of the linear displacement of the screw assembly. Since the grating scale assembly directly measures the linear displacement of the screw assembly using the optical principle of the grating, the detection accuracy and response speed are improved. In addition, full closed-loop control is achieved, thereby improving the control accuracy of the screw assembly.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and in particular to a screw displacement detection device and a parallel mechanism. Background Art

[0002] A lead screw is a transmission element that converts rotary motion into linear motion, or converts linear motion into rotary motion. It is widely used in the machine tool industry or the robotics industry.

[0003] In the process of implementing the prior art, the inventors found that:

[0004] In the machine tool and robotics industries, where precision control is crucial, precise control of a lead screw's displacement requires comparing the current displacement with the target displacement. Existing methods for detecting lead screw displacement rely on counting the number of revolutions of the lead screw and then calculating the displacement. This semi-closed-loop control method makes it difficult to guarantee precise lead screw control.

[0005] Furthermore, conventional techniques typically mount a scale displacement sensor on the guide rail of the lead screw assembly. However, in parallel mechanisms using a motor to drive the lead screw, due to limited space, a guide rail is typically not provided, leaving no space for a scale displacement sensor. Furthermore, the motion of the scale displacement sensor differs from that of the lead screw, making it impossible to simply combine the scale displacement sensor with the lead screw.

[0006] Therefore, it is necessary to provide a screw displacement detection solution to solve the technical problem of low screw control accuracy. Summary of the Invention

[0007] The embodiments of the present application provide a lead screw displacement detection solution to solve the technical problem of low lead screw control accuracy.

[0008] Specifically, a screw displacement detection device includes:

[0009] Drive components;

[0010] A lead screw assembly connected to the driving assembly is driven by the driving assembly to perform displacement motion;

[0011] A grating ruler assembly for measuring the displacement of the lead screw assembly;

[0012] Wherein, the screw assembly at least includes a screw;

[0013] The grating ruler assembly at least includes:

[0014] Grating scale tape with grating scale;

[0015] Grating scale reading head for reading grating scale;

[0016] A mounting base for mounting the grating ruler reading head;

[0017] The grating scale tape is fixedly arranged on the lead screw;

[0018] The mounting seat is sleeved on the lead screw;

[0019] The grating scale reading head is embedded in the mounting seat, and the mounting position of the grating scale reading head corresponds to the projection position of the grating scale tape on the mounting seat;

[0020] When the lead screw rotates, the mounting seat rotates together with the lead screw, and the grating scale tape moves linearly with the lead screw relative to the grating scale reading head.

[0021] Furthermore, the screw displacement detection device further includes:

[0022] A limiting component for limiting the mounting seat from linearly moving with the lead screw;

[0023] Wherein, the limiting component includes:

[0024] A bearing sleeved on the lead screw and matched with the mounting seat, used to limit the mounting seat from linear movement with the lead screw;

[0025] A bearing fixing seat sleeved on the bearing;

[0026] When the lead screw rotates, the limiting assembly limits the mounting seat from moving linearly with the lead screw.

[0027] Furthermore, the lead screw has a mounting plane for fixing the grating scale tape;

[0028] The mounting plane is cut out by the thread surface of the lead screw.

[0029] Furthermore, the mounting seat has an inner hole;

[0030] The shape of the inner hole of the mounting seat matches the cross-sectional shape of the lead screw with the mounting plane.

[0031] The embodiment of the present application also provides a parallel mechanism.

[0032] Specifically, a parallel mechanism includes:

[0033] frame;

[0034] a main shaft connected to the frame;

[0035] a plurality of branch chains respectively connected to the rack;

[0036] The plurality of branches are respectively connected to the main shaft to achieve parallel motion;

[0037] Among them, any of the several branches includes:

[0038] Drive components;

[0039] A lead screw assembly connected to the driving assembly is driven by the driving assembly to perform displacement motion;

[0040] A grating ruler assembly is used to measure the displacement of the lead screw assembly.

[0041] Furthermore, the screw assembly at least includes a screw;

[0042] The grating ruler assembly at least includes:

[0043] Grating scale tape with grating scale;

[0044] Grating scale reading head for reading grating scale;

[0045] A mounting base for mounting the grating ruler reading head;

[0046] The grating scale tape is fixedly arranged on the lead screw;

[0047] The mounting seat is sleeved on the lead screw;

[0048] The grating scale reading head is embedded in the mounting seat, and the mounting position of the grating scale reading head corresponds to the projection position of the grating scale tape on the mounting seat;

[0049] When the lead screw rotates, the mounting seat rotates together with the lead screw, and the grating scale tape moves linearly with the lead screw relative to the grating scale reading head.

[0050] Furthermore, any of the several branches further includes:

[0051] A limiting component for limiting the mounting seat from linearly moving with the lead screw;

[0052] Wherein, the limiting component includes:

[0053] A bearing sleeved on the lead screw and matched with the mounting seat is used to limit the mounting seat from linear movement with the lead screw;

[0054] A bearing fixing seat sleeved on the bearing;

[0055] When the lead screw rotates, the limiting assembly limits the mounting seat from moving linearly with the lead screw.

[0056] Furthermore, the lead screw has a mounting plane for fixing the grating scale tape;

[0057] The mounting plane is cut out by the thread surface of the lead screw.

[0058] Furthermore, the mounting seat has an inner hole;

[0059] The shape of the inner hole of the mounting seat matches the cross-sectional shape of the lead screw with the mounting plane.

[0060] Further, the drive assembly includes a hollow motor having a rotating end;

[0061] The lead screw passes through the hollow motor and is connected to the rotating end of the hollow motor.

[0062] The technical solutions provided in the embodiments of the present application have at least the following beneficial effects:

[0063] By fixing the grating scale tape to the lead screw and embedding the grating scale reading head in the mounting base, the mounting base rotates with the lead screw as the lead screw rotates, and the grating scale tape moves linearly with the lead screw relative to the grating scale reading head, thereby detecting the linear displacement of the lead screw assembly. Because the grating scale assembly directly measures the linear displacement of the lead screw assembly using the optical principle of the grating, detection accuracy and response speed are improved. Furthermore, fully closed-loop control is achieved, thereby improving the control accuracy of the lead screw assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0065] Figure 1 A schematic structural diagram of a lead screw displacement detection device provided in an embodiment of the present application.

[0066] Figure 2 A schematic structural diagram of a parallel mechanism provided in an embodiment of the present application.

[0067] Figure 3 A schematic diagram of the structure of a branched chain provided in an embodiment of the present application.

[0068] Figure 4 This is an exploded schematic diagram of a branched chain provided in an embodiment of the present application.

[0069] 100 Screw displacement detection device

[0070] 11. Drive Components

[0071] 12 Screw assembly

[0072] 13 Grating scale assembly

[0073] 131 Grating scale tape

[0074] 132 Grating scale reading head

[0075] 133 Mounting Block

[0076] 14 Limiting components

[0077] 141 bearings

[0078] 142 bearing fixed seat

[0079] 200 Parallel Mechanism

[0080] 21 racks

[0081] 22 Spindle

[0082] 23 branches

[0083] 231 drive components

[0084] 232 Screw Assembly

[0085] 233 grating scale assembly

[0086] 2331 Grating Scale Tape

[0087] 2332 Grating Scale Reading Head

[0088] 2333 Mount

[0089] 234 limit assembly

[0090] 2341 Bearings

[0091] 2342 bearing retainer

[0092] 235 Hooke's hinge DETAILED DESCRIPTION

[0093] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0094] Please refer to Figure 1 The present application provides a screw displacement detection device 100. Specifically, the screw displacement detection device 100 includes:

[0095] Drive assembly 11;

[0096] The lead screw assembly 12 connected to the driving assembly 11 is driven by the driving assembly 11 to perform displacement motion;

[0097] A grating scale assembly 13 for measuring the displacement of the lead screw assembly 12;

[0098] Wherein, the screw assembly 12 at least includes a screw;

[0099] The grating ruler assembly 13 at least includes:

[0100] A grating scale tape 131 provided with a grating scale;

[0101] A grating scale reading head 132 for reading the grating scale;

[0102] A mounting base 133 for mounting the grating ruler reading head 132;

[0103] The grating scale tape 131 is fixedly arranged on the lead screw;

[0104] The mounting seat 133 is sleeved on the lead screw;

[0105] The grating scale reading head 132 is embedded in the mounting seat 133 , and the mounting position of the grating scale reading head 132 corresponds to the projection position of the grating scale tape 131 on the mounting seat 133 ;

[0106] When the lead screw rotates, the mounting seat 133 rotates together with the lead screw, and the grating scale tape 131 moves linearly with the lead screw relative to the grating scale reading head 132.

[0107] It is understandable that the drive assembly 11 is used to provide a power source to enable the screw assembly 12 to perform displacement motion. In a specific application scenario, the drive assembly 11 can be manifested as a motor with a rotating end. The rotating end can provide torque to enable the screw or screw nut to perform rotational motion. When the screw rotates relative to the screw nut, the screw nut performs linear motion relative to the screw. When the screw nut rotates relative to the screw, the screw performs linear motion relative to the screw nut.

[0108] Furthermore, in a preferred embodiment provided in the present application, the driving assembly 11 is manifested as a hollow motor having a rotating end;

[0109] The lead screw passes through the hollow motor and is connected to the rotating end of the hollow motor.

[0110] It should be noted that in the prior art, the displacement of the lead screw is detected by counting the number of rotations of the lead screw and then calculating the displacement of the lead screw. This semi-closed loop control method is difficult to accurately control the displacement of the lead screw.

[0111] A linear scale displacement sensor is a measurement feedback device that uses the optical principle of a grating and can be used to detect linear displacement. Its output signal is a digital pulse, which features a large detection range, high detection accuracy, and fast response speed.

[0112] However, in the prior art, when the lead screw rotates relative to the lead nut, the lead nut moves linearly relative to the lead screw. Alternatively, when the lead nut rotates relative to the lead screw, the lead screw moves linearly relative to the lead nut. However, the grating scale displacement sensor operates by linearly moving the scale reading head 132 relative to the scale tape 131. Therefore, the motion of the grating scale displacement sensor differs from that of the lead screw, and a simple combination of the grating scale displacement sensor and the lead screw is not feasible.

[0113] To this end, the inventors of this application separated the grating scale displacement sensor into a grating scale tape 131 fixedly mounted on the lead screw and a grating scale reading head 132 embedded in a mounting base 133. Specifically, the mounting position of the grating scale reading head 132 corresponds to the projection position of the grating scale tape 131 on the mounting base 133, ensuring that the grating scale reading head 132 can read the grating scale on the grating scale tape 131.

[0114] Furthermore, the mounting base 133 rotates along with the lead screw, which can be considered as the grating scale reading head 132 rotating along with the grating scale tape 131. In this case, the grating scale reading head 132 can still read the grating scale on the grating scale tape 131. Thus, the separate grating scale tape 131 and grating scale reading head 132 do not cause measurement errors due to the different motions of the lead screw assembly 12.

[0115] The following describes how to fix the grating scale tape 131 to the lead screw.

[0116] Furthermore, in a specific embodiment provided in the present application, the lead screw has a mounting plane for fixing the grating scale tape 131;

[0117] The mounting plane is cut out by the thread surface of the lead screw.

[0118] It should be noted that the lead screw typically has a spiral groove or thread around its perimeter. To install the optical scale tape 131 on the lead screw's perimeter, milling can be performed to partially remove the threads or spiral grooves, thereby creating a mounting surface around the lead screw. The width of the mounting surface should be greater than or equal to the width of the optical scale tape 131. Since only a portion of the threads or spiral grooves are milled off the mounting surface, this does not invalidate the lead screw's ability to convert rotary motion into linear motion, or vice versa.

[0119] The following describes how to ensure that the mounting seat 133 rotates together with the lead screw.

[0120] Furthermore, in a specific embodiment provided in the present application, the mounting seat 133 has an inner hole;

[0121] The inner hole shape of the mounting seat 133 matches the cross-sectional shape of the lead screw with the mounting plane.

[0122] It can be understood that, because the surface of the lead screw is provided with a flat surface, the cross-sectional shape of the lead screw is a combination of a straight line and a circular arc. The shape of the inner hole of the mounting seat 133 matches the cross-sectional shape of the lead screw having the mounting surface. It can be understood that the shape of the inner hole of the mounting seat 133 is also a combination of a straight line and a circular arc, and the shape and size of the inner hole of the mounting seat 133 are the same as the cross-sectional shape of the lead screw.

[0123] Thus, when the lead screw rotates, the mounting seat 133 sleeved on the lead screw will be subjected to the torque from the lead screw and rotate along with the lead screw, thereby ensuring that the grating scale reading head 132 can read the grating scale on the grating scale tape 131.

[0124] Measuring the displacement of the lead screw assembly 12 is essentially measuring the distance moved between the grating scale reading head 132 and the grating scale tape 131. To this end, it is necessary to ensure that the grating scale reading head 132 does not move linearly with the grating scale tape 131, that is, it is necessary to ensure that the mounting base 133 does not move linearly with the grating scale tape 131.

[0125] Furthermore, in a specific embodiment provided in the present application, the lead screw displacement detection device 100 further includes:

[0126] A limiting assembly 14 for limiting the mounting seat 133 from linearly moving with the lead screw;

[0127] Wherein, the limiting component 14 includes:

[0128] A bearing 141 sleeved on the lead screw and matched with the mounting seat 133 is used to limit the mounting seat 133 from linearly moving with the lead screw;

[0129] A bearing fixing seat 142 sleeved on the bearing 141;

[0130] When the lead screw rotates, the limiting assembly 14 limits the mounting seat 133 from moving linearly with the lead screw.

[0131] It can be understood that the inventor sets the limiting component 14 to limit the mounting seat 133 from moving linearly with the lead screw. Specifically, the limiting component 14 is sleeved on the lead screw and matched with the mounting seat 133. In a specific application scenario, the limiting component 14 can be expressed as a bearing 141 sleeved on the lead screw and matched with the mounting seat 133, and a bearing fixing seat 142 sleeved on the bearing 141. The mounting seat 133 is arranged between the bearing 141 and the bearing fixing seat 142. In other words, the bearing 141 and the bearing fixing seat 142 are combined to form a structure that limits the mounting seat 133 from moving linearly with the lead screw.

[0132] When the lead screw rotates, the mounting base 133 rotates along with it. The position limiting assembly 14 restricts the mounting base 133 from linear movement with the lead screw. The grating scale tape 131 moves linearly with the lead screw relative to the grating scale reading head 132. The grating scale reading head 132 reads the grating scale tape 131 to directly determine the linear displacement of the lead screw assembly 12. Because the measurement principle of the grating scale assembly 133 is based on the optical principle of grating, the lead screw displacement detection device 100 has higher detection accuracy and faster response speed.

[0133] Please refer to Figure 2 The present application further provides a parallel mechanism 200. Specifically, the parallel mechanism 200 includes:

[0134] Frame 21;

[0135] A main shaft 22 connected to the frame 21;

[0136] a plurality of branch chains respectively connected to the frame 21;

[0137] The plurality of branches are respectively connected to the main shaft 22 to achieve parallel motion;

[0138] Among them, any branch 23 among the plurality of branches includes:

[0139] Drive assembly 231;

[0140] The lead screw assembly 232 connected to the driving assembly 231 is driven by the driving assembly 231 to perform displacement motion;

[0141] The grating scale assembly 233 measures the displacement of the screw assembly 232.

[0142] It should be noted that, compared to a series mechanism, a parallel mechanism 200 is a closed-loop mechanism consisting of multiple kinematic branches 23 that can control the terminal to achieve a certain output motion. The parallel mechanism 200 has the advantages of compact layout, high dynamic performance, and modularity. The parallel mechanism 200 provided in the embodiment of the present application achieves multiple degrees of freedom of rotation of the main shaft 22 through the linear motion of multiple branches, thereby achieving the technical effect of flexible operation.

[0143] In a specific embodiment provided in the present application, the frame 21 is a semi-arched truss structure. This truss frame 21 has a compact structure and, after topological optimization, is light in weight and has a strong load-bearing capacity.

[0144] The plurality of branches connect the frame 21 and the main shaft 22, and the plurality of branches extend in different directions. Specifically, any branch 23 among the plurality of branches is connected to the frame 21 via a Hooke's hinge, and any branch 23 among the plurality of branches is connected to the main shaft 22 via a ball joint perpendicular to the axis of the branch 23.

[0145] It is understood that the Hooke's joint between any of the several branches 23 and the frame 21 can be replaced by a revolute joint with two mutually perpendicular rotation axes. The spherical joint between any of the several branches 23 and the main shaft 22 can be replaced by a composite joint consisting of a Hooke's joint and a revolute pair.

[0146] Furthermore, the Hooke's joint between any of the multiple branches 23 and the frame 21 can be replaced by a revolute joint with three mutually perpendicular rotation axes. When three revolute pairs are provided between any of the multiple branches 23 and the frame 21, the spherical joint between any of the multiple branches 23 and the main shaft 22 can be replaced by a revolute pair with two perpendicular rotation axes. When two revolute pairs are provided between the connecting rod of any of the multiple branches 23 and the main shaft 22, the plane formed by the axes of the two revolute pairs is perpendicular to the axis of any of the multiple branches 23.

[0147] For further information, please refer to Figure 3 and Figure 4 , any branch 23 of the plurality of branches includes:

[0148] Drive assembly 231;

[0149] A lead screw assembly 232 driven by the driving assembly 231 to perform displacement motion;

[0150] The grating scale assembly 233 measures the displacement of the screw assembly 232.

[0151] It is understood that the drive assembly 231 is used to provide a power source to cause the screw assembly 232 to perform displacement motion. In a specific application scenario, the drive assembly 231 can be a motor with a rotating end, and the rotating end can provide torque to cause the screw or screw nut to perform rotational motion. When the screw rotates relative to the screw nut, the screw nut performs linear motion relative to the screw. When the screw nut rotates relative to the screw, the screw performs linear motion relative to the screw nut.

[0152] Furthermore, in a preferred embodiment provided in the present application, the driving assembly 231 is manifested as a hollow motor having a rotating end;

[0153] The lead screw passes through the hollow motor and is connected to the rotating end of the hollow motor.

[0154] It should be noted that in the prior art, the displacement of the lead screw is detected by counting the number of rotations of the lead screw and then calculating the displacement of the lead screw. This semi-closed loop control method makes it difficult to accurately control the displacement of the lead screw, and thus it is difficult to control the control accuracy of the entire parallel mechanism 200.

[0155] A linear scale displacement sensor is a measurement feedback device that uses the optical principle of a grating and can be used to detect linear displacement. Its output signal is a digital pulse, which features a large detection range, high detection accuracy, and fast response speed.

[0156] In the prior art, the grating scale displacement sensor is usually installed on the guide rail of the screw assembly. However, the present application takes into account that when the parallel mechanism uses a motor to drive the screw, due to its own limited space, a guide rail is usually not provided, so there is no space to install the grating scale displacement sensor. In addition, when the lead screw makes a rotational motion relative to the lead screw nut, the lead screw nut makes a linear motion relative to the lead screw. Or when the lead screw nut makes a rotational motion relative to the lead screw, the lead screw makes a linear motion relative to the lead screw nut. The working mode of the grating scale displacement sensor is that the grating scale reading head 2332 makes a linear motion relative to the grating scale tape 2331. It can be seen that the movement mode of the grating scale displacement sensor is different from that of the lead screw, and the grating scale displacement sensor cannot be simply combined with the lead screw.

[0157] To this end, the inventors of this application separated the grating scale displacement sensor into a grating scale tape 2331 fixedly mounted on the lead screw and a grating scale reading head 2332 embedded in a mounting base 2333. Specifically, the mounting position of the grating scale reading head 2332 corresponds to the projection position of the grating scale tape 2331 on the mounting base 2333, ensuring that the grating scale reading head 2332 can read the grating scale on the grating scale tape 2331.

[0158] Furthermore, the mounting base 2333 rotates along with the lead screw, which can be considered as the grating scale reading head 2332 rotating along with the grating scale tape 2331. In this case, the grating scale reading head 2332 can still read the grating scale on the grating scale tape 2331. Thus, the separate grating scale tape 2331 and grating scale reading head 2332 do not experience measurement errors due to the different motions of the lead screw assembly 232.

[0159] The following describes how to fix the grating scale tape 2331 to the lead screw.

[0160] Furthermore, in a specific embodiment provided in the present application, the lead screw has a mounting plane for fixing the grating scale tape 2331;

[0161] The mounting plane is cut out by the thread surface of the lead screw.

[0162] It should be noted that the lead screw typically has a spiral groove or thread around its perimeter. To install the grating scale tape 2331 on the lead screw's perimeter, milling can be performed to partially remove the threads or spiral grooves, thereby creating a mounting surface around the lead screw. The width of the mounting surface should be greater than or equal to the width of the grating scale tape 2331. Since only a portion of the threads or spiral grooves are milled off the mounting surface, this does not invalidate the lead screw's ability to convert rotary motion into linear motion, or vice versa.

[0163] The following describes how to ensure that the mounting seat 2333 rotates together with the lead screw.

[0164] Furthermore, in a specific embodiment provided in the present application, the mounting seat 2333 has an inner hole;

[0165] The inner hole shape of the mounting seat 2333 matches the cross-sectional shape of the lead screw with the mounting plane.

[0166] It can be understood that, because the surface of the lead screw is provided with a flat surface, the cross-sectional shape of the lead screw is a combination of a straight line and a circular arc. The inner hole shape of the mounting seat 2333 matches the cross-sectional shape of the lead screw having the mounting surface. It can be understood that the inner hole shape of the mounting seat 2333 also presents a combination of a straight line and a circular arc, and the shape and size of the inner hole of the mounting seat 2333 are the same as the cross-sectional shape of the lead screw.

[0167] Thus, when the lead screw rotates, the mounting seat 2333 sleeved on the lead screw will be subjected to the torque from the lead screw and rotate along with the lead screw, thereby ensuring that the grating scale reading head 2332 can read the grating scale on the grating scale tape 2331.

[0168] Measuring the displacement of the lead screw assembly 232 essentially involves measuring the distance traveled between the grating scale reading head 2332 and the grating scale tape 2331. To this end, it is necessary to ensure that the grating scale reading head 2332 does not move linearly with the grating scale tape 2331, that is, it is necessary to ensure that the mounting base 2333 does not move linearly with the grating scale tape 2331.

[0169] Furthermore, in a specific embodiment provided in the present application, any branch 23 among the plurality of branches further includes:

[0170] A limiting component 234 for limiting the mounting seat 2333 from linearly moving with the lead screw;

[0171] The limiting component 234 includes:

[0172] A bearing 2341 sleeved on the lead screw and matched with the mounting seat 2333 is used to restrict the mounting seat 2333 from linearly moving with the lead screw;

[0173] A bearing fixing seat 2342 sleeved on the bearing 2341;

[0174] When the lead screw rotates, the limiting assembly 234 limits the mounting seat 2333 from moving linearly with the lead screw.

[0175] It can be understood that the inventor sets the limiting component 234 to limit the mounting seat 2333 from moving linearly with the lead screw. Specifically, the limiting component 234 is sleeved on the lead screw and matched with the mounting seat 2333. In a specific application scenario, the limiting component 234 can be expressed as a bearing 2341 sleeved on the lead screw and matched with the mounting seat 2333, and a bearing fixing seat 2342 sleeved on the bearing 2341. The mounting seat 2333 is arranged between the bearing 2341 and the bearing fixing seat 2342. In other words, the bearing 2341 and the bearing fixing seat 2342 are combined to form a structure that limits the mounting seat 2333 from moving linearly with the lead screw.

[0176] Furthermore, the Hooke's hinge 235 is sleeved on the lead screw, one end of the Hooke's hinge 235 is matched with the end of the bearing fixing seat 2342 that is not sleeved with the bearing 2341, and the other end of the Hooke's hinge 235 is matched with the hollow motor.

[0177] When the hollow motor drives the lead screw to rotate, the mounting seat 2333 rotates along with the lead screw. The position limiting assembly 234 restricts the mounting seat 2333 from linear movement with the lead screw. The grating scale tape 2331 moves linearly along with the lead screw relative to the grating scale reading head 2332. The grating scale reading head 2332 directly determines the linear displacement of the lead screw assembly 232 by reading the grating scale tape 2331. This enables the parallel mechanism 200 to achieve full closed-loop control of the lead screw displacement, improves the control accuracy of the parallel mechanism 200 over each branch chain 23, and further accurately controls the movement position of the main shaft 22.

[0178] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, product, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, product, or apparatus. In the absence of further limitations, the phrase "comprises a..." to define an element does not preclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0179] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A screw displacement detection device, characterized in that: include: Drive components; A lead screw assembly connected to the driving assembly is driven by the driving assembly to perform displacement motion; A grating ruler assembly for measuring the displacement of the lead screw assembly; Wherein, the screw assembly at least includes a screw; The grating ruler assembly at least includes: Grating scale tape with grating scale; Grating scale reading head for reading grating scale; A mounting base for mounting the grating ruler reading head; The grating scale tape is fixedly arranged on the lead screw; The mounting seat is sleeved on the lead screw; The grating scale reading head is embedded in the mounting seat, and the mounting position of the grating scale reading head corresponds to the projection position of the grating scale tape on the mounting seat; When the lead screw rotates, the mounting seat rotates together with the lead screw, and the grating scale tape moves linearly with the lead screw relative to the grating scale reading head; a plane is provided on the surface of the lead screw, and the cross-section of the lead screw is a combination of a straight line and a circular arc; The shape of the inner hole of the mounting seat matches the cross-sectional shape of the lead screw with the mounting plane, and is also a combination of a straight line and a circular arc, and the shape and size of the inner hole of the mounting seat are the same as the cross-sectional shape of the lead screw; The screw displacement detection device also includes: A limiting component for limiting the mounting seat from linearly moving with the lead screw; Wherein, the limiting component includes: A bearing sleeved on the lead screw and matched with the mounting seat is used to limit the mounting seat from linear movement with the lead screw; A bearing fixing seat sleeved on the bearing; When the lead screw rotates, the limiting assembly limits the mounting seat from moving linearly with the lead screw.

2. The screw displacement detection device according to claim 1, characterized in that: The lead screw has a mounting plane for fixing the grating scale tape; The mounting plane is cut out by the thread surface of the lead screw.

3. The screw displacement detection device according to claim 2, characterized in that: The mounting seat has an inner hole; The shape of the inner hole of the mounting seat matches the cross-sectional shape of the lead screw with the mounting plane.

4. A parallel mechanism, characterized in that: include: frame; a main shaft connected to the frame; a plurality of branch chains respectively connected to the rack; The plurality of branches are respectively connected to the main shaft to achieve parallel motion; Among them, any of the several branches includes: Drive components; A lead screw assembly connected to the driving assembly is driven by the driving assembly to perform displacement motion; A grating ruler assembly for measuring the displacement of the lead screw assembly; the lead screw assembly at least comprises a lead screw; The grating ruler assembly at least includes: Grating scale tape with grating scale; Grating scale reading head for reading grating scale; A mounting base for mounting the grating ruler reading head; The grating scale tape is fixedly arranged on the lead screw; The mounting seat is sleeved on the lead screw; The grating scale reading head is embedded in the mounting seat, and the mounting position of the grating scale reading head corresponds to the projection position of the grating scale tape on the mounting seat; When the lead screw rotates, the mounting seat rotates together with the lead screw, and the grating scale tape moves linearly with the lead screw relative to the grating scale reading head; Any of the several branches further includes: A limiting component for limiting the mounting seat from linearly moving with the lead screw; Wherein, the limiting component includes: A bearing sleeved on the lead screw and matched with the mounting seat is used to limit the mounting seat from linear movement with the lead screw; A bearing fixing seat sleeved on the bearing; When the lead screw rotates, the limiting assembly limits the mounting seat from moving linearly with the lead screw; The lead screw has a mounting plane for fixing the grating scale tape; The mounting plane is cut out by the thread surface of the lead screw; The mounting seat has an inner hole; The shape of the inner hole of the mounting seat matches the cross-sectional shape of the lead screw with the mounting plane.

5. The parallel mechanism according to claim 4, characterized in that: The drive assembly includes a hollow motor having a rotating end; The lead screw passes through the hollow motor and is connected to the rotating end of the hollow motor.

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