Small-sized light-weight high-precision locking and positioning device

Abstract

The invention discloses a small light high-precision locking and positioning device which comprises a locking base, a motor, a fixed fluted disc, a worm gear, a worm, a linear needle bearing, a movable fluted disc and an identification component. The locking base is mounted on a box body of the inertial measurement unit, and the fixed fluted disc is mounted on a rotating frame of the inertial measurement unit; hollow guide devices are symmetrically arranged in the locking base, the linear needle bearing is installed in the guide devices, and the supporting structure of the movable fluted disc is inserted into the linear needle bearing. A needle roller of the linear needle roller bearing is in interference fit with the guide device and the movable fluted disc, and the movable fluted disc can only move in the axial direction of the fluted disc; the motor drives the worm to drive the worm gear to rotate, and under the action of the linear needle bearing, the trapezoidal thread on the worm gear drives the movable fluted disc to linearly move along the axis of the fluted disc to get close to or get away from the fixed fluted disc; the position of the movable fluted disc is recognized through the recognition component, whether the movable fluted disc reaches the locking or unlocking position between the movable fluted disc and the fixed fluted disc or not is judged, and switching between the self-calibration and self-alignment function and the strapdown function is completed.

Description

Technical Field

[0001] This invention relates to the field of locking and positioning device design, and in particular to a small, lightweight, and high-precision locking and positioning device. Background Technology

[0002] Strapdown inertial navigation systems (INS) consist of gyroscopes, accelerometers, and circuitry directly mounted on the carrier, without a rotating frame structure. In contrast, strapdown INS systems add a rotating frame and a locking and positioning device. The rotation of the rotating frame enables self-calibration and self-alignment, while the locking and positioning device switches between the rotation of the indexing mechanism and the strapdown function (rotation mechanism locked). During self-calibration and self-alignment, the locking and positioning device executes an unlocking command to separate the moving and stationary gear disks, allowing the indexing mechanism to rotate freely. When switching to strapdown function, the locking and positioning device executes a locking command to engage the moving and stationary gear disks, precisely locking the indexing mechanism and preventing rotation. With the increasing demand for high-precision aircraft, the requirements for INS size, weight, and accuracy are becoming increasingly stringent. Traditional locking and positioning devices cannot meet these requirements due to their size, weight, and accuracy limitations. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a small, lightweight, high-precision locking and positioning device: solving the problem of excessive size and weight of the locking and positioning device.

[0004] The technical solution of the present invention is to provide a small, lightweight, high-precision locking and positioning device, comprising: a locking base, a motor, a fixed gear plate, a worm gear, a worm, a linear needle roller bearing, a movable gear plate, and an identification component;

[0005] The locking base is installed on the inertial navigation system's housing, and the fixed gear plate is installed on the rotating frame of the inertial navigation system;

[0006] The locking base is symmetrically equipped with hollow guide devices. The linear needle roller bearing is installed in the guide device. The support structure of the moving gear plate is inserted into the linear needle roller bearing. The needle rollers of the linear needle roller bearing are interference-fitted with the guide device and the moving gear plate, so that the moving gear plate can only move along the gear plate axis.

[0007] The motor drives the worm gear to rotate. Under the action of the linear needle roller bearing, the worm gear drives the moving gear plate to move linearly along the gear plate axis, approaching or moving away from the fixed gear plate. The identification component identifies the position of the moving gear plate and determines whether it has reached the locking or unlocking position with the fixed gear plate, thus completing the locking or unlocking of the moving and fixed gear plates, thereby realizing the switching between the inertial navigation system's self-calibration and self-alignment function and the strapdown function.

[0008] Furthermore, two hollow guide devices are symmetrically arranged inside the locking base, and each guide device has four linear needle roller bearings installed in a ring-shaped combination inside the guide device.

[0009] Furthermore, the worm wheel has a trapezoidal thread, and the helix angle between the worm and the worm wheel is smaller than the equivalent friction angle between the tooth surfaces.

[0010] Furthermore, the interference fit between the needle rollers of the linear needle roller bearing and the guide device and the moving gear plate is 0.007 to 0.008 mm.

[0011] Furthermore, the identification component uses two photoelectric switches, each equipped with a first trigger plate and a second trigger plate, to determine whether the moving gear plate has reached the locking or unlocking position between itself and the fixed gear plate.

[0012] Furthermore, the base is made of titanium alloy.

[0013] Furthermore, the motor is a coreless motor.

[0014] Furthermore, the locking base is also equipped with a linear needle roller bearing limiter to prevent the linear needle roller bearing from coming off under random vibration.

[0015] This invention also relates to a method for switching between inertial navigation system self-calibration and self-alignment functions and strapdown functionality, utilizing the aforementioned small, lightweight, high-precision locking and positioning device, comprising:

[0016] Switch to strapdown function:

[0017] Sending a locking command, the motor drives the worm gear to rotate the worm wheel. Under the interference fit of the needle rollers of the linear needle roller bearing, the guide device, and the moving toothed disc, the worm wheel drives the moving toothed disc to make a linear axial movement towards the fixed toothed disc.

[0018] The identification component continuously identifies the position of the moving gear plate. When the motor current stalls and the identification component detects that the moving gear plate has reached the locking position, the motor stops driving and the locking command is completed. The moving gear plate and the fixed gear plate are fully engaged. Under the self-locking action of the worm and worm wheel, the axial movement of the moving gear plate is restricted.

[0019] Switch to self-calibration and self-alignment function:

[0020] Sending an unlock command causes the motor to drive the worm gear to rotate. Under the interference fit of the needle rollers of the linear needle roller bearing, the guide device, and the moving gear plate, the worm gear drives the moving gear plate to make a linear axial movement away from the fixed gear plate.

[0021] The identification component continuously identifies the position of the moving gear plate. When the motor current stalls and the component identifies that the moving gear plate has reached the unlock position, the motor stops driving and the unlocking command is completed; the moving gear plate and the fixed gear plate are completely separated, and the fixed gear plate is in a free state.

[0022] The advantages of this invention compared to the prior art are:

[0023] (1) The positioning function component of the present invention adopts a linear needle roller bearing. The line contact fit of the needle roller is more reliable and has a longer service life than the point contact fit of the traditional ball bearing solution. The interference fit between the needle roller of the linear needle roller bearing and the titanium alloy locking base and the moving gear plate is increased to 0.007-0.008mm, and the locking repeatability is improved from 10 arcseconds to 3 arcseconds.

[0024] (2) The present invention has a power-off self-locking function through the design parameters of the worm gear;

[0025] (3) The position switch of the present invention adopts a photoelectric switch scheme, which has the advantages of non-contact detection, high-precision identification and long life compared with the traditional mechanical switch scheme; the locking position of the moving tooth disk adopts a two-photoelectric switch identification scheme. By combining the positions of the two photoelectric switches, the position of the moving tooth disk can be accurately identified, and the success rate of unlocking or retracting state identification is 100%, avoiding the logic error caused by a single photoelectric switch.

[0026] (4) This invention meets the requirements of a wide temperature range operating environment. The entire structure uses aerospace-grade grease and can be used in an environment of -50℃ to 100℃.

[0027] (5) The present invention optimizes the structural space layout, reducing the volume from 142mm*125mm*50mm of the traditional device to 105mm*82mm*28.5mm; the weight is reduced from 1.5kg to 0.5kg by using lightweight materials;

[0028] (6) The linear needle roller bearing limiting structure of the present invention can prevent the linear needle roller bearing from accidentally coming out under harsh mechanical conditions and can resist random vibrations of up to 55g. Attached Figure Description

[0029] Figure 1 This is a structural diagram of the locking and positioning device of the present invention;

[0030] Figure 2 This is a diagram showing the unlocking and locking states of the locking and positioning device of the present invention;

[0031] Figure 3 This is a structural diagram showing the fit between the linear needle roller bearing, guide rail, and moving gear plate of the present invention.

[0032] Figure 4 This is a schematic diagram of the installation of the locking and positioning device of the present invention. Detailed Implementation

[0033] To better understand the technical solution of the present invention, specific embodiments of the present invention are described below. The various structural parts in the accompanying drawings will be described separately. Elements not shown in the drawings or not described in words are in forms known to those skilled in the art. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination. The present invention is not particularly limited to the preferred embodiments.

[0034] Small, lightweight, high-precision locking and positioning device, reference Figure 1 As shown, it consists of a locking base 1, a hollow cup motor 2, a fixed gear plate 3, a worm gear 4, a worm 5, a linear needle roller bearing 6, a moving gear plate 7, a bearing 8, a photoelectric switch 9, a first trigger plate 10, a second trigger plate 11, and a linear needle roller bearing limiter 12. (Refer to...) Figure 4 As shown, the fixed gear plate 3 is mounted on the inertial navigation system rotating frame 14, and the locking base 1 is mounted on the inertial navigation system housing 15.

[0035] The main body of the locking and positioning device is a titanium alloy locking base 1. The hollow cup motor 2, worm gear 4, worm 5, linear needle roller bearing 6, moving gear plate 7, bearing 8, photoelectric switch 9, first trigger plate 10, second trigger plate 11, and linear needle roller bearing limit 12 are all installed on the titanium alloy locking base 1.

[0036] like Figure 3 As shown, two guide rails 13 are mounted on the locking base 1, and eight linear needle roller bearings 6 are mounted on the two guide rails 13 in a two-ring combination. The needle rollers of the linear needle roller bearings 6 are interference-fitted with the guide rails 13 and the moving gear plate 7, and the moving gear 7 can only move along the axial direction of the gear plate.

[0037] The hollow cup motor 2 drives the worm gear 5. Supported by two angular contact bearings 8, the worm gear 5 drives the worm wheel 4 to rotate. Under the interference fit of the linear needle roller bearing, the trapezoidal thread on the worm wheel 4 drives the moving gear disk 7 to make precise linear motion along the axis of the gear disk. The position of the moving gear disk 7 is determined by two photoelectric switches 9 and the first trigger plate 10 and the second trigger plate 11, completing the engagement or disengagement with the fixed gear disk 3, realizing the unlocking or locking command, thereby completing the switching of the indexing mechanism rotation and the strapdown function. The helix angle of the worm gear 5 and the worm wheel 4 is 2°52', which is less than the equivalent friction angle between the tooth surfaces of 3°, and has a power-off self-locking function. The linear needle roller bearing limit 12 can prevent the linear needle roller bearing 6 from dislodging under large-scale random vibration.

[0038] Reference Figure 2 As shown, the moving gear disk 7 and the fixed gear disk 3 are engaged and locked or unlocked. The movement position of the moving gear disk is accurately identified by a combination of two photoelectric switches 9.

[0039] Locking function implementation: After sending the locking command, the hollow cup motor 2 drives the worm gear 5 to rotate the worm wheel 4. Under the interference fit between the linear needle roller bearing 6, the locking base 1, and the moving gear 7, the worm wheel 4 drives the moving gear 7 to make high-precision linear axial movement of the gear 7 in the direction close to the fixed gear 3 through the trapezoidal thread. During the process, the photoelectric switch 9 continuously identifies the position of the moving gear 7. When the current stall is detected and the photoelectric switch 9 identifies that the moving gear 7 has reached the locking position, the hollow cup motor 2 stops driving and determines that the locking command is completed. At this time, the moving gear 7 and the fixed gear 3 are fully engaged. Under the self-locking function of the worm gear 5 and the worm wheel 4, the axial movement of the moving gear 7 is restricted, and the fixed gear 3, which is fully engaged with the moving gear 7, is fully positioned, so that the inertial navigation system rotation frame 14 with the fixed gear 3 installed is fastened to the inertial navigation system housing 15, realizing the strapdown function.

[0040] Unlocking Function Implementation: After sending the unlocking command, the hollow cup motor 2 drives the worm gear 5 to rotate the worm wheel 4. Under the interference fit of the linear needle roller bearing 6, the titanium alloy locking base 1, and the moving gear plate 7, the worm wheel 4 drives the moving gear plate 7 to perform a high-precision linear motion along the gear plate axial direction away from the fixed gear plate 3 through the trapezoidal thread. During this process, the photoelectric switch 9 continuously identifies the position of the moving gear plate 7. When current stall is detected and the photoelectric switch 9 identifies that the moving gear plate 7 has reached the unlocking position, the hollow cup motor 2 stops driving, and the unlocking command is determined to be complete. At this time, the moving gear plate 7 and the fixed gear plate 3 are completely separated, the fixed gear plate 3 is in a free state, and the inertial navigation system rotation frame 14 can rotate freely to achieve self-calibration and self-alignment functions.

[0041] It is understood that this invention has been described through embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific circumstances without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention.

[0042] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A small, lightweight, high-precision locking and positioning device, characterized in that: include: Locking base (1), motor, fixed gear plate (3), worm gear (4), worm (5), linear needle roller bearing (6), moving gear plate (7), identification component; The locking base (1) is installed on the inertial group housing, and the fixed gear plate (3) is installed on the rotating frame of the inertial group; Hollow guide devices are symmetrically provided inside the locking base (1). The linear needle roller bearing (6) is installed inside the guide device. The support structure of the moving gear plate (7) is inserted into the linear needle roller bearing (6). The needle rollers of the linear needle roller bearing (6) are interference-fitted with the guide device and the moving gear plate (7), so that the moving gear plate (7) can only move along the gear plate axis. The motor drives the worm gear (5) to rotate the worm wheel (4). Under the action of the linear needle roller bearing (6), the worm wheel (4) drives the moving gear plate (7) to move linearly along the gear plate axis, approaching or moving away from the fixed gear plate (3). The identification component identifies the position of the moving gear plate (7) and determines whether it has reached the locking or unlocking position with the fixed gear plate (3), thus completing the locking or unlocking of the moving and fixed gear plates, thereby realizing the switching between the inertial navigation system self-calibration and self-alignment function and the strapdown function.

2. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: Two hollow guide devices are symmetrically arranged inside the locking base (1). Each guide device has four linear needle roller bearings (6) installed in a ring combination inside the guide device.

3. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: The worm wheel (4) has a trapezoidal thread, and the helix angle between the worm (5) and the worm wheel (4) is smaller than the equivalent friction angle between the tooth surfaces.

4. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: The interference fit between the needle rollers of the linear needle roller bearing (6) and the guide device and the moving gear plate (7) is 0.007 to 0.008 mm.

5. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: The identification component uses two photoelectric switches (9), each equipped with a first trigger plate (10) and a second trigger plate (11), to determine whether the moving gear plate (7) has reached the locking or unlocking position between itself and the fixed gear plate (3).

6. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: The base is made of titanium alloy.

7. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: The motor is a coreless motor (2).

8. The small, lightweight, high-precision locking and positioning device according to claim 1, characterized in that: The locking base (1) is also provided with a linear needle roller bearing limiter (12) to prevent the linear needle roller bearing (6) from coming off under random vibration.

9. A method for switching between inertial navigation system self-calibration and self-alignment functions and strapdown function, characterized in that: The small, lightweight, high-precision locking and positioning device as described in claim 1 includes: Switch to strapdown function: Sending a locking command, the motor drives the worm (5) to rotate the worm wheel (4). Under the interference fit between the needle rollers of the linear needle roller bearing (6) and the guide device and the moving gear plate (7), the worm wheel (4) drives the moving gear plate (7) to make a linear motion along the gear plate axis towards the fixed gear plate (3). The identification component continuously identifies the position of the moving gear disk (7). When the motor current stalls and the identification component identifies that the moving gear disk (7) has reached the locking position, the motor stops driving and the locking command is completed. The moving gear disk (7) is fully engaged with the fixed gear disk (3). Under the self-locking action of the worm (5) and the worm wheel (4), the axial movement of the moving gear disk (7) is restricted. Switch to self-calibration and self-alignment function: Sending an unlock command, the motor drives the worm (5) to rotate the worm wheel (4). Under the interference fit between the needle rollers of the linear needle roller bearing (6) and the guide device and the moving gear plate (7), the worm wheel (4) drives the moving gear plate (7) to make a linear motion along the gear plate axis away from the fixed gear plate (3). The identification component continuously identifies the position of the moving gear disk (7). When the motor current stalls and the component identifies that the moving gear disk (7) has reached the unlock position, the motor stops driving and the unlocking command is completed. The moving gear disk (7) and the fixed gear disk (3) are completely separated, and the fixed gear disk (3) is in a free state.

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