Cam limiting device for crane luffing mechanism

Abstract

The utility model provides a cam limiting device for a luffing mechanism of a crane, which comprises a gear box arranged on an end cover of the luffing mechanism; the first gear shaft is rotatably arranged in the gear box and is used for being connected with an input shaft of the luffing mechanism; the second gear shaft is rotatably arranged in the gear box, and a first gear on the first gear shaft is meshed with a second gear on the second gear shaft; one end of the flange seat is connected with the outer side of the gear box; the cam limiter is connected with the other end of the flange seat, and a mounting shaft of the cam limiter is connected with the output end of the second gear shaft through a coupler. The cam limiting device provided by the utility model can effectively solve the problem that the mounting shaft for limiting the cam is easy to generate fatigue fracture, and the use and maintenance cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical design and manufacturing, in particular to a cam limiting device for a crane luffing mechanism. Background Art

[0002] The rack-and-pinion luffing gantry crane realizes the luffing action of the boom through rack transmission. The safety contact point of the cam switch limit is set in advance to limit the range of the boom and ensure that the gantry crane operates within the designed range.

[0003] The cam limiter configured for the luffing mechanism is usually installed at the end of the low-speed pinion shaft. The principle is that after the cam limit safety contact is triggered, the signal is transmitted to the control inverter to achieve automatic deceleration before the maximum / minimum amplitude, automatic stop when the maximum / minimum amplitude is reached, etc. The luffing mechanism pinion stroke of conventional rack-and-pinion luffing gantry cranes is short, and the number of working turns is small. It is not compatible with the brand of cam limit switch required by users, and it is necessary to add a first-level speed-increasing mechanism to achieve the appropriate working turn range of the cam limiter.

[0004] However, in the existing variable amplitude cam limit speed increasing device, due to certain structural defects, the mounting shaft of the cam limit is prone to fatigue fracture, which greatly increases the use and maintenance costs. Utility Model Content

[0005] In view of this, the utility model provides a cam limiter for a crane luffing mechanism, which can effectively improve the problem that the mounting shaft of the cam limiter is prone to fatigue fracture and reduce the use and maintenance costs.

[0006] In order to solve at least one of the above technical problems, the present invention adopts the following technical solutions:

[0007] The cam limiting device for a crane luffing mechanism according to an embodiment of the utility model comprises:

[0008] A gear box, the gear box being arranged on an end cover of the luffing mechanism;

[0009] a first gear shaft, the first gear shaft being rotatably disposed in the gear box and being used to be connected to an input shaft of the amplitude varying mechanism;

[0010] a second gear shaft, the second gear shaft being rotatably disposed in the gear box, the first gear on the first gear shaft being meshed with the second gear on the second gear shaft;

[0011] A flange seat, one end of which is connected to the outer side of the gear box;

[0012] A cam limiter is connected to the other end of the flange seat, and a mounting shaft of the cam limiter is connected to the output end of the second gear shaft through a coupling.

[0013] Furthermore, a hole body connected to the input shaft of the luffing mechanism is provided on the shaft of the first gear shaft, the hole body and the input shaft of the luffing mechanism are connected by a key, and the hole body, the input shaft of the luffing mechanism and the first gear shaft are coaxial.

[0014] Furthermore, the flange seat comprises a sleeve, flanges are respectively arranged at both ends of the sleeve, and the coupling is a cross slider coupling and is located in the sleeve.

[0015] Further, a first protrusion is formed outwardly on the surface of the end cover of the amplitude varying mechanism, and a first recessed portion matching with the first protrusion is formed on the gear box;

[0016] A second protrusion is formed outwardly on the outer side surface of the gear box connected to the flange seat, and a second recessed portion matched with the second protrusion is correspondingly formed on the flange seat.

[0017] Furthermore, the cam limiter also includes a mounting seat, and the mounting seat is detachably connected to the flange seat by bolts.

[0018] Furthermore, an injection port is provided at the upper end of the gear box, and an oil drain port is provided at the lower end of the gear box. Sealing plugs are detachably provided on the injection port and the oil drain port, respectively.

[0019] Furthermore, the gear box is provided with first through holes corresponding to the two ends of the first gear shaft and second through holes corresponding to the two ends of the second gear shaft, and the two first through holes are respectively provided with first bearings matching with the first gear shaft, and the two second through holes are respectively provided with second bearings matching with the second gear shaft, and the first bearing and the second bearing are both rolling bearings.

[0020] Furthermore, a skeleton oil seal is used to seal the first through hole and the first gear shaft, and the skeleton oil seal is located on a side of the first bearing away from the inner cavity of the gear box.

[0021] Furthermore, a gap seal is adopted between the second through hole and the second gear shaft.

[0022] Furthermore, the cam limiter of the utility model further comprises a cover shell, and the cover shell is arranged to cover the outside of the gear box, the flange seat and the cam limiter.

[0023] The above technical solution of the utility model has at least one of the following beneficial effects:

[0024] According to the embodiment of the utility model, the cam limiter for the crane luffing mechanism comprises: a gear box, a first gear shaft, a second gear shaft, a flange seat and a cam limiter, wherein the first gear shaft is rotatably arranged in the gear box and is used to be connected with the input shaft of the luffing mechanism; the second gear shaft is rotatably arranged in the gear box, and the first gear on the first gear shaft is meshed with the second gear on the second gear shaft; one end of the flange seat is connected to the outside of the gear box; the cam limiter is connected to the other end of the flange seat, and the mounting shaft of the cam limiter is connected to the output end of the second gear shaft through a coupling. Therefore, the utility model adopts an improved gear transmission structure, arranges the first gear shaft and the second gear shaft in the gear box, optimizes the structure, and under the coordinated action of the flange seat and the coupling, effectively alleviates the problem of additional radial force and stress concentration of the mounting shaft of the cam limiter due to the cantilever structure, improves the stability and durability of the overall structure, thereby reducing the risk of fatigue fracture of the mounting shaft of the cam limiter and reducing the use and maintenance costs.

[0025] In addition, the cam limit device of the utility model also optimizes the lubrication method of the gears. The gears in the gear box can be lubricated by oil bath lubrication, ensuring that there is enough lubricating oil in the gear box to reduce the resistance between the driving first gear and the second gear. It is also easy to replace and reduce the daily maintenance and after-sales repair costs of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural schematic diagram of a cam limiter for a crane luffing mechanism according to an embodiment of the utility model;

[0027] Figure 2 for Figure 1 The enlarged schematic diagram at A in the middle;

[0028] Figure 3 for Figure 1 The enlarged schematic diagram of point B in the middle;

[0029] Figure 4 It is a schematic diagram of the structure of a variable amplitude cam position limiting and speed increasing device in some implementation modes.

[0030] Reference numerals: 1. gear box; 11. second protrusion; 12. injection port; 13. oil drain port; 14. groove;

[0031] 2. First gear shaft; 21. First gear; 22. First bearing; 23. Skeleton oil seal;

[0032] 3. Second gear shaft; 31. Second gear; 32. Second bearing;

[0033] 4. Flange seat; 41. Sleeve; 42. Flange; 43. Bolt;

[0034] 5. Cam limiter; 51. Mounting seat; 52. Mounting shaft;

[0035] 6. Coupling;

[0036] 7. end cap; 71. first protrusion;

[0037] 8. Input shaft of the luffing mechanism;

[0038] 9. Cover. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings of the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the utility model.

[0040] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate quantity restrictions, but indicate the existence of at least one. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship also changes accordingly.

[0041] Figure 4 A schematic structural diagram of a variable amplitude cam position limiting and speed increasing device in some embodiments is shown.

[0042] like Figure 4 As shown, the existing variable amplitude cam limit speed increasing device adopts an internal gear transmission type, the transmission internal gear is installed on the shaft end of the variable amplitude gear shaft pressure plate, and the transmission external gear is installed on the cam limit installation shaft. In this speed increasing device, the cam limit installation shaft is a cantilever structure. During the gear transmission process, the cam limit installation shaft is subjected to additional radial force, and the root stress is particularly concentrated. In addition, the cam limit installation shaft itself is small in size, and fatigue fracture is prone to occur under the action of repeated alternating stress, which greatly increases the use and maintenance costs.

[0043] In addition, in the existing variable amplitude cam limit speed increasing device, the gears are lubricated by applying grease, which easily leads to uneven lubrication on the gear surface and difficulty in forming a stable lubrication film, thereby increasing friction and wear between the gears.

[0044] The following is combined with Figure 1-3 The cam limit device for the luffing mechanism of a crane according to an embodiment of the utility model (hereinafter sometimes simply referred to as "cam limit device") is described in detail.

[0045] Figure 1 A schematic structural diagram of a cam limiter for a crane luffing mechanism according to an embodiment of the utility model is shown; Figure 2 for Figure 1 The enlarged schematic diagram at A in the middle; Figure 3 for Figure 1 Enlarged schematic diagram of point B in the middle.

[0046] Specifically, Figures 1 to 3 As shown, the cam limiter for the crane luffing mechanism according to the embodiment of the utility model may include: a gear box 1, a first gear shaft 2, a second gear shaft 3, a flange seat 4 and a cam limiter 5.

[0047] The gear box 1 is used to be arranged on the end cover 7 of the luffing mechanism. The first gear shaft 2 is rotatably arranged in the gear box 1 and is used to be connected with the input shaft 8 of the luffing mechanism. The second gear shaft 3 is rotatably arranged in the gear box 1, and the first gear 21 on the first gear shaft 2 is meshed with the second gear 31 on the second gear shaft 3. One end of the flange seat 4 is connected to the outside of the gear box 1, the cam limiter 5 is connected to the other end of the flange seat 4, and the mounting shaft 52 of the cam limiter 5 is connected to the output end of the second gear shaft 3 through the coupling 6. When the luffing mechanism is in operation, the input shaft 8 of the luffing mechanism drives the first gear shaft 2 to rotate, the first gear shaft 2 drives the second gear shaft 3 to rotate, and the second gear shaft 3 drives the mounting shaft 52 of the cam limiter 5 to rotate through the coupling 6, so that the cam of the cam limiter 5 interacts with the preset limit switch, and as the cam rotates, it touches or disengages the limit switch, thereby sending a control signal at a predetermined position, thereby realizing automatic deceleration before the maximum / minimum amplitude, automatic stop when reaching the maximum / minimum amplitude, and other actions.

[0048] Specifically, refer to Figure 1On the one hand, the first gear shaft 2 and the second gear shaft 3 are arranged in the gear box 1. Through the meshing of the first gear 21 on the first gear shaft 2 and the second gear 31 on the second gear shaft 3, the first gear shaft 2 is connected to the input shaft 8 of the amplitude variation mechanism, and the second gear shaft 3 is connected to the mounting shaft 52 of the cam limiter 5, thereby realizing the effective transmission of power from the input shaft of the amplitude variation mechanism to the mounting shaft 52 of the cam limiter 5. During this period, the direction of the force is mainly along the gear axis. In other words, the radial force (i.e., the force perpendicular to the axis) on the transmission member in this design is relatively small.

[0049] On the other hand, one end of the flange seat 4 is connected to the outside of the gear box 1, and the other end is connected to the cam limiter 5, which provides additional support for the cam limiter 5, helps to disperse the force acting on the mounting shaft 52 of the cam limiter 5, reduces the stress concentration at the root of the mounting shaft 52, and also enhances the rigidity of the overall structure through the connection with the gear box 1. In addition, the mounting shaft 52 of the cam limiter 5 and the output end of the second gear shaft 3 are connected through the coupling 6, so that the coupling 6 can absorb certain vibrations and impacts, reduce the impact of dynamic loads on the mounting shaft 52 of the cam limiter 5, and ensure the stability of the transmission, and reduce the damage of the mounting shaft 52 of the cam limiter 5 caused by alternating stress.

[0050] In summary, the cam limit device of the utility model adopts an improved gear transmission design, arranges the first gear shaft 2 and the second gear shaft 3 in the gear box 1, optimizes the structure, and under the coordinated action of the flange seat 4 and the coupling 6, effectively alleviates the additional radial force and stress concentration problems of the mounting shaft 52 of the cam limit 5 caused by the cantilever structure, improves the stability and durability of the overall structure, thereby reducing the risk of fatigue fracture of the mounting shaft 52 of the cam limit 5 and reducing the use and maintenance costs.

[0051] In addition, since the first gear shaft 2 and the second gear shaft 3 are arranged in the gear box 1, the gears in the gear box 1 can be lubricated by oil bath lubrication. The oil bath lubrication can form a stable lubricating film to ensure that there is enough lubricating oil in the gear box 1 to reduce the resistance between the driving first gear 21 and the second gear 31, effectively reduce the friction between the gears, extend the service life of the gears, and facilitate replacement, thereby reducing the cost of daily maintenance and after-sales repair of the equipment.

[0052] In some embodiments of the present invention, reference Figure 1 A hole body connected to the input shaft 8 of the luffing mechanism is provided on the shaft of the first gear shaft 2. The hole body and the input shaft 8 of the luffing mechanism are connected by a key. The hole body and the input shaft 8 of the luffing mechanism and the first gear shaft 2 are coaxial, so that the input shaft 8 of the luffing mechanism rotates together with the first gear shaft 2.

[0053] That is to say, reference Figure 1The so-called hole body is actually a shaft hole formed on the shaft of the first gear shaft 2 that matches the input shaft 8 of the luffing mechanism. Key slots are respectively provided on the input shaft 8 of the luffing mechanism and the inner wall of the shaft hole. The keys are respectively matched with the two key slots, so that the input shaft 8 of the luffing mechanism rotates together with the first gear shaft 2. Therefore, the structure is simple and maintenance is convenient, which ensures that the first gear shaft 2 and the input shaft 8 of the luffing mechanism are coaxial, can reduce the deflection and vibration during the transmission process, effectively improve the transmission efficiency, and avoid the additional bending moment or shear stress caused by the misalignment of the shaft, thereby extending the service life of the device.

[0054] In some embodiments of the present invention, reference Figure 1 The flange seat 4 includes a sleeve 41, and flanges 42 are respectively provided at both ends of the sleeve 41. The coupling 6 is an Oldham coupling and is located in the sleeve 41. Therefore, the sliding between the sleeve and the middle piece of the Oldham coupling can allow large radial and angular deviations without generating bending moment, so that the axial load of the mounting shaft 52 of the cam limiter 5 is reduced to a minimum.

[0055] In some embodiments of the present invention, reference Figure 1 and Figure 3 A first protrusion 71 is formed outwardly on the surface of the end cover 7 of the amplitude varying mechanism, and a first recessed portion (not shown) matching with the first protrusion 71 is formed on the gear box 1; a second protrusion 11 is formed outwardly on the outer surface where the gear box 1 is connected to the flange seat 4, and a second recessed portion (not shown) matching with the second protrusion 11 is correspondingly formed on the flange seat 4.

[0056] That is to say, Figure 1 , Figure 3 As shown, the gearbox 1 and the end cover 7 of the variable amplitude mechanism are positioned by a positioning structure, the first protrusion 71 can be a boss structure on the end cover 7, the first recessed portion can be a groove structure on the gearbox 1, the first protrusion 71 is inserted into the first recessed portion to position the gearbox 1 and the end cover 7 of the variable amplitude mechanism, and ensure that the first gear shaft 2 and the input shaft 8 of the variable amplitude mechanism are installed concentrically. Similarly, the flange seat 4 and the gearbox 1 are positioned by a positioning structure, and correspondingly the second protrusion 11 can be a boss structure on the gearbox 1, the second recessed portion can be a groove structure on the surface of the flange seat 4, the second protrusion 11 is inserted into the second recessed portion to position the flange seat 4 and the gearbox 1, and ensure that the second gear shaft 3 and the installation shaft 52 of the cam limiter 5 are installed concentrically. In this way, the deflection and vibration in the transmission process can be reduced, the transmission efficiency is effectively improved, and at the same time, the additional bending moment or shear stress caused by shaft misalignment is avoided, and the service life of the device is extended.

[0057] In some embodiments of the present invention, reference Figure 1The cam limiter 5 further includes a mounting seat 51, and the mounting seat 51 is detachably connected to the flange seat 4 through bolts 43. Therefore, on the one hand, the design of the mounting seat 51 improves the stability of the cam limiter 5; on the other hand, the design of the detachable connection improves the flexibility of the device and facilitates maintenance.

[0058] In some embodiments of the present invention, reference Figure 1 The upper end of the gearbox 1 is provided with an injection port 12, and the lower end of the gearbox 1 is provided with an oil drain port 13. The injection port 12 and the oil drain port 13 are respectively provided with sealing plugs which can be detachably provided. Thus, lubricating oil can be added into the gearbox 1 through the injection port 12, and the lubricating oil in the gearbox 1 can be discharged through the oil drain port 13. The gears in the gearbox 1 are lubricated by oil bath, and the oil bath lubrication can form a stable lubricating film, effectively reduce the friction between the gears, extend the service life of the gears, and reduce the maintenance cost and the risk of environmental pollution.

[0059] In some embodiments of the present invention, reference Figure 1 The gear box 1 is provided with first through holes (not shown) corresponding to the two ends of the first gear shaft 2 and second through holes (not shown) corresponding to the two ends of the second gear shaft 3. The two first through holes are respectively provided with first bearings 22 matched with the first gear shaft 2, and the two second through holes are respectively provided with second bearings 32 matched with the second gear shaft 3. Both the first bearings 22 and the second bearings 32 are rolling bearings. Therefore, when the amplitude changing mechanism is running, the meshing first gear 21 and the second gear 31 rotate, and there is a radial thrust between the two gears. Both ends of the first gear shaft 2 and the second gear shaft 3 are supported by bearings, so that after the force is applied, the fixed ends of the first gear shaft 2 and the second gear shaft 3 will not be offset and the radial force will not be transmitted to the output end of the second gear shaft 3 and the mounting shaft 52 of the cam limiter 5.

[0060] In some embodiments of the present invention, reference Figure 1 to Figure 2 The first through hole and the first gear shaft 2 are sealed by a skeleton oil seal 23, which is located on the side of the first bearing 22 away from the inner cavity of the gear box 1. There can be one or more skeleton oil seals 23. Thus, the sealing performance of the gear box 1 is effectively improved.

[0061] In some embodiments of the present invention, reference Figures 1 to 3 , a gap seal is used between the second through hole and the second gear shaft 3. Specifically, Figure 3 As shown, an appropriate gap is left between the output end of the second gear shaft 3 and the inner wall of the second through hole, and a plurality of grooves 14 can be provided on the inner wall of the second through hole, and the grooves 14 are usually annular grooves arranged along the circumferential direction of the output end of the second gear shaft 3, thereby forming a gap sealing structure. Thus, the sealing performance of the gear box 1 is improved.

[0062] It should be noted that the sealing structure between the second through hole and the second gear shaft 3 includes but is not limited to a gap seal, and may also be a sealing ring or a skeleton oil seal.

[0063] In some embodiments of the present invention, reference Figure 1 The cam limiter device of the present invention further comprises a cover 9, which is arranged outside the gear box 1, the flange seat 4 and the cam limiter 5. Thus, it is possible to effectively prevent external mitigation factors from damaging the internal precision components, such as dust, moisture or corrosive substances, thereby extending the service life of the device and reducing maintenance costs.

[0064] In some embodiments of the present invention, reference Figure 1 and Figure 2 The gearbox 1 is provided with a bearing end cover, which is used to fix the corresponding bearing on the gearbox 1. The bearing end cover can be one, two or more. For example, Figure 1 and Figure 2 As shown, there is one bearing end cover, which corresponds to the end of the first gear shaft 2 away from the luffing mechanism, and is mounted on the gear box 1 by bolts, thereby fixing the first bearing 22 in the first through hole. Therefore, in actual use, the operator can quickly open the designated bearing end cover to inspect, lubricate or replace the corresponding bearing without destroying the overall structure, which is convenient for disassembly and maintenance, greatly shortens downtime, improves work efficiency, and effectively reduces maintenance costs.

[0065] The above is a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A cam limiter for a crane luffing mechanism, characterized in that: include: A gear box, the gear box being arranged on an end cover of the luffing mechanism; a first gear shaft, the first gear shaft being rotatably disposed in the gear box and being used to be connected to an input shaft of the amplitude varying mechanism; a second gear shaft, the second gear shaft being rotatably disposed in the gear box, the first gear on the first gear shaft being meshed with the second gear on the second gear shaft; A flange seat, one end of which is connected to the outer side of the gear box; A cam limiter is connected to the other end of the flange seat, and a mounting shaft of the cam limiter is connected to the output end of the second gear shaft through a coupling.

2. The cam limiting device according to claim 1, characterized in that: A hole body connected to the input shaft of the luffing mechanism is arranged on the shaft of the first gear shaft. The hole body and the input shaft of the luffing mechanism are connected via a key. The hole body, the input shaft of the luffing mechanism and the first gear shaft are coaxial.

3. The cam limiting device according to claim 1, characterized in that: The flange seat comprises a sleeve, flanges are respectively arranged at both ends of the sleeve, and the coupling is a cross slider coupling and is located in the sleeve.

4. The cam limiting device according to claim 1, characterized in that: A first protrusion is formed outwardly on the surface of the end cover of the amplitude varying mechanism, and a first recessed portion matching with the first protrusion is formed on the gear box; A second protrusion is formed outwardly on the outer side surface of the gear box connected to the flange seat, and a second recessed portion matched with the second protrusion is correspondingly formed on the flange seat.

5. The cam limiting device according to claim 4, characterized in that: The cam limiter also includes a mounting seat, and the mounting seat is detachably connected to the flange seat by bolts.

6. The cam limiting device according to claim 1, characterized in that: The upper end of the gear box is provided with an injection port, and the lower end of the gear box is provided with an oil drain port. Sealing plugs are detachably provided on the injection port and the oil drain port, respectively.

7. The cam limiting device according to claim 1, characterized in that: The gear box is provided with first through holes corresponding to the two ends of the first gear shaft and second through holes corresponding to the two ends of the second gear shaft. The two first through holes are respectively provided with first bearings matching with the first gear shaft, and the two second through holes are respectively provided with second bearings matching with the second gear shaft. Both the first bearing and the second bearing are rolling bearings.

8. The cam limiting device according to claim 7, characterized in that: A skeleton oil seal is used to seal the first through hole and the first gear shaft. The skeleton oil seal is located on a side of the first bearing away from the inner cavity of the gear box.

9. The cam limiting device according to claim 7, characterized in that: A gap seal is adopted between the second through hole and the second gear shaft.

10. The cam limiting device according to claim 1, characterized in that: It also includes a cover shell, which is arranged outside the gear box, the flange seat and the cam limiter.

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