Quick lead screw transmission device

Abstract

The invention discloses a lead screw quick transmission device. A nut and a lead screw are arranged in a shell; comprising a nut with a left-hand internal thread section and a nut with a right-hand internal thread section, and further comprises a lead screw with a left-hand external thread section and a lead screw with a right-hand external thread section, the nuts are fixed in the circumferential direction, and the lead screws are also fixed in the circumferential direction. The motor enables the nut and the lead screw to do relative circumferential rotation and enables the nut and the lead screw to do relative axial movement. And the screw threads with opposite screwing directions drive the nut and the screw rod to move in opposite directions, so that the working part operates in a double lead manner under the condition of not increasing the rotating speed of the motor and the screw pitch of the screw threads, and the purpose of quick transmission of the screw rod mechanism is achieved. Technically, a ball nut is allowed to replace a common T-shaped thread.

Description

Technical Field

[0001] This invention pertains to lead screw transmission devices, and particularly relates to a high-speed lead screw transmission device. Background Technology

[0002] Lead screw drives are a widely used linear transmission technology. Electric linear actuators that utilize the lead screw drive principle are also widely used products. The speed of a lead screw type electric linear actuator is limited by the lead of the lead screw and nut. With the lead constant, increasing the extension and retraction speed of the lead screw can only be achieved by increasing the rotational speed of the power input shaft.

[0003] By nesting multiple nuts of different diameters in multiple stages, the working end can be extended and retracted at multiple speeds. However, the structure is relatively complex, occupies more radial space, and significantly increases material and processing costs. Summary of the Invention

[0004] To double the working speed of a lead screw using a simple structure and method, without increasing the power input speed, the lead, or the use of multiple nut stacking, this invention proposes a rapid lead screw transmission device.

[0005] Its characteristics are:

[0006] Its components include a housing, inside which are a nut and a lead screw that engages with the nut.

[0007] At least one nut has a section of left-hand internal thread;

[0008] At least one nut has a right-hand internal thread section;

[0009] The left-hand internal thread segment and the right-hand internal thread segment are circumferentially fixed to each other;

[0010] At least one lead screw has a section of left-hand external thread that engages with the left-hand internal thread of a nut;

[0011] At least one lead screw has a right-hand external thread section that engages with the right-hand internal thread of a nut;

[0012] The left-hand external thread segment and the right-hand external thread segment are circumferentially fixed to each other;

[0013] The motor causes the nut and the lead screw to rotate relative to each other in the circumferential direction and to move relative to each other in the axial direction.

[0014] Based on the above-mentioned necessary technical features, one more specific preferred solution is:

[0015] The nut has a nut in which both the left-hand internal thread segment and the right-hand internal thread segment are located;

[0016] The nut can be moved axially relative to the housing;

[0017] It has two lead screws, one of which has the left-hand external thread section and the other has the right-hand external thread section;

[0018] The two lead screws mentioned above are fixed circumferentially relative to the housing;

[0019] One of the lead screws can be moved axially, while the other lead screw is fixed axially relative to the housing;

[0020] The motor causes the nut to rotate circumferentially relative to the housing and drives a nut and a lead screw to move axially.

[0021] The second preferred option is:

[0022] The nut has a nut in which both the left-hand internal thread segment and the right-hand internal thread segment are located;

[0023] The nut is axially fixed relative to the housing;

[0024] It has two lead screws, with the left-hand external thread section and the right-hand external thread section located on different lead screws;

[0025] The aforementioned lead screw is fixed circumferentially relative to the housing;

[0026] The aforementioned lead screw can be moved axially;

[0027] The motor causes the nut to rotate circumferentially relative to the housing and drives the two lead screws to move in opposite directions along the axial direction.

[0028] The third preferred option is:

[0029] It has two nuts,

[0030] One nut has a left-hand internal thread section, and the other nut has a right-hand internal thread section.

[0031] One of the nuts can be driven axially, and the outer end of the nut is movably connected to a drive rod that is circumferentially fixed relative to the housing.

[0032] The screw has an axially movable lead screw with a left-hand external thread section and a right-hand external thread section. The left-hand external thread section engages with the left-hand internal thread section of one of the aforementioned nuts, and the right-hand external thread section engages with the right-hand internal thread section of the aforementioned other nut.

[0033] The motor causes the nut to rotate circumferentially relative to the housing and drives a nut and a transmission rod to move axially.

[0034] The fourth preferred option is:

[0035] The device has three nuts, wherein the first nut and the second nut each have a left-hand internal thread section and a right-hand internal thread section, and these two nuts can be driven axially, while the third nut is axially fixed.

[0036] The system has three axially movable lead screws, wherein the first and second lead screws each have a left-hand external thread section and a right-hand external thread section;

[0037] The aforementioned lead screws are circumferentially fixed;

[0038] Each nut and each lead screw are arranged along the axis and mesh with each other accordingly;

[0039] The motor causes the nut to rotate circumferentially relative to the housing and drives multiple nuts and lead screws to move axially.

[0040] The fifth preferred option is:

[0041] It has two nuts,

[0042] One nut has a left-hand internal thread section, and the other nut has a right-hand internal thread section.

[0043] The aforementioned nut is circumferentially fixed relative to the housing;

[0044] The device has two lead screws that are axially fixed, one of which has a left-hand external thread section that engages with a nut having a left-hand internal thread section, and the other lead screw has a right-hand external thread section that engages with a nut having a right-hand internal thread section.

[0045] The motor causes the two lead screws to rotate circumferentially relative to the housing and drives the two nuts to move in opposite directions along the axial direction.

[0046] The sixth specific preferred option is:

[0047] It has two nuts,

[0048] One nut has a left-hand internal thread section, and the other nut has a right-hand internal thread section.

[0049] The aforementioned nut is circumferentially fixed relative to the housing;

[0050] The screw has an axially movable lead screw with a left-hand external thread section and a right-hand external thread section. The left-hand external thread section engages with the left-hand internal thread section of one of the aforementioned nuts, and the right-hand external thread section engages with the right-hand internal thread section of the aforementioned other nut.

[0051] The motor, by means of a torque-transmitting component, causes the lead screw to rotate circumferentially relative to the housing, and drives at least one nut and at least one lead screw to move axially.

[0052] The seventh specific preferred option is:

[0053] It has two nuts, which are circumferentially fixed to the housing but axially movable;

[0054] One of the nuts has a left-hand internal thread section and a right-hand internal thread section;

[0055] It has two lead screws, one of which can be moved axially and the other is fixed axially;

[0056] These two lead screws are fixed circumferentially.

[0057] The axially movable lead screw has a left-hand external thread section and a right-hand external thread section, and the different helical external thread sections of the lead screw respectively mesh with the internal thread sections of the two nuts mentioned above;

[0058] The motor, through a torque-transmitting component, causes the two lead screws to rotate circumferentially relative to the housing, and drives the two nuts and one lead screw to move axially.

[0059] The eighth specific preferred option is:

[0060] There are at least two lead screws that can be moved axially, and these two lead screws are circumferentially fixed to each other.

[0061] There are at least three nuts that are circumferentially locked to the housing, wherein at least two nuts are axially movable and one nut is axially fixed;

[0062] At least one axially movable nut has a left-hand internal thread segment and a right-hand internal thread segment, the two internal thread segments of the nut with opposite directions of rotation respectively meshing with the corresponding external thread segments of the two lead screws; the other two nuts mesh with the remaining thread segments of the lead screws.

[0063] The motor causes the lead screw to rotate circumferentially relative to the housing and drives multiple nuts and lead screws to move axially.

[0064] The ninth preferred option is:

[0065] It has two motors, one of which drives the lead screw to rotate and the other motor drives the nut to rotate.

[0066] This invention utilizes multiple nuts or multiple lead screws connected in series to increase the extension and retraction speed of the output end by one to several times while keeping the rotational speed of the power input shaft constant. The structure is relatively simple and easy to manufacture and assemble.

[0067] Obviously, this invention can be applied to both the simplest sliding screw pairs with direct thread engagement and ball screw pairs.

[0068] In this article, the terms "up", "down", "left", and "right" are used according to the top, bottom, left, and right of the referenced figures;

[0069] The above-mentioned directional terms are only for the purpose of accurately describing the relative positional relationship of the various parts of the present invention, and are not intended to indicate or imply that the components referred to must have a specific orientation, or must be combined and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0070] More specific technical features and beneficial effects of the present invention will be described in further detail in conjunction with the accompanying drawings in the following nine embodiments of the lead screw rapid transmission device. Attached Figure Description

[0071] Figure 1 This is a perspective view of the assembly cut along the axial direction according to Example 1;

[0072] Figure 2 This is a perspective view of the assembly cut along the axial direction of Example 1 and its main components after disassembly;

[0073] Figure 3 This is a perspective view of the assembly cut along the axial direction in Example 2 and its main components after disassembly;

[0074] Figure 4 This is a perspective view of the assembly and its main components after disassembly, cut along the axial direction in Example 3.

[0075] Figure 5 This is a perspective view of the assembly cut along the axial direction in Example 4 and its main components after disassembly.

[0076] Figure 6 This is a perspective view of the assembly cut along the axial direction in Example 5 and its main components after disassembly;

[0077] Figure 7 This is a perspective view of the assembly cut along the axial direction in Example 6 and its main components after disassembly.

[0078] Figure 8 This is a perspective view of the assembly cut along the axial direction in Example 7 and its main components after disassembly;

[0079] Figure 9This is a perspective view of the assembly cut along the axial direction in Example 8 and its main components after disassembly.

[0080] Figure 10 This is a perspective view of the assembly and its main components after disassembly, cut along the axial direction, according to Example 9.

[0081] Figure label:

[0082] 1_Outer shell, 11_Inner cavity of outer shell, 12_Left end hole of outer shell, 13_Right end hole of outer shell, 14_Pin hole of outer shell,

[0083] 141_Right end pin hole of housing, 15_Right end pin of housing, 16_Internal spline type of housing, 17_Motor housing section_

[0084] 171_Inner cavity of motor housing section;

[0085] 2_Nut, 21_Internal thread section of nut, 22_External spline key type of nut, 23_Locking pin hole of nut, 241_Middle section of nut,

[0086] 242_Nut extension section, 25_Nut power output end, 251_Nut end functional screw hole;

[0087] 3_Lead screw, 31_External thread section of lead screw, 32_Internal spline hole of lead screw, 33_Led screw locating pin hole, 34_Lead screw extension section

[0088] 341_Flat surface of lead screw extension section, 35_Power output end of lead screw, 351_Functional screw hole at lead screw end;

[0089] 4_Splined cylinder, 41_Splined cylinder positioning pin hole, 42_Splined cylinder internal spline type;

[0090] 5_Spline rod, 51_Spline rod power input end shank, 52_Spline end locating pin hole, 53_Spline rod key type,

[0091] 54_Spline rod end, 55_Bearing retaining ring;

[0092] 6_Transmission rod, 61_Transmission rod flat surface, 62_Transmission rod power output end;

[0093] 71_Motor stator coil group, 72_Motor rotor magnetic block group;

[0094] 8_Bearings;

[0095] 9. Assembly of the lead screw rapid transmission device. Detailed Implementation

[0096] Embodiment 1 of the lead screw rapid transmission device of the present invention is as follows: Figure 1 , Figure 2 As shown.

[0097] Figure 1 This is a half-section three-dimensional schematic diagram along the axial direction of the assembly 9-1 of this lead screw rapid transmission device.

[0098] See Figure 1 , Figure 2 The components of this lead screw rapid transmission device 9-1 include a cylindrical outer shell 1 with a length of about 28cm. A nut 2 with a length of 16cm is installed in the inner cavity of the outer shell 1. The inner cavity of the nut 2 has a left-hand internal thread section 21R with a length of about 3cm at the left end and a right-hand internal thread section 21L with a length of about 3cm at the right end. The inner diameter of the cavity of the middle section 241 of the nut between the left and right thread sections is larger than the major diameter of the threads of the left and right internal threads.

[0099] The inner cavity of the outer shell 1 is equipped with two hollow lead screws 3-2 and 3-1, with the left lead screw 3-2 having a total length of 20cm and a left-hand external thread section 31R with a length of 8cm on the right side, and the right lead screw 3-1 having a total length of 10cm and a right-hand external thread section 31L with a length of 8cm on the left side.

[0100] The left extension section 34 of the left lead screw 3-2 extends to the left from the left end hole 12 of the housing.

[0101] The inner walls of these two hollow lead screws 3-2 and 3-1 are provided with lead screw internal spline holes 32 of the same specification.

[0102] The outer casing 1 contains a splined rod 5. The right side of the splined rod 5 is inserted into and fixed in the splined hole 32 of the right lead screw 3-1, and the left side of the splined rod 5 is inserted into the splined hole 32 of the left lead screw 3-2. The splined holes 32 of the two lead screws match the key type 53 of the splined rod 5. The right end of the splined rod 5 is fixedly connected to the right end pin 15 of the outer casing by means of the splined end positioning pin hole 52.

[0103] The function of spline rod 5 is to fix the two lead screws circumferentially.

[0104] The right lead screw 3-1 is fixedly connected to the rear end pin 15 of the outer casing 1 at the rear end hole 13 of the outer casing 1 via the lead screw positioning pin hole 33.

[0105] The inner cavity of the outer casing 1 contains the stator coil group 71 of the frameless motor.

[0106] To simplify the illustrations, the motor stator coil 71 in the accompanying drawings of each embodiment is a schematic representation and not the actual appearance. For clarity, the components such as the housing 1 and nut 2 in the figures of each embodiment are schematic diagrams after being radially cut along the axis.

[0107] On the outer cylindrical surface of nut 2, motor rotor magnetic block assemblies 72 are evenly installed circumferentially, each magnetic block being approximately 15cm in length. Clearly, in actual engineering design, the motor rotor magnetic block assembly 72 may first need to be fixedly mounted on a thin-walled steel pipe, and then this steel pipe, along with the magnets, may be fixedly nested around the outside of nut 2.

[0108] During assembly, it must be ensured that when the device is in the fully retracted state, the right boundary of the internal thread section 21L on the right side of the nut 2 is aligned with the right boundary of the external thread section 31L on the right lead screw 3-1, and the left boundary of the internal thread section 21R on the left side of the nut 2 is aligned with the left boundary of the external thread section 31R on the left lead screw 3-2.

[0109] When the device is running, the two oppositely rotating internal threaded sections of the nut 2, driven by the motor, cause the nut 2 and the left lead screw 3-2 to move to the left, allowing the lead screw power output end 35 at the left end of the left lead screw 3-2 to push the workpiece. The lead screw power output end 35 can be equipped with a lead screw end functional screw hole 351 for mounting work heads of different shapes and functions.

[0110] To ensure stable motor operation, the stator section length in this embodiment is set to 10cm, which is 5cm shorter than the rotor magnet length. This ensures that the magnet, which moves with the nut, remains within the stator's coverage area during operation.

[0111] Obviously, if the thread lead of the nut and the lead screw are the same, then when the motor starts to rotate, causing the nut 2 to move to its extreme position of 4.5cm to the left, the power output end 35 of the left lead screw 3-2 will push out to the left by 9cm through the two pairs of internal and external thread segments with opposite directions. In other words, with the motor speed remaining constant, the leftward movement of the left lead screw 3-2 is twice as large as the maximum leftward movement of the nut 2, thus achieving the purpose of doubling the speed of the device's extension and retraction.

[0112] This embodiment can achieve a working stroke of 9cm at the working end.

[0113] As is common sense, in order to improve the transmission load capacity of the device, the length of the left and right internal thread sections of the nut 2 in this embodiment can be appropriately increased, even to nearly half the total length of the nut 2. However, excessively long internal thread sections of the nut will obviously increase wear on the parts, reduce transmission efficiency, and increase the difficulty of precision machining of the nut.

[0114] Replacing the ordinary nuts and lead screws in the various embodiments of this article with ball screws and nuts will obviously improve the performance of the device.

[0115] In the embodiments described herein, the outer shell 1 can be made of a variable diameter sleeve that is axially joined together, or it can be made of two molded shells that are halved along the axial direction and joined together by bolts.

[0116] Embodiment 2 of the lead screw rapid transmission device of the present invention is as follows Figure 3 As shown.

[0117] Figure 3 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly body 9-2 of this lead screw rapid transmission device.

[0118] The components of this lead screw rapid transmission device 9-2 include a cylindrical outer shell 1 with a length of about 28cm. A nut 2 with a length of 16cm is installed in the inner cavity of the outer shell 1. The inner cavity of the nut 2 has a left-hand internal thread section 21R with a length of about 3cm at the left end and a right-hand internal thread section 21L with a length of about 3cm at the right end. The inner diameter of the cavity of the middle section 241 of the nut between the left and right threads is larger than the major diameter of the threads of the left and right internal threads.

[0119] The inner cavity of the outer shell 1 is equipped with two hollow lead screws 3-2 and 3-1, with the left lead screw 3-2 having a total length of 16cm and a left-hand external thread section 31R with a length of 8cm on the right side, and the right lead screw 3-1 having a total length of 16cm and a right-hand external thread section 31L with a length of 8cm on the left side.

[0120] The left extension section 34-2 of the left lead screw 3-2 extends to the left from the left end hole 12-2 of the housing.

[0121] The right lead screw extension section 34 of the right lead screw 3-1 extends to the left from the right end hole 12-2 of the housing.

[0122] The left end hole 12-2 and the right end port 12-1 of the outer casing have flat surfaces, and the lead screw extension sections of the left lead screw 3-2 and the right lead screw 3-1 have corresponding flat surfaces 341-2 and 341-1. These flat surface structures allow the lead screw to be circumferentially fixed relative to the outer casing.

[0123] The inner cavity of the outer casing 1 contains the stator coil group 71 of the frameless motor.

[0124] On the outer cylindrical surface of nut 2, motor rotor magnetic block group 72 is evenly installed circumferentially. Each magnetic block is about 13cm long, the same as the stator length.

[0125] Nut 2 is connected to the housing at both ends by bearings 8. These two bearings allow nut 2 to rotate circumferentially, but are fixed axially.

[0126] During assembly, it must be ensured that the left lead screw 3-2 and the right lead screw 3-1 are symmetrical in the nut 2.

[0127] When the device is running, the two internally threaded sections of the nut 2, which are rotated by the motor, with opposite directions of rotation, will drive the left lead screw 3-2 and the right lead screw 3-1 to move synchronously in opposite directions, so that the two lead screw power output ends 35-2 and 35-1 at the outer ends of the left and right lead screws will push or pull the working object synchronously.

[0128] Clearly, this embodiment also achieves the purpose of doubling the speed of the device's extension and retraction.

[0129] Embodiment 3 of the lead screw rapid transmission device of the present invention is as follows: Figure 4 As shown.

[0130] Figure 4 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly body 9-3 of this lead screw rapid transmission device.

[0131] The components of this lead screw rapid transmission device 9-3 include a cylindrical outer shell 1 with a cavity length of about 30cm, and a motor stator coil group 71 is installed in the middle of the inner cavity of the outer shell 1.

[0132] The outer casing 1 also contains a 28cm long splined cylinder 4. The left and right ends of the splined cylinder 4 are connected to the outer casing 1 by bearings 8-1 and are kept axially fixed. The outer cylindrical surface of the splined cylinder 4 is equipped with a motor rotor magnetic block assembly 72 that corresponds to and matches the motor stator coil assembly 71 of the outer casing.

[0133] A left nut 2-2 is installed on the left side of the splined cylinder 4, and a right nut 2-1 is installed on the right side. The left nut 2-2, which is 10cm long, has a right-hand internal thread section 21R about 3cm long near its right end, and the right nut 2-1, which is 8cm long, has a left-hand internal thread section 21L about 3cm long near its left end. The outer cylindrical surfaces of both the left nut 2-2 and the right nut 2-1 are provided with nut external spline key type 22 that matches the spline type 42 inside the splined cylinder.

[0134] The right nut 2-1 is fixedly connected to the splined cylinder 4 by means of the nut positioning pin hole 23 and the splined cylinder positioning pin hole 41.

[0135] A lead screw 3, 16cm in length, has an 8cm long left-hand external thread section 31L on its right side and an 8cm long right-hand external thread section 31R on its left side. The right side of the lead screw 3 is screwed into a right nut 2-1, and the left side is screwed into a left nut 2-2. The lead screw 3 has a through spline hole 32.

[0136] A 17cm long spline rod 5 passes through the spline hole of the lead screw 3. The tail end 54 of the spline rod 5 is fixedly connected to the hole 13 on the right end of the housing.

[0137] The left end of the left nut 2-2 is connected to a transmission rod 6 by a bearing 8-2. The transmission rod 6 is circumferentially fixed by means of the transmission rod flat surface 61 and the left end hole 12 of the housing with a matching flat surface.

[0138] During assembly, it is necessary to ensure that the left nut 2-2 and the right nut 2-1 are symmetrically positioned within nut 2.

[0139] When the device is running, the splined cylinder 4, which is driven to rotate by the motor, simultaneously drives the left nut 2-2 and the right nut 2-1 to rotate synchronously.

[0140] Since the right nut 2-1 is axially locked, its rotation causes the lead screw 3 to move to the left.

[0141] The lead screw 3, which moves to the left, synchronously drives the left nut 2-2 and the transmission rod 6 to move to the left at double speed. Finally, the power output end 62 of the transmission rod drives the working object, thereby achieving the purpose of double speed extension and retraction of the device.

[0142] Embodiment 4 of the lead screw rapid transmission device of the present invention is as follows Figure 5 As shown.

[0143] Figure 5 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly 9-4 of this lead screw rapid transmission device.

[0144] The components of this lead screw rapid transmission device 9-4 include a cylindrical outer shell 1 with a cavity length of about 44cm, and a motor stator coil group 71 is installed in the right part of the inner cavity of the outer shell 1.

[0145] The outer casing 1 also contains a 42cm long splined cylinder 4. The left and right ends of the splined cylinder 4 are connected to the outer casing 1 by bearings 8 and are kept axially fixed. The outer cylindrical surface of the splined cylinder 4 is equipped with a motor rotor magnetic block assembly 72 that corresponds to and matches the motor stator coil assembly 71 of the outer casing.

[0146] A left nut 2-3 is installed on the left side of the splined cylinder 4, a middle nut 2-2 is installed in the middle, and a right nut 2-1 is installed on the right side. The left nut 2-3 and the middle nut 2-2, which are 12cm long, have a left-hand internal thread section 21L and a right-hand internal thread section 21R, respectively, with a length of about 3cm, on their left and right sides. The right nut 2-1, which is 6cm long, has a left-hand internal thread section 21L with a length of about 3cm near its left end. The outer cylindrical surfaces of the left nut 2-3, the middle nut 2-2, and the right nut 2-1 are all provided with nut external spline key type 22 that matches the spline type 42 inside the splined cylinder.

[0147] The right nut 2-1 is fixedly connected to the splined cylinder 4 by means of the nut positioning pin hole 23 and the splined cylinder positioning pin hole 41.

[0148] There are three hollow lead screws. The left lead screw 3-3, which is 24cm long, has a 6cm long left-hand external thread section 31L on its right side. The middle lead screw 3-2 and the right lead screw 3-1 have a 6cm long right-hand external thread section 31R and a 6cm long left-hand external thread section 31L on their left and right sides, respectively. All three lead screws have a through-hole internal spline hole 32.

[0149] A 44cm long spline rod 5 passes through the spline hole 32 of three lead screws. The spline end positioning pin hole 33 of the spline rod 5 is fixedly connected to the pin hole 141 on the right end of the housing by a pin.

[0150] The left and right internal threads of the left nut 2-3 mesh with the right external thread of the left lead screw 3-3 and the left external thread of the middle lead screw 3-2, respectively. The left and right internal threads of the middle nut 2-2 mesh with the right external thread of the middle lead screw 3-2 and the left external thread of the right lead screw 3-1, respectively.

[0151] During assembly, it is essential to ensure that all nuts and lead screws are close together.

[0152] When the device is running, the splined cylinder 4, which is driven to rotate by the motor, simultaneously drives each nut to rotate synchronously. Since the right nut 2-1 is fixedly connected to the splined cylinder 4 by means of the nut positioning pin hole 23 and the splined cylinder positioning pin hole 41, when the splined cylinder rotates, under the combined action of the meshing internal and external threads, the left nut 2-3 and the middle nut 2-2 will move axially to the left at different speeds together with each lead screw.

[0153] Simple calculations show that when the right lead screw 3-1 is moved 3cm to the left, the left lead screw 3-3 will move 15cm to the left. In other words, the working speed of the device increases to 5 times its original speed.

[0154] Clearly, as speed increases, transmission efficiency decreases significantly, and cumulative frictional resistance increases significantly. Although the friction area can be reduced by shortening the length of the threaded section inside the nut, this only provides a limited improvement in transmission efficiency and reduces load-bearing capacity. Therefore, in multi-speed applications, ball screw mechanisms or roller screw mechanisms should be used instead of sliding screw mechanisms.

[0155] Embodiment 5 of the lead screw rapid transmission device of the present invention is as follows Figure 6 As shown.

[0156] Figure 6 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly body 9-5 of this lead screw rapid transmission device.

[0157] The components of this lead screw rapid transmission device 9-5 include a cylindrical outer shell 1 with a cavity length of about 30cm, and a motor stator coil group 71 is installed in the middle of the inner cavity of the outer shell 1.

[0158] Referring to the attached diagram, the outer casing 1 contains two fixed splined cylinders 4-2 and 4-1, each 10cm in length, of the same shape. The splined cylinders are fixedly connected via positioning pin holes 41 and pin holes 14 in the outer casing.

[0159] The motor stator coil group 71 is installed in the middle of the cavity of the outer casing 1.

[0160] Nuts 2-2 and 2-1 are respectively installed inside the upper and lower splined cylinders 4-2 and 4-1. The spline type 42 inside the splined cylinder matches the spline type 22 outside the nut, thus maintaining mutual circumferential fixation.

[0161] The lower part of the inner cavity of the upper nut 2-2 (11cm in length) and the upper part of the inner cavity of the lower nut 2-1 each have a left-hand internal thread section 21L and a right-hand internal thread section 21R, each approximately 3cm long. Both nuts have a nut end functional threaded hole 251 at their outer ends. The inner diameter of the nut extension section 242 in the middle of the inner cavity of both nuts is larger than the major diameter of the nut's thread. Both nuts 2-2 and 2-1 have nut end functional threaded holes 251 at their power output ends 25 to accommodate different working heads.

[0162] At the center of the device is a 28cm long lead screw 3 that passes through the upper and lower nuts. The middle 8cm section of the lead screw 3 is surrounded by a ring of motor rotor magnetic blocks 72; the upper 9cm section of the lead screw 3 is a left-hand external thread section 31L; the lower 9cm section of the lead screw 3 is a right-hand external thread section 31R. The upper left-hand external thread section 31L of the lead screw 3 meshes with the left-hand internal thread section 21L of the upper nut 2-2, and the lower right-hand external thread section 31R of the lead screw 3 meshes with the right-hand internal thread section 21R of the lower nut 2-1. The middle section of the lead screw 3 is connected to the outer casing 1 by two bearings 8, which restrict the lead screw 3 to circumferential rotation only.

[0163] During assembly, it is necessary to ensure that the positions of the upper and lower nuts 2-2 and 2-1 are symmetrical about the geometric center of the outer shell.

[0164] When the device is running, the lead screw 3, driven by the motor, simultaneously drives the upper and lower nuts 2-2 and 2-1 to rotate synchronously in the same direction. Driven by the threads with opposite directions of rotation, the upper and lower nuts 2-2 and 2-1 move in opposite directions along the axial direction, together completing a working stroke of 12cm, achieving the purpose of speed doubling transmission.

[0165] Embodiment 6 of the lead screw rapid transmission device of the present invention is as follows Figure 7 As shown.

[0166] Figure 7 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly 9-6 of this lead screw rapid transmission device.

[0167] The lead screw rapid transmission device 9-6 consists of a cylindrical outer shell 1 with a cavity length of approximately 26 cm. The inner surface of the outer shell 1 is provided with an inner spline type 16.

[0168] The outer casing 1 contains two nuts, 2-2 and 2-1, on the left and right sides. The outer cylindrical surfaces of the left and right nuts 2-2 and 2-1 are provided with nut external spline key type 22 that mates with the spline type 16 inside the outer casing.

[0169] The right section of the inner cavity of the left nut 2-2, which is 17cm long, and the left section of the inner cavity of the right nut 2-1, which is 9cm long, each have a right-hand internal thread section 21R and a left-hand internal thread section 21L, each about 3cm long.

[0170] The left end of the left nut 2-2 is provided with a nut end functional screw hole 251 at the nut power output end 25.

[0171] The right nut 2-1 is fixedly connected to the right end pin 15 of the outer casing 1 by means of the nut positioning pin hole 23, thereby maintaining circumferential fixation.

[0172] At the center of the device is a hollow lead screw 3 with an internal spline hole 32, which is 18cm long and passes through the left and right nuts 2-2 and 2-1. The left 9cm section of the lead screw 3 is a right-hand external thread section 31R, and the right 9cm section is a left-hand external thread section 31L.

[0173] The left section of the lead screw 3, the right-hand external thread section 31R, meshes with the right-hand internal thread section 21R of the left nut 2-2, and the right section of the lead screw 3, the left-hand external thread section 31L, meshes with the left-hand internal thread section 21L of the right nut 2-1.

[0174] A splined rod 5 passes through the splined hole 32 of the lead screw. The right end of the splined rod 5 is fixedly connected to the right end of the housing 1 by means of a bearing 8, and remains axially fixed. The splined rod power input end shank 51 of the right end of the splined rod 5 passes through the hole 13 at the right end of the housing to the right and is connected to the motor power output shaft. The motor is omitted in the figure.

[0175] During assembly, it is necessary to ensure that the positions of the left and right nuts 2-2 and 2-1 are symmetrical about the geometric center of the lead screw 3.

[0176] When the device is running, the lead screw 3, which is driven to rotate by the motor, moves 6cm to the left under the thread drive of the right nut 2-1, and drives the left nut 2-2 to move to the left at double speed, completing a working stroke of 12cm, thus achieving the purpose of double speed transmission.

[0177] Embodiment 7 of the lead screw rapid transmission device of the present invention is as follows Figure 8 As shown.

[0178] Figure 8 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly 9-7 of this lead screw rapid transmission device.

[0179] The rapid lead screw transmission device 9-7 consists of a cylindrical outer shell 1 with a cavity length of approximately 22 cm. The inner surface of the outer shell 1 is provided with an inner spline 16.

[0180] The outer casing 1 contains two nuts, 2-2 and 2-1, on the left and right sides. The outer cylindrical surfaces of the left and right nuts 2-2 and 2-1 are provided with nut external spline key type 22 that mates with the spline type 16 inside the outer casing.

[0181] The right section of the inner cavity of the 11cm long left nut 2-2 has a right-hand internal thread section 21R with a length of about 2cm; the left and right sections of the inner cavity of the 9cm long right nut 2-1 are respectively provided with a left-hand internal thread section 21L and a right-hand internal thread section 21R with a length of about 2cm.

[0182] The left end of the left nut 2-2 is provided with a nut end functional screw hole 251 at the nut power output end 25.

[0183] The inner diameters of the left extension section 242 of the left nut 2-2 and the middle section 241 of the right nut 2-1 are larger than the major diameter of the internal thread.

[0184] The device contains two hollow lead screws, left and right. The left lead screw 3-2 is 9cm long, and the right lead screw 3-1 is 4.5cm long. Both lead screws have internal spline holes 32.

[0185] The left and right parts of the left lead screw 3-2 are respectively the right-hand external thread section 31R and the left-hand external thread section 31L; the right lead screw 3-1 is entirely composed of the right-hand external thread section 31R.

[0186] The left section of the left lead screw 3-2, the right-hand external thread section 31R, meshes with the right-hand internal thread section 21R of the left nut 2-2, and the right section, the left-hand external thread section 31L, meshes with the left-hand internal thread section 21L of the right nut 2-1.

[0187] The right-hand external thread section 31R of the right lead screw 3-1 meshes with the right-hand internal thread section 21R of the right nut 2-1.

[0188] A splined rod 5 passes through the splined holes 32 of the left and right lead screws 3-2 and 3-1. The right end of the splined rod 5 is fixedly connected to the right end of the housing 1 by means of a bearing 8, and is kept axially fixed. The splined rod power input end shank 51 of the right end of the splined rod 5 passes through the hole 13 at the right end of the housing to the right and is connected to the motor power output shaft. The motor is omitted in the figure.

[0189] During assembly, it is necessary to ensure that the left and right nuts 2-2 and 2-1 are aligned and close to each other at the geometric center of the left lead screw 3-2, and at the same time, the left and right lead screws are also close to each other.

[0190] When the device is running, the spline rod 5 driven by the motor drives the left and right lead screws 3-2 and 3-1 to drive the left and right nuts 2-1 and 2-2 to move to the left at a differential speed. When the right nut 2-1 moves to the left to its limit distance of 2.5cm, the nut power output end 25 of the left nut 2-2 moves to the left by 75cm, which is 3 times the moving speed of the right nut 2-1, thus realizing the device's 3 times speed working capability.

[0191] Embodiment 8 of the lead screw rapid transmission device of the present invention is as follows Figure 9 As shown.

[0192] Figure 9 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly 9-8 of this lead screw rapid transmission device.

[0193] The lead screw rapid transmission device 9-8 consists of a cylindrical outer shell 1 with a cavity length of approximately 28 cm. The inner surface of the outer shell 1 is provided with an inner spline type 16.

[0194] The outer casing 1 contains three sections of nuts 2-3, 2-2, and 2-1, located on the left, middle, and right sides. The outer cylindrical surface of each nut is provided with an external spline key 22 that mates with the spline key 16 inside the casing.

[0195] The left nut 2-3, which is 14cm long, has a right-hand internal thread section 21R with a length of about 2cm on the right side of its inner cavity; the middle nut 2-2, which is 9cm long, has a left-hand internal thread section 21L and a right-hand internal thread section 21R with a length of about 2cm on the left and right sides of its inner cavity, respectively. The right nut 2-1 has a left-hand internal thread section 21L with a length of about 2cm on the left side of its inner cavity.

[0196] The left end of the left nut 2-3 is provided with a nut end functional screw hole 251 at the nut power output end 25.

[0197] The inner diameters of the left extension section 242 of the left nut 2-3, the middle section 241 of the middle nut 2-2, and the right extension section 242 of the right nut 2-1 are larger than the major diameter of the internal thread.

[0198] The device contains two identical hollow lead screws, 3-2 and 3-1, each 9cm long, with internal spline holes of 32.

[0199] The left and right parts of the lead screws 3-2 and 3-1 are respectively the right-hand external thread section 31R and the left-hand external thread section 31L.

[0200] The left section of the left lead screw 3-2, with a right-hand external thread 31R, meshes with the right-hand internal thread 21R of the left nut 2-3, and the right section, with a left-hand external thread 31L, meshes with the left-hand internal thread 21L of the middle nut 2-2.

[0201] The left section of the right lead screw 3-1, the right-hand external thread section 31R, meshes with the right-hand internal thread section 21R of the middle nut 2-2, and the right section, the left-hand external thread section 31L, meshes with the left-hand internal thread section 21L of the right nut 2-1.

[0202] The right nut 2-1 is fixedly connected to the right end pin 15 of the outer casing 1 by means of the nut positioning pin hole 23, thereby maintaining circumferential fixation.

[0203] A splined rod 5 passes through the splined holes 32 of the left and right lead screws 3-2 and 3-1. The right end of the splined rod 5 is fixedly connected to the right end of the housing 1 by means of a bearing 8, and is kept axially fixed. The splined rod power input end shank 51 of the right end of the splined rod 5 passes through the hole 13 at the right end of the housing to the right and is connected to the motor power output shaft. The motor is omitted in the figure.

[0204] During assembly, it is necessary to ensure that the left nut 2-3 and the middle nut 2-2 are aligned and close to each other at the geometric center of the left lead screw 3-2, and that the middle nut 2-2 and the right nut 2-1 are aligned and close to each other at the geometric center of the right lead screw 3-1; at the same time, it is necessary to ensure that the left and right lead screws 3-2 and 3-1 can be close to each other.

[0205] When the device is running, the spline rod 5 driven by the motor drives the left and right lead screws 3-2 and 3-1 to drive the left nut 2-3 and the middle nut 2-2 to move to the left at a differential speed. When the right lead screw 3-1 moves to the left to its limit distance of 2.5cm, the nut power output end 25 of the left nut 2-3 moves to the left by 10cm, which is 4 times the moving speed of the right nut 2-1, thus realizing the device's 4 times speed working capability.

[0206] Embodiment 9 of the lead screw rapid transmission device of the present invention is as follows Figure 10 As shown.

[0207] Figure 10 The central figure is a half-section three-dimensional schematic diagram along the axial direction of the assembly 9-9 of this lead screw rapid transmission device.

[0208] The lead screw rapid transmission device 9-9 consists of a cylindrical outer shell 1 with a cavity length of approximately 30cm. The inner cavity of the outer shell 1 is divided into left and right inner cavities. The right inner cavity, with a length of approximately 8cm, is the motor housing section 17. The motor stator coil assembly 71 is installed in the middle section of the left inner cavity of the outer shell 1.

[0209] The outer casing 1 also contains a splined cylinder 4 with a length of 18cm. The left and right ends of the splined cylinder 4 are connected to the left inner cavity section of the outer casing 1 by bearings 8-1 and are kept axially fixed. The middle section of the outer cylindrical surface of the splined cylinder 4 is equipped with a motor rotor magnetic block group 72 that corresponds to and matches the motor stator coil group 71 of the outer casing.

[0210] A left nut 2-2 is installed on the left side of the splined cylinder 4, and a right nut 2-1 is installed on the right side. The left nut 2-2, which is 12cm long, has a right-hand internal thread section 21R of about 2cm in length on its right side. The right nut 2-1, which is 9cm long, has a left-hand internal thread section 21L of about 2cm in length on its left side and a right-hand internal thread section 21R of about 2cm in length on its right side. The outer cylindrical surfaces of both the left nut 2-2 and the right nut 2-1 are provided with nut external spline key type 22 that matches the spline type 42 inside the splined cylinder.

[0211] There are two hollow lead screws. The left lead screw 3-2, which is 9cm long, has a right-hand external thread section 31R and a left-hand external thread section 31L, each with a length of 4.5cm, on its left and right sides respectively. The entire outer cylindrical surface of the right lead screw 3-1 is a left-hand external thread section 31L. Both lead screws have a through-hole internal spline hole 32.

[0212] A splined rod 5 passes through the splined holes 32 of the two lead screws. The right end of the splined rod 5 is connected to the housing 1 by a bearing 8-2 and a bearing retainer 55 to keep it axially fixed.

[0213] The right lead screw 3-1 is fixedly connected to the spline rod 5 via the lead screw positioning pin hole 33.

[0214] The right internal thread of the left nut 2-2 meshes with the left external thread of the left lead screw 3-3, and the left and right internal threads of the right nut 2-1 mesh with the right external thread of the left lead screw 3-2 and the external thread of the right lead screw 2-1, respectively.

[0215] An auxiliary motor is installed inside the motor housing section 17 of the outer casing 1. The diagram of this motor is omitted in the figure. The splined rod power input end handle 51 at the right end of the splined rod 5 is connected to the power output end of the motor.

[0216] During assembly, it is essential to ensure that all nuts and lead screws can be brought close together.

[0217] When the device is running, the main motor, which consists of the motor stator coil 71 and the motor rotor magnetic block group 72, can drive the splined cylinder 4 to rotate, and at the same time drive each nut to rotate synchronously.

[0218] During device operation, the auxiliary motor can also be started, driving the two lead screws 3-1 and 3-2 to rotate via the spline rod 5.

[0219] The two motors can operate independently or simultaneously, and can synthesize complex movement curves. When the two motors rotate in the same direction, the working part can reach a maximum extension speed of 6 times. When the two motors rotate smoothly in opposite directions at different speeds, the working part can reciprocate and extend along a smooth curve. When the two motors rotate in opposite directions at the same speed, the extension speed of the working part can be reduced to 0.

[0220] The above nine embodiments are merely examples of some typical implementations of the present invention. In actual implementation, there are obviously many more application methods. Furthermore, the motor driving method can also be chosen from a wider range of options.

Claims

1. A lead screw rapid transmission device, characterized by: Its components include a housing, inside which are a nut and a lead screw that engages with the nut. At least one nut has a section of left-hand internal thread; At least one nut has a right-hand internal thread section; The left-hand internal thread segment and the right-hand internal thread segment are circumferentially fixed to each other; At least one lead screw has a section of left-hand external thread that engages with the left-hand internal thread of a nut; At least one lead screw has a right-hand external thread section that engages with the right-hand internal thread of a nut; The left-hand external thread segment and the right-hand external thread segment are circumferentially fixed to each other; The motor causes the nut and the lead screw to rotate relative to each other in the circumferential direction and to move relative to each other in the axial direction.

2. The lead screw rapid transmission device according to claim 1, characterized in that: The nut has a nut in which both the left-hand internal thread segment and the right-hand internal thread segment are located; The nut can be moved axially relative to the housing; It has two lead screws, one of which has the left-hand external thread section and the other has the right-hand external thread section; The two lead screws mentioned above are fixed circumferentially relative to the housing; One of the lead screws can be moved axially, while the other lead screw is fixed axially relative to the housing; The motor causes the nut to rotate circumferentially relative to the housing and drives a nut and a lead screw to move axially.

3. The lead screw rapid transmission device according to claim 1, characterized in that: The nut has a nut in which both the left-hand internal thread segment and the right-hand internal thread segment are located; The nut is axially fixed relative to the housing; It has two lead screws, with the left-hand external thread section and the right-hand external thread section located on different lead screws; The aforementioned lead screw is fixed circumferentially relative to the housing; The aforementioned lead screw can be moved axially; The motor causes the nut to rotate circumferentially relative to the housing and drives the two lead screws to move in opposite directions along the axial direction.

4. The lead screw rapid transmission device according to claim 1, characterized in that: It has two nuts, One nut has a left-hand internal thread section, and the other nut has a right-hand internal thread section. One of the nuts can be driven axially, and the outer end of the nut is movably connected to a drive rod that is circumferentially fixed relative to the housing. The screw has an axially movable lead screw with a left-hand external thread section and a right-hand external thread section. The left-hand external thread section engages with the left-hand internal thread section of one of the aforementioned nuts, and the right-hand external thread section engages with the right-hand internal thread section of the aforementioned other nut. The motor causes the nut to rotate circumferentially relative to the housing and drives a nut and a transmission rod to move axially.

5. The lead screw rapid transmission device according to claim 1, characterized in that: The device has three nuts, wherein the first nut and the second nut each have a left-hand internal thread section and a right-hand internal thread section, and these two nuts can be driven axially, while the third nut is axially fixed. The system has three axially movable lead screws, wherein the first and second lead screws each have a left-hand external thread section and a right-hand external thread section; The aforementioned lead screws are circumferentially fixed; Each nut and each lead screw are arranged along the axis and mesh with each other accordingly; The motor causes the nut to rotate circumferentially relative to the housing and drives multiple nuts and lead screws to move axially.

6. The lead screw rapid transmission device according to claim 1, characterized in that: It has two nuts, One nut has a left-hand internal thread section, and the other nut has a right-hand internal thread section. The aforementioned nut is circumferentially fixed relative to the housing; The device has two lead screws that are axially fixed, one of which has a left-hand external thread section that engages with a nut having a left-hand internal thread section, and the other lead screw has a right-hand external thread section that engages with a nut having a right-hand internal thread section. The motor causes the two lead screws to rotate circumferentially relative to the housing and drives the two nuts to move in opposite directions along the axial direction.

7. The lead screw rapid transmission device according to claim 1, characterized in that: It has two nuts, One nut has a left-hand internal thread section, and the other nut has a right-hand internal thread section. The aforementioned nut is circumferentially fixed relative to the housing; The screw has an axially movable lead screw with a left-hand external thread section and a right-hand external thread section. The left-hand external thread section engages with the left-hand internal thread section of one of the aforementioned nuts, and the right-hand external thread section engages with the right-hand internal thread section of the aforementioned other nut. The motor, by means of a torque-transmitting component, causes the lead screw to rotate circumferentially relative to the housing, and drives at least one nut and at least one lead screw to move axially.

8. The lead screw rapid transmission device according to claim 1, characterized in that: It has two nuts, which are circumferentially fixed to the housing but axially movable; One of the nuts has a left-hand internal thread section and a right-hand internal thread section; It has two lead screws, one of which can be moved axially and the other is fixed axially; These two lead screws are fixed circumferentially. The axially movable lead screw has a left-hand external thread section and a right-hand external thread section, and the different helical external thread sections of the lead screw respectively mesh with the internal thread sections of the two nuts mentioned above; The motor, through a torque-transmitting component, causes the two lead screws to rotate circumferentially relative to the housing, and drives the two nuts and one lead screw to move axially.

9. The lead screw rapid transmission device according to claim 1, characterized in that: There are at least two lead screws that can be moved axially, and these two lead screws are circumferentially fixed to each other. There are at least three nuts that are circumferentially locked to the housing, wherein at least two nuts are axially movable and one nut is axially fixed; At least one axially movable nut has a left-hand internal thread segment and a right-hand internal thread segment, the two internal thread segments of the nut with opposite directions of rotation respectively meshing with the corresponding external thread segments of the two lead screws; the other two nuts mesh with the remaining thread segments of the lead screws. The motor causes the lead screw to rotate circumferentially relative to the housing and drives multiple nuts and lead screws to move axially.

10. The lead screw rapid transmission device according to any one of claims 1 to 9, characterized in that: It has two motors, one of which drives the lead screw to rotate and the other motor drives the nut to rotate.

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