CN201739343U - Elliptical raceway double-row eight-point contact type slewing bearing - Google Patents

Abstract

The utility model discloses an elliptical raceway double-row eight-point contact type slewing bearing, which is characterized in that the raceway type of the double-row eight-point contact type slewing bearing is an elliptical type. In the calculation formula of a major semi axis and a minor semi axis of the elliptical raceway, a is the major semi axis of the elliptical raceway, b is the minor semis axis of the elliptical raceway, r is the curvature radius of a steel tall, t is the ratio of a curvature radius R of a point where the raceway contacts with the steel ball to the curvature radius of the steel ball r, that is, R/r, Beta is a contact angle between the steel ball and the raceway, the value range of the curvature ratio t is from 1.01 to 1.12, and the value range of the contact angle Beta is from 30 degrees to 60 degrees. When the raceway quenching hardness, the hardened depth and the contact angle are identical, the bearing capacity of the double-row eight-point contact type slewing bearing, after the adoption of the elliptical raceway, can be enhanced by 33%, relative to the bearing capacity of a peach-like raceway double-row eight-point contact type slewing bearing.

Description

Double 8 contact-type pivoting supports of elliptic roller track

Technical field

The utility model relates to a kind of double 8 contact-type pivoting supports with elliptic roller track.

Background technique

Pivoting support is the mechanical necessary important force transfer element that needs to do to turn round relatively, need to bear simultaneously again axial force, radial force, tilting moment between all two-part as the important foundation element of engineering machinery and building machinery.Wherein double eight point contact ball slewings supporting is called the biserial ball-type slewing bearing again, mainly form by outer race, inner race and steel ball, outer race, inner race respectively have the identical parallel raceway of upper and lower two rows, can bear axial force, radial force and tilting moment simultaneously, the driftage and the pitch-controlled system that are widely used in wind-driven generator are applicable on the main frames such as harbour machinery, engineering machinery, metallurgical machinery, army's construction machinery simultaneously.But the ball receway pattern of existing double eight point contact ball slewings supporting is the two centers of circle of two circular arcs for peach shape is, R/r＞1, raceway symmetry up and down.Raceway quenching hardness, depth of hardening zone, raceway radius of curvature and wrapping angle are to influence the bearing capacity of peach shape raceway pivoting support and four important parameters in working life.The raceway quenching hardness is subjected to the restriction of steel ball surface hardness can only be 55～60HRC, and is limited from the effect of this respect raising bearing capacity; As long as depth of hardening zone is deepened depth of hardening zone except meeting improves the quenching cost greater than specified value, can not aspect the raising bearing capacity big effect arranged; Wrapping angle increases the possibility that can increase raceway limit mouth conquassation, also should not improve the bearing capacity of pivoting support by the method that increases wrapping angle; The ratio of raceway radius of curvature R and steel ball radius r is generally 1.04～1.08, and the more little bearing capacity of ratio is big more, but the control difficulty of the more little raceway accuracy to shape of ratio is big more.So under the existing processes condition, can not improve the bearing capacity of pivoting support by the method that reduces the raceway ratio of curvature.

Summary of the invention

Problem to be solved in the utility model provides a kind of double 8 contact-type pivoting supports with novel raceway, by the raising of raceway bearing capacity, and then the service behaviour and the life-span of improving double 8 contact-type pivoting supports.

The raceway pattern of double 8 the contact-type pivoting supports of the utility model is oval, and the major semi axis of elliptic roller track, semi-minor axis formula are as follows:

$a=\frac{r\·{\sin }^2\mathrm{\β}\sqrt{t}}{1-t\·{\cos }^2\mathrm{\β}}$

$b=\sqrt{\frac{r^2\·{\sin }^2\mathrm{\β}}{1-t\·{\cos }^2\mathrm{\β}}}$

In the following formula: a---the major semi axis of elliptic roller track;

The semi-minor axis of b---elliptic roller track;

R---steel ball radius of curvature;

The ratio of the radius of curvature R of t---raceway and steel ball point of contact and steel ball radius of curvature r, R/r

The wrapping angle of β---steel ball and raceway;

Ratio of curvature t span is 1.01～1.12, and wrapping angle β span is 30 °～60 °.

Facts have proved, make peach shape raceway into oval raceway, the raceway accuracy to shape is more easy to control, and because elliptic roller track is the raceway of variable curvature, when wrapping angle changed, the raceway curvature of point of contact was made corresponding change, therefore can improve the contact stress state of steel ball and raceway, improve the raceway bearing capacity, and then improve the service behaviour and the life-span of pivoting support.After adopting elliptic roller track, under the identical situation of raceway quenching hardness, depth of hardening zone and wrapping angle, the bearing capacity of double 8 the contact-type pivoting supports of this kind can improve 33% with respect to the bearing capacity of double 8 contact-type pivoting supports of peach shape raceway.

Description of drawings

Fig. 1 is double 8 contact-type pivoting support schematic representation of the utility model elliptic roller track;

Fig. 2 is the enlarged diagram of the place of A shown in Fig. 1 elliptic roller track;

Fig. 3 is the raceway shape schematic representation of existing double 8 contact-type pivoting supports.

Embodiment

From Fig. 1 and Fig. 2 as can be seen, the raceway pattern of double 8 the contact-type pivoting supports of the utility model is designed to ellipse, and the major semi axis of elliptic roller track, semi-minor axis formula are as follows:

$a=\frac{r\·{\sin }^2\mathrm{\β}\sqrt{t}}{1-t\·{\cos }^2\mathrm{\β}}$

$b=\sqrt{\frac{r^2\·{\sin }^2\mathrm{\β}}{1-t\·{\cos }^2\mathrm{\β}}}$

In the following formula: a---the major semi axis of elliptic roller track;

The semi-minor axis of b---elliptic roller track;

R---steel ball radius of curvature;

The ratio of the radius of curvature R of t---raceway and steel ball point of contact and steel ball radius of curvature r, R/r;

The wrapping angle of β---steel ball and raceway;

Ratio of curvature t span is 1.01～1.12, and wrapping angle β span is 30 °～60 °.

For example: when the raceway parameter value of double 8 contact-type pivoting supports is: the raceway radius of curvature of steel ball radius of curvature r=9.922mm, point of contact and the ratio t=1.04 of steel ball radius of curvature and wrapping angle β=50 °.According to top formula, can obtain major semi axis a=10.412mm, the semi-minor axis b=10.065mm of elliptic roller track.

Facts have proved, make peach shape raceway into oval raceway, the raceway accuracy to shape is more easy to control, and because elliptic roller track is the raceway of variable curvature, when wrapping angle changed, the raceway curvature of point of contact was made corresponding change, therefore can improve the contact stress state of steel ball and raceway, improve the raceway bearing capacity, and then improve the service behaviour and the life-span of pivoting support.After adopting elliptic roller track, under the identical situation of raceway quenching hardness, depth of hardening zone and wrapping angle, the bearing capacity of double 8 the contact-type pivoting supports of this kind can improve 33% with respect to the bearing capacity of double 8 contact-type pivoting supports of peach shape raceway.

Claims (1)

1. double 8 contact-type pivoting supports of an elliptic roller track is characterized in that: the raceway pattern of these double 8 contact-type ball-type slewing bearings is for oval, and the major semi axis of elliptic roller track, semi-minor axis formula are as follows:

$a=\frac{r\·{\sin }^2\mathrm{\β}\sqrt{t}}{1-t\·{\cos }^2\mathrm{\β}}$

$b=\sqrt{\frac{r^2\·{\sin }^2\mathrm{\β}}{1-t\·{\cos }^2\mathrm{\β}}}$

In the following formula: a---the major semi axis of elliptic roller track;

The semi-minor axis of b---elliptic roller track;

R---steel ball radius of curvature;

The ratio of the radius of curvature R of t---raceway and steel ball point of contact and steel ball radius of curvature r, R/r;

The wrapping angle of β---steel ball and raceway;

Ratio of curvature t span is: 1.01～1.12, and wrapping angle β span is: 30 °～60 °.

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