A roller device for extending a scissor lift aerial work platform

Abstract

This utility model discloses a roller device for extending a scissor lift aerial work platform, comprising symmetrically arranged mounting plates, rollers that roll within a square tube of the main platform, bearings, and a central shaft. The mounting plates are detachably connected to both sides of the end of the square tube of the extension platform. The outer ring of the bearing is mounted to the inner ring of the roller, and the inner ring of the bearing is mounted to the outer surface of the central shaft. Both ends of the central shaft are detachably connected to the mounting plates on both sides of the end of the square tube of the extension platform. Bosses are provided on both ends of the central shaft, and these bosses are detachably connected to the mounting plates. By adding boss structures detachably connected to the mounting plates at both ends of the central shaft, the anti-tilting and anti-torsional load-bearing capacity of the roller device is improved, enhancing the operational stability and reliability of the entire extension platform under high load or assembly deviation conditions.

Description

Technical Field

[0001] This utility model relates to a roller device for extending a scissor lift aerial work platform, belonging to the technical field of mechanical engineering. Background Technology

[0002] As the rated load capacity of scissor lift aerial work platforms continues to increase, the load borne by their extension platforms also increases accordingly, which significantly increases the motion resistance of the extension platforms during push-pull operations.

[0003] Currently, the relative movement between the extension platform and the main platform is mostly achieved using a roller-type guide structure: the rollers are mounted on a central shaft via bearings, and the central shaft is fixed to mounting plates at both ends by bolts. The mounting plates are connected to the guide square tubes of the extension platform. When the extension platform moves, the rollers can roll inside the square tubes of the main platform to support the platform load and assist in relative displacement.

[0004] Under low load conditions, this type of roller structure can effectively reduce push-pull resistance and ensure smooth operation. However, as the load on the extended platform increases, if the machining accuracy of related components is insufficient or there are assembly deviations, the rollers are prone to tilting. This tilting will cause the bearing to bear lateral forces, further causing the central shaft to rotate unexpectedly. Under long-term operation, the mounting bolts of the central shaft are prone to loosening or even falling off due to continuous additional torque.

[0005] Because the rollers and their central shaft mounting structure are located inside the main platform's square tube, their condition is difficult to observe directly during routine inspections. Therefore, problems such as loose bolts often go undetected. Once the bolts fail, the extension platform's movement can easily become stuck, affecting not only the normal operation of the equipment but also posing a potential safety risk. Summary of the Invention

[0006] Purpose of the invention: To solve the above-mentioned technical problems, this utility model provides a roller device for extending a scissor lift aerial work platform. This device effectively prevents the central shaft from rotating unexpectedly by adding boss structures that can be detachably connected to the mounting plate on both ends of the central shaft.

[0007] Technical solution: A roller device for extending a scissor lift aerial work platform includes symmetrically arranged mounting plates, rollers that roll inside the square tube of the main platform, bearings, and a central shaft. The mounting plates are detachably connected to both sides of the end of the square tube of the extension platform. The outer ring of the bearing is mounted to the inner ring of the roller, and the inner ring of the bearing is mounted to the outer surface of the central shaft. Both ends of the central shaft are detachably connected to the mounting plates on both sides of the end of the square tube of the extension platform. Bosses are provided on both ends of the central shaft, and the bosses are detachably connected to the mounting plates.

[0008] This invention, by adding boss structures that are detachably connected to the mounting plate on both ends of the central shaft, enables the rigid fit between the bosses and the mounting plate to directly resist the circumferential torque transmitted from the bearing when the rollers tilt due to high load or assembly deviation. This effectively prevents the central shaft from rotating unintended. It fundamentally solves the problem in traditional structures where the mounting bolts are subjected to additional shear torque due to central shaft rotation, leading to loosening and detachment. This improves the operational reliability and safety of the extension platform under high load conditions. Furthermore, this core structure is located inside the square tube, requiring no maintenance and reducing potential risks and maintenance costs.

[0009] In a preferred embodiment, in order to maximize the processability and economy of the boss while ensuring that the boss has sufficient shear and torsional strength, the cross-section of the boss is semi-circular, and the boss extends from the outer edge of the central axis end face in a direction away from the central axis end face.

[0010] By designing the boss cross-section as a semi-circular shape, it can be efficiently formed in one go using general-purpose equipment such as lathes, avoiding the processing difficulty and cost increase caused by complex contour milling, and achieving a balance between excellent mechanical performance and low manufacturing cost.

[0011] In a preferred embodiment, to ensure that the connection between the central shaft and the mounting plate has both precise positioning function and can transmit huge torque, the mounting plate is provided with a limiting through hole, and the boss passes through the limiting through hole, so that the end face of the central shaft abuts against the end face of the mounting plate.

[0012] By setting a limiting through hole that matches the shape of the boss and ensuring that the end face of the central shaft abuts tightly against the end face of the mounting plate, the radial positioning of the central shaft is achieved through the hole-shaft fit, simplifying assembly; the large-area end face contact provides stable axial support, avoiding stress concentration; and the surface contact between the boss and the through hole wall provides strong anti-reverse torque, realizing axial fixation and circumferential limiting of the central shaft, making the mechanical model more reasonable and reliable.

[0013] In a preferred embodiment, to prevent the boss from protruding from the outer surface of the mounting plate and interfering with the inner wall of the square tube after the entire roller device is installed into the main platform square tube, which would increase the pushing and pulling resistance or even cause jamming, the height of the boss is less than or equal to the depth of the limiting through hole.

[0014] By limiting the height of the boss to no more than the depth of the limiting through hole, a smooth assembly plane is formed on the outer surface of the mounting plate, enabling the roller device to roll smoothly and without obstruction or resistance within the enclosed square tube space, thus ensuring ease of operation.

[0015] In a preferred embodiment, to further provide a reliable and interference-free connection method while using a boss to prevent the conical screw from loosening, and to facilitate later maintenance through a detachable structure, the two ends of the central shaft are provided with coaxial mounting holes facing inward, and the mounting plate is provided with a conical countersunk hole coaxial with the mounting hole. The mounting hole and the conical countersunk hole are detachably connected by a conical screw, and the conical end face of the conical screw does not extend beyond the outer end face of the mounting plate.

[0016] By using a combination of tapered screws and tapered countersunk holes, the self-locking properties of the tapered surface can be used to pre-tighten and prevent loosening. At the same time, it ensures that the screw head is completely sunk into the mounting plate without any additional protrusion, thus achieving a flat connection structure and completely eliminating the risk of scratching or colliding with the inner wall of the main platform square tube, taking into account both connection strength and operational safety.

[0017] In a preferred embodiment, to prevent installation interference between the conical screw and the boss, and to provide double protection, the axis of the mounting hole is offset from the axis of the central axis in a direction away from the boss. On the projection surface of the mounting plate parallel to and away from the end face of the central axis, the conical countersunk hole and the limiting through hole are spaced apart.

[0018] If the screws loosen due to vibration, the semi-circular boss alone can limit the movement of the central shaft. If the semi-circular boss breaks or is damaged and cannot provide a limiting function, the mounting hole, which is off-center from the central shaft's axis, can also restrict the central shaft's movement. By offsetting the mounting hole's axis from the central shaft's axis and maintaining a safe distance between the tapered countersunk hole and the limiting through hole on the projection plane, the physical separation of the two independent functional units is achieved.

[0019] In a preferred embodiment, in order to axially limit the bearing, a shim is also fitted on the central shaft section between the bearing and the mounting plate. The outer diameter of the shim is the same as the outer diameter of the bearing inner ring, and the two end faces of the shim abut against the end face of the bearing inner ring and the end face of the mounting plate, respectively.

[0020] Beneficial Effects: This utility model improves the anti-tilting and anti-torsional load-bearing capacity of the roller device by adding boss structures at both ends of the central shaft that can be detachably connected to the mounting plate. This enhances the operational stability and reliability of the entire extension platform under high load or assembly deviation conditions. Simultaneously, the rigid fit between the bosses and the limiting through holes effectively suppresses unintended rotation of the central shaft, fundamentally eliminating the risk of the mounting bolts loosening due to additional shear torque. Located inside the square tube, this structure combines maintenance-free operation with high safety, effectively reducing long-term maintenance costs and potential failure rates. Furthermore, the semi-circular boss design, countersunk head screw connection, and double redundant limiting layout further optimize the manufacturability, assembly convenience, and smooth movement, meeting the comprehensive requirements of aerial work platforms for high strength, high reliability, and smooth operation of the extension mechanism. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a partial view of the roller device of this utility model; Figure 2 This is an assembly drawing of the roller device and the square tube of the extension platform of this utility model; Figure 3 This is a schematic diagram of the assembly of the roller and the mounting plate of this utility model; Figure 4 This is a cross-sectional view of the roller device assembly of this utility model. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] like Figures 1-4As shown, a roller device for extending a scissor lift aerial work platform includes symmetrically arranged mounting plates 1, rollers 2 that roll inside a main platform square tube 6, bearings 3, and a central shaft 4. The mounting plates 1 are detachably connected to both ends of the extension platform square tube 5. The outer ring of the bearing 3 is mounted to the inner ring of the roller 2, and the inner ring of the bearing 3 is mounted to the outer circular surface of the central shaft 4. Both ends of the central shaft 4 are detachably connected to the mounting plates 1 on both ends of the extension platform square tube 5. Bosses 7 are provided on both ends of the central shaft 4, and the bosses 7 are detachably connected to the mounting plates 1.

[0027] By adding bosses 7, which are detachably connected to mounting plates 1, to both ends of the central shaft 4, the rigid fit between the bosses 7 and mounting plates 1 directly resists the circumferential torque transmitted from the bearings 3 when the rollers 2 tilt due to high load or assembly deviation. This effectively prevents the central shaft 4 from rotating unexpectedly. This fundamentally solves the problem in traditional structures where the mounting bolts are subjected to additional shear torque due to the rotation of the central shaft 4, leading to loosening and detachment. It improves the operational reliability and safety of the extension platform under high load conditions. Furthermore, this core structure is located inside the main platform square tube 6, requiring no maintenance and reducing potential risks and maintenance costs.

[0028] In order to ensure that the boss 7 has sufficient shear and torsional strength while maximizing its manufacturability and economy, the cross-section of the boss 7 is semi-circular, and the boss 7 extends from the outer edge of the end face of the central axis 4 in a direction away from the end face of the central axis 4.

[0029] By designing the 7th boss section as a semi-circular shape, it can be efficiently formed in one go using general-purpose equipment such as lathes, avoiding the processing difficulty and cost increase caused by complex contour milling, and achieving a balance between excellent mechanical performance and low manufacturing cost.

[0030] To ensure that the connection between the central shaft 4 and the mounting plate 1 has both precise positioning function and can transmit huge torque, the mounting plate 1 is provided with a limiting through hole 8, and the boss 7 passes through the limiting through hole 8, so that the end face of the central shaft 4 abuts against the end face of the mounting plate 1.

[0031] By setting a limiting through hole 8 that matches the shape of the boss 7 and ensuring that the end face of the central shaft 4 is in close contact with the end face of the mounting plate 1, the radial positioning of the central shaft 4 is achieved through the hole-shaft fit, simplifying the assembly; the large-area end face contact provides stable axial support and avoids stress concentration; the surface contact between the boss 7 and the through hole wall provides a strong anti-reverse torque, realizing the axial fixation and circumferential limiting of the central shaft 4, making the mechanical model more reasonable and reliable.

[0032] To prevent the boss 7 from protruding from the outer surface of the mounting plate 1 and interfering with the inner wall of the main platform square tube 6 after the entire roller 2 device is installed into the main platform square tube 6, which would increase the pushing and pulling resistance or even cause jamming, the height of the boss 7 is less than or equal to the depth of the limiting through hole 8.

[0033] By limiting the height of the boss 7 to no greater than the depth of the limiting through hole 8, a smooth assembly plane is formed on the outer surface of the mounting plate 1, enabling the roller 2 device to roll smoothly and without obstruction or resistance in the enclosed square tube space, thus ensuring ease of operation. Example 1

[0034] In order to provide a reliable and interference-free connection method based on the use of boss 7 to prevent the conical screw 9 from loosening, and to facilitate later maintenance through a detachable structure, the two ends of the central shaft 4 are provided with coaxial mounting holes 41 facing inward. The mounting plate 1 is provided with a conical countersunk hole 11 coaxial with the mounting hole 41. The mounting hole 41 and the conical countersunk hole 11 are detachably connected by a conical screw 9. The conical end face of the conical screw 9 does not extend beyond the outer end face of the mounting plate 1.

[0035] By employing a tapered screw 9 in conjunction with a tapered countersunk hole 11, the self-locking property of the tapered surface allows for pre-tightening and prevents loosening. Simultaneously, it ensures the screw head is completely recessed into the mounting plate 1, preventing any additional protrusions and achieving a smooth connection structure. This completely eliminates the risk of scratching or colliding with the inner wall of the main platform square tube 6, balancing connection strength and operational safety. The tapered end face of the tapered screw 9 does not extend beyond the outer end face of the mounting plate 1; that is, in the projection plane perpendicular to the central axis 4, the tapered end face of the tapered screw 9 is flush with the end face of the mounting plate 1, or the outer end face of the mounting plate 1 extends beyond the tapered end face of the tapered screw 9. Example 2

[0036] To prevent installation interference between the tapered screw 9 and the boss 7, and to provide double protection, the axis of the mounting hole 41 is offset from the axis of the central axis 4 in a direction away from the boss 7. On the projection surface of the mounting plate 1, which is parallel to and away from the end face of the central axis 4, the tapered countersunk hole 11 and the limiting through hole 8 are spaced apart.

[0037] If the screws loosen due to vibration, the semi-circular boss 7 alone can limit the movement of the central shaft 4. If the semi-circular boss 7 breaks or is damaged and cannot provide a limiting function, the mounting hole 41, which is offset from the axis of the central shaft 4, can also limit the movement of the central shaft 4. By offsetting the axis of the mounting hole 41 from the axis of the central shaft 4 and maintaining a safe distance between the tapered countersunk hole 11 and the limiting through hole 8 on the projection plane, the physical separation of the two independent functional units is achieved. Example 3

[0038] In order to limit the axial movement of the bearing 3, a shim 10 is also fitted on the shaft section of the central shaft 4 between the bearing 3 and the mounting plate 1. The outer diameter of the shim 10 is the same as the outer diameter of the inner ring of the bearing 3, and the two end faces of the shim 10 abut against the end face of the inner ring of the bearing 3 and the end face of the mounting plate 1, respectively.

[0039] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0040] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A roller device for extending a scissor lift aerial work platform, comprising symmetrically arranged mounting plates (1), rollers (2) that roll within a main platform square tube (6), bearings (3), and a central shaft (4), wherein the mounting plates (1) are detachably connected to both sides of the end of the extension platform square tube (5), the outer ring of the bearing (3) is mounted to the inner ring of the roller (2), the inner ring of the bearing (3) is mounted to the outer surface of the central shaft (4), and both ends of the central shaft (4) are detachably connected to the mounting plates (1) on both sides of the end of the extension platform square tube (5), characterized in that: The central shaft (4) is provided with bosses (7) on both ends, and the bosses (7) are detachably connected to the mounting plate (1).

2. The scissor lift aerial work platform extension roller device according to claim 1, characterized in that: The cross-section of the boss (7) is semi-circular, and the boss (7) extends from the outer edge of the end face of the central axis (4) in a direction away from the end face of the central axis (4).

3. The scissor lift aerial work platform extension roller device according to claim 2, characterized in that: The mounting plate (1) is provided with a limiting through hole (8), and the boss (7) passes through the limiting through hole (8), so that the end face of the central shaft (4) abuts against the end face of the mounting plate (1).

4. The scissor aerial work platform extension roller arrangement of claim 3, wherein: The height of the boss (7) is less than or equal to the depth of the limiting through hole (8).

5. The scissor aerial work platform extension roller arrangement of claim 2, wherein: The two ends of the central shaft (4) are provided with coaxial mounting holes (41) facing inward. The mounting plate (1) is provided with a conical countersunk hole (11) coaxial with the mounting hole (41). The mounting hole (41) and the conical countersunk hole (11) are detachably connected by a conical screw (9). The conical end face of the conical screw (9) does not extend beyond the end face of the outer mounting plate (1).

6. The scissor aerial work platform extension roller arrangement of claim 5, wherein: The axis of the mounting hole (41) is offset from the axis of the central axis (4) in a direction away from the boss (7). On the projection surface of the mounting plate (1) which is parallel to and away from the end face of the central axis (4), the tapered countersunk hole (11) and the limiting through hole (8) are spaced apart.

7. The scissor aerial work platform extension roller arrangement of claim 1, wherein: A gasket (10) is also fitted on the shaft section of the central shaft (4) between the bearing (3) and the mounting plate (1). The outer diameter of the gasket (10) is the same as the outer diameter of the inner ring of the bearing (3). The two end faces of the gasket (10) abut against the end face of the inner ring of the bearing (3) and the end face of the mounting plate (1), respectively.

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