At present, the online sawing equipment for ERW welded pipe units with a diameter of 325 or less is mainly made up of ordinary flying saws. It is characterized by relatively small equipment investment, simple operation, easy to master, good product adaptability and high production efficiency. But at the same time, it has the disadvantages of high sawing noise, high energy consumption, low single sawing life and poor fracture quality. In addition, because the saw blade is sawing at high speed, it is easy to produce splits even after impact. The debris creates a great safety hazard to the production site. In a small number of 219325mm straight seam welded pipe units, it is equipped with turning and hobbing online flying saws. Although it has the advantages of safety, energy saving and high efficiency, it is only suitable for round pipe cutting and cannot be used for square tube and opening. The cutting of steel sections has certain limitations. For large-size welded pipe units, such as 610mm20mm or 500mm500mm20mm square rectangular pipe sets, if ordinary flying saws are used, the saw blade specifications should reach 2000mm or more in diameter, the sawing machine power should reach 300kW or more, and the whole machine weight should reach 20t or more, which gives online tracking. Sawing is very difficult. From the development of foreign online sawing technology, the large-scale flying saw with a diameter of about 2000mm has been eliminated, and replaced with a new type of CNC-like flying saw, which uses multiple small saw blades to quickly cut the steel pipe around the contour of the steel pipe. It saves energy and reduces noise, and it also improves on-site safety and quality of steel pipe processing. At present, foreign large-scale 219mm round tube units and 200mm200mm square rectangular tube units have adopted this sawing method in large quantities. Newly built Shanghai Baosteel, Zhongyou Tianbao, Jinzhou Pipeline ERW610mm, etc. Many sets of large-scale units have been introduced from abroad or developed their own sawing equipment, which has achieved good results after being put into production. 1The working principle of the steel pipe numerical control profile sawing machine When the ordinary flying saw saws the steel pipe, in addition to the tracking movement of the steel pipe, the saw blade has to be rotated and unidirectionally fed, and sawed once with a saw blade. The entire steel tube, so the diameter of the saw blade is at least 34 times larger than the largest workpiece. The steel pipe numerical control profile sawing machine, at the same time install 24 saw blades on their respective main shafts, evenly arranged around the steel pipe, each saw blade only needs to cut through the wall thickness of the steel pipe, and then cut along the pipe wall. Therefore, regardless of the size of the steel pipe, the saw blade diameter is generally between 300400mm. Carragide teeth are often used for saw blades, and high-speed steel saw blades are also used abroad, but they are not commonly used. In addition to self-rotation, each set of saw blade spindles is driven by multiple servo motors to complete the feeding of any curved path. It can follow the circular contour of the circular steel tube and follow the square shape. The shape of the rectangular steel tube travels in a segmented linear path. Each saw blade cuts through the wall thickness of the steel pipe into the pipe 510mm, cutting 1/41/2 of the circumference of the whole steel pipe, and the multiple saw blades synchronously revolve and cut the entire steel pipe, thereby greatly improving the sawing efficiency. Due to the smaller saw blade diameter, the sawing power consumption can be greatly reduced. The general installed capacity is between 50120 kW, which is much lower than the ordinary flying saw power of the same specification unit. Since the saw blade used for sawing is a hard alloy insert or an integral high-speed steel saw blade, the serrated edge portion is ground to a certain cutting inclination angle, and the sawing principle is used for the sawing process, thereby improving the service life of the saw blade and greatly improving the saw blade. The quality of the kerf of the steel pipe. The use of multi-blade milling flying saws can reduce the weight of the flying saw of large units, making the accuracy of positioning tracking easier. The working principle of steel pipe numerical control profile saw cutting is as shown. 2The type of steel pipe numerical control sawing machine Because the steel tube numerical control sawing technology has been applied in foreign countries for many years, the sawing machine manufacturing technology is quite mature. At present, the main manufacturers are Japan Nakata Co., ABBEY, and SMSmeer. Companies, etc., sawing machine can be divided into polar coordinate imitation form and double-column rectangular coordinate imitation form according to the profiling principle, which can be applied to the profile sawing of circular, square and rectangular steel pipes. Since 2003, the CNC profile sawing machine that has been introduced or developed by itself in China has developed a segmental linear profile sawing machine, which is specially designed for use in addition to the above two types of profiling. The sawing of square rectangular steel tubes. 2.1 Polar coordinate profiling flying saw machine The main structure of the sawing machine is a large disc with a hole in the middle to allow the welded pipe to pass through. The whole disc is driven by a servo motor, which can complete the whole rotation (also called the revolving of the saw blade). ). 24 linear guide rails are installed in the radial direction of the disc body, and a set of saw blade spindles are respectively mounted on the guide rails. Each set of spindles is driven by a motor and can be steplessly regulated. Each guide rail is controlled by a servo motor. The movement in the radial direction completes the cut-through movement of the steel pipe, the cut-through positioning of the steel pipe and the profiling movement. The specific working sequence is that after each saw blade cuts through the steel pipe, the disc starts to rotate rapidly, the saw blade travels along the outer contour of the steel pipe, cuts the whole steel pipe, and finally the saw blade returns to the starting position, ready for the next sawing cycle. This model is suitable for sawing steel pipes of various sections. Since the servo motor is controlled by the numerical control system, there is no need to replace the saw blade, and the CNC program can be adjusted to meet the requirements. The device structure diagram is as shown. 2.2 Cartesian-shaped profile flying saw machine The main structure of the flying saw machine of this model is in the form of double-column or four-column gantry. Horizontal and vertical linear guides are respectively installed on each column, and a set of saw blade spindles are installed on the outer guide rails. Each set of saw blade spindles is controlled by a motor and can be adjusted. Each guide rail is driven by a servo motor, and each servo motor is centrally controlled by a numerical control system. The saw blades on each guide rail can synthesize various trajectories by moving the horizontal and vertical coordinates to adapt to the sawing of steel pipes of different cross sections. The general working process is that the two saw blades quickly approach the steel pipe and directly cut through it. The depth of cut can be selected by itself, and then the two saw blades rotate rapidly along the outer contour of the steel pipe to cut the steel pipe quickly. Since multiple sets of numerical control systems are used to control the running path of the saw blade, a square, rectangular and circular steel tube can be sawed using a saw blade. The device structure diagram is as shown. 2.3 Segmental linear profiling flying saw machine This type of flying sawing machine is a variant of the ordinary rectangular coordinate profiling sawing machine. It is converted into four horizontal and vertical guide rails arranged in a single line on the basis of the original two sets of horizontal and vertical rails. Four sets of saw blade spindles can be installed at the same time, separated by 90. The whole machine shares 4 servo motors to drive the saw blade for linear sawing movement. Because it can't imitate the curved shape of the workpiece, it is only suitable for sawing square and rectangular steel tubes. 3 The scope of application of the flying saw machine In general, the steel pipe numerical control profile flying saw machine is used to saw large and medium-sized ERW welded steel pipe. The specification range of the sawn steel pipe is (219610mm) (420mm) round pipe and 200 mm (200500mm). 500mm (420mm) square rectangular tube. Because the saw blade uses carbide sawtooth, it can cut high-strength oil and gas pipelines, the highest steel grade can reach X80, and the maximum steel pipe wall thickness can reach 20mm, which is difficult for ordinary flying saws. 4 Auxiliary function of the flying saw machine In order to ensure that the steel pipe is synchronized with the saw blade during the sawing, no relative movement occurs. A hydraulic clamping device is arranged at the inlet and outlet of the steel pipe of the saw machine, which are arranged in two directions, horizontal and vertical. Depending on the manufacturer of the saw, different cooling methods are used for the saw blade, such as oil mist cooling and emulsion cooling, and some models adopt a completely dry cutting method. 5 Summary (1) For large-size ERW welded pipes, ordinary flying saws have high energy consumption, high noise, high risk, poor sawing quality, and difficult production, which needs to be updated. (2) CNC numerical control sawing technology replaces friction sawing by milling, which has the advantages of energy saving, noise reduction and safety, and can greatly improve the quality of saw cutting of steel pipes. (3) Domestic steel pipe manufacturers have begun to adopt steel pipe numerical control sawing technology through introduction and independent development. Due to their high economic and social benefits, they will be more and more widely used. (Finish)
Tower Crane gear mainly including 19/38/99 teeth gear, bevel gear, Tower Crane Sun Gear, and so on, which are the critical
parts of the tower crane reducer. 19 teeth gear and 38 teeth gear are
connected with two motor shaft repectively, which are connected with 99
teeth gear. The speed is reduced by the transmission of gears.
A bevel gear is a type of gear that has teeth cut on a conical surface. It is commonly used in tower cranes to transmit power between the vertical and horizontal shafts. Bevel Gear,Tower Crane Sun Gear,Crane Pinion Gear,Tower Crane Transmission Gear,Tower Crane Drive Shaft SHEN YANG BAOQUAN BUSINESS CO., LTD , https://www.sczenghui.com
In a tower crane, the bevel gear is typically used to change the direction of rotation. The vertical shaft, which is connected to the motor, rotates vertically, while the horizontal shaft, which is connected to the crane's boom, rotates horizontally.
The bevel gear consists of two gears with intersecting axes. The teeth on the gears are cut at an angle, allowing them to mesh smoothly and transmit power. The gear ratio of the bevel gear determines the speed and torque of the rotation.
The bevel gear in a tower crane is designed to withstand heavy loads and provide efficient power transmission. It is usually made of high-strength steel to ensure durability and reliability in demanding crane operations.
Overall, the bevel gear plays a crucial role in the functioning of a tower crane by enabling the transfer of power and changing the direction of rotation between the vertical and horizontal shafts.