Belt tensioning mechanism

Abstract

The present application provides a belt tensioning mechanism. The belt tensioning mechanism comprises a support wall, a first support member, a second support member, a force receiving column, a first spring and a second spring. The first support member has a bending portion passing through an opening of the support wall, so that a first portion and a second portion connected thereto are respectively arranged on a first side and a second side of the support wall. The first spring and the second spring are arranged on the first side and the second side of the support wall through the force receiving column. Another transmission belt is arranged on the second side of the support wall through the force receiving column. The spring force of the first spring and the second spring can balance the force of the belt tension generated by the transmission belt in the opposite direction. When the force of the belt tension generates a moment on the force receiving column, the first portion and the second portion of the support member respectively contact the surface of the first side and the second side of the support wall and generate the abutting force opposite to each other and towards the support wall, thereby canceling the moment.

Description

Technical Field

[0001] This invention relates to a belt tensioning mechanism, and more particularly to a belt tensioning mechanism with an automatic stabilizing structure. Background Technology

[0002] Currently, printer drive belts mainly use two structures to achieve belt tension: one is a bolt (or screw), and the other is a spring.

[0003] In the bolt-mounted method, the bolts apply force to the load-bearing column that mounts the drive belt, and the belt tension is affected by changing the magnitude of the applied force. The disadvantage of this method is that, due to the low ductility of the drive belt material, if the frame shifts due to printer movement or other factors such as thermal expansion and contraction caused by environmental changes, even slight deformation can lead to rapid changes in belt tension, especially since the bolts are made of rigid, inelastic materials and cannot provide fine-tuning. For example, a displacement of 0.25mm can cause a rapid increase in tension of 1-1.5kg. Such rapid tension changes can easily cause the belt to loosen over time, requiring frequent bolt adjustments to maintain belt tension.

[0004] In the spring-based method, a spring applies force to the tensioning post on which the drive belt is mounted. There are two types of spring operation: one uses torque to achieve force application, where a fulcrum is established between the spring and the tensioning post, with the spring and post located on opposite sides of this fulcrum. Therefore, the spring's force is applied to the post via torque. The other method uses direct tension, where the spring's force directly reaches and affects the post. While using a spring reduces abrupt changes in belt tension due to displacement because of the spring's elasticity, the concentrated force on the post can easily damage it due to uneven stress. Over time, this can lead to an imbalance in the internal structure of the belt tensioning mechanism, ultimately affecting the belt tension.

[0005] Therefore, it is necessary to develop a belt tensioning mechanism that can improve upon the shortcomings of known technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a belt tensioning mechanism that achieves an automatic and stable balance of internal forces through structural design.

[0007] Another objective of this invention is to provide a belt tensioning mechanism that solves the problem of internal structural damage caused by the concentration of force on the load-bearing column in the prior art by setting up double springs.

[0008] To achieve the above objectives, the present invention provides a belt tensioning mechanism, comprising: a support wall having a first side, a second side, a first opening, and a second opening; a first support member having a first portion, a second portion, and a turning portion connecting the first portion and the second portion, wherein the turning portion passes through the second opening and the first portion and the second portion are respectively located on the first side and the second side of the support wall; and a force-bearing column for a transmission belt to be sleeved thereon, having a first section and a second section, wherein the force-bearing column is perpendicular to the first portion of the first support member, and the force-bearing column passes through the first opening of the support wall, and the first section and the second section are respectively located on the first side and the second opening of the support wall. On the second side, the transmission belt is disposed in the second section of the force-bearing column and generates belt tension when driven; a second support member is disposed in the second section of the force-bearing column; a first spring is connected to the first section of the force-bearing column to provide a first spring force; and a second spring is connected to the second support member to provide a second spring force; wherein the resultant force of the first spring force and the second spring force is balanced with the force of the belt tension, and when the force of the belt tension generates a torque on the force-bearing column, the first part and the second part of the support member respectively contact the surface of the first side and the surface of the second side of the support wall and generate a pushing force relative to each other and toward the support wall, thereby counteracting the torque.

[0009] In one embodiment, the resultant force of the first spring force and the second spring force is opposite in direction to the force exerted by the belt tension.

[0010] In one embodiment, the resultant force of the first spring force and the second spring force is equal to the force exerted by the belt tension.

[0011] In one embodiment, the first spring force is greater than the second spring force.

[0012] In one embodiment, the force-bearing column further includes a root portion that passes through the first support member, and the first spring has a first distance from the root portion and the second spring has a second distance from the root portion, wherein the product of the first spring force and the first distance is greater than or equal to the product of the second spring force and the second distance.

[0013] In one embodiment, the turning portion of the first support member has a turning height corresponding to a thickness of the support wall, so that the first portion and the second portion of the support member contact the surface of the first side and the surface of the second side of the support wall.

[0014] In one embodiment, a plurality of fasteners are further included for fixing the first support member to the support wall, wherein the support wall and the first support member each have a plurality of fixing holes for the plurality of fasteners to pass through.

[0015] In one embodiment, the second support member is disposed across both sides of the drive belt on the second section of the force-bearing column.

[0016] In one embodiment, a spring fixing seat is further included, having a first fixing part and a second fixing part, wherein the first spring is coupled to the first fixing part and the second spring is coupled to the second fixing part.

[0017] In one embodiment, the spring fixing seat is perpendicular to the support wall, and the first fixing part and the second fixing part are disposed on the first side and the second side of the support wall.

[0018] The beneficial effects of this invention are that, by setting up double springs, the force on the root of the force-bearing column can be effectively reduced in both static and dynamic states, which helps to maintain the force balance of the internal structure of the belt tensioning mechanism, making the overall structure less prone to damage due to force imbalance. In addition, such a design also allows the distance between the transmission belt and the support wall to be changed according to requirements. Attached Figure Description

[0019] Figure 1 This diagram shows a printer employing the belt tensioning mechanism of the present invention.

[0020] Figure 2A This is a schematic diagram of the belt tensioning mechanism according to an embodiment of the present invention from a first-view perspective.

[0021] Figure 2B A schematic diagram of the belt tensioning mechanism according to an embodiment of the present invention from a second perspective.

[0022] Figure 3A This diagram shows the first support member, the force-bearing column, and the fixing member in the belt tensioning mechanism of an embodiment of the present invention.

[0023] Figure 3B This shows a top view of the first support member and the force-bearing column in the belt tensioning mechanism of an embodiment of the present invention.

[0024] Figure 4 This shows a top view of the belt tensioning mechanism according to an embodiment of the present invention.

[0025] The attached figures are labeled as follows:

[0026] 1: Printer

[0027] 11: Framework Body

[0028] 12: Belt pulley assembly

[0029] 121: Drive Wheel

[0030] 122: Passive Wheel

[0031] 123: Drive belt

[0032] 13: Slide

[0033] 14: Printing Module

[0034] 2: Belt tensioning mechanism

[0035] 21: Supporting wall

[0036] 211: First side

[0037] 212: Second side

[0038] 213: First Opening

[0039] 214: Second opening

[0040] 215: Fixing hole

[0041] 216: Spring retainer

[0042] 2161: First fixing part

[0043] 2162: Second fixing part

[0044] 22: First support component

[0045] 221: Part One

[0046] 222: Part Two

[0047] 223: Turning Point

[0048] 224: Fixing hole

[0049] 23: Second support component

[0050] 24: Load-bearing column

[0051] 241: First Section

[0052] 242: Second Section

[0053] 243: Root

[0054] 25: First Spring

[0055] 26: The second spring

[0056] 27: Fasteners

[0057] A: First distance

[0058] B: Second distance

[0059] D1: First Resistance Force

[0060] D2: Second Resistance Force

[0061] F: Force

[0062] H: Turning height

[0063] S1: First spring force

[0064] S2: Second spring force Detailed Implementation

[0065] Some typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can be varied in different ways without departing from the scope of the invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the invention.

[0066] Please see Figure 1 The diagram shows a schematic of a device employing the belt tensioning mechanism of the present invention. The present invention primarily provides a belt tensioning mechanism, applicable to office machines such as printers, scanners, fax machines, or multifunction printers, but not limited thereto. Taking a printer as an example... Figure 1 As shown, printer 1 includes a frame body 11, a pulley assembly 12, a slide 13, a printing module 14, and a belt tensioning mechanism 2. The pulley assembly 12 is mounted on the frame body 11 and primarily drives other components to rotate under the drive control of a computer system connected to printer 1, thus performing printing operations. The pulley assembly 12 may include a drive pulley 121, a driven pulley 122, and a transmission belt 123. The drive pulley 121 is driven by a power source (not shown), such as a motor, and the transmission belt 123 is wound around the drive pulley 121 and the driven pulley 122, thus coordinating with the rotation of the drive pulley 121. The slide 13 is mounted on the transmission belt 123, and the printing module 14 is connected to the slide 13. When the transmission belt 123 is driven, it moves the slide 13 and the printing module 14 to perform printing. The belt tensioning mechanism 2 is installed on the frame body 11 on the side of the driven pulley 122 to adjust the tension of the transmission belt 123.

[0067] Please refer to the following: Figures 2A to 3B ,in Figure 2A This diagram shows a belt tensioning mechanism according to an embodiment of the present invention from a first-view perspective. Figure 2B This diagram shows a belt tensioning mechanism according to an embodiment of the present invention from a second perspective. Figure 3A This diagram shows a first support member, a force-bearing column, and a fixing member in a belt tensioning mechanism according to an embodiment of the present invention. Figure 3BThis figure shows a top view of the first support member and the force-bearing column in the belt tensioning mechanism of this embodiment of the invention. As shown, the belt tensioning mechanism 2 of this embodiment includes a support wall 21, a first support member 22, a second support member 23, a force-bearing column 24, a first spring 25, and a second spring 26. The support wall 21 can be a side plate of the frame body 11 of the printer 1. The first support member 22 is mounted on the support wall 21, and the belt tensioning mechanism 2 is fixed to the frame body 11. In addition, the transmission belt 123 is sleeved on the force-bearing column 24 through the driven pulley 122, thereby adjusting its belt tension by the belt tensioning mechanism 2.

[0068] like Figure 3A and Figure 3B As shown, the first support member 22 is a stepped plate, including a first portion 221, a second portion 222, and a turning portion 223 connecting the first portion 221 and the second portion 222. The first portion 221 and the second portion 222 are arranged approximately parallel to each other. The load-bearing column 24 is vertically disposed on the first portion 221 of the first support member 22, and is therefore divided into a first section 241, a second section 242, and a branch 243 passing through the first support member 22. In other words, the first section 241 and the second section 242 are located on opposite sides of the first support member 22, that is, the first section 241 and the second section 242 extend from the first support member 22 in opposite directions. In one embodiment, as... Figure 3A As shown, the first section 241 and the second section 242 of the load-bearing column 24 can be two different components assembled (e.g., locked) to form the load-bearing column 24, such that the first section 241 extends to the other side of the first support member 22 opposite to the second section 242, and the length of the load-bearing column 24 can be adjusted according to the setting position of the driven wheel 122. Of course, the first section 241 and the second section 242 can also be integrally formed, or the first support member 22 and one section of the load-bearing column 24 (e.g., the second section 242) can be integrally formed, and then the other section (e.g., the first section 241) can be assembled. Therefore, it can be varied without limitation according to actual usage requirements and processes.

[0069] like Figure 2A and Figure 2BAs shown, the support wall 21 includes a first side 211, a second side 212, a first opening 213, and a second opening 214. The first support member 22 is mounted on the support wall 21 with the turning portion 223 passing through the second opening 214, and the first portion 221 located on the first side 211 and the second portion 222 located on the second side 212. The load-bearing column 24 passes through the first opening 213 of the support wall 21, and the second section 242 is located on the second side 212 of the support wall 21, while the first section 241 is located on the first side 211 of the support wall 21.

[0070] Here, the turning portion 223 is constructed to have a turning height H, corresponding to the thickness of the support wall 21, so that the first portion 221 and the second portion 222 respectively just contact the surface of the first side 211 and the surface of the second side 212 of the support wall 21, so as to achieve a stable contact arrangement between the first support member 22 and the support wall 21.

[0071] Furthermore, the first support member 22 is further secured to the support wall 21 by a plurality of fasteners 27, which may be stepped screws, but are not limited thereto. Figures 2A to 3A As shown, the first portion 221 and the second portion 222 of the first support member 21 are respectively mounted on the support wall 21 using fasteners 27. At this time, the support wall 21 and the first support member 22 are respectively provided with multiple fixing holes 215 and multiple fixing holes 224 for the fasteners 27 to pass through. In one embodiment, at least one of the multiple fixing holes 215 and 224 used to fix the first portion 221 and at least one of the multiple fixing holes 215 and 224 used to fix the second portion 222 can serve as a limiting groove, further providing the function of adjusting the fixed position of the fastener 27. For example, the width of the limiting groove is approximately parallel to the transmission direction of the transmission belt 123, and its width is larger than the diameter of the hole required for the fixing member 27 to pass through. Therefore, it provides space for elastic movement in the belt transmission direction, allowing the force-bearing column 24, which is perpendicular to the first support member 22, to adjust its position using the movement space provided by the multiple fixing holes 215 and 224, thereby allowing the belt tension of the transmission belt 123 to be adjusted. In other words, the multiple fixing members 27 and the multiple fixing holes 215 and 224 primarily position the first support member 22 on the support wall 21 to prevent it from falling off, while retaining the freedom of elastic movement in the belt transmission direction. On the other hand, the first opening 213 and the second opening 214 of the support plate 21 also correspondingly provide space for the first support member 22 to move elastically.

[0072] The drive belt 123 and the driven pulley 122 are sleeved on the second section 242 of the force-bearing column 24, and generate belt tension when driven. Additionally, the second support member 23 is also disposed on the second section 242 of the force-bearing column 24, wherein the second support member 23 can be configured as follows: Figure 2A and Figure 2B The spring 25 is shown spanning both sides of the transmission belt 123, but this is not a limitation; it can also be positioned on one side of the transmission belt 123. Furthermore, one end of the first spring 25 is connected to the first section 241 of the force-bearing column 24, while one end of the second spring 26 is connected to the second support member 23. Additionally, a spring fixing seat 216 is further provided on the support wall 21, which can be arranged to abut against the support wall perpendicularly, but this is not a limitation. The spring fixing seat 216 has a first fixing part 2161 and a second fixing part 2162, respectively located on the first side 211 and the second side 212 of the support wall 21. The other ends of the first spring 25 and the second spring 26 are respectively connected to the first fixing part 2161 and the second fixing part 2162 on the spring fixing seat 216, thereby generating a first spring force and a second spring force. For example, the other ends of the first spring 25 and the second spring 26 can be fitted onto the hooks on the first fixing part 2161 and the second fixing part 2162 by means of hooks, but this is not a limitation.

[0073] Please see Figure 4 This shows a top view of the belt tensioning mechanism according to an embodiment of the present invention. Figure 4As shown, for the force-bearing column 24, the force F generated by the belt tension of the transmission belt 123 mainly falls on the second section 242 of the force-bearing column 24, and its direction is towards the printing module 14. Therefore, when the force-bearing column 24 is arranged perpendicularly to the first support member 22, the root 243 of the force-bearing column 24 passing through the first support member 22 is prone to damage. To solve this problem, the present invention provides the first spring 25 and the second spring 26 in the first section 241 and the second section 242 of the force-bearing column 24, respectively. In this way, compared with the prior art that only uses a single spring to apply force to the force-bearing column 24, the double spring arrangement of the present invention can more effectively distribute the force throughout the force-bearing column 24, avoiding the concentration of force on the root 243 of the force-bearing column 24. In this architecture, the first spring 25 and the second spring 26 provide a first spring force S1 and a second spring force S2 in the direction away from the printing module 14. That is, the first spring force S1 and the second spring force S2 are opposite in direction to the force F of the belt tension. Preferably, the magnitude of the resultant force of the first spring force S1 and the second spring force S2 is equal to the magnitude of the force F to achieve a balance between them. Furthermore, since the force is provided by the resultant force through the setting of two springs, even if there is a slight deviation in the setting position of the springs or a slight deformation of the transmission belt, it can be effectively compensated to avoid a sudden change in tension.

[0074] Here, the magnitudes of the first spring force S1 and the second spring force S2 can be designed and configured differently according to actual application requirements. For example, when the force F of the belt tension is 2700g, the first spring force S1 can be designed to be 1800g and the second spring force S2 to be 900g to achieve a balance with the force F of the belt tension, but this is not a limitation.

[0075] On the other hand, in the belt tensioning mechanism 2, in addition to generating a force F parallel to the direction of the support wall 21, the belt tension also generates a torque on the support column 24 because the transmission belt 123 is separated from the root 243 of the force-bearing column 24 by a distance. This further increases the burden on the root 243 and may even cause the force-bearing column 24 to tilt. The present invention solves this problem through the structural design of the first support member 21 described above. As mentioned above, the first support member 22 is designed to have a turning part 223 so that when passing through the second opening 214, the first part 221 is located on the first side 211 of the support wall 21 and the second part 222 is located on the second side 212 of the support wall 21. That is, the first part 221 and the second part 222 are respectively located on opposite sides of the first support member 22. With this design, when the belt tension force F acts on the second section 241 of the force-bearing column 24 and generates a counterclockwise torque, the first support member 22 will tend to rotate counterclockwise due to the pull of the force-bearing column 24, causing both the first part 221 and the second part 222 to generate a resisting force towards the support wall 12, that is, as Figure 4 The first resisting force D1 and the second resisting force D2 shown are the resisting forces generated by the first part 221 and the second part 222 relative to each other and toward the support wall 21. In this way, the torque can be canceled out by the resisting force between the first part 221 and the second part 222 and the support wall 21, thus achieving an automatically stable and balanced structure. Advantageously, the greater the torque, the greater the resisting force generated by the support member 21, and the more stable the entire mechanism becomes.

[0076] It is worth noting that the positional relationship between the first portion 221 and the second portion 222 of the first support member 22 and the support wall 21 must be such that the first portion 221 is located on the first side 211 and the second portion 222 is located on the second side 212 to achieve a counteracting effect when a torque occurs. If the configuration is reversed (i.e., the first portion is located on the second side and the second portion is located on the first side), the first support member will tilt and will not be able to stably support the support wall and counteract the torque. More specifically, in addition to the first portion 221 and the second portion 222 being located on the first side 211 and the second side 212 respectively, the second portion 222 is located closer to the printing module 14 than the first portion 221, thereby achieving a counteracting effect when a torque occurs.

[0077] Furthermore, the placement and force magnitude of the first spring 25 and the second spring 26 are also crucial to the overall structural balance. For example, assuming the first spring 25 is positioned at a distance A from the root 243 of the force-bearing column 24 in the direction of spring force extension, and the second spring 26 is positioned at a distance B from the root 243 of the force-bearing column 24 in the direction of spring force extension, then in order to ensure that both the first portion 221 and the second portion 222 of the first support member 22 are in close contact with the support wall 21, it is preferable that the product of the first spring force S1 and the first distance A is greater than or equal to the product of the second spring force S2 and the second distance B. For example, if the first spring force S1 is 1800g and the second spring force S2 is 900g, then the first distance A can be designed to be 8mm and the second distance B to be 15mm, so that the product of the first spring force S1 and the first distance A (1800g*8mm=14400g-mm) is greater than or equal to the product of the second spring force S2 and the second distance B (900g*15mm=13500g-mm). By adjusting the spring forces S1, S2 and the first distance A and the second distance B, the internal structural balance can be maintained while also meeting the actual implementation requirements.

[0078] Thus, it can be seen that the dual-spring configuration of the present invention provides many advantages. First, in a static state, the dual springs can effectively balance the force F exerted by the belt tension on the second section 242 of the force-bearing column 24, avoiding the concentration of force at the root 243 caused by setting a single spring on only one side of the force-bearing column 24 (the first section 241 or the second section 242). For example, assuming only the first spring 25 is provided, the force F of the belt tension (e.g., 2700g as mentioned above) must be balanced by a single spring force, which will increase the force on the root 243 of the force-bearing column 24. However, by setting the second spring 26, the spring force required by the first spring 25 can be reduced, and the force on the root 243 can also be reduced. Furthermore, assuming the torque generated by the belt tension force F is at least 13500 g-mm (the product of the second spring force S2 and the second distance B), then without the second spring 26, the strength of the root 243 of the force-bearing column 24 would need to be able to resist at least the sum of the belt tension force F and the torque of the first spring force S1 (e.g., 13500 + 14400 = 27900 g-mm). Conversely, with the second spring 26, since the belt tension force F is canceled out, the strength of the root 243 of the force-bearing column 24 only needs to resist at least the torque generated by the first spring force S1 (e.g., 1800 g * 8 mm = 14400 g-mm), which also helps to reduce the force on the root 243 of the force-bearing column 24.

[0079] Furthermore, in a dynamic state, especially when the drive belt 123 is driven, the drive belt 123 will have an acceleration and generate another force, and the second spring 26 can further and effectively counteract this other force. For example, if the weight of the printing module 14 is 1.2 kg, then the 0.9 kg second spring force S2 can additionally counteract an acceleration force of 0.9 kg * 9.8 / 1.2 kg = 7.35 m / sec. 2 In actual implementation, the printing acceleration required by the printing module 14 is approximately 6.73 m / sec. 2 Therefore, the force generated by acceleration is also canceled out by the setting of the second spring 26.

[0080] Therefore, by setting up double springs, the force on the root 243 of the force-bearing column can be effectively reduced in both static and dynamic states, which helps to maintain the force balance of the internal structure of the belt tensioning mechanism 2, making the overall structure less prone to damage due to force imbalance. In addition, such a design also allows the distance between the transmission belt 123 and the support wall 21 to be changed according to requirements, for example, it can be extended according to the position of the printing module 14, increasing the flexibility of the design.

[0081] In addition, the design of the belt tensioning mechanism 2 of the present invention also takes into account the ease of operation. For example, when there is a need to replace the transmission belt 123, it is only necessary to disconnect the connection between the second spring 26 and the second support member 23, remove the second support member 23, and push the force column 24 toward the printing module 14 to loosen and remove the transmission belt 123, which is quite convenient to operate.

[0082] It should be noted that the above are merely preferred embodiments for illustrating the present invention, and the present invention is not limited to the described embodiments. The scope of the present invention is defined by the appended claims. Furthermore, the present invention can be modified in various ways by those skilled in the art, but all such modifications will not depart from the protection sought by the appended claims.

Claims

1. A belt tensioning mechanism, comprising: A supporting wall having a first side, a second side, a first opening and a second opening; A first support member has a first part, a second part, and a turning portion connecting the first part and the second part, wherein the turning portion passes through the second opening and positions the first part and the second part on the first side and the second side of the support wall, respectively. A force-bearing column, on which a transmission belt is fitted, has a first section and a second section, wherein the force-bearing column is perpendicular to the first part of the first support member, and the force-bearing column passes through the first opening of the support wall, and the first section and the second section are respectively located on the first side and the second side of the support wall, and the transmission belt is disposed on the second section of the force-bearing column, and generates a belt tension when driven; A second support member is provided in the second section of the load-bearing column; A first spring, connected to the first section of the force-bearing column, to provide a first spring force; and A second spring is connected to the second support member to provide a second spring force; The resultant force of the first spring force and the second spring force is balanced with the force of the belt tension. When the force of the belt tension generates a torque on the force-bearing column, the first part and the second part of the support member respectively contact the surface of the first side and the surface of the second side of the support wall and generate a pushing force relative to each other and toward the support wall, thereby counteracting the torque.

2. The belt tensioning mechanism as claimed in claim 1, wherein the resultant force of the first spring force and the second spring force is opposite in direction to the force of the belt tension.

3. The belt tensioning mechanism as claimed in claim 1, wherein the resultant force of the first spring force and the second spring force is equal to the force of the belt tension.

4. The belt tensioning mechanism as claimed in claim 1, wherein the first spring force is greater than the second spring force.

5. The belt tensioning mechanism as claimed in claim 1, wherein the force-bearing column further includes a root portion that passes through the first support member, and the first spring and the root portion have a first distance and the second spring and the root portion have a second distance, wherein the product of the first spring force and the first distance is greater than or equal to the product of the second spring force and the second distance.

6. The belt tensioning mechanism as claimed in claim 1, wherein the turning portion of the first support member has a turning height corresponding to a thickness of the support wall, so that the first portion and the second portion of the support member contact the surface of the first side and the surface of the second side of the support wall.

7. The belt tensioning mechanism as described in claim 1 further includes a plurality of fixing members for fixing the first support member to the support wall, wherein the support wall and the first support member each have a plurality of fixing holes for the plurality of fixing members to pass through.

8. The belt tensioning mechanism as claimed in claim 1, wherein the second support member is disposed across both sides of the transmission belt on the second section of the force-bearing column.

9. The belt tensioning mechanism as claimed in claim 1 further includes a spring fixing seat having a first fixing part and a second fixing part, wherein the first spring is coupled to the first fixing part and the second spring is coupled to the second fixing part.

10. The belt tensioning mechanism as claimed in claim 9, wherein the spring fixing seat abuts perpendicularly against the support wall, and the first fixing part and the second fixing part are disposed on the first side and the second side of the support wall.

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