EA045270B1 - LOAD-LIFTING MECHANISM OF BRIDGE, TOWER AND GANTRY CRANES - Google Patents

Description

systems.

The invention relates to equipment designed for lifting, lowering and moving cargo by means of bridge, tower and gantry cranes.

A known lifting mechanism is the closest in technical essence, which is a prototype [1,2], proposed, containing a three-phase squirrel-cage asynchronous electric motor connected by means of couplings with a multi-stage cylindrical gear reducer and a rope driving drum, mounted on two supports, the rotation of which is accompanied by winding of the cargo rope, and therefore by lifting a load rigidly connected directly to the crane trolley platform, as well as shoe brakes.

The main disadvantages of this main mechanism of load-lifting cranes are that it does not provide a wide range of regulation of operating speeds, as well as the landing speed of lowering the load; when lifting or lowering large and small loads, the mechanism does not operate in favorable conditions, which is accompanied by significant energy consumption; when using the classical approach of creating a multi-stage gearbox, its weight and overall dimensions increase significantly; manufacturing existing gearboxes for lifting mechanisms is relatively expensive; there is no automatic control and regulation of the electric motor rotation speed depending on the mode of ascent, descent, as well as the size of the load.

The objective of the invention is energy saving; using a creative approach to creating a two-flow three-stage cylindrical gear reducer [3]; reduction in overall dimensions; ensuring the required range of automatic control of operating speeds and lifting or lowering modes depending on the size of the load; increasing the level of reliability and efficiency lifting mechanism.

The problem of the invention is solved by the fact that in the proposed lifting mechanism, to ensure energy saving and a certain range of regulation of operating speeds, it has two three-phase squirrel-cage asynchronous servo-electric motors with the same power and rotation speed, operating in stages in several modes depending on the size of the load and the required speed value when lifting it or descent; to enhance the torque of two servo-electric motors in the process of assembling the gearbox, two cylindrical gears and a gear wheel are used, rigidly connected by means of keyed connections with two drive shafts mounted on the corresponding rolling bearings in the gearbox housing; three double-crown gear blocks rotating freely on plain bearings mounted on the axles of the drive shafts, as well as on an intermediate shaft installed in the middle of the gearbox housing, which together constitute an innovative two-flow three-stage transmission mechanism; in this case, the double-crown blocks of gear wheels located on the axes of two drive and intermediate shafts rotate freely on double plain bearings around their axes in the same direction, and thus during the operation of the gearbox, due to the micro-roughness of the corresponding contacting surfaces, they engage with each other , provides a positive effect on increasing torque and leads to a significant increase in reliability and efficiency. of this mechanical system. This shows that the above features are significant and affect the achieved result, in particular, providing an innovative solution to the problem of improving the design of the lifting mechanism of cranes, energy saving, reducing overall dimensions, the possibility of using a special device for automatically regulating operating speeds and the mode of lifting or lowering at low and heavy loads, increasing the level of reliability and efficiency of this mechanical system.

The drawing shows a top view of the kinematic diagram of the cranes' lifting mechanism.

The lifting mechanism contains a three-phase squirrel-cage asynchronous servo-electric motor (1), connected by means of couplings (2) with a multi-stage cylindrical gear reducer (3) and a rope driving drum (4), mounted on two supports (5), the rotation of which is accompanied by winding of the load rope (6) , and therefore by lifting the load, which are rigidly connected directly to the platform (7) of the crane trolley; shoe brakes (8), and to ensure energy saving and a certain range of regulation of operating speeds, it has two three-phase squirrel-cage asynchronous servo-electric motors with a variable number of pairs of stator poles, operating in stages in several modes depending on the size of the load and the required speed value when lifting or lowering it; To enhance the torque of these low-power two electric motors, in the process of assembling the gearbox, two cylindrical gears (9) and a gear wheel (10) are used, rigidly connected by means of key connections (11) with two drive shafts (12), mounted on the corresponding rolling bearings (13 ) in the gearbox housing (14), three double-crown blocks of gear wheels (15), freely rotating on plain bearings (16) mounted on the axes of the drive shafts, as well as on the axis of the intermediate shaft (17) installed in the middle of the gearbox housing, which in the aggregates represent a two-flow three-stage transmission mechanism; in this case, the double-crown blocks of gear wheels located on the axes of two drive and intermediate shafts rotate freely on plain bearings around their axes in the same direction, and thus during the operation of the gearbox due to micro-non-

Claims (3)

the evenness of the corresponding contacting surfaces engages them with each other, which provides a positive effect on increasing the torque, and thereby leads to a significant increase in the level of reliability and efficiency. of this mechanical system. The load-lifting mechanism of cranes works as follows: After switching on three-phase squirrel-cage asynchronous servo-electric motors (1) with a variable number of pairs of stator poles, operating in stages in several modes depending on the size of the load and the required speed when lifting or lowering it, connected through friction clutches (2) , the rotational motion is transmitted to a two-flow three-stage gearbox (3), from where to a rope driving drum (4) mounted on two supports (5); the rotation of the drum is carried out by winding the cargo rope (6), therefore the load is raised or lowered; by means of shoe brakes (8) rigidly connected directly to the platform (7) of the crane trolley, stopping and rotation of the cargo drum is ensured; Moreover, the amplification of the rotational moment of low-power two servo-electric motors is provided by means of two cylindrical gears (9) and a gear wheel (10), rigidly connected by keyed connections (11) with two drive shafts (12) mounted on the corresponding rolling bearings (13) in the gearbox housing (14 ), as well as three double-crown blocks of gear wheels (15), freely rotating on plain bearings (16), mounted on the axes of the drive and intermediate shafts (17); in this case, the lifting mechanism, through the use of a control unit, operates in two favorable modes: a) when lifting a large load, both servo-electric motors work, and when lowering the load, one of them works, therefore saving energy by 25%; b) when lifting or lowering half of the total load, only one of the servo-electric motors works, therefore saving energy by 50%. Ultimately, the overall energy savings are 75%, which is of great practical importance. A working model of an innovative design solution for a crane lifting mechanism has been developed, manufactured and tested. Based on the results obtained, it was established that the proposed design of the crane lifting mechanism has the following advantages compared to other types: electricity is reduced by up to 75%; a wide range of regulation of the required operating speeds and landing speed of lowering the load is provided; the lifting mechanism has relatively small overall dimensions; the possibility of automatically adjusting the load capacity when lifting or lowering a load is created. Literature: 1. Federal Service for Intellectual Property of the Russian Federation Overhead crane. Patent RU 2492134,2013. 2. NPAOP 0.00-1.01-07 “Rule for the design and safe operation of load-lifting cranes”, 2007, No. 132. 3. Abdullaev A.I., Najafov A.M. Eurasian Patent Organization. Eurasian Patent Office. Patent No. 017053, 2012. CLAIM Load-lifting mechanism of bridge, tower and gantry cranes, containing a three-phase squirrel-cage asynchronous electric motor (1), connected by means of couplings (2) with a multi-stage cylindrical gear reducer (3) and a rope driving drum (4), mounted on two supports (5), during rotation which ensures the winding of the cargo rope (6), therefore lifting or lowering the load, which is directly connected to the platform (7) of the crane trolley and shoe brakes (8), characterized in that to ensure energy saving and a certain range of regulation of operating speeds, it has adaptive to external load two three-phase squirrel-cage asynchronous servo-electric motors with the same power and rotation frequency, consisting of variable numbers of pairs of stator poles, operating in stages in several modes depending on the size of the load and the required speed value when lifting or lowering it; To enhance the torque of these low-power two electric motors, an innovative gear transmission mechanism of three stages of sequentially connecting, separating and combining the input energy flow is used in the gearbox assembly process; two cylindrical gears (9) and a gear (10), rigidly connected by means of key connections (11) with two drive shafts (12) mounted on corresponding rolling bearings (13) in the gearbox housing (14), three double-crown gear blocks (15), freely rotating on plain bearings (16) mounted on the axes of the drive shafts, as well as on the axis of the intermediate shaft (17) installed in the middle of the gearbox housing, which together constitute a two-flow three-stage transmission mechanism; in this case, the double-crown blocks of gear wheels located on the axes of the two drive and intermediate shafts rotate freely on double