Electric cylinder and safety nut module thereof

Abstract

The invention discloses an electric cylinder and a safety nut module thereof, the safety nut module is used for a leading screw, the leading screw is provided with external threads, the safety nut module comprises a nut body, a safety nut and a fixed cover plate, the inner periphery of the nut body is provided with first internal threads, one end of the nut body is provided with a fixed side, and the fixed side is concavely provided with a groove; the safety nut is tightly embedded and fixed in the groove, and the inner periphery of the safety nut is provided with second inner threads corresponding to the first inner threads. The fixed cover plate is fixedly connected to the fixed side, covers the groove and stops the safety nut, and the fixed cover plate is provided with a transparent opening; the guide screw penetrates through the through opening, the nut body and the safety nut, and the first inner thread or the second inner thread and the outer thread are in mutual threaded connection transmission. Therefore, the fixing cover plate can stop the safety nut so as to achieve the effect of preventing the safety nut from loosening from the groove.

Description

Technical Field

[0001] The present invention relates to a nut structure of an electric cylinder, and more particularly to an electric cylinder and a safety nut module thereof. Background Art

[0002] An electric cylinder mainly includes an outer tube, an inner tube, a nut, a screw rod and a motor. The nut is disposed inside the outer tube and has the inner tube sleeved at one end. The nut is hollow and has the screw rod passing through it. The nut engages with the screw thread of the screw rod with the inner thread on its inner side. The motor drives the screw rod to rotate through a worm gear. When the screw rod rotates, it drives the nut to move axially, and at the same time the inner tube follows the nut to move axially.

[0003] In addition, a safety nut with an inner thread is installed on one side of the nut. When the inner thread of the nut is damaged, the inner thread of the safety nut can engage with the screw rod to prevent the electric cylinder from losing the gravity support point and causing danger. However, if the safety nut detaches from the nut, it will also hinder the movement of the nut and cause danger. Therefore, how to firmly combine the safety nut with the nut is the research focus of electric cylinder manufacturers.

[0004] In view of this, the inventor has specifically studied the above-mentioned prior art, and cooperated with the application of theory, and tried his best to solve the above problems, which has become the goal of the inventor's development. Summary of the Invention

[0005] The present invention provides an electric cylinder and a safety nut module thereof, which utilize a fixed cover plate to stop the safety nut to achieve the effect of preventing the safety nut from loosening out of the groove.

[0006] In an embodiment of the present invention, a safety nut module is provided for a lead screw. The lead screw is provided with an external thread. The safety nut module includes: a nut body having a first inner thread on its inner periphery and a fixed side at one end, and a groove is recessed in the fixed side; a safety nut tightly embedded in the groove, and the safety nut has a second inner thread corresponding to the first inner thread disposed on its inner periphery; and a fixed cover plate fixedly connected to the fixed side, covering the groove and stopping at the safety nut, and the fixed cover plate is provided with a through hole; wherein, the lead screw passes through the through hole, the nut body and the safety nut, and the first inner thread or the second inner thread is screwed and driven with the external thread.

[0007] In an embodiment of the present invention, the present invention provides an electric cylinder, comprising: an electric cylinder body including a motor and a lead screw driven by the motor to rotate, the lead screw being provided with an external thread; a safety nut module including: a nut body having a first internal thread on its inner peripheral edge and a fixed side at one end, the fixed side being recessed with a groove; a safety nut tightly fitted in the groove, the safety nut having a second internal thread corresponding to the first internal thread on its inner peripheral edge; and a fixed cover plate fixedly connected to the fixed side, covering the groove and blocking the safety nut, the fixed cover plate being provided with a through hole; and a telescopic tube sleeved outside the lead screw and fixedly connected to the nut body at one end to move along with the nut body; wherein, the lead screw passes through the through hole, the nut body and the safety nut, and the first internal thread or the second internal thread is screwed and driven with the external thread.

[0008] Based on the above, the safety nut is tightly fitted in the groove of the nut body, which can avoid danger when the internal teeth of the nut are damaged. The fixed cover plate is fixedly connected to the fixed side of the nut body, covers the groove and blocks the safety nut. When the safety nut bears too heavy a load, it may loosen from the groove, but the fixed cover plate can block the safety nut to prevent the safety nut from loosening from the groove. Description of the Drawings

[0009] Figure 1 is an exploded perspective view of the safety nut module of the present invention;

[0010] Figure 2 is a perspective schematic view of the safety nut module of the present invention to be sleeved on a screw;

[0011] Figure 3 is a perspective schematic view of the safety nut module of the present invention already sleeved on a screw;

[0012] Figure 4 is a cross-sectional schematic view of the safety nut module of the present invention already sleeved on a screw;

[0013] Figure 4A is the present invention Figure 4 an enlarged schematic view of the circled area A in;

[0014] Figure 5 is an assembled perspective view of the electric cylinder of the present invention;

[0015] Figure 6 is an assembled cross-sectional view of the electric cylinder of the present invention;

[0016] Figure 7 is a partial assembled cross-sectional view of the electric cylinder of the present invention;

[0017] Figure 8 is a schematic view of the usage state of the electric cylinder of the present invention;

[0018] Figure 9 is an exploded perspective view of another embodiment of the safety nut module of the present invention;

[0019] Figure 10 is a perspective schematic view of another embodiment of the safety nut module of the present invention with a screw rod sleeved thereon;

[0020] Figure 11 is a cross-sectional schematic view of another embodiment of the safety nut module of the present invention with a screw rod sleeved thereon;

[0021] Figure 11A is the present invention Figure 11 an enlarged schematic view of the circled area A therein;

[0022] Figure 12 is a partial combined cross-sectional view of another embodiment of the electric cylinder of the present invention;

[0023] Among them, reference numerals:

[0024] 10: Electric cylinder;

[0025] 1: Electric cylinder body;

[0026] 11: Electric motor;

[0027] 12: Lead screw;

[0028] 121: External thread;

[0029] 2: Safety nut module;

[0030] 21: Nut body;

[0031] 210: Fixed side;

[0032] 211: First internal thread;

[0033] 212: Groove;

[0034] 213: First locking hole;

[0035] 214: Clamping groove;

[0036] 215: Concave groove;

[0037] 22: Safety nut;

[0038] 220: Second internal thread;

[0039] 221: Ring body;

[0040] 23: Fixed cover plate;

[0041] 231: Through hole;

[0042] 232: Second locking hole;

[0043] 233: Flaring;

[0044] 234: Elastic catch;

[0045] 235: Stopper;

[0046] 24: Locking element;

[0047] 241: Head;

[0048] 3: Telescopic tube;

[0049] 4: Outer tube;

[0050] H1, H2: Spacing. Detailed implementation mode

[0051] The detailed description and technical content of the present invention will be described below in conjunction with the accompanying drawings. However, the accompanying drawings are only for illustrative purposes and are not intended to limit the present invention.

[0052] Please refer to Figures 1 to 8 As shown, the present invention provides an electric cylinder and its safety nut module. This electric cylinder 10 mainly includes an electric cylinder body 1, a safety nut module 2 and a telescopic tube 3. The safety nut module 2 mainly includes a nut body 21, a safety nut 22 and a fixed cover plate 23.

[0053] As Figures 2 to 8 shown, the electric cylinder body 1 includes a motor 11 and a lead screw 12 driven by the motor 11 to rotate. The lead screw 12 is provided with an external thread 121. Among them, the motor 11 drives the worm gear to rotate and drives the lead screw 12 to rotate in the positive and negative directions.

[0054] As Figures 1 to 8 shown, the safety nut module 2 includes a nut body 21, a safety nut 22 and a fixed cover plate 23. The inner peripheral edge of the nut body 21 has a first internal thread 211 and one end has a fixed side 210. The fixed side 210 is recessed with a groove 212. Among them, the nut body 21 is made of plastic material, but it is not limited thereto.

[0055] In addition, the safety nut 22 has a ring body 221 tightly embedded in the groove 212. The inner peripheral edge of the safety nut 22 has a second internal thread 220 arranged corresponding to the first internal thread 211. The second internal thread 220 is arranged along the inner peripheral edge of the ring body 221. Among them, the safety nut 22 is made of metal or plastic material, but it is not limited thereto.

[0056] Furthermore, the fixed cover plate 23 is fixedly connected to the fixed side 210, covers the groove 212 and stops the safety nut 22. The fixed cover plate 23 is provided with a through hole 231. Among them, the fixed cover plate 23 is made of metal or plastic, but it is not limited thereto.

[0057] Furthermore, on one side of the fixed cover plate 23 adjacent to the nut body 21, there are a plurality of stoppers 235 capable of stopping the safety nut 22. When the safety nut 22 slightly moves away from the groove 212 towards the fixed cover plate 23, the stoppers 235 can first press against the safety nut 22, thereby enhancing the ability of the fixed cover plate 23 to stop the safety nut 22.

[0058] Among them, each stopper 235 in this embodiment is an L-shaped elastic rib, but it is not limited thereto. The shape of each L-shaped elastic rib has elasticity and can elastically press against the safety nut 22, thereby buffering the extrusion force exerted on the fixed cover plate 23 when the safety nut 22 moves away from the groove 212 towards the fixed cover plate 23.

[0059] The detailed description is as follows. As Figures 1 to 4 shown, in the structure where the fixed cover plate 23 of this embodiment is fixedly connected to the fixed side 210, the safety nut module 2 further includes a plurality of locking elements 24. The fixed side 210 is provided with a plurality of first locking holes 213, and the fixed cover plate 23 is provided with a plurality of second locking holes 232. Each locking element 24 is fixedly penetrated through each first locking hole 213 and each second locking hole 232, so that the fixed cover plate 23 is firmly combined with the fixed side 210.

[0060] Furthermore, one end of each second locking hole 232 far from the nut body 21 is provided with a flared opening 233, and each locking element 24 has a head 241. Each head 241 is buried in each flared opening 233.

[0061] In addition, the guide screw 12 passes through the through hole 231, the nut body 21 and the safety nut 22, and the first internal thread 211 or the second internal thread 220 is threadedly engaged with the external thread 121 for transmission. The further description is as follows. When the first internal thread 211 is not worn out, as Figure 4 、 Figure 4A shown, the distance H1 between the external thread 121 and the first internal thread 211 is less than the distance H2 between the external thread 121 and the second internal thread 220, so that the first internal thread 211 will be threadedly engaged with the external thread 121 for transmission. When the first internal thread 211 is worn out, it will cause the distance H1 between the external thread 121 and the first internal thread 211 to be greater than the distance H2 between the external thread 121 and the second internal thread 220, so that the second internal thread 220 will be threadedly engaged with the external thread 121 for transmission.

[0062] As Figures 3 to 8 shown, the electric cylinder 10 of the present invention further includes a telescopic tube 3 sleeved outside the guide screw 12 and fixedly connected to one end of the nut body 21 to move with the nut body 21.

[0063] As Figures 5 to 8As shown in the figure, the electric cylinder 10 of the present invention further includes an outer tube 4. One end of the outer tube 4 is fixedly connected to the electric cylinder body 1 and sleeved outside the telescopic tube 3. The outer peripheral edge of the nut body 21 is provided with a concave-convex limit structure (not labeled in the figure) that can only linearly displace relative to the outer tube 4, so that when the lead screw 12 rotates in the forward and reverse directions, the safety nut module 2 can be driven to rise or fall relative to the lead screw 12, and the telescopic tube 3 can move with the nut body 21 and expand and contract relative to the outer tube 4.

[0064] As Figures 1 to 9 shown, the usage state of the electric cylinder 10 of the present invention is that the safety nut 22 has a ring body 221 that is tightly fitted into the groove 212 at one end of the nut body 21 and a second internal thread 220 arranged along the inner peripheral edge of the ring body 221 and corresponding to the first internal thread 211. When the first internal thread 211 is worn and damaged after long-term use, the second internal thread 220 can still firmly engage with the external thread 121 of the lead screw 12 to avoid danger caused by the damage of the first internal thread 211 of the nut body 21, thereby increasing the structural strength and usage safety of the safety nut module 2.

[0065] In addition, the safety nut 22 is tightly fitted into the groove 212 of the nut body 21, which can avoid danger when the internal thread of the nut is damaged and make the safety nut 22 and the nut body 21 in an interference fit. The fixed cover plate 23 is fixedly connected to the fixed side 210 of the nut body 21, covers the groove 212 and stops at the safety nut 22. When the safety nut 22 bears too heavy a load, it may loosen from the groove 212, but the fixed cover plate 23 can stop the safety nut 22 to prevent the safety nut 22 from loosening from the groove 212.

[0066] Furthermore, the nut body 21 of the present invention is made of plastic material. Compared with the conventional nut made of metal material, it can reduce the noise generated by friction more effectively. And the safety nut 22 is preferably made of metal material, so that the structural strength of the safety nut 22 is greater than that of the nut body 21, enabling the safety nut 22 to effectively provide support when the first internal thread 211 of the nut body 21 is damaged, thereby improving the structural strength of the safety nut module 2. Generally speaking, it can effectively simplify the manufacturing process and reduce costs, so as to achieve the advantages of the safety nut module 2 of the present invention in simplifying the assembly process and saving costs.

[0067] Moreover, the distance H1 between the external thread 121 and the first internal thread 211 is less than the distance H2 between the external thread 121 and the second internal thread 220. Therefore, when the first internal thread 211 is not worn and damaged, the lead screw 12 only engages and drives with the nut body 21. The nut body 21 is the main load-bearing support of the telescopic tube 3, and at this time the safety nut 22 is not stressed.

[0068] However, when the first inner thread 211 is worn and damaged, causing the distance H1 between the outer thread 121 and the first inner thread 211 to be greater than the distance H2 between the outer thread 121 and the second inner thread 220, the lead screw 12 will become threadedly connected with the safety nut 22 for transmission. At this time, the safety nut 22 will be subjected to force. The safety nut 22 is the main load-bearing support of the telescopic tube 3, thereby enhancing the safety of the safety nut module 2.

[0069] like Figures 9 to 12 FIG. 2 is another embodiment of the electric cylinder 10 and the safety nut module 2 of the present invention. Figures 9 to 12 Examples and Figures 1 to 8 The embodiments are roughly the same, Figures 9 to 12 Examples and Figures 1 to 8 The difference lies in the different structures of the fixed cover plate 23 fixed to the fixed side 210 .

[0070] In the present embodiment, the fixed cover plate 23 is fixedly connected to the fixed side 210, and the fixed side 210 is provided with a plurality of grooves 214. A side of the fixed cover plate 23 adjacent to the nut body 21 is provided with a plurality of elastic hooks 234 extending axially along the through hole 231. Each elastic hook 234 is engaged with each groove 214, so that the fixed cover plate 23 is firmly combined with the fixed side 210.

[0071] In addition, the fixed side 210 is provided with a plurality of recessed grooves 215 surrounding the outer periphery of the groove 212, each groove 214 is opened from the inner wall of each recessed groove 215, each elastic hook 234 is penetrated through each recessed groove 215, each elastic hook 234 is an L-shaped hook and the end thereof is engaged with each groove 214, so that the fixed cover plate 23 is firmly combined with the fixed side 210, and the same Figures 1 to 8 The functions and effects of the embodiments.

[0072] The fixed cover plate 23 of the present invention is fixedly connected to the fixed side 210 of the nut body 21, the cover groove 212 and stops the safety nut 22. When the safety nut 22 is subjected to an excessive load, it may become loose. However, the fixed cover plate 23 can stop the safety nut 22 to prevent the safety nut 22 from loosening from the groove 212 when the load is too heavy.

[0073] In summary, the electric cylinder and its safety nut module of the present invention have never been seen in similar products and have not been used publicly. They are industrially applicable, novel and progressive, and fully meet the requirements for patent applications. Therefore, an application is filed in accordance with the Patent Law to protect the rights of the inventor.

Claims

1. A safety nut module for a lead screw, the lead screw being provided with an external thread, characterized in that, The safety nut module includes: A nut body having a first internal thread on its inner periphery and a fixed side at one end, and a groove is recessed in the fixed side; A safety nut tightly embedded in the groove, and a second internal thread corresponding to the first internal thread is provided on the inner periphery of the safety nut; and A fixed cover plate fixed to the fixed side, covering the groove and stopping at the safety nut, and a through hole is provided in the fixed cover plate; Wherein, the lead screw passes through the through hole, the nut body and the safety nut, and the first internal thread or the second internal thread is screwed and driven with the external thread.

2. The safety nut module according to claim 1, wherein, It further includes a plurality of locking elements. The fixed side is provided with a plurality of first locking holes, and the fixed cover plate is provided with a plurality of second locking holes. Each locking element is fixedly penetrated through each first locking hole and each second locking hole.

3. The safety nut module according to claim 2, wherein, One end of each second locking hole away from the nut body is provided with a flared opening. Each locking element has a head, and each head is embedded in each flared opening.

4. The safety nut module according to claim 1, wherein The fixed side is provided with a plurality of card grooves. A plurality of elastic hooks extend along the axial direction of the through hole on the surface of the fixed cover plate adjacent to the nut body. Each elastic hook is engaged with each card groove.

5. The safety nut module according to claim 4, wherein, The fixed side is provided with a plurality of recessed grooves surrounding the periphery of the groove. Each card groove is opened from the inner wall of each recessed groove. Each elastic hook passes through each recessed groove. Each elastic hook is an L-shaped hook and the end is engaged with each card groove.

6. The safety nut module according to claim 1, characterized in that, A plurality of stop blocks capable of stopping the safety nut extend on the surface of the fixed cover plate adjacent to the nut body.

7. The safety nut module according to claim 1, wherein, The safety nut has an annular body tightly embedded in the groove. The second internal thread is arranged along the inner periphery of the annular body. The distance between the external thread and the first internal thread is smaller than the distance between the external thread and the second internal thread.

8. An electric cylinder, characterized in that, It includes: An electric cylinder body including a motor and a lead screw driven by the motor to rotate. The lead screw is provided with an external thread; A safety nut module, comprising: A nut body having a first internal thread on its inner periphery and a fixed side at one end, and a groove is recessed in the fixed side; A safety nut tightly embedded in the groove, and a second internal thread corresponding to the first internal thread is provided on the inner periphery of the safety nut; and A fixed cover plate fixed to the fixed side, covering the groove and stopping at the safety nut, and a through hole is provided in the fixed cover plate; and A telescopic tube sleeved outside the lead screw and fixedly connected to one end of the nut body to move with the nut body; Wherein, the lead screw passes through the through hole, the nut body and the safety nut, and the first internal thread or the second internal thread is screwed and driven with the external thread.

9. The electric cylinder according to claim 8, characterized in that, The safety nut module includes a plurality of locking elements. The fixed side is provided with a plurality of first locking holes, and the fixed cover plate is provided with a plurality of second locking holes. Each locking element is fixedly penetrated through each first locking hole and each second locking hole.

10. The electric cylinder according to claim 9, wherein One end of each second locking hole away from the nut body is provided with a flared opening. Each locking element has a head, and each head is embedded in each flared opening.

11. The electric cylinder according to claim 8, characterized in that, The fixed side is provided with a plurality of card grooves. A plurality of elastic hooks extend along the axial direction of the through hole on the surface of the fixed cover plate adjacent to the nut body. Each elastic hook is engaged with each card groove.

12. The electric cylinder according to claim 11, wherein, The fixed side is provided with a plurality of recessed grooves surrounding the outer periphery of the groove. Each of the clamping grooves is opened from the inner wall of each of the recessed grooves. Each of the elastic hooks is inserted into each of the recessed grooves. Each of the elastic hooks is an L-shaped hook and the end thereof is clamped in each of the clamping grooves.

13. The electric cylinder according to claim 8, characterized in that, On one side of the fixed cover plate adjacent to the nut body, there extend a plurality of stoppers capable of stopping the safety nut.

14. The electric cylinder according to claim 8, wherein The safety nut has an annular body tightly embedded in the groove. The second internal thread is arranged along the inner peripheral edge of the annular body. The distance between the external thread and the first internal thread is smaller than the distance between the external thread and the second internal thread.

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