RU2408468C2 - All-rolled railroad wheel - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: proposed wheel comprises rim 1, hub 2 and disk 3 with outer 4 and inner 5 curvilinear surfaces. Central line 6 of radial rim cross section is displaced along wheel axis 7 relative to central line 8 of hub radial cross section toward outer curvilinear surface 4. Generatrix of outer curvilinear surface 4 consists of at least two connecting outer curves R_1, R₂ with opposed direction curvature. First outer curve R_i fairs with rim 1 by first outer transition section R₄. Second outer curve R₂ fairs with hub 2 by second outer transition section R₅. Generatrix of inner curvilinear surface 5 consists of at least one of inner curves (R₃) that fairs with rim 1 by first inner transition section R₆ and, with hub 2, by second inner transition section R₇. First outer curve R₁ features radius r₄ equal to 0.145-0.16 of diametre D of the wheel rolling circumference. First outer curve R₂ features radius r₂ equal to 0.245-0.26 of diametre D of the wheel rolling circumference. First outer curve R₃ features radius r₃ equal to 0.264-0.285 of diametre D of the wheel rolling circumference. First outer transition section R₄ features radius r₄ equal to 0.065-0.09 of diametre D of the wheel rolling circumference. Second outer transition section R₅ features radius r₅ equal to 0.035-0.06 of diametre D of the wheel rolling circumference. First outer transition section R₄ features radius r₄ equal to 0.05-0.06 of diametre D of the wheel rolling circumference. Second outer transition section R₇ features radius r₇ equal to 0.145-0.165 of diametre D of the wheel rolling circumference.

EFFECT: reduced wheel total inner strains.

3 dwg

Description

The invention relates to the production of disk wheels of railway vehicles with a disk made integrally with the rim, and having rail-engaging elements.

Recently, there has been a significant change in the operating conditions of the rolling stock of railway transport, due to the increase in speed and increase in loads of up to 30 tons per axle.

During operation, the solid-rolled railway wheel is exposed to a wide range of both external loads from the track and rolling stock elements, as well as the effects of temperature stresses arising in the wheel of the braking process. The actual total stresses resulting from this largely determine the resistance of the wheels to damage and, ultimately, its service life.

One of the most important factors affecting the life of a solid-rolled railway wheel is the value of the total internal stresses that arise during its operation, as well as the nature of the distribution of stresses over the volume of the wheel.

The occurrence of significant total stresses in a whole-rolled railway wheel is due to the combined action of normal static and alternating dynamic loads acting in the radial and axial directions, and temperature stresses caused by friction of the brake pads on the wheel rim during the braking of the rolling stock.

In the case when the values of the total stresses are close or for a long time exceed the endurance limit of the material of which the wheel is made, the formation of fatigue cracks occurs in it, which in turn leads to premature failure of the wheel.

Under unfavorable loading conditions in a solid-rolled railway wheel, a concentration of stresses from acting external loads and temperature effects is observed, while the total value of internal stresses may exceed the yield strength of the material of which the wheel is made. In this case, residual deformations occur in the wheel, which lead to a change in its operational properties, which also leads to a reduction in its service life.

Operational experience of solid-rolled railway wheels shows that most cases of wheel failure due to disk failure are associated with the occurrence of significant fatigue stresses.

The traditional way to reduce the total internal stresses and their optimal distribution over the volume of the wheel is to choose a rational design of the disk of a solid-rolled railway wheel, as well as the relative position of its structural elements.

It is known from the prior art a solid-rolled railway wheel containing a rim, a hub and a disk formed by external and internal curved surfaces, made in such a way that the central line of the radial section of the rim is offset along the axis of the wheel relative to the central line of the radial section of the hub towards the external curved surface, forming an external a curved surface consists of at least two conjugate external curves (R ₁ , R ₂ ) with a curvature opposite in direction, while the first the outer external curve (R ₁ ) is connected to the rim by the first external transition section (R ₄ ), the second external curve (R ₂ ) is connected to the hub by the second external transition section (R ₅ ), and the generator of the internal curved surface consists of at least one internal curve (R ₃ ), which is associated with the rim with the first internal transitional section (R ₃ ), and with the hub with the second internal transitional section (R ₇ ) / SU 885083 (Dnepropetrovsk Order of the Red Banner of Labor, Metallurgical Institute), 11/30/1981 /.

In the known wheel, the first external curve R ₁ (in the prototype - R ₂ ) is made with a radius equal to 0.11-0.125 diameter D of the skating circle, the second external curve R ₂ (in the prototype - R ₃ ) is made with a radius equal to 0.2-0 , 25 of the diameter D of the skating circle, the inner curve R ₄ (in the prototype - R ₄ ) is made with a radius equal to 0.222-0.263 of the diameter D of the skating circle, the first external transition section R ₄ (in the prototype is R ₅ ) is made with a radius of 0.04 -0.042 diameter D of the ski circle, the second outer transition section R ₅ (in the prototype - R ₆ ) is made with a radius equal to 0,067-0,077 diameter D of the ski circle, the first in the inner transition section R ₆ (in the prototype - R ₅ ) is made with a radius equal to 0.04-0.042 diameter D of the ski circle, the second inner R ₇ (in the prototype - R ₆ ) the transition section is made with a radius equal to 0.067-0.077 diameter D of the ski circle .

A disadvantage of the known solid-rolled railway wheels is the great importance of stresses on the inner and outer surfaces of the wheel disk in places of its interface with the rim and hub. This drawback is due to the uneven distribution of the total internal stresses in the volume of the wheel resulting from the combined action of thermal stresses caused by friction of the brake pads on the wheel rim during braking of the rolling stock, and the voltage from external loads.

The basis of the present invention is the task of creating such a design of a solid-rolled railway wheel, the use of which would reduce the total internal stresses in the wheel due to their optimal distribution over the volume of the wheel and, thereby, increase its service life.

The problem is solved in that in an all-rolled railway wheel containing a rim, a hub and a disk formed by external and internal curved surfaces, made in such a way that the center line of the radial section of the rim is offset along the axis of the wheel relative to the center line of the radial section of the hub towards the outer curved surface forming a curved external surface consists of at least two conjugated external curves (R _1, R ₂₎ from the opposite direction of curvature, When this first outer curve (R ₁₎ interfaced with the rim first outer transition section (R _4), the second outer curve (R ₂₎ interfaced with the hub second outer transition section (R ₅₎ and forming the inner curved surface composed of at least , from one internal curve (R ₃ ), which is associated with the rim of the first internal transition section (R ₆ ), and with the hub, the second internal transition section (R ₇ ), according to the invention, the first external curve (R ₁ ) is made with a radius r ₁ equal to 0.145-0.16 of the diameter of the ski circle, the second outer cr -hand (R ₂₎ of radius r ₂ equal 0,245-0,26 rolling circle diameter, the inner curve (R ₃₎ is a radius r ₃ equal to the diameter of 0,264-0,285 rolling circle, first outer transition portion (R ₄₎ is a radius of r ₄ equal to 0.065-0.09 of the diameter of the ski circle, the second outer transition section (R ₅ ) is made with a radius r ₅ equal to 0.035-0.06 of the diameter of the ski circle, the first inner transition section (R ₆ ) is made with a radius r ₆ of 0, 05-0.06 of the diameter of the ski circle, the second inner transition section (R ₇ ) is made with a radius r ₇ equal to 0.145-0.165 of the diameter of the ski circle.

The implementation of the solid-rolled railway wheels in such a way that the first external curve (R ₁ ) is made with a radius r ₁ equal to 0.145-0.16 of the diameter of the skating circle, the second external curve (R ₂ ) with a radius of r ₂ equal to 0.245-0.26 of the diameter of the skating circle , the inner curve (R ₃ ) is made with a radius r ₃ equal to 0.264-0.285 of the diameter of the skating circle, the first outer transition section (R ₄ ) is made with a radius of r ₄ equal to 0.065-0.09 of the diameter of the skating circle, the second outer transition section (R ₅ ) is made with a radius r ₅ equal to 0.035-0.06 of the diameter of the ski circle, the first internal transitional part the current (R ₆ ) is made with a radius r ₆ equal to 0.05-0.06 of the diameter of the skating circle, the second inner transition section (R ₇ ) is made with a radius of r ₇ equal to 0.145-0.165 of the diameter of the skating circle, it is optimal, as it reduces values of total stresses due to the combined influence of thermal stresses and external loads at the interface between the disk and the hub and rim, which ultimately leads to a uniform distribution of the total stresses in the wheel and a decrease in their values.

A further increase in the radius r _{1 of the} first external curve (R ₁ ) over 0.16 of the diameter of the wheel circle, as well as the radius r _{4 of the} first external transition section (R ₄ ) and the radius r _{6 of the} first internal transition section (R ₆ ) over the claimed range to increase the thickness of the wheel at the interface between the disk and the rim, which, in turn, leads to the appearance of significant temperature stresses during braking of the rolling stock caused by friction of the brake pads on the wheel rim.

The increase in the radius r _{2 of the} second external curve (R ₂ ) and the radius r _{3 of the} internal curve (R ₃ ) more than the claimed range leads to the approximation of the disk shape to a rectilinear shape, which increases the stiffness of the wheel and, in turn, leads to a reduction in the service life of a solid-rolled railway wheels.

The decrease in the radius r _{2 of the} second external curve (R ₂ ) and the radius r _{3 of the} internal curve (R ₃ ) more than the claimed range leads to an increase in the total internal stresses at the interface between the first external curve (R ₁ ) and the second external curve (R ₂ ), which also leads to a reduction in the service life of the solid-rolled railway wheel. In addition, such a decrease leads to a decrease in the displacement of the rim relative to the hub, which in turn leads to an increase in temperature stresses and axial displacement of the rim relative to the hub when the wheel is heated during braking.

The inventive combination of features as a whole allows to reduce the total internal stresses in the wheel due to their optimal distribution over the wheel volume, which reduces the likelihood of fatigue cracks in the most loaded areas of the solid-rolled railway wheel, which, in turn, allows to increase the operational stability and reliability of the design and , thereby, allows to increase the service life of the wheel.

The invention is further explained in the detailed description of its implementation with reference to the drawings, which depict:

figure 1 is a cross section of a solid-rolled railway wheels;

figure 2 is a cross section of a solid-rolled railway wheels (arrangement of curved sections of the wheel);

figure 3 - diagram of determining the location of the center line of the radial section of the disk.

The seamless-rolled railway wheel (Figs. 1-3) contains a rim 1 (Fig. 1), a hub 2, and a disk 3 formed by an external curved surface 4 and an internal curved surface 5. The disk 3 is designed so that the center line 6 of the radial section of the rim 1 offset along the axis 7 of the wheel relative to the center line 8 of the radial section of the hub 2 in the direction of the outer curved surface 4 of the wheel. The generatrix of the external curved surface 4 consists of at least two conjugated external curves R ₁ and R ₂ (figure 2) with the opposite curvature, while the first external curve R _{1 is} associated with the rim 1 (figure 1) of the first external transition section R ₂ (FIG. 2), the second external curve R _{2 is} coupled with the hub 2 (FIG. 1) by the second outer transition portion R ₅ (FIG. 2), and the generatrix of the inner curved surface 5 (FIG. 1) consists of at least , from one internal curve R ₃ (FIG. 2), paired with the rim 1 (FIG. 1) by the first inner transition portion R ₆ (phi g.2), and with the hub 2 (Fig. 1), the second inner transition section R ₇ (Fig. 2).

The first external curve R _{1 is} made with a radius r ₁ equal to 0.145-0.16 of the diameter D of the skating circle, the second external curve R _{2 with a} radius of r ₂ equal to 0.245-0.26 of the diameter D of the skating circle, the internal curve R _{3 is} made with a radius r ₃ , equal to 0.264-0.285 of the diameter D of the skating circle. The first external transition section R _{4 is} made with a radius r ₄ equal to 0,065-0,09 diameter D of the skating circle, the second external transition section R _{5 is} made with a radius r ₅ equal to 0,035-0,06 the diameter D of the skating circle, the first internal transition section R ₆ made with a radius r ₆ equal to 0.05-0.06 diameter D of the skating circle, the second inner transition section R ₇ made with a radius r ₇ equal to 0.145-0.165 diameter D of the skating circle.

The central line 9 of the radial section of the disk 3 in the place of its interface with the hub 2 is shifted along the axis 7 of the wheel relative to the center line 8 of the radial section of the hub 2 towards the inner curved surface 5 by a distance S1 equal to from 10 to 25 mm.

The center line 6 of the radial section of the rim 1 is shifted along the axis 7 of the wheel relative to the center line 8 of the radial section of the hub 2 towards the outer curved surface 4 by a distance S2 equal to 40 to 55 mm.

Point A (Fig. 2) of the conjugation of the first external curve R ₁ and the second external curve R _{2 is} removed from the axis of the wheel 7 by a distance L1 equal to 0.32 to 0.35 of the diameter D of the wheel circle (L1 = (0.32- 0.35) D), and the point B of the interface between the inner curve R ₃ and the first inner transition section R _{6 is} removed from the axis 7 of the wheel by a distance L2 equal to 0.33 to 0, 36 of the diameter D of the wheel circle (L2 = (0 , 33-0.36) D).

The location of the center line 9 of the radial section of the disk 3 in the place of its interface with the hub 2 is determined as the middle of the segment CD (figure 3). The segment CD is formed by the intersection of the continuation of the second external curve R ₂ and the internal curve R ₃ with the segment EF, which is formed between the point E of the connection of the outer side surface of the hub 2 with the second external transition section R ₅ and the point F of the connection of the inner side surface of the hub 2 with the second internal transition plot R ₇ .

Studies have shown that the shift of the center line 6 of the radial section of the wheel rim 1 along the axis 7 of the wheel relative to the center line 8 of the radial section of the hub 2 towards the outer curved surface 4 of the wheel leads to a significant decrease in the temperature stresses arising in the solid-rolled railway wheel during braking.

At the same time, an excessive increase in the indicated displacement leads to an increase in the values of internal stresses from the action of vertical and lateral loads at the junctions of the disk 3 with the rim 1 and disk 2. Therefore, if the value of the indicated displacement exceeds 90 mm, then the increase in the wheel stress vertical and lateral load is greater than the decrease in stresses from the action of thermal stress, which is due to the implementation of the specified displacement.

The angle (Fig. 3) α of the inclination of the tangent 11 to the first external curve R ₁ and the second external curve R ₂ at the point A of their conjugation to the axis of the wheel 7 is in the range of 40-55 degrees, and the angle β of the inclination of the tangent 12 at the point B of the inner a curved surface 5 with a first outer transition section R ₆ to the axis of the wheel 7 is in the range of 40-55 degrees.

The inner curved surface 5 may consist of at least one external curve. In some embodiments of the invention, the inner curved surface 5 consists of two conjugate internal curves with opposite curvature (not shown).

The operation of the claimed design of the solid-rolled railway wheels is as follows.

When the wheel is rolling along the rail (not indicated), the load from the vertical force acting in the plane of the skating circle is transmitted through the rim 2 to the disk 3 and to the hub 2. Moreover, due to kinematic vibrations and, especially, when the rolling stock moves along curved sections the way there is a load from the lateral pressure of the ridge 10 of the wheel rim 1 per rail, which is also transmitted to the disk 3.

The maximum values of dynamic loads that perceive a rolling stock wheel with an axle load of up to 30 tons during operation are two times higher than the maximum static load and, as a rule, do not exceed 300 kN for vertical load and 147 kN for lateral load. In this case, the maximum value of the total internal stresses in the wheel from the action of the loads applied to it should not exceed the yield strength of the material from which the solid-rolled railway wheel is made, which is 800 MPa.

In the inventive design of a solid-rolled railway wheel, the two most stressed zones are distinguished: the place of mating of the disk 3 with the rim 1 and the place of the mating of the disk 3 with the hub 2.

The maximum stresses in the 3-wheel drive in most cases of loading occur in a vertical section (in that section where loads are applied).

The vertical load causes mainly compressive stresses in the wheel, which reach a maximum value at the interface between the disk 3 and the hub 2 in the second outer transition section R ₇ . In this case, the stress values in the indicated place do not exceed 100 MPa, which is significantly less than the permissible value.

At the same time, the lateral load that occurs when the rolling stock passes curved sections of the track and acts on the wheel ridge 10 in the direction of the inner surface 5, in combination with the remaining vertical load, causes a bending moment in the disk 3 of the wheel, increasing from rim 1 to hub 2 wheels.

As a result of the combined effect of vertical and lateral loading, the most stressed section of the wheel is the interface between the disk 3 and the hub 2 in the second outer transition section R ₇ , with tensile stresses arising from the outside of the disk 3 and compressive stresses from the inside of the disk 3.

In this case, the maximum stress values do not exceed 120 MPa, which is also significantly less than the permissible value.

In addition, during prolonged braking of the rolling stock, significant thermal stresses occur in the wheel, which are caused by intense heat generation when brake pads (not shown) come in contact with the wheel rim 1.

In this case, in the absence of external loads applied to the wheel, the highest stress values occur at the interface between the disk 3 and the rim 1 (in the first internal transition section R ₆ ) and with the hub 2 (in the second external transition section R ₅ ), which do not exceed 550 and 560 kN, respectively, which is below the permissible values.

When vertical loads are applied to the wheel in most of its sections, mutual compensation of temperature stresses and stresses caused by the action of external forces is observed. Such compensation is due to the fact that external forces cause mainly compressive stresses, which are compensated by tensile thermal stresses.

The maximum stresses in the wheel in the event of a combined impact on it, on the one hand, of vertical and lateral loads, and on the other hand, of thermal stresses, arise from the outside of the wheel at the interface between the disk 3 and the hub 2, which are close to the value of permissible values. The increased stress concentration in this place of the wheel is due to the fact that tensile thermal stresses, reaching their maximum value in this place, add up to tensile stresses arising in the same place from the action of the side load applied to the wheel.

The implementation of the second external transition section R _{5 with a} radius r ₅ less than the radius r _{7 of the} second internal transition section R ₇ allows to reduce the stress concentration due to the action of thermal stresses due to their uniform distribution in this section of the interface of the outer curved surface 4 of the disk 3 with the hub 2.

As the research results show, the stress state of the wheel at the transition points of the disk 3 to the rim 1 and hub 2 does not exceed the critical value of 800 MPa (yield strength of the wheel material).

Thus, the proposed wheel design provides both a uniform distribution of stresses over the entire volume of the wheel, and can reduce stresses in the most loaded areas and, thus, reduce the likelihood of fatigue cracks, which in turn increases the service life of the wheels.

In addition, the use of the inventive design of the wheel allows to increase its damping properties, which in turn allows to improve the operational properties of the wheel and, thus, to improve the safety of railway traffic in general.

The inventive solid-rolled railway wheel can be manufactured in industrial production using standard equipment. The greatest economic effect from the use of the claimed invention is achieved when it is used in freight cars with an increased axle load of up to 30 tons.

Claims (1)

An all-rolled railway wheel containing a rim (1), a hub (2) and a disk (3) formed by external (4) and internal (5) curved surfaces, made in such a way that the center line (6) of the radial section of the rim (1) is offset along the axis (7) of the wheel relative to the center line (8) of the radial section of the hub (2) towards the external curved surface (4), the generatrix of the external curved surface (4) consists of at least two conjugated external curves (R ₁ , R ₂ ) with a curvature opposite in direction, with the first I, the external curve (R ₁ ) is connected with the rim (1) by the first external transition section (R ₄ ), the second external curve (R ₂ ) is connected with the hub (2) by the second external transition section (R ₅ ), and the generatrix of the inner curved surface ( 5) consists of at least one internal curve (R ₃ ), which is connected with the rim (1) by the first internal transition section (R ₆ ), and with the hub (2) by the second internal transition section (R ₇ ), characterized in that the first external curve (R ₁ ) is made with a radius r ₁ equal to 0.145-0.16 of the diameter D of the wheel, the second external the curved curve (R ₂ ) is made with a radius r ₂ equal to 0.245-0.26 of the diameter D of the wheel, the inner curve (R ₃ ) is made with a radius r ₃ equal to 0.264-0.285 of the diameter D of the wheel, the first outer transition section (R ₄ ) is made with a radius r ₄ equal to 0,065-0,09 diameter D of the wheel, the second outer transition section (R ₅ ) is made with a radius r ₅ equal to 0,035-0,06 diameter D of the wheel circle, the first inner transition section (R ₆ ) is made with a radius r ₆ equal to 0.05-0.06 of the diameter D of the wheel, the second inner transition section (R ₇ ) is made p radius r ₇ equal to 0.145-0.165 of the diameter D of the wheel.

Images