A device for adjusting the rack hinge point

Abstract

This utility model discloses a device for adjusting the hinge point of a rack, comprising two eccentric bushings. Each eccentric bushing includes a bushing and a flange. An eccentric circular hole is axially formed inside the bushing. On the radial cross-section of the bushing, the center of the eccentric circular hole is offset from the center of the outer circle of the bushing. A flange is provided on the outer side of one end of the bushing. The bushings of the two eccentric bushings are respectively inserted into the support holes of the boom supports on both sides. The flange is connected to the outer side walls of the boom supports on both sides. The eccentric circular holes of the two bushings are respectively for the two ends of the rack shaft of the rack located between the two boom supports to be inserted and rotated. This utility model device absorbs the impact force generated by the luffing mechanism through the eccentric bushings, avoiding the impact and wear caused by direct contact between the rack shaft and the support hole. The eccentric design allows the rack shaft to rotate normally in the eccentric circular hole without affecting the fixation of the eccentric bushing to the boom support, and the rotatable bushings compensate for the connection between the rack shaft and the boom support.

Description

Technical Field

[0001] This utility model relates to the field of hinge point adjustment technology for racks used in lifting equipment, and specifically to a device for adjusting the hinge point of a rack. Background Technology

[0002] As a conventional lifting device, the structural components of a four-bar gantry crane that bear the load mainly consist of the boom, trunk beam, main tie rod, and upper swivel column. A counterbalance beam and small tie rod are installed at the rear to balance the weight of the four-bar structure during the luffing process. The luffing mechanism, as one of the main mechanisms of the gantry crane, is responsible for changing the distance of the lifted load relative to the center of rotation. Currently, rack and pinion luffing mechanisms are commonly used. The main layout is shown in the attached figure. Figure 8 As shown, the entire rack and pinion mechanism is connected to the boom support on the boom structure via the hinge point shaft and clamping plate at the head. The working principle of the luffing mechanism is as follows: the motor rotates, driving the gear shaft at the center of the rocker arm to rotate through the floating shaft, various couplings, and the reducer. The rack and pinion mechanism's gear plate meshes with the gear shaft through a gear pair. The rotation of the gear shaft moves the rack back and forth. The rack and pinion mechanism is hinged to the support hole of the boom support at the head hinge point. The lower end of the boom is hinged and fixed to the boom support at the front end of the turntable. The movement of the rack and pinion shaft drives the boom structure to rotate along the lower support of the boom. The rotation of the boom structure further drives the movement of the four-bar linkage, thereby achieving the purpose of moving the cargo back and forth.

[0003] During luffing, the boom structure rotates along the lower support of the boom, and the luffing rack rotates along the gear shaft at the center of the cradle while moving back and forth. Simultaneously, due to its own weight and the unbalanced torque of the cargo, the magnitude and direction of the force on the rack continuously change throughout the luffing process. Based on the interaction of forces, similarly, the magnitude and direction of the force on the rack shaft and the support hole of the boom support also continuously change. Over time, this will cause the rack shaft to form a stepped shaft, and the boom support will be stretched into an irregular circular hole, as shown in the attached diagram. Figure 9 Appendix Figure 10 and attached Figure 11 As shown, this can lead to loose connections, misalignment of the shaft end baffle, shearing or even falling off of fastening bolts. In more serious cases, the rack shaft may even detach and fall off, eventually becoming completely disconnected from the boom support, causing the entire machine to lose its luffing function. Furthermore, a rack shaft falling from a height could cause injury to personnel or equipment, posing a significant safety hazard.

[0004] To address this situation, the following measures are generally taken: First, to reduce the stress on the rack shaft and boom support, the thickness of the boom support main plate or weighing plate is increased. By increasing the contact area between the rack shaft and boom support, the stress is reduced. Second, bolts with holes in the head are used, and steel wire is threaded through them in a figure-eight pattern to ensure the bolts are tightened, thereby ensuring the tightness of the shaft end baffle and preventing the rack shaft from shifting.

[0005] However, both of the above measures have certain drawbacks:

[0006] By increasing the thickness of the boom support main board or weighing plate: The contact area between the rack shaft and the boom support is relatively small. To achieve this, the thickness of the boom support main board or weighing plate needs to be increased significantly. Otherwise, the effect will be insignificant and it will result in wasted costs. Moreover, all other supporting components will need to be modified.

[0007] Preventing rack shaft movement by tightening bolts: However, there are no preventative measures for problems such as the rack shaft becoming stepped and the boom support developing irregular circular holes due to prolonged use. When the hinge between the rack shaft and boom support loosens, the shaft end plate will be subjected to extreme shear force, easily shearing the steel wire and even causing the fastening bolts to break. This method requires frequent inspection of the fastening bolts, which is time-consuming and labor-intensive.

[0008] Therefore, there is an urgent need for a device for adjusting the rack hinge point to solve the problem that the hinge point of the gantry crane rack head may cause the support hole of the boom support to connect with the rack to expand during long-term use. Utility Model Content

[0009] This utility model addresses the shortcomings of existing technologies by providing a device for adjusting the hinge point of a rack and pinion, thereby solving the problem that the hinge point at the head of the gantry crane rack may enlarge during long-term use, leading to the risk of the support hole for the boom support connecting to the rack expanding.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A device for adjusting the hinge point of a rack includes two eccentric bushings. Each eccentric bushing includes a bushing and a flange. An eccentric circular hole is formed axially inside the bushing. On the radial cross-section of the bushing, the center of the eccentric circular hole is offset from the center of the outer circle of the bushing. A flange protruding radially is also provided on the outer side of one end of the bushing. The bushings of the two eccentric bushings are respectively inserted into the support holes of the boom supports on both sides. The flange at one end of the bushing is used to connect to the outer side walls of the boom supports on both sides that are far apart. The eccentric circular holes of the two bushings are used to allow the two ends of the rack shaft of the rack located between the two boom supports to be inserted and rotated.

[0012] To optimize the above technical solution, the specific measures also include:

[0013] Furthermore, the stop edge is provided with several annularly distributed connecting holes at equal intervals, and the outer wall of the boom support is provided with mounting holes corresponding to the connecting holes. The stop edge is screwed into the mounting holes and connecting holes respectively by bolts, and is connected to the outer wall of the boom support.

[0014] Furthermore, it also includes a shaft end baffle, which is installed on the outside of the baffle and is used to connect the baffle and the outer wall of the boom support.

[0015] Furthermore, the outer ring sidewall of the retaining edge is provided with several radially protruding adjustment protrusions at equal intervals.

[0016] Furthermore, it also includes an adjusting wrench, which includes an adjusting end with a circular adjusting hole. The inner wall of the adjusting hole has a protrusion groove corresponding to the adjusting protrusion for engaging with the adjusting protrusion.

[0017] Furthermore, the adjusting wrench also includes a handle, with the handle connected to one side of the adjusting end.

[0018] Furthermore, the sum of the wall thicknesses of the narrowest and widest ends of the bushing is equal to the sum of the wall thicknesses of the other two ends perpendicular to the narrowest and widest ends.

[0019] Furthermore, the bushing is made of a wear-resistant and extrusion-resistant plastic polymer material.

[0020] The beneficial effects of this utility model are:

[0021] This utility model device, through the setting of an eccentric bushing, separates the rack shaft and the support hole during use, avoiding wear caused by frequent rotation when in direct contact. Furthermore, the eccentric bushing, located between the rack shaft and the support hole, absorbs the impact force generated during sudden starting and braking of the luffing mechanism, preventing direct impact on the support hole. Simultaneously, the eccentric design of the eccentric circular hole allows the rack shaft to rotate normally within it without affecting the relative fixation between the eccentric bushing and the boom support. Moreover, when the bore diameter of a portion of the bushing changes due to prolonged use, the bushing can be rotated by rotating the flange, thereby adjusting the rack hinge point position, i.e., adjusting the relative position of the bushing and the rack shaft. This changes the vulnerable position of the bushing, compensating for the gap that appears in the connection between the rack shaft and the boom support due to bore diameter changes, ensuring the safety of the luffing mechanism and equipment. Attached Figure Description

[0022] Figure 1This is a schematic diagram illustrating the use of a device for adjusting the hinge point of a rack according to the present invention.

[0023] Figure 2 This is a top sectional view of the structure of a device for adjusting the hinge point of a rack and pinion proposed in this utility model;

[0024] Figure 3 This is a side view of the structure of a device for adjusting the hinge point of a rack according to the present invention;

[0025] Figure 4 This is a schematic diagram of the installation of the shaft end baffle of a device for adjusting the hinge point of a rack according to the present invention;

[0026] Figure 5 This is a schematic diagram of the shaft end baffle of a device for adjusting the hinge point of a rack and pinion proposed in this utility model;

[0027] Figure 6 This is a schematic diagram of the eccentric circular hole in a device for adjusting the hinge point of a rack and pinion, as proposed in this utility model.

[0028] Figure 7 This is a schematic diagram of the structure of an adjusting wrench for adjusting the rack hinge point proposed in this utility model;

[0029] Figure 8 This is a diagram illustrating boom adjustment.

[0030] Figure 9 This is a structural schematic diagram of the boom support;

[0031] Figure 10 A schematic diagram showing that the support holes of the boom support are not worn.

[0032] Figure 11 This is a schematic diagram showing that the support holes of the boom support are worn.

[0033] Reference numerals in the attached drawings: 1. boom support, 2. rack, 3. rack shaft, 4. eccentric bushing, 41. bushing, 42. flange, 43. eccentric round hole, 44. adjusting protrusion, 5. shaft end baffle, 6. adjusting wrench, 61. protrusion slot. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings.

[0035] As attached Figure 1 and attached Figure 2As shown, an embodiment of the present invention provides a device for adjusting the hinge point of a rack, comprising two eccentric bushings 4. Each eccentric bushing 4 includes a bushing 41 and a flange 42. An eccentric circular hole 43 is provided axially inside the bushing 41. On the radial cross-section of the bushing 41, the center of the eccentric circular hole 43 is offset from the center of the outer circle of the bushing 41. A flange 42 protruding radially is also provided on the outer side of one end of the bushing 41. The bushings 41 of the two eccentric bushings 4 are respectively inserted into the support holes of the two boom supports 1. The flange 42 at one end of the bushing 41 is used to connect to the outer side walls of the two boom supports 1 that are far apart. The eccentric circular holes 43 of the two bushings 41 are used to allow the rack shafts 3 of the rack 2 located in the middle of the two boom supports 1 to be inserted and rotated.

[0036] This utility model device, through the setting of the eccentric bushing 4, separates the rack shaft and the support hole during use, avoiding wear caused by frequent rotation when in direct contact. Furthermore, the eccentric bushing 4, located between the rack shaft and the support hole, can absorb the impact force generated during sudden starting and braking of the luffing mechanism, preventing direct impact on the support hole. Simultaneously, the eccentric design of the eccentric circular hole 43 allows the rack shaft 3 to rotate normally within the eccentric circular hole 43 without affecting the relative fixation of the eccentric bushing 4 and the boom support 1. Moreover, when the diameter of a portion of the bushing 41 changes due to prolonged use, the bushing 41 can be rotated by rotating the retaining flange 42, thereby adjusting and changing the rack hinge point position, i.e., adjusting and changing the relative position of the bushing 41 and the rack shaft 3. This changes the vulnerable position of the bushing 41, compensating for the gap that appears in the connection between the rack shaft and the boom support due to changes in the diameter, ensuring the safety of the luffing mechanism and equipment.

[0037] Furthermore, even if the eccentric bushing 4 is sheared due to repeated rotations and changes in the operating angle during use, the rack shaft will still remain in the support hole of the boom support, further ensuring the safety of the luffing mechanism and equipment.

[0038] When using the above solution, the angle of the boom can be adjusted as needed, such as the vertical angle, which can reduce the impact of the boom's own weight on the rotating bushing 41.

[0039] As attached Figure 3 As shown, in another specific embodiment based on the above, the flange 42 is provided with several annularly distributed connecting holes at equal intervals. The outer wall of the boom support 1 is provided with mounting holes corresponding to the connecting holes. The flange 42 is screwed into the mounting holes and connecting holes respectively by bolts, and connected to the outer wall of the boom support 1. In this way, the stability of the eccentric bushing 4 during use can be increased by the structure of bolts, mounting holes and connecting holes. When rotation is required, the corresponding bolts can be removed.

[0040] As attached Figure 4 and attached Figure 5 As shown, the system also includes a shaft end baffle 5, which is installed on the outside of the flange 42 and used to connect the flange 42 and the outer wall of the boom support 1. In this design, the shaft end baffle 5 can also have corresponding holes for threaded positioning installation. The shaft end baffle 5 can increase the connection strength between the eccentric bushing 4 and the boom support 1 and provide a certain degree of protection for the eccentric bushing 4.

[0041] In another specific embodiment based on the above, the outer ring sidewall of the retaining edge 42 is provided with several radially protruding adjusting protrusions 44 at equal intervals. Thus, in use, the protruding adjusting protrusions 44 facilitate gripping and driving the retaining edge 42 to rotate.

[0042] As attached Figure 7 As shown, the device also includes an adjusting wrench 6, which has an adjusting end with a circular adjusting hole. The inner wall of the adjusting hole has a protrusion groove 61 corresponding to the adjusting protrusion 44, allowing the adjusting protrusion 44 to engage. Therefore, in use, the adjusting wrench 6 can be fitted onto the outer ring of the retaining edge 42, and the adjusting protrusions 44 of the retaining edge 42 can be engaged in the protrusion grooves 61 of the adjusting hole, allowing for convenient rotation of the retaining edge 42 using the adjusting wrench 6 to complete the adjustment.

[0043] The adjusting wrench 6 also includes a handle, which is connected to one side of the adjusting end. This allows the adjusting end to be easily driven via the handle.

[0044] As attached Figure 6 As shown, the sum of the wall thicknesses of the narrowest and widest ends of the aforementioned bushing 41 is equal to the sum of the wall thicknesses of the other two ends perpendicular to the narrowest and widest ends. In this scheme, as shown in the attached... Figure 6 As shown, T1 + T2 = T3 + T4, where T3 and T4 can be of different values. Due to the eccentric design, the bushing 41 will have a difference Δt = T1 + T2 - T3 - T4 during use. Thus, different Δt values ​​can be obtained by rotating the eccentric bushing to different angles.

[0045] In another specific embodiment based on the above, the bushing 41 is made of a wear-resistant and extrusion-resistant plastic polymer material. This allows it to better absorb the impact forces generated during sudden starting and braking of the luffing mechanism.

[0046] One specific embodiment of this utility model is as follows:

[0047] As attached Figure 11As shown, during the entire luffing process, only two opposing sections of the rack shaft 3 and boom support 1 continuously bear the alternating forces, making these two sections most susceptible to wear and deformation. In operation, when the luffing mechanism suddenly starts or brakes, the sudden impact force between the rack shaft 3 and boom support 1 can be preferentially absorbed by the eccentric bushing 4, preventing the boom support 1 from being subjected to sudden and violent impact.

[0048] When prolonged use causes severe wear on opposite sides of the eccentric bushing 4, resulting in a loose connection and gap between the rack shaft 3 and the support hole of the boom support 1, the eccentric bushing 4 can be rotated to a certain angle by adjusting the wrench 6 to compensate for this gap and ensure a tight connection between the rack shaft 3 and the support hole.

[0049] Finally, if the eccentric bushing 4 is severely worn and cannot be compensated for by rotation angle, only the eccentric bushing 4 needs to be replaced, without causing wear or other destructive effects on the rack shaft 3 and boom support 1. Moreover, replacing the eccentric bushing 4 is simple; only the shaft end baffle 5 and the corresponding bolts need to be removed and replaced, saving time and effort. This greatly ensures the integrity of the rack shaft 3 and boom support 1 structure, thereby guaranteeing the safety of the luffing mechanism and equipment.

[0050] This utility model device has a simple and practical structure. Without significantly altering the rack head hinge point structure, it only requires adding an eccentric bushing 4 and correspondingly changing the dimensions of the shaft end baffle 5, the bore diameter of the boom support 1, and the length and diameter of the rack shaft 3. The components of this utility model device are simple to manufacture, widely applicable, and modularly designable, making it suitable for all crane models with similar rack hinge point structures.

[0051] This greatly avoids the problems of the rack shaft wearing down to form a stepped shaft and the boom support being pulled into an irregular circular hole, thus ensuring the stability of the hinge at this point and preventing the fastening bolts from loosening, the rack shaft from slipping out or even falling off, which could lead to the failure of the luffing mechanism and endanger the safety of personnel and equipment.

[0052] It should be noted that the terms such as "upper", "lower", "left", "right", "front", and "back" used in this utility model are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0053] The above are merely preferred embodiments 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 within its protection scope. 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 be considered within its protection scope.

Claims

1. A device for adjusting the hinge point of a rack and pinion, characterized in that: The device includes two eccentric bushings (4), each eccentric bushing (4) comprising a bushing (41) and a flange (42). The bushing (41) has an eccentric circular hole (43) axially formed inside. On the radial cross section of the bushing (41), the center of the eccentric circular hole (43) is offset from the center of the outer circle of the bushing (41). A flange (42) convex in the radial direction is also provided on the outer side of one end of the bushing (41). The bushings (41) of the two eccentric bushings (4) are respectively inserted into the support holes of the two boom supports (1). The flange (42) at one end of the bushing (41) is used to connect to the outer side walls of the two boom supports (1) that are far apart. The eccentric circular holes (43) of the two bushings (41) are used to allow the rack shafts (3) of the racks (2) set in the middle of the two boom supports (1) to be inserted and rotated.

2. The device for adjusting the hinge point of a rack and pinion according to claim 1, characterized in that: The flange (42) is provided with several annularly distributed connecting holes at equal intervals. The outer wall of the boom support (1) is provided with mounting holes corresponding to the connecting holes. The flange (42) is screwed into the mounting holes and connecting holes respectively by bolts, and is connected to the outer wall of the boom support (1).

3. The device for adjusting the hinge point of a rack and pinion according to claim 2, characterized in that: It also includes a shaft end baffle (5), which is installed on the outside of the baffle (42) and is used to connect the baffle (42) and the outer wall of the boom support (1).

4. The device for adjusting the rack hinge point according to claim 1, characterized in that: The outer ring sidewall of the retaining edge (42) is provided with several radially protruding adjustment protrusions (44) at equal intervals.

5. The device for adjusting the rack hinge point according to claim 4, characterized in that: It also includes an adjusting wrench (6), which includes an adjusting end and a circular adjusting hole. The inner sidewall of the adjusting hole is provided with a protrusion groove (61) for the adjusting protrusion (44) to engage.

6. The device for adjusting the rack hinge point according to claim 5, characterized in that: The adjusting wrench (6) also includes a handle, and the adjusting end is connected to the handle on one side.

7. The device for adjusting the hinge point of a rack and pinion according to claim 1, characterized in that: The sum of the wall thicknesses of the narrowest and widest ends of the bushing (41) is equal to the sum of the wall thicknesses of the other two ends perpendicular to the narrowest and widest ends.

8. The device for adjusting the hinge point of a rack and pinion according to claim 1, characterized in that: The bushing (41) is made of wear-resistant and extrusion-resistant plastic polymer material.

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