Linear push rod

Abstract

The utility model provides a linear push rod, which belongs to the technical field of linear driving elements, and comprises an outer pipe, a main screw rod, an inner pipe and an outer pipe, the speed reducing mechanism comprises a gear box shell, an inner gear ring, a first-stage planetary plate and a second-stage planetary plate, the gear box shell is connected with the end of the outer pipe, and the inner gear ring is fixedly arranged in the gear box shell; the first-stage planetary plate is rotatably installed in the gearbox shell, and all the first planetary gears are engaged with the inner gear ring. The second-stage planetary plate is rotatably installed in the gearbox shell, all the second planetary gears are engaged with the inner gear ring, and the second-stage planetary plate is connected with the main lead screw and can drive the main lead screw to rotate; a rotating shaft of the motor is connected with an input gear; the input gear is meshed with each first planetary gear; the linear push rod has the advantages that the linear push rod is larger in torque and higher in self-locking performance, and the linear push rod can be suitable for intelligent office equipment such as an electric lifting table and an electric lifting platform.

Description

Technical Field

[0001] The utility model belongs to the technical field of linear drive elements and relates to a linear push rod. Background Art

[0002] Lift table legs are widely used in smart office equipment such as electric lift tables and electric lift platforms, as well as in medical equipment and other fields. The structure of existing lift table legs generally includes a driving mechanism and at least two mutually nested vertical tubes that can move and retract relative to each other. Currently, linear push rods are generally used as driving mechanisms. Since the lift table legs have high requirements for torque and self-locking, if the linear push rod cannot achieve the set torque and self-locking performance within a limited space volume, it will seriously affect the performance of the product. Utility Model Content

[0003] The utility model aims to solve the above problems in the prior art and proposes a linear push rod.

[0004] The purpose of the utility model can be achieved through the following technical solutions: a linear push rod, comprising:

[0005] A telescopic tube mechanism, the telescopic tube mechanism comprising an outer tube and a main screw rod, the main screw rod being rotatably installed in the outer tube;

[0006] A speed reduction mechanism, the speed reduction mechanism comprising a gear box housing, an inner gear ring, a first-stage planetary disk and a second-stage planetary disk, the gear box housing is connected to the end of the outer tube, and the inner gear ring is fixedly arranged in the gear box housing;

[0007] The first-stage planetary disk is rotatably mounted in the gearbox housing, and the first-stage planetary disk is provided with at least two first planetary gears arranged around the rotation center of the first-stage planetary disk and rotatable around their own rotation axes, each of the first planetary gears is meshed with the inner gear ring, and a transmission gear is provided at the rotation center of the first-stage planetary disk;

[0008] The second-stage planetary disk is rotatably mounted in the gearbox housing, and the second-stage planetary disk is provided with at least two second planetary gears arranged around the rotation center of the second-stage planetary disk and rotatable around their own rotation axes, and each of the second planetary gears is meshed with the inner gear ring, and the second-stage planetary disk is connected to the main screw and can drive the main screw to rotate;

[0009] A motor is connected to the gear box housing, a rotating shaft of the motor is connected to an input gear, and the input gear is meshed with each of the first planetary gears.

[0010] Preferably, the first-stage planetary disk and the second-stage planetary disk are stacked along the axial direction of the motor shaft.

[0011] Preferably, a connecting seat is provided at the end of the main screw rod, a first contact block is provided on the end face of the connecting seat, two second contact blocks are provided on an end face of the second-stage planetary disk facing the connecting seat, the first contact block is located between the two second contact blocks, and the second-stage planetary disk can be rotated relative to the connecting seat to a linkage position where the first contact block is in contact with any of the second contact blocks.

[0012] Preferably, the bottom of the gear box housing is connected to the motor by screws.

[0013] Preferably, one of the outer wall of the inner gear ring and the inner wall of the gear box housing is provided with a slot and the other is provided with an insert block, and when the inner gear ring is inserted into the gear box housing, the insert block is inserted into the slot to keep the inner gear ring and the gear box housing circumferentially locked.

[0014] Preferably, one of the port of the outer tube and the port of the gear box housing is provided with an internal thread and the other is provided with an external thread, and the outer tube and the gear box housing are detachably connected via the internal thread and the external thread.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. Provides a linear actuator with greater torque and stronger self-locking performance, which can be used in intelligent office equipment such as electric lifting tables and electric lifting platforms.

[0017] 2. The two-stage planetary disks are not placed in parallel, but are stacked one on top of the other along the extension direction of the motor shaft. This design helps to increase the number of transmission stages within a limited space while reducing the longitudinal size of the entire device, which is conducive to achieving a more compact structural layout.

[0018] 3. When the inner gear ring is inserted into the gearbox housing, the insert block can be inserted into the slot accurately, thereby achieving circumferential locking between the two. The matching mode of the slot and the insert block can greatly simplify the assembly process. When the assembler inserts the inner gear ring into the gearbox housing, the circumferential locking can be completed. If the inner gear ring or related parts need to be repaired or replaced, this simple plug-in design can also facilitate disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a partial structural schematic diagram of the linear push rod of the utility model.

[0020] Figure 2 It is an axonometric view of the linear push rod of the utility model.

[0021] Figure 3It is a structural exploded view of the speed reduction mechanism of the utility model.

[0022] Figure 4 This is a structural exploded view of the speed reduction mechanism of the utility model from another perspective.

[0023] Figure 5A This is a schematic structural diagram of the first-stage planetary disk of the utility model.

[0024] Figure 5B It is a structural schematic diagram of the second-stage planetary disk of the utility model.

[0025] In the figure, 100, outer tube; 110, internal thread; 200, main screw; 210, connecting seat; 220, first contact block; 300, gear box housing; 310, plug block; 320, external thread; 400, inner ring gear; 410, slot; 500, first-stage planetary disk; 510, first planetary gear; 520, transmission gear; 530, input gear; 600, second-stage planetary disk; 610, second planetary gear; 620, second contact block; 700, motor. DETAILED DESCRIPTION

[0026] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0027] like Figure 1-5B As shown, a linear push rod comprises: a telescopic tube mechanism, the telescopic tube mechanism comprises an outer tube 100 and a main screw 200, and the main screw 200 is rotatably installed in the outer tube 100; a reduction mechanism, the reduction mechanism comprises a gear box housing 300, an inner gear ring 400, a first-stage planetary disk 500 and a second-stage planetary disk 600, the gear box housing 300 is connected to the end of the outer tube 100, and the inner gear ring 400 is fixedly arranged in the gear box housing 300; the first-stage planetary disk 500 is rotatably installed in the gear box housing 300, and the first-stage planetary disk 500 is provided with at least two first planetary gears 510 arranged around the rotation center of the first-stage planetary disk 500 and rotatable around its own rotation axis, and each first planetary gear 510 is arranged around the rotation center of the first-stage planetary disk 500 and can rotate around its own rotation axis. The wheels 510 are all meshed with the inner gear ring 400, and a transmission gear 520 is provided at the rotation center of the first-stage planetary disk 500; the second-stage planetary disk 600 is rotatably installed in the gear box housing 300, and the second-stage planetary disk 600 is provided with at least two second planetary gears 610 arranged around the rotation center of the second-stage planetary disk 600 and rotatable around its own rotation axis, and each second planetary gear 610 is meshed with the inner gear ring 400, and the second-stage planetary disk 600 is connected to the main screw 200 and can drive the main screw 200 to rotate; the motor 700, the motor 700 is connected to the gear box housing 300, and the rotation shaft of the motor 700 is connected with an input gear 530, and the input gear 530 is meshed with each first planetary gear 510.

[0028] This linear actuator is mainly used to provide a larger torque output and enhance the self-locking performance. It is particularly suitable for applications with high requirements for torque and self-locking capabilities, such as electric lifting tables, electric lifting platforms and other intelligent office equipment and lifting table leg drives in medical equipment.

[0029] Among them, the telescopic tube mechanism realizes the basic telescopic function. The complete telescopic tube mechanism also includes an inner tube, a hollow screw rod and a nut seat. The telescopic tube mechanism is basically the same as the screw telescopic structure of the existing lifting table legs, which will not be repeated here. In short, the motor 700 drives the main screw rod 200 to rotate forward and reverse through the reduction mechanism to realize the extension and retraction of the telescopic tube mechanism.

[0030] The speed reduction mechanism is composed of a gearbox housing 300, an inner gear ring 400, a first-stage planetary disc 500 and a second-stage planetary disc 600. The first-stage planetary disc 500 and the second-stage planetary disc 600 are respectively equipped with a plurality of planetary gears, which are arranged around the rotation center of each planetary disc and can rotate freely around their own axis. The movement logic of the speed reduction mechanism is: when the motor 700 shaft rotates, it can drive each first planetary gear 510 to rotate through the input gear 530. Since the first planetary gear 510 is meshed with the inner gear ring 400, it can drive the first-stage planetary disc 500 to rotate. A transmission gear 520 is provided at the center of the first-stage planetary disc 500. When the first-stage planetary disc 500 rotates, it can drive each second planetary gear 610 to rotate through the transmission gear 520. Since the second planetary gear 610 is meshed with the inner gear ring 400, it can drive the second-stage planetary disc 600 to rotate. The second-stage planetary disc 600 is directly connected to the main screw 200 and drives the main screw 200 to rotate through its own rotation. The power of the motor 700 is amplified step by step through a two-stage planetary gear reduction system, and is ultimately efficiently and stably converted into a high-torque rotation of the main screw 200. At the same time, the two-stage planetary gear reduction system has extremely strong self-locking performance.

[0031] This linear actuator achieves high torque output, good self-locking performance and compact structural layout through a carefully designed multi-stage planetary reduction structure and a sophisticated mechanical linkage device, greatly improving the reliability and flexibility of use in smart office and medical equipment.

[0032] On the basis of the above-mentioned embodiment, the first-stage planetary disk 500 and the second-stage planetary disk 600 are stacked along the axial direction of the rotating shaft of the motor 700 .

[0033] The two-stage planetary disks are not placed in parallel, but are stacked one on top of the other along the extension direction of the rotating shaft of the motor 700. Such a design helps to increase the number of transmission stages within a limited space while reducing the longitudinal size of the entire device, which is conducive to achieving a more compact structural layout. Through this stacking method, the rotational power of the motor 700 is first transmitted to the first-stage planetary disk 500 through the input gear 530, and then the torque is transmitted to the second-stage planetary disk 600 after the planetary gear system of the first-stage planetary disk 500 speeds up or slows down. The second-stage planetary disk 600 also uses its own planetary gear structure to amplify the torque again, and finally acts on the main screw 200, causing it to rotate, thereby driving the telescopic tube mechanism to complete the telescopic movement.

[0034] like Figure 1 , Figure 3-4 As shown, on the basis of the above embodiment, a connecting seat 210 is provided at the end of the main screw rod 200, and a first contact block 220 is provided on the end face of the connecting seat 210, and two second contact blocks 620 are provided on an end face of the second-stage planetary disk 600 facing the connecting seat 210, and the first contact block 220 is located between the two second contact blocks 620, and the second-stage planetary disk 600 can be rotated relative to the connecting seat 210 to a linkage position where the first contact block 220 is in contact with any second contact block 620.

[0035] The head of the main screw 200 is provided with a connecting seat 210, and the end face of the connecting seat 210 is provided with three first contact blocks 220, and there is a gap between two adjacent first contact blocks 220, and the end face of the second-stage planetary disk 600 is also provided with three second contact blocks 620, and the three second contact blocks 620 are respectively arranged in the three gaps.

[0036] In one embodiment, the size of the gap is adapted to the size of the second contact block 620, and the second-stage planetary disk 600 is always in a linkage position, that is, the second contact block 620 is respectively connected to the two first contact blocks 220 on both sides, so the second-stage planetary disk 600 can transmit torque to the connecting seat 210.

[0037] In another embodiment, the gap is larger than the second contact block 620. Although the second contact block 620 is inserted into the gap, it can only be connected with the first contact block 220 to transmit torque when the second-stage planetary disk 600 is in the linkage position.

[0038] like Figure 1-5B As shown, based on the above embodiment, the bottom of the gearbox housing 300 is connected to the motor 700 by screws. The gearbox housing 300 and the motor 700 are fixed together by screw connection, which simplifies the assembly process of the linear actuator and can be easily disassembled and reinstalled.

[0039] On the basis of the above-mentioned embodiment, one of the outer wall of the inner ring gear 400 and the inner wall of the gear box housing 300 is provided with a slot 410 and the other is provided with an insert block 310. When the inner ring gear 400 is inserted into the gear box housing 300, the insert block 310 is inserted into the slot 410 to keep the inner ring gear 400 circumferentially locked with the gear box housing 300.

[0040] In order to ensure that the inner gear ring 400 does not rotate in the gearbox housing 300, a slot 410 is specially provided on one side (the outer wall of the inner gear ring 400 or the inner wall of the gearbox housing 300), and a matching plug block 310 is provided on the other side. When the inner gear ring 400 is inserted into the gearbox housing 300, the plug block 310 can be accurately inserted into the slot 410, thereby achieving circumferential locking between the two. The matching mode of the slot 410 and the plug block 310 can greatly simplify the assembly process. When the assembler inserts the inner gear ring 400 into the gearbox housing 300, the circumferential locking can be completed. If the inner gear ring 400 or related components need to be repaired or replaced, this simple plug-in design can also facilitate disassembly.

[0041] Based on the above embodiment, one of the ports of the outer tube 100 and the gearbox housing 300 is provided with an internal thread 110 and the other is provided with an external thread 320 , and the outer tube 100 and the gearbox housing 300 are detachably connected via the internal thread 110 and the external thread 320 .

[0042] Designing the reduction mechanism into the above structure can achieve the advantage of easy assembly. During the specific assembly, the gearbox housing 300 and the motor 700 are first fixedly connected by screws, and the motor 700 shaft is inserted into the gearbox housing 300 to mesh with the input gear 530. Then, the inner ring gear 400 is installed in the gearbox housing 300. Before insertion, ensure that the slot 410 is aligned with the plug block 310. After the inner ring gear 400 is inserted into the gearbox housing 300, the slot 410 and the plug block 310 are used to achieve circumferential locking to ensure that the inner ring gear 400 does not rotate during operation. Then, the first-stage planetary disk 500 with the first planetary gear 510 installed is installed into the inner ring gear 400. , ensuring that the input gear 530 is meshed with the first planetary gear 510 to form a power transmission path, then the second-stage planetary disc 600 equipped with the second planetary gear 610 is installed in the inner gear ring 400, and the first-stage planetary disc 500 and the second-stage planetary disc 600 are stacked along the axial direction of the rotating shaft of the motor 700 to ensure that the transmission gear 520 is meshed with the second planetary gear 610 to form a power transmission path; finally, the assembled reduction mechanism is installed on the telescopic tube mechanism, so that the second interference block 620 on the end face of the second-stage planetary disc 600 is inserted into the gap between the two adjacent first interference blocks 220, and finally the gear box housing 300 is fixedly connected to the outer tube 100.

[0043] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, in the present invention, the descriptions of "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A linear actuator, characterized in that: include: A telescopic tube mechanism, the telescopic tube mechanism comprising an outer tube (100) and a main screw rod (200), wherein the main screw rod (200) is rotatably mounted in the outer tube (100); A speed reduction mechanism, the speed reduction mechanism comprising a gearbox housing (300), an inner gear ring (400), a first-stage planetary disk (500) and a second-stage planetary disk (600), the gearbox housing (300) being connected to an end of the outer tube (100), and the inner gear ring (400) being fixedly disposed in the gearbox housing (300); The first-stage planetary disk (500) is rotatably mounted in the gearbox housing (300); the first-stage planetary disk (500) is provided with at least two first planetary gears (510) arranged around the rotation center of the first-stage planetary disk (500) and rotatable around their own rotation axes; each of the first planetary gears (510) is meshed with the inner gear ring (400); and a transmission gear (520) is provided at the rotation center of the first-stage planetary disk (500); The second-stage planetary disk (600) is rotatably mounted in the gearbox housing (300); the second-stage planetary disk (600) is provided with at least two second planetary gears (610) arranged around the rotation center of the second-stage planetary disk (600) and rotatable around their own rotation axes; each of the second planetary gears (610) is meshed with the inner gear ring (400); the second-stage planetary disk (600) is connected to the main screw (200) and can drive the main screw (200) to rotate; A motor (700) is connected to the gear box housing (300), and a rotating shaft of the motor (700) is connected to an input gear (530), and the input gear (530) is meshed with each of the first planetary gears (510).

2. A linear actuator according to claim 1, characterized in that: The first-stage planetary disk (500) and the second-stage planetary disk (600) are stacked along the axial direction of the rotating shaft of the motor (700).

3. A linear actuator according to claim 2, characterized in that: A connecting seat (210) is provided at the end of the main screw rod (200), a first contact block (220) is provided on the end surface of the connecting seat (210), and two second contact blocks (620) are provided on one end surface of the second-stage planetary disk (600) facing the connecting seat (210), the first contact block (220) is located between the two second contact blocks (620), and the second-stage planetary disk (600) can be rotated relative to the connecting seat (210) to a linkage position where the first contact block (220) is in contact with any of the second contact blocks (620).

4. A linear actuator according to claim 1, characterized in that: The bottom of the gear box housing (300) is connected to the motor (700) via screws.

5. A linear actuator according to claim 4, characterized in that: One of the outer wall of the inner gear ring (400) and the inner wall of the gear box housing (300) is provided with a slot (410) and the other is provided with an insert block (310); when the inner gear ring (400) is inserted into the gear box housing (300), the insert block (310) is inserted into the slot (410) so that the inner gear ring (400) and the gear box housing (300) are kept circumferentially locked.

6. A linear actuator according to claim 1, characterized in that: One of the ports of the outer tube (100) and the gear box housing (300) is provided with an internal thread (110) and the other is provided with an external thread (320), and the outer tube (100) and the gear box housing (300) are detachably connected via the internal thread (110) and the external thread (320).

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