Lifting mechanism for a height adjustable desk

Abstract

The utility model discloses a lifting mechanism for lifting table, relate to lifting equipment technical field, and its technical scheme main points are: including big screw rod, transmission nut seat and small screw rod, the keyway groove is seted up in big screw rod, and the keyway sliding block is fixed with small screw rod, and transmission nut seat includes small seat and big seat, is equipped with ball bearing in big seat, is equipped with screw rod seat in small seat, and screw rod seat is fixedly connected with small seat through deformation bridge, and one side of deformation bridge is equipped with friction ring. When the weight on the table board exceeds the load of lifting mechanism, the deformation of deformation bridge exceeds the threshold value and makes the friction ring and the inner ring of ball bearing resist, makes the rotation of the inner ring of ball bearing produce resistance, makes big screw rod not easy to rotate, and the resistance of the inner ring of ball bearing produces, makes big screw rod not easy to rotate through the resistance of the keyway groove side wall and the keyway sliding block, and the small screw rod is also not easy to rotate, and the sudden drop of lifting mechanism is avoided, and the possibility of falling damage of the article on the table board is reduced.

Description

Technical Field

[0001] This utility model relates to the field of lifting equipment technology, and more specifically, to a lifting mechanism for a height-adjustable table. Background Technology

[0002] A height-adjustable desk is a type of desk that can flexibly adjust its height. It uses a mechanical or electric drive structure to raise or lower the desktop to accommodate different heights, usage scenarios, and functional needs. It is a common piece of furniture in modern healthy office and home learning settings.

[0003] Existing height-adjustable desks include a tabletop, legs, and a lifting mechanism installed in the legs. The lifting mechanism consists of components such as a drive motor and ball screws. In order to reduce the storage volume of the desk, a three-stage telescopic lifting mechanism has been developed. The three-stage telescopic lifting mechanism includes a first transmission nut seat, a small lead screw, a second transmission nut seat, and a large lead screw sleeved outside the small lead screw. The outer peripheral wall of the large lead screw mates with the second transmission nut seat. The first transmission nut seat is rotatably connected to the end of the large lead screw, while the outer peripheral wall of the small lead screw mates with the first transmission nut seat. The large lead screw has a spline groove inside, and the end of the small lead screw is fixedly connected to a spline slider. When the drive motor drives the small lead screw to rotate, the large lead screw rotates synchronously with the small lead screw under the action of the spline slider, thereby changing the height of the small lead screw relative to the first transmission nut seat, and the height of the large lead screw relative to the second transmission nut seat, thus completing the height adjustment operation of the desk legs.

[0004] Since there is no self-locking between the small lead screw and the first transmission nut seat, and between the large lead screw and the second transmission nut seat, in practice, a static locking device is added to the drive motor. When the drive motor is not rotating, neither the large nor the small lead screw can rotate, thus allowing the lifting mechanism to maintain its original height. However, when there are many items on the table, the load on the static locking device becomes large, which may cause the locking device to fail. This could cause the small lead screw to rotate relative to the first transmission nut seat. The rotating small lead screw will simultaneously drive the large lead screw and the second transmission nut seat to rotate, causing the table to suddenly drop and the items on the table to fall and be damaged.

[0005] Therefore, a new solution is needed to address this problem. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a lifting mechanism for a height-adjustable desk.

[0007] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a lifting mechanism for a height-adjustable table, comprising a large lead screw, a transmission nut seat, and a small lead screw. The transmission nut seat is rotatably connected to one end of the large lead screw and is sleeved on the outer peripheral wall of the small lead screw. The large lead screw has a spline groove, and a spline slider that slides in the spline groove is fixed at the end of the small lead screw. The transmission nut seat includes a small square seat and a large square seat. A ball bearing is provided in the large square seat, and the inner ring of the ball bearing is fixedly installed at one end of the large lead screw. A lead screw seat that abuts against the outer peripheral wall of the small lead screw is provided in the small square seat. The lead screw seat is fixedly connected to the small square seat through a deformation bridge. A friction ring extending into the large square seat is provided on one side of the deformation bridge. There is a gap between the side wall of the friction ring facing away from the lead screw seat and the side wall of the inner ring of the ball bearing.

[0008] The present invention is further configured such that: an annular ring is provided in the large seat, and an end cap for pressing the ball bearing against the annular ring is screwed on the large seat.

[0009] The present invention is further configured such that the inner diameter of the annular ring is greater than the outer diameter of the friction ring and less than the inner diameter of the outer ring of the ball bearing.

[0010] The present invention is further configured such that: a stop bar is provided on the annular ring, and the distance between the stop bar and the deformation bridge is equal to the distance between the friction ring and the inner ring sidewall of the ball bearing.

[0011] The present invention is further configured such that the end of the abutment facing the deformation bridge has a rounded corner.

[0012] The present invention is further configured such that the lead screw seat, the small seat, the deformation bridge and the friction ring are integrally formed, and the lead screw seat, the small seat, the deformation bridge and the friction ring are all made of polyoxymethylene material.

[0013] In summary, this utility model has the following beneficial effects: When people place items on the table exceeding the limit, the deformation bridge deforms beyond the threshold, causing the friction ring to come into contact with the inner ring of the ball bearing. Since the friction ring does not rotate relative to the deformation bridge, it creates resistance to the rotation of the inner ring of the ball bearing. In this case, when people adjust the lifting mechanism later, the friction between the friction ring and the inner ring of the ball bearing will generate noise and cause jerking during the lifting process, effectively reminding people to reduce the weight of items placed on the table. When the weight of the items on the table is too great, the friction ring will come into close enough contact with the inner ring of the ball bearing, making it difficult for the inner ring of the ball bearing to rotate. This prevents the large lead screw from rotating, and the contact force between the spline groove sidewall and the spline slider also makes it difficult for the small lead screw to rotate. Therefore, when items exceeding the lifting table's load capacity are placed on the table, the lifting mechanism is less likely to suddenly descend, effectively preventing items on the table from falling and being damaged due to the failure of the static locking device in the drive motor. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a cross-sectional view of the present invention.

[0015] In the diagram: 1. Large lead screw; 2. Small lead screw; 3. Spline groove; 4. Spline slider; 5. Small seat; 6. Large seat; 7. Ball bearing; 8. Lead screw seat; 9. Deformation bridge; 10. Friction ring; 11. Annular ring; 12. End cap; 13. Push rod. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] The height-adjustable desk uses a lifting mechanism, such as Figure 2As shown, the table includes a large lead screw 1, a transmission nut seat, and a small lead screw 2, all installed in the table legs. The transmission nut seat is rotatably connected to one end of the large lead screw 1 and is sleeved on the outer peripheral wall of the small lead screw 2. The large lead screw 1 has a spline groove 3, and a spline slider 4 that slides in the spline groove 3 is fixed to the end of the small lead screw 2. The transmission nut seat includes a small square seat 5 and a large square seat 6. The small square seat 5 and the large square seat 6 are fixedly connected to each other by fixing screws. The outer peripheral wall of the small square seat 5 contacts the inner peripheral wall of the table leg, preventing the small square seat 5 from rotating inside the table leg. The large square seat 6 has a ball bearing 7, and the inner ring of the ball bearing 7 is interference-fitted onto one end of the large lead screw 1. The small square seat 5 has a lead screw seat 8 that abuts against the outer peripheral wall of the small lead screw 2. The lead screw seat 8 is connected by a deformation bridge. 9 is fixedly connected to the small seat 5. The outer peripheral wall of the deformation bridge 9 is fixedly connected to the inner peripheral wall of the small seat 5, and the deformation bridge 9 is located near the bottom of the small seat 5. The outer peripheral wall of the lead screw seat 8 is fixedly connected to the inner peripheral wall of the deformation bridge 9. The connection between the lead screw seat 8 and the deformation bridge 9 is located near the bottom of the lead screw seat 8. One end of the lead screw seat 8 is provided with a friction ring 10 that extends into the large seat 6. There is a gap between the side wall of the friction ring 10 facing away from the lead screw seat 8 and the inner ring side wall of the ball bearing 7. When a lot of items are placed on the table, the weight of the items will be transmitted to the deformation bridge 9 through the small lead screw 2 and the lead screw seat 8, causing the deformation bridge 9 to deform to a certain extent. When setting the effective load of the lifting table, the deformation of the deformation bridge 9 is used as a reference for the load of the lifting table. When the deformation of the deformation bridge 9 exceeds the threshold, the friction ring 10 will abut against the inner ring of the ball bearing 7. When people use the lifting table normally within its maximum load capacity, the small lead screw 2 is directly driven by the drive motor to rotate and rotates synchronously with the large lead screw 1, allowing the lifting mechanism to normally adjust the height of the table legs. After adjustment, the static locking device in the drive motor prevents the small lead screw 2 and the large lead screw 1 from rotating, thus maintaining the tabletop at the adjusted height to meet people's needs. When people place items on the tabletop beyond the limit, the deformation of the deformation bridge 9 exceeds the threshold, causing the friction ring 10 to abut against the inner ring of the ball bearing 7. Since the friction ring 10 does not rotate relative to the deformation bridge 9, the friction ring 10 will abut against the ball bearing 7. The rotation of the inner ring of bearing 7 generates resistance. In this case, when people adjust the lifting mechanism later, the friction between the friction ring 10 and the inner ring of the ball bearing 7 will generate noise and cause jerking during the lifting process. This can effectively remind people to reduce the weight of items placed on the table. When the weight of the items on the table is too large, the friction ring 10 will be in close enough contact with the inner ring of the ball bearing 7, making it difficult for the inner ring of the ball bearing 7 to rotate. This prevents the large lead screw 1 from rotating. The contact force between the side wall of the spline groove 3 and the spline slider 4 also makes it difficult for the small lead screw 2 to rotate. Therefore, when items exceeding the load capacity of the lifting table are placed on the table, the lifting mechanism is less likely to suddenly descend.This effectively prevents items placed on the table from falling and getting damaged due to the failure of the stationary locking device in the drive motor.

[0018] like Figure 1 and Figure 2As shown, the large seat 6 has an annular ring 11. An end cap 12, which holds the ball bearing 7 against the annular ring 11, is screwed onto the large seat 6. During the assembly of the lifting mechanism, the ball bearing 7 is installed on the lead screw 1, and then installed into the large seat 6. The end of the lead screw 1 passes through the end cap 12 and fits against the large seat 6. The end cap 12 is then fixed to the large seat 6 with screws, thus securing the ball bearing against the annular ring 11. This arrangement prevents relative rotation between the outer ring of the ball bearing 7 and the large seat 6, and also facilitates the disassembly and assembly of the ball bearing 7 and the large seat 6, making subsequent maintenance of the ball bearing 7 easier. The inner diameter of the annular ring 11 is larger than the outer diameter of the friction ring 10. The design ensures that when the deformation bridge 9 deforms, the outer peripheral wall of the friction ring 10 will not contact the inner peripheral wall of the annular ring 11, allowing the friction ring 10 to better abut against the inner ring of the ball bearing 7. The inner diameter of the annular ring 11 is smaller than the inner diameter of the outer ring of the ball bearing 7. This design prevents interference between the annular ring 11 and the inner ring of the ball bearing 7 during normal rotation, ensuring smooth operation of the ball bearing 7. The annular ring 11 is equipped with a stop rod 13, the distance between the stop rod 13 and the deformation bridge 9 being equal to the distance between the friction ring 10 and the side wall of the inner ring of the ball bearing 7. Since the deformation of the deformation bridge 9 increases with the weight of the items on the table, when the deformation of the deformation bridge 9 exceeds... When the threshold is exceeded, the abutment 13 will directly contact the deformation bridge 9, providing better support for the deformation bridge 9 and preventing it from failing due to excessive deformation. This effectively extends the service life of the deformation bridge 9. The abutment 13 has a rounded end facing the deformation bridge 9. Compared to abutment 13 without a rounded end, the rounded end makes stress concentration less likely at the contact point with the deformation bridge 9, thus better protecting its surface. The lead screw seat 8, small seat 5, deformation bridge 9, and friction ring 10 are integrally formed. All rings 10 are made of polyoxymethylene (POM) material. Specifically, the lead screw seat 8, small seat 5, deformation bridge 9, and friction ring 10 are integrally molded using an injection molding die. This design can significantly improve the connection strength between the lead screw seat 8, small seat 5, deformation bridge 9, and friction ring 10. The wall thickness of the deformation bridge 9 is less than that of the small seat 5 and the lead screw seat 8. This design allows the deformation bridge 9 to deform better under stress. POM material has good toughness, which can better meet the needs of the deformation bridge 9 for micro-deformation. At the same time, POM has good self-lubricating ability. The lead screw seat 8 made of this material can better ensure the smoothness when rotating relative to the small lead screw 2, ensuring the smoothness of the lifting mechanism.

[0019] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A lifting mechanism for a height-adjustable table, comprising a large lead screw (1), a transmission nut seat, and a small lead screw (2), wherein the transmission nut seat is rotatably connected to one end of the large lead screw (1), the transmission nut seat is sleeved on the outer peripheral wall of the small lead screw (2), a spline groove (3) is provided in the large lead screw (1), and a spline slider (4) that slides in the spline groove (3) is fixed at the end of the small lead screw (2), characterized in that: The transmission nut seat includes a small square seat (5) and a large square seat (6). The large square seat (6) is provided with a ball bearing (7). The inner ring of the ball bearing (7) is fixedly installed at one end of the large lead screw (1). The small square seat (5) is provided with a lead screw seat (8) that abuts against the outer peripheral wall of the small lead screw (2). The lead screw seat (8) is fixedly connected to the small square seat (5) through a deformation bridge (9). A friction ring (10) is provided on one side of the deformation bridge (9) and extends into the large square seat (6). There is a gap between the side wall of the friction ring (10) facing away from the lead screw seat (8) and the side wall of the inner ring of the ball bearing (7).

2. The lifting mechanism for a height-adjustable desk according to claim 1, characterized in that: The base (6) is provided with an annular ring (11), and the base (6) is screwed with an end cap (12) that presses the ball bearing (7) against the annular ring (11).

3. The lifting mechanism for a height-adjustable desk according to claim 2, characterized in that: The inner diameter of the annular ring (11) is greater than the outer diameter of the friction ring (10) and less than the inner diameter of the outer ring of the ball bearing (7).

4. The lifting mechanism for a height-adjustable desk according to claim 3, characterized in that: The annular ring (11) is provided with a stop rod (13), and the distance between the stop rod (13) and the deformation bridge (9) is equal to the distance between the friction ring (10) and the inner ring sidewall of the ball bearing (7).

5. The lifting mechanism for a height-adjustable desk according to claim 4, characterized in that: The abutment (13) has a rounded corner at one end facing the deformation bridge (9).

6. The lifting mechanism for a height-adjustable desk according to claim 1, characterized in that: The lead screw seat (8), small seat (5), deformation bridge (9) and friction ring (10) are integrally formed, and the lead screw seat (8), small seat (5), deformation bridge (9) and friction ring (10) are all made of polyoxymethylene material.

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