SU1330366A1 - V-belt transmission - Google Patents

Description

1133

The invention relates to mechanical engineering and can be used in drives of both general and special purpose machines where V-belt transmissions are used.

The purpose of the invention is to increase the adhesion to pulleys and durability by limiting the deformations of the corrugations.

FIG. 1 shows schematically the proposed transmission, the general view; in FIG. 2, a belt; on fig.Z - section aa on fig, 3; in fig. 4 is a section B-B in FIG. 3, passing through the support belt; in fig. 5 - grooved belt in a static position; in fig. 6 - the same, in working condition.

A belt 1 with parallel grooves 2 bends around the cabinet 3. The corrugations 2, which are the protrusions of a certain profile, oriented across the belt, round the pulley 3 and coincide with the radial straight lines drawn from the axis 4 of the pulley 3. In the longitudinal direction, the sizes of the corrugations are variable , increasing from the inner flat face 5 to the outer one 6. The corrugations are made of a trapezoidal profile in their longitudinal and transverse directions. Angle (f is the angle of the pulley groove profile.

When creating a preliminary tension and the absence of rotation, the corrugations 2 are partially deformed (Fig. 5), and the parameters of the section are chosen so that the relative elastic deformation of compression does not exceed 20%.

In the working state, when the drive pulley 3 rotates at a speed V, additional elastic shear deformations (Fig. 6) occur in the grooves, which, together with the elastic compressive deformations, determine the amount of friction force between the belt and the pulley. A similar picture takes place in the area of the driven pulley around the bend, only the deformation. The shift here inclines the corrugations in the opposite direction. .

The pitch between the corrugations Pj is determined by the relation, where

H is the width of the base grooved. The coefficient of proportionality K, a definite ratio between tj and P, was found from the condition of limiting the relative elastic deformation of corrugations to 20% by the formula

five

K 50644

dtn.hE,

where P is the nominal power, kW, transmitted by one belt of a standard cross section (O, A, B ,, ,, ,, D, E) at the estimated length Lp, m ;.

estimated diameter of the smaller pulley;

pulley rotational speed; / height of the belt section, m; the elastic modulus of the material of the belt wrap, on which there are corrugations, in compression, Pa.

d. p - h E.

is determined

The height of riffony S ratio

,

where Kg is the coefficient of proportionality of height S to the width of the base of the corrugation Kn is the coefficient of proportionality D

the height of the S to the width of the belt Lp,

As a result of calculations for different sections of V-belts, it is recommended to take 25-0.3.

The values of the coefficients, 11,, 8, -At the same, 1Ibp; Р5 (0,46... ,, 0,55) Lp; t.0.14 b raudius

R

The roundings of the tops and bases of the corrugations (Fig. 4) are as follows:, 02b; , 01bp.

The calculated parameters are given in the plane of the gov. 7,

Formula and image

V-belt drive containing two pulleys and a V-belt with transverse evenly spaced grooves, characterized in that, in order to increase traction with the pulleys and durability by limiting the deformations of the corrugations, the grooves made the trapezoidal profile in their longitudinal and transverse directions x with a decrease in height from the larger base of the belt to a smaller one, and the grooved pitch is determined by the ratio

PS 50644

1o dl p.

-five

where tg is the width of the base of the corrugation; Р - nominal power of a standard belt;

d is the diameter of the smaller pulley; n is the frequency of rotation of the smaller pulley;

1330366

h is the height of the belt section; Ep is the modulus of elasticity of a belt wrap material.

1

2

h

ZA 777

Fig.z

Q3UB.5

Fig.b

Claims (1)

Claim V-belt drive containing two pulleys and a V-belt with transverse evenly spaced corrugations, characterized in that, in order to increase traction on the pulleys with decreasing height from the larger base of the belt to the smaller, and the step of the corrugation is determined by the ratio P _s = 50644 -b --- t ₅ , d ² n, hE _c I '' where t _s is the width of the corrugation base; P _about - rated power of a standard belt; d _< is the diameter of the smaller pulley; rv is the rotational speed of the smaller pulley; h is the height of the section of the belt; E _c ~ modulus of elasticity of the material of the wrapper of the belt.