RU2271257C2 - Drive unit for pilger tube cold rolling mill - Google Patents

Abstract

FIELD: improved designs of drive un its for pilger tube cold rolling mills, possibly used in any mills with stand performing reciprocation motion.

SUBSTANCE: drive unit of mill for cold pilger rolling of tubes includes mounted in casing planetary gear-crank unit with vertical rotation axis and with crank-up pin performing straight reciprocation motion and supporting rolling bearing assembly; tie rod joining crank-up pin carrying movable cassette with working rolls and balancing weights. One of said weights is arranged on shaft of crank and other weight is mounted in planetary gear-crank unit. Drive unit also includes additional casing mounted on rolling bearing assembly and second tie rod. One ends of both tie rods are rigidly secured to additional casing; their other ends are coupled with movable cassette carrying working rolls. Additional casing is arranged lower than guide mounted along rolling process axis. Rolling bearing assembly of crank-up pin is spherical. Tie rods are mounted at both sides of said spherical bearing assembly in plane parallel to rolling axis. Balancing weight mounted in shaft of crank is arranged under tie rods and guide over casing that houses planetary gear-crank unit.

EFFECT: improved operational reliability, increased useful life period of drive unit due to its lowered loads.

3 dwg

Description

The invention relates to the field of pipe production, and more specifically to the improvement of the drive of the cold pilger pipe mill, and can be used for any type of mill with a reciprocating working stand.

Known drive mill cold pilger pipe rolling, see US patent No. 4052898, cl. 72-214, claimed 09/13/76, publ. 10/10/77 g.

This drive contains a drive crank unit located in the housing with a vertical axis of rotation and performing a rotational movement of the crank finger with a rolling support mounted on it, a movable cassette moving along the guides and carrying work rolls, and balancing the moving mass of the load. The working stand is connected to the crank by one connecting rod. The balancing weight is located on the crank shaft.

In addition, the drive is equipped with an additional movable casing and frame, the casing being mounted on the crank pin on the rolling support and making a rectilinear movement in the frame guides along the rolling axis, and the frame moves in the drive guides in the direction transverse to the rolling axis.

A disadvantage of the known drive is the rapid wear of the guides of the movable cartridge:

- lateral guides due to the application of forces from the connecting rod at an angle that tend to deploy it in a horizontal plane;

- horizontal guides due to the occurrence of a tilting moment from the shoulder of the application of rolling forces, moving masses of the cartridge and drive forces.

Depreciation of the side rails leads to a reversal of the cartridge and deterioration of product quality. The introduction of additionally movable stone and frame guides requires an increase in drive power. Increased clearances in the guides lead to jamming and damage to the drive.

Another disadvantage is the lack of balancing moments that occur during operation of the drive. All this reduces the reliability and durability of the drive.

Also known is the drive of the cold pilger mill, see German Patent No. 3613036, M. cl. At 21 At 21/00, stated 04/15/83, publ. 08/13/87 (Fig. 5), comprising a planetary-crank unit located in the housing with a vertical axis of rotation and rectilinear reciprocating movement of the crank finger with a rolling support mounted on it, a movable cassette carrying work rolls and balancing loads , one of which is located on the crank shaft and balances the masses, and the other on the body of the planetary-crank block and balances the moments. The movable cartridge is located above the planetary-crank mechanism.

The disadvantage of this drive design is the increased load on the guides from the axial rolling forces and their rapid wear due to the overturning moment arising from a significant removal of the application of the drive force to the movable cartridge relative to the center of the cartridge and the rolling axis, which reduces the reliability and durability of the drive.

Of the known drives of the cold pilger mill, the closest in technical essence is the drive described in the patent of Germany No. 3706129, M. cl. At 21 At 21/00, stated 02/23/87, publ. 03/10/08, (Fig.3).

The known drive of the cold pilger rolling mill includes a planetary crank block located in the housing with a vertical axis of rotation and making a rectilinear reciprocating movement with a crank finger mounted on it with a rolling support, moving along the guides of a movable cassette carrying work rolls and connected via a rod to with a crank finger, and balancing loads, one of which is located on the crank shaft and balances the masses, and the other on the planetary-crank body block and counterbalances the moments. The drive has an additional load, which makes a reciprocating movement synchronously with the movable cartridge and parallel to it. The center of gravity of the additional load is below the point of possible application of centrifugal force created by the balancing mass of the crank.

A disadvantage of the known design of the drive of the cold pilger mill is that the introduction of an additional load to compensate for the overturning moment arising from the application in different planes of the drive force and the forces arising from rolling and moving the center of mass of the cartridge leads to:

- an increase in the mass transferred;

- increased loads on the bearing support of the crank pin and drive.

To compensate for the increase in the moved mass of the cartridge, it is necessary to increase the balancing weights, which leads to an increase in the dimensions of the mill and the need to install an overpowered drive.

Increased load on the bearing bearings reduces the reliability and durability of the drive.

The objective of the present invention is to create a drive of the cold pilger mill, which allows to increase its reliability and durability by reducing dynamic loads on the drive and reduce moving masses.

This object is achieved in that the drive of the cold pilger mill, comprising a planetary-crank drive unit with a vertical axis of rotation and performing a rectilinear reciprocating movement of the crank pin with a rolling support mounted on it, a rod connecting the crank pin to the movable cassette, carrying work rolls, and balancing loads, one of which is located on the crank shaft, and the other on the planetary-crank block, according to the invention it is equipped with ment of the rolling bearing on crank pin secondary body and a second rod, wherein the two rods are rigidly fixed at one end in an additional housing, and the other is rigidly connected with the movable cassette supporting the work rolls, but additional housing located below the wiring mounted on the rolling axis. In addition, the rolling support of the crank pin is spherical, and the rods are located on opposite sides of the spherical rolling support of the crank pin in a plane parallel to the rolling axis. Moreover, the balancing load mounted on the crank shaft is located under the rods and wiring over the housing in which the planetary crank block is located.

Such a constructive implementation of the drive of the cold pilger mill will increase the reliability and durability of the drive by placing the center of mass of the movable cartridge and rods moving it, as well as the closest possible balancing mass of the load to it. This embodiment of the drive will also allow to avoid the overturning moment acting on the cartridge and its guides, and the installation on the cartridge of an additional load compensating for this moment.

The dynamic loads are reduced by approaching the balancing mass of the load to the plane of displacement of the center of mass of the moving cassette with rolls and eliminating the additional load mounted on the moving cassette.

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

figure 1 shows the drive of the cold pilger mill, side view;

figure 2 is the same, plan view;

figure 3 is a section aa in figure 1.

The drive of the cold pilger pipe rolling mill comprises a housing 1, in which a planetary crank unit 4 with a vertical axis of rotation and a crank 7 mounted on it on rolling bearings 5, 6, a finger 8 of which with a spherical support mounted on it, is placed on rolling bearings 2, 3 rolling 9 makes a reciprocating movement. The planetary-crank unit 4 receives rotation from the gear 10 fixed thereon through the gear system from the electric motor 11. The gear 12 located on the crank shaft 7 interacts with the internal gear gear 13 fixed in the housing 1 coaxially with the planet-crank unit 4.

On the shaft of the crank 7 is located balancing mass load 14, and on the planetary-crank block 4 is located balancing the moments of the load 15.

On the spherical rolling support 9 of the finger 8 of the crank 7, an additional housing 16 is installed located below the wiring 17 installed along the rolling axis O-O.

The drive of the cold pilger tube mill includes two rods 18 located on opposite sides of pin 8 of crank 7 in a plane parallel to the axis of rolling. Rod 18 is fixed at one end in an additional housing 16, and the other is rigidly connected to a movable cartridge 19, moving along the guides 20 and carrying the work rolls 21.

A balancing weight 14 mounted on the crank shaft is located under the rods 18 and wiring 17 above the housing 1.

The device operates as follows.

The rotation from the electric motor 11 through the gear system is transmitted to the gear 10 mounted on the planetary crank unit 4, while in one revolution of the planetary crank unit 4 the gear 12 located on the shaft of the crank 7 and engaged with the wheel 13 makes two turns and the axis of the finger 8 of the crank 7 moves reciprocating in a straight line parallel to the axis of rolling, in one cycle.

The additional housing 16, connected by rods 18 to the cassette 19, the bearing rolls 21, and mounted on a spherical support 9 of the finger 8, also makes this movement. In this case, the rolled product or workpiece is in the wiring 17, the rods 18 are moved parallel to the axis of the rolling on different sides of the wiring 17 in a plane passing through the center of mass of the movable cartridge, thus not creating a tilting moment acting on its guides. Placing the crank pin passing under the wiring and the spherical support of the finger at the minimum possible distance helps to reduce the dynamic loads that occur in the drive. The spherical bearing compensates for possible inaccuracies in the manufacture and installation of the cartridge.

The proposed drive of the cold pilger tube mill compared with the known ones will reduce dynamic loads and reduce moving masses, and therefore increase its reliability and durability.

Claims (1)

The drive of the cold pilger tube mill, comprising a planetary crank block with a vertical axis of rotation and performing a rectilinear reciprocating movement of the crank finger with a rolling support mounted on it, a rod connecting the crank pin with a movable cassette carrying work rolls and balancing loads, one of which is located on the crank shaft, and the other on the planetary-crank block, characterized in that it is equipped with an additional gearbox mounted on the rolling support a pus and a second rod, while both rods at one end are rigidly fixed in the additional housing and the other are connected to a movable cartridge carrying work rolls, and the additional housing is located below the wiring installed along the rolling axis, in addition, the rolling support of the crank pin is made spherical, and the rods are located on opposite sides of the spherical support of the crank pin in a plane parallel to the rolling axis, and the balancing weight mounted on the crank shaft is located under the rods and wiring over the housing, which hosts a planetary crank block.

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