Self-locking lead screw driving structure

Abstract

The utility model relates to a self-locking type lead screw driving structure which comprises an installation shell provided with a lead screw installation hole, a first gear connected with a lead screw and a second gear meshed with the first gear are arranged in the installation shell, the second gear is connected to a gear shaft with at least one end exposed out of the installation shell, and a driving hole is formed in the end face of the exposed end of the gear shaft. The second gear is connected with an elastic piece and movably connected with a locking block, a braking groove is formed in the inner surface of the mounting shell, the locking block is provided with a braking part and an unlocking part, the gear shaft is provided with a communicating space communicating the outer circumferential face of the gear shaft and the driving hole, and the unlocking part is arranged in the communicating space in a penetrating mode when the braking part is inserted into the braking groove for braking. The tripping piece is inserted into the driving hole to drive the unlocking part so that the braking part can be separated from the braking groove, and when the braking part is located outside the braking groove, the elastic piece is in an energy storage state. The lead screw has the advantage of being capable of being locked and is used for preventing an object driven by the lead screw from moving due to the fact that the object receives force in the extending direction of the lead screw.

Description

Technical Field

[0001] The utility model relates to a lifting component, in particular to a self-locking screw drive structure. Background Art

[0002] In order to adjust the height of tables and chairs, the support legs of the tables and chairs are designed as lifting structures. One of the design structures designs the support legs into two parts, a threaded sleeve is fixed on one part, and a rotatable screw (shaft) is hung on the other part. The screw is threadedly connected in the threaded sleeve, and the table board or the seat board of the chair is connected to the threaded sleeve. The screw is driven by a motor or manually rotated to rotate the screw, so that the screw sleeve is raised and lowered on the screw, thereby realizing the lifting and lowering of the table and chair. Corresponding to the motor drive method, the motor brake can be used to prevent the screw from rotating so that the position of the threaded sleeve is different, so that the table and chair are maintained at the current height. If the height is adjusted by manually driving the screw to rotate, a self-locking gear box needs to be designed after the height is adjusted to prevent the height of the table seat from being lowered due to the load. For this reason, it is necessary to make the screw drive mechanism have a locking function to prevent the threaded sleeve from moving due to the force along the extension direction of the screw. Utility Model Content

[0003] The utility model provides a self-locking screw drive structure that can be locked, which is used to prevent an object driven by the screw from moving due to a force received along the extending direction of the screw.

[0004] The above technical problems are solved by the following technical solutions: a self-locking screw drive structure, characterized in that it includes a mounting shell, the mounting shell is provided with a screw mounting hole, a first gear and a second gear meshing with the first gear are provided in the mounting shell, the first gear is used to connect with the screw inserted in the screw mounting hole to drive the screw to rotate, the second gear is connected to the gear shaft, the gear shaft is rotatably connected in the mounting shell and at least one end is exposed to the mounting shell, a driving hole is provided on the end face of the gear shaft, an elastic member and a locking block are movably connected to the second gear, the The inner surface of the mounting shell is provided with a plurality of brake grooves distributed along the circumference of the gear shaft, the locking block is provided with a brake part and an unlocking part, the elastic member is used to drive the brake part to be inserted into the brake groove to prevent the second gear from rotating, the gear shaft is provided with a connecting space connecting the outer circumference of the gear shaft and the driving hole, when the brake part is inserted into the brake groove for braking, the unlocking part is penetrated in the connecting space, the driving hole is provided for the release part to be inserted to drive the unlocking part so that the brake part is disengaged from the brake groove, and the elastic member is in an energy storage state when the brake part is located outside the brake groove. When the screw rod needs to be rotated, the release part is inserted into the driving hole and has an unlocking part, so that the brake part is disengaged from the brake groove, the gear shaft is rotated to drive the second gear to rotate, the second gear drives the first gear to rotate, and the first gear drives the screw rod to rotate, so that the screw rod drives the component threadedly connected to the screw rod to translate along the extension direction of the screw rod. After the release member is pulled out, when the second gear rotates to align the braking part with a prepared groove, the braking part is inserted into the prepared groove under the action of the elastic member, so that the second gear cannot rotate, and the screw rod is braked to prevent rotation. The elastic member can be a spring, a spring sheet, a rubber block, etc. The connecting space can be a connecting hole or a groove. The locking groove can be surrounded by a convex tooth and a convex block of the mounting shell.

[0005] Preferably, the unlocking portion is provided with a guide surface for contacting with the release member to guide the unlocking portion to shrink toward the communicating space, so that the release member can reliably drive the unlocking portion to make the braking portion escape from the braking groove.

[0006] Preferably, the driving hole passes through the gear shaft, both ends of the gear shaft are exposed from the mounting shell, and both ends of the unlocking portion along the axial direction of the gear shaft are provided with the guide surface, so that the release member can be unlocked by inserting it from either end of the driving hole, which improves the convenience of unlocking.

[0007] Preferably, one end of the guide surface is located outside the space surrounded by the wall surface of the driving hole. After the release member is inserted into the driving hole, it can contact the guide surface without alignment, which improves the convenience of use.

[0008] Preferably, the mounting shell comprises a box body with a gear mounting opening and a cover plate detachably connected to the box body to cover the gear mounting opening, the brake groove is arranged on the cover plate, and the cover plate is provided with an escape through hole for inserting the release member. The device is convenient to assemble and maintain.

[0009] Preferably, the end surface of one end of the housing provided with the gear installation opening is provided with a plurality of connection pits, and the cover plate is provided with connection ears which are correspondingly inserted into the connection pits, and the connection ears are connected to the connection pits by connection bolts. This makes it difficult for the connection between the cover plate and the housing to tear when a force is generated to rotate the second gear during the locking process, thereby improving the load capacity of the utility model after locking.

[0010] Preferably, the surface of the connecting ear connected to the box body extends beyond the inner surface of the cover plate toward the side where the box body is located, so as to further improve the load capacity after locking.

[0011] Preferably, the driving hole is a prism hole, the release piece is a prism with the same number of prisms as the driving hole, and the release piece can drive the gear shaft to rotate after being inserted into the driving hole. The rod body that can drive the gear shaft to rotate also serves as the release piece.

[0012] Preferably, the brake groove is provided with a first abutting surface and a second abutting surface, the first abutting surface and the second abutting surface are distributed along the circumference of the second gear, the second gear rotates with the first abutting surface at the rear and the second abutting surface at the front until the first abutting surface abuts against the brake part, the brake part can prevent the second gear from rotating, and the second gear rotates with the first abutting surface at the front and the second abutting surface at the rear until the second abutting surface abuts against the brake part, the second abutting surface drives the brake part to escape from the brake groove. One-way manufacturing is achieved.

[0013] Preferably, when the screw rod is in a state of extending up and down, the second gear is rotated in a manner that the first abutting surface is at the rear and the second abutting surface is at the front, and the second gear drives the screw rod to rotate in a direction that moves the component when the thread is connected to the screw rod, so that the component threadedly connected to the screw rod will not drive the screw rod to rotate and move downward when loaded.

[0014] The utility model has the following advantages: it is convenient to unlock, the release piece can be used as a rocker for driving the gear to rotate, and only one-way locking and braking can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the utility model after the installation shell is removed;

[0016] Figure 2 This is a schematic diagram of the utility model when connected with the screw rod;

[0017] Figure 3 is a schematic diagram of the cover;

[0018] Figure 4 It is a schematic diagram of the cover plate, the second gear and the gear shaft being connected together.

[0019] In the figure: mounting shell 1, box body 3, cover plate 4, avoidance through hole 5, connecting pit 6, connecting ear 7, surface 9 on the side where the connecting ear is connected to the box body, inner surface 10 of the cover plate, screw 11, first gear 13, second gear 14, gear shaft 15, drive hole 16, connecting space 17, elastic member 23, locking block 24, braking convex tooth 25, braking groove 26, base ring 27, unlocking portion 29, braking portion 30, guide surface 32, hook head 34, first abutting surface 35, second abutting surface 36, cylindrical head 37. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figures 1 to 4 A self-locking screw drive structure includes a mounting shell 1. The mounting shell includes a box body 3 with a gear mounting port and a cover plate 4 detachably connected to the box body to cover the gear mounting port. The cover plate is provided with an escape through hole 5 for inserting a release member. A plurality of connecting pits 6 are provided on the end surface of one end of the box body with the gear mounting port, and a connecting ear 7 is provided on the cover plate, which is correspondingly inserted into the connecting pit. The connecting ear is connected by a connecting bolt ( Figure 2 The connecting ear is connected to the housing (not shown) in the connecting pit. The surface 9 of the connecting ear on the side connected to the housing extends beyond the inner surface 10 of the cover plate toward the side where the housing is located. The mounting shell is provided with a screw mounting hole, and the screw 11 is supported in the screw mounting hole by a support bearing. A first gear 13 and a second gear 14 meshing with the first gear are provided in the mounting shell, and the first gear is used to connect with the screw inserted in the screw mounting hole to drive the screw to rotate. The second gear is connected to the gear shaft 15, and the gear shaft is rotatably connected in the mounting shell and at least one end is exposed to the mounting shell (in this embodiment, the gear shaft is exposed to the mounting shell at both ends). The avoidance through hole is aligned with the gear shaft. A drive hole 16 is provided on the end face of the gear shaft. The drive hole passes through the gear shaft. A connecting space 17 connecting the outer circumference of the gear shaft and the drive hole is provided on the gear shaft. In this embodiment, the connecting space is a hole structure. A groove 22 is provided on the inner circumference of the drive hole, and the groove passes through the end face of the second gear to form a connecting space 17.

[0022] The second gear is connected with an elastic member 23 and a locking block 24 that is movably connected. The elastic member is a spring sheet. One end of the elastic member is removably clamped on the end surface of the second bearing, and the other end is pressed on the side of the locking block away from the gear shaft. The inner surface of the mounting shell (specifically, the braking convex teeth are arranged on the cover plate) is provided with a plurality of braking convex teeth 25 distributed along the circumference of the gear shaft, and a braking groove 26 is formed between adjacent braking convex teeth. Specifically: a base ring 27 is arranged on the inner surface of the cover plate, and the braking convex teeth are connected to the outer circumference of the base ring. A cylindrical head 37 is arranged at one end of the locking block and is rotatably connected to a circular hole with an opening on the end surface of the second gear to achieve a movable connection with the second gear. An unlocking portion 29 is arranged at the other end of the locking block. A braking portion 30 is arranged between the cylindrical head and the unlocking portion. The elastic member is used to drive the braking portion to be inserted into the braking groove to prevent the second gear from rotating. When the braking portion is inserted into the braking groove for braking, the unlocking portion is arranged in the connecting space and protrudes from the driving hole. The driving hole is a prismatic hole (specifically, a regular hexagonal prism hole), and the release piece is a prism with the same number of prisms as the driving hole. After the release piece is inserted into the driving hole and rotated, it can drive the gear shaft to rotate. The driving hole is for the release piece to be inserted to drive the unlocking part so that the braking part is released from the braking groove. In this embodiment, the release piece also constitutes a release piece. When the braking part is located outside the braking groove, the elastic part is in an energy storage state. The unlocking part is provided with a guide surface 32 for contacting the release piece and guiding the unlocking part to shrink toward the connecting space. Guide surfaces 32 are provided at both ends of the unlocking part along the axial direction of the gear shaft. One end of the guide surface is located outside the space surrounded by the wall surface of the driving hole, specifically in the groove. A hook head 34 is provided at one end of the brake block located in the connecting space, and the hook head is penetrated into the part of the groove located on the second gear. The brake groove is provided with a first abutting surface 35 and a second abutting surface 36, and the first abutting surface and the second abutting surface are distributed along the circumference of the second gear. When the second gear rotates with the first abutting surface at the rear and the second abutting surface at the front until the first abutting surface abuts against the brake part, the brake part can prevent the second gear from rotating. When the second gear rotates with the first abutting surface at the front and the second abutting surface at the rear until the second abutting surface abuts against the brake part, the second abutting surface drives the brake part to escape from the brake groove. When the screw rod is in a state of extending up and down, the second gear is rotated with the first abutting surface at the rear and the second abutting surface at the front, and the direction in which the second gear drives the screw rod to rotate is such that the component when the thread is connected to the screw rod moves in the direction.

[0023] When the screw rod needs to be rotated, the release piece is inserted into the driving hole and has an unlocking part, so that the braking part is disengaged from the braking groove, the release piece is rotated to rotate the gear shaft to drive the second gear to rotate, the second gear drives the first gear to rotate, and the first gear drives the screw rod to rotate, so that the screw rod drives the component threadedly connected to the screw rod to translate along the extension direction of the screw rod. After the release piece is pulled out, when the second gear rotates to align the braking part with a prepared groove, the braking part is inserted into the prepared groove under the action of the elastic member, so that the second gear cannot rotate, which plays a role in braking the screw rod and preventing it from rotating.

[0024] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A self-locking screw drive structure, characterized in that: The invention comprises a mounting shell, wherein the mounting shell is provided with a screw mounting hole, wherein a first gear and a second gear meshing with the first gear are provided in the mounting shell, wherein the first gear is used to be connected with a screw rod passing through the screw mounting hole to drive the screw rod to rotate, wherein the second gear is connected to a gear shaft, wherein the gear shaft is rotatably connected in the mounting shell and at least one end is exposed from the mounting shell, wherein a driving hole is provided on the end surface of the gear shaft, wherein an elastic member and a locking block are movably connected to the second gear, wherein a plurality of braking grooves distributed along the circumference of the gear shaft are provided on the inner surface of the mounting shell, wherein the locking block is provided with a braking part and an unlocking part, wherein the elastic member is used to drive the braking part to be inserted into the braking groove so as to prevent the second gear from rotating, wherein a connecting space connecting the outer circumferential surface of the gear shaft and the driving hole is provided on the gear shaft, wherein the unlocking part is provided in the connecting space when the braking part is inserted into the braking groove for braking, wherein the driving hole is provided for the insertion of a release member to drive the unlocking part so as to make the braking part disengage from the braking groove, and wherein the elastic member is in an energy storage state when the braking part is located outside the braking groove.

2. A self-locking screw drive structure according to claim 1, characterized in that: The unlocking portion is provided with a guide surface for contacting with the release member to guide the unlocking portion to shrink toward the communicating space.

3. A self-locking screw drive structure according to claim 2, characterized in that: The driving hole passes through the gear shaft, both ends of the gear shaft are exposed from the mounting shell, and both ends of the unlocking portion along the axial direction of the gear shaft are provided with the guide surfaces.

4. A self-locking screw drive structure according to claim 2 or 3, characterized in that: One end of the guide surface is located outside the space surrounded by the wall surface of the driving hole.

5. A self-locking screw drive structure according to claim 1, 2 or 3, characterized in that: The mounting shell comprises a box body with a gear mounting opening and a cover plate detachably connected to the box body to cover the gear mounting opening, the brake groove is arranged on the cover plate, and the cover plate is provided with an avoidance through hole for inserting a release member.

6. A self-locking screw drive structure according to claim 5, characterized in that: The end surface of one end of the box body provided with the gear installation opening is provided with a plurality of connection pits, and the cover plate is provided with connection ears which are correspondingly inserted into the connection pits, and the connection ears are connected to the connection pits through connection bolts.

7. A self-locking screw drive structure according to claim 6, characterized in that: The surface of the connecting ear at the side connected to the box body extends beyond the inner surface of the cover plate toward the side where the box body is located.

8. A self-locking screw drive structure according to claim 1, 2 or 3, characterized in that: The driving hole is a prismatic hole, and the release member is a prismatic shape with the same number of prisms as the driving hole. After the release member is inserted into the driving hole and rotated, it can drive the gear shaft to rotate.

9. A self-locking screw drive structure according to claim 1, 2 or 3, characterized in that: The braking groove is provided with a first abutting surface and a second abutting surface, and the first abutting surface and the second abutting surface are distributed along the circumference of the second gear. When the second gear rotates with the first abutting surface at the back and the second abutting surface at the front until the first abutting surface abuts against the braking part, the braking part can prevent the second gear from rotating. When the second gear rotates with the first abutting surface at the front and the second abutting surface at the back until the second abutting surface abuts against the braking part, the second abutting surface drives the braking part to escape from the braking groove.

10. A self-locking screw drive structure according to claim 9, characterized in that: When the screw rod is in a state of extending up and down, the second gear is rotated with the first abutment surface at the rear and the second abutment surface at the front. The second gear drives the screw rod to rotate in a direction that moves the component when the thread is connected to the screw rod.

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