RU2578883C1 - Pipes cold rolling mill - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: mill contains reciprocating movement along bedplate guides of the work mill, installed on it rollers with gauges and pinions, driven crank gear, connected via the piston rods with the work mill, that contains horizontally installed crank-type and balance shafts with pinions and counterweights installed between piston rods to balance the inertia forces from the work mill. The rollers with gauges are installed in the work mill vertically, the crank-type and balance shafts have additional pinions, axles for the piston rods installation are arranged on pinions of the crank shaft. The crank gear has two labyrinth seals between the piston rod and toothed rim of the pinion of the crank shaft.

EFFECT: possibility of complete balance of the inertia forces from the work mill.

7 dwg

Description

The invention relates to the field of metal forming, and more specifically to cold rolling mills with a moving reciprocating working stand, the mass of inertia of which can be compensated by counterweights, eccentrically located on the crank mechanism connected via connecting rods to the working stand.

Known cold rolling pipe mill, see RF patent No. 2247613, class. B21B 21/00 claimed 09/05/2003, publ. 03/10/2005 (Fig. 3a, 3b). The known cold pipe rolling mill comprises a working stand reciprocating along the bed guides, rolls with gauges and gears placed therein, a drive crank mechanism connected via connecting rods to the working stand, which includes horizontally located crank and balancing shafts with the cranks located between the rods gears and balances to balance the forces of inertia from the working stand. Rolls with calibers in the working stand are installed horizontally. The drive mechanism is located below the level of the working stand. The connecting rods are fixed to the base of the working stand.

A disadvantage of the known cold rolling mill is a significant tilting moment on the working stand due to the fastening of the connecting rods to the base of the housing of the working stand, resulting in accelerated wear of the guide stands and bed. The durability of the equipment decreases, the cost of repair and maintenance of the mill increases.

The next disadvantage of this mill is the need to carry out a deep foundation for the mill, which leads to high costs and complicates maintenance.

Another disadvantage of the known mill is the lack of reliability and durability of the drive crank mechanism. This is because the shaft with cranks is mounted on two large-diameter bearings, while the diameter of the bearing is greater than the stroke length of the working stand, and the distance between the bearings is unacceptably small - less than 5 times less than the diameter of the bearing. In essence, the shaft stands on a spherical support and in operation will undergo alternating distortion, which will lead to intensive wear of the gear mechanism and its failure.

In addition, it is impossible to balance the working stand with counterweights integrated into the corresponding gears with their location along the rolling axis. The mass of the counterweight of the crank shaft is too small and can only balance the mass of the cranks with connecting rods. The mass of the counterweight balancing shaft is selected from the condition of equality of the imbalances of the crank shaft and the balancing shaft to ensure that the stand stops in any position along the stroke length. In this case, the mass of the counterweight will be zero. As a result, balancing stands is absent. In the event of an attempt to completely balance the working stand in dynamics, the dimensions of the gears of the crank and balancing shafts will increase sharply, which will lead to an increase in the dimensions of the drive crank mechanism, an increase in the diameter of the bearings of the crank shaft and a decrease in the reliability and durability of the mill.

Of the known cold pipe rolling mills, the closest in technical essence is the cold pipe rolling mill described in RF patent No. 2048218, class. B21B 21/00 claimed 05/26/1992, publ. November 20, 1995 (Fig. 8, 9).

This cold tube rolling mill contains a working stand reciprocating along the guides of the bed, rolls with gauges and gears placed in it, a drive crank mechanism connected through connecting rods to the working stand and including horizontally located crank and balancing shafts with gears placed between the connecting rods and counterweights to balance inertia from the working stand. Rolls with calibers in a working stand are located horizontally. The connecting axles of the connecting rods are placed in counterweights.

A disadvantage of the known design of the cold rolling mill is that the installation of rolls of the working stand horizontally determines the presence of a small distance between the connecting rods, which does not allow balancing weights (balances) required by the magnitude of the balancing masses between the connecting rods on the shafts of the drive crank mechanism, therefore, it is possible to provide only partial balancing of inertia forces (≈ up to 50%). The imbalance of the drive mechanism with the stand leads to increased losses of electricity, reducing the reliability and durability of the mill.

The disadvantage is the use of one row of gears offset from the rolling axis, which creates an asymmetric action of forces on the drive shafts, alternating distortions of the shafts occur, as a result of intense gear wear, a decrease in the reliability and durability of the mill.

In addition, the horizontal installation of the rolls in the working stand complicates the handling of the stand, increases the downtime of the mill when replacing the rolling tool, resulting in reduced annual productivity of the mill.

Another drawback of the known design of the cold rolling mill is that the placement of the connecting axles of the connecting rods in the balances reduces the effectiveness of these balances, since part of the mass of the balances will not balance the mass of the stand, but the mass of the installation points of the crank axes, as a result, the degree of equilibrium of the system of the work stand drive, the efficiency of the mill is reduced.

Another disadvantage of the mill is that the use of three shafts with counterweights in the drive mechanism leads to an increase in the metal consumption and the laboriousness of manufacturing the drive mechanism.

The objective of the present invention is to create a cold rolling mill, which improves reliability, durability, efficiency and productivity due to the complete balancing of the inertial forces from the working stand, the optimal placement of balances and cranks and the use of labyrinth seals.

The problem is achieved in that in a cold rolling mill of pipes containing a working stand reciprocating along the bed guides, rolls with gauges and gears placed therein, a drive crank mechanism connected through connecting rods to the working stand and including a horizontally arranged crank and balancing shafts with gears and counterweights placed between the connecting rods to balance the inertia forces from the working stand, according to the invention, the rolls with calibers are installed in the working it stands vertically, the crank and balancing shafts are equipped with additional gears, the connecting axles of the connecting rods are located on the gears of the crank shaft, and the drive crank mechanism is equipped with two labyrinth seals, each of which is located between the connecting rod and the ring gear of the crank shaft.

Such a constructive implementation of the cold pipe rolling mill can improve reliability and durability, improve efficiency, increase productivity.

Improving the reliability and durability, improving the efficiency is achieved due to the complete balancing of the inertial forces from the working stand by the counterweights of the crank and balancing shafts of the drive crank mechanism. There is an unloading of the units and mechanisms of the mill, reducing the total cost of electricity while maintaining useful work.

This is also achieved by installing the rolls of the working stand vertically, which allows you to increase the distance between the connecting rods, which freely accommodates the required dimensions of the counterweights of the crank and balancing shafts of the drive crank mechanism. This allows you to perform a drive crank mechanism with a minimum number of shafts and two-flow symmetrical with respect to the vertical plane passing through the rolling axis. In addition, with the use of labyrinth seals, each of which is installed between the connecting rod and the gear ring of the crankshaft gear, the ingress of technological cutting fluid into the circulation lubrication system is excluded, which extends the service life of bearings and gears of mechanisms.

The increase in the annual productivity of the mill is achieved by reducing downtime when replacing the rolling rolls. Replacement of vertical rolls in the stand is carried out with minimal disassembly of the mill.

To explain the invention, a specific embodiment of the invention is provided below with reference to the accompanying drawings, in which:

in FIG. 1 shows a cold pipe rolling mill, general view;

in FIG. 2 is a section AA in FIG. one;

in FIG. 3 is a section BB in FIG. 2;

in FIG. 4 is a section bb in FIG. one;

in FIG. 5 is a section GG in FIG. one;

in FIG. 6 - place D in FIG. 5;

in FIG. 7 is a section EE in FIG. 3.

The cold tube rolling mill contains a working stand 1, reciprocating along the guides 2 of the bed 3, located in the working stand of the roll 4 with gauges 5 and gears 6, a drive crank mechanism connected through connecting rods 7 to the working stand 1. The drive crank the connecting rod mechanism includes horizontally located crank 8 and balancing 9 shafts, on which gears 10, 11, additional gears 12, 13, counterweights 14, 15, 16, 17 for balancing the inertia forces from the working stand 1 and the drive shaft 18, are installed tained on bearings 19, 20. All of the gear pinion and the counterweights are arranged between the connecting rod 7. A crank shaft 8 mounted in bearings 21. The counterweight shaft is mounted in bearings 22. The rollers 4 with gauges 5 are in the work stand 1 and are driven vertically. The connecting rod axes 23 are mounted on the gears 10, 12 of the crank shaft 8. Between the connecting rods 7 and the gear rims of the gears 10, 12 of the crank shaft 8 there are labyrinth seals 24 that provide waterproofing of the cavity Ж, where liquid circulating lubricant from the cavity 3, into which the process fluid is applied grease used in pipe rolling. The labyrinth seal 24 consists of a ring 25 with a protrusion And, which is lined with antifriction plates 26, a rubber cord 27 and a ring 28 with a depression K under the protrusion And of the ring 25. The ring 25 with a rubber cord 27 is installed in a detachable housing of the crank mechanism between the base 29 and the cover 30, and the ring 28 is mounted on the gears 10, 12 of the crank shaft 8. For removal and collection of process grease falling into the cavity 3, the drive crank mechanism is equipped with covers 31 and a drain manifold 32.

The cold pipe rolling mill operates as follows.

When rolling the pipe, the rotating crank shaft 8 of the drive crank mechanism reports through the connecting rods 7 of the working stand 1 with the rolls 4 the reciprocating motion of the stationary frame 3, while gauges 5 periodically run the pipe with the profiles of their streams, deforming it in the extreme positions of the stand, during periods of the opening of streams of calibers 5, the pipe is intermittently turned and fed forward.

During the operation of the mill, the inertia force from the working stand is balanced by the total inertial force from the counterweights of the drive crank mechanism, which minimizes torque fluctuations on the drive shaft 18, the loads on the drive crank mechanism are reduced, the reliability and durability of the mill are increased, and energy costs are reduced. to the work of the camp.

When rolling the pipe, a cutting fluid (coolant) is supplied to the deformation zone. The main amount of coolant flows into the bed 3 and returns via a drain pipe to the process lubrication system, but part of the coolant is sprayed by a moving working stand and gets on the connecting rods 7 of the drive mechanism, and from them - on the connecting axis of the connecting rods 23 and the side surfaces of the gears 10. At the same time time to gears of gears 10, 11, 20 and bearings 21, 22, 19 of the crank drive gear oil comes from a special system of liquid circulation lubrication (ZhSS).

To exclude mixing of the coolant and the LCS, labyrinth seals 24 were used, operating as follows. When the crank shaft 8 is rotated, centrifugal forces displace the coolant and the LC from the depression K along the protrusion And to the ring 25, preventing the mixing of lubricants. The coolant flows into the cavity 3, is collected by the collector 32 and returned to the process lubrication system. ZHSS gathers in a cavity Zh and returns to the liquid circulation lubrication system through a drain pipe. The mill does not allow the mixing of coolant and ZHSS, which reduces the consumption of lubricants and increases the reliability and durability of the equipment.

The transfer of rolls 4 mounted vertically in the working stand 1 is carried out quickly with minimal disassembly of the mill. Rolls 4 in a pair are removed from stand 1 vertically upwards and are set in place by a pair. Dismantling and assembling of the rolls 4 is carried out away from the mill on the stand, while the mill can continue to work using other previously prepared rolls.

The proposed cold pipe rolling mill in comparison with the known ones allows to increase reliability and durability, efficiency and productivity due to the complete balancing of inertial forces from the working stand, optimal placement of counterweights and cranks and the use of labyrinth seals.

Claims (1)

Cold pipe rolling mill, comprising a working stand reciprocating along the guides of the bed, rolls with gauges and gears placed therein, a drive crank mechanism connected through connecting rods to the working stand and including horizontally located crank and balancing shafts with gears placed between the connecting rods and counterweights for balancing the inertia forces from the working stand, characterized in that the rolls with calibers are installed vertically in the working stand, crank and Shiva shafts are provided with further gear wheels, connecting rods placed on the mounting axis of the crank shaft gears, and the drive crank mechanism is provided with two labyrinth seals, each of which is arranged between a rod and a toothed ring gear of the crank shaft.

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