SU1627777A1 - Worm gearing - Google Patents

Abstract

The invention relates to mapping, and h, to gnost to gears with variable center distance. The goal of iiaoC CTL is not nl with the expansion of jKcnryaa- tion in mpnit and the counting and change of axial distance. In the transmission there are housing 1, a worm to 2 and a worm wheel 3. The latter is rigidly mounted on shaft 4, and a worm to 2 with the possibility of autumnal movement to a fallen 5. Black to 2 is made with a split surface of r г, η / myc R pmemok no u - but ri and permshn cher rv chpi koltata 3 nmGfan i votnosmponi: R g / ips maxichim-. IM; I p, 1 dim lepitelyyuyu surface black 2, 0 - goal nlkl1na tangent to ooramtos-i 1GNSLY1OI povor / pp (te black) -, 2., point with r ..... ,,. AA (J KL Val J paiMLiiieii and frame 6, set

Description

The invention relates to mechanical engineering, in particular to transmissions with a variable center distance.

The purpose of the invention is to expand the operational capabilities by changing the center distance.

FIG. 1 shows the worm gear; in fig. 2 is a section A-A in FIG. -1; in fig. 3 is a circuit for outputting geometrical parameters; in fig. 4 is a diagram illustrating the output of geometrical parameters.

The worm gear contains a housing 1, a worm to 2 and a worm gear 3 mounted on a crossing shaft 4 and B. The worm gear 3 is rigidly mounted on its shaft 4, and the worm to the 2nd has axial movement on the shaft 5. Worm to 2 is made with a variable radius r, dividing the surface. The step of turns of the screw 2 is constant along the dividing surface forming it. The radius R of the notches on the surfaces of the tops of the teeth of the worm gear 3 is chosen from the ratio

mchs (1)

C08 uo

h is the maximum radius of the dividing surface of the screw, o

lfo is the angle of inclination of the tangent to the generatrix of the dividing surface of the screw at the point with r (d

The relation (1) is obtained as follows.

Worm gears to make the best contact between the worm 2 and the worm gear 3 make recesses on the tops of the teeth

 make

0

five

0

five

0

five

0

five

I

the last one. The contact will be correct if the radius of the grooves R is greater than or equal to that of the dividing radi-: 4, i.e. the condition must be observed

g

(2)

If the separating radius of the worm, 2 g is variable and varies from r to miido r MM (W, then the radius of the notch R must be greater than or equal to the maximum dividing radius of the worm to r4L, ax- the transmission is common tangent at the point of contact P0 of the dividing surfaces of the worm 2 and the worm gear 3 corresponding to r (wai (C is tilted to the axis of rotation of the worm 2 at an angle of $ 0). Considering this, the equations in Fig. 4 give relation (1).

The shaft 4 of the worm gear 3 is mounted on the rotation supports in the housing 1. The shaft 5 of the screw 2 is located in frame 6. It is installed in the guides 7, made in the housing 1 perpendicular to the axis of rotation of the screw 2 and the worm gear 3. Frame 6 is provided with a drive in the form of a screw pair consisting of a lead screw b and a nut 9. The lead screw 8 is rotatably connected to the frame 6 - and the Nut 9 is fixedly mounted in the housing 1.

A fork 10 is mounted on the hub of the screw 2 with the possibility of rotating the screw 2. The longitudinal axis of the fork 10 coincides with the axis of rotation of the screw 2,

The transmission is also fitted with a camshaft cam mechanism. His cam 11 still

2 varies in length, the divider is installed in the housing 1, and the pusher 12 is connected to the fork 10. The shape of the cam 11 is described by the dependencies shown. Since the dividing radius r of the screw is not the last b (

the surface of the worm 2 is described by the dependence r, (b). This may be different. The main restriction imposed on its choice is that its radius of curvature at all points is greater than the pitch radius of the worm wheel 3 (otherwise there will be a contact of the dividing surfaces at two points).

When the center distance of the wedge changes, the surface of the worm 2 moves along the pitch circle of the worm gear 3. Obviously, the cam 11 must be equidistant dividing the worm surface 2. The origin of the x, y coordinate system is aligned with the center of the worm gear 3. This provides convenience of reference, since the center O does not change its position in space. At the point of contact P of the dividing surfaces of the worm 2 and the worm gear 3 corresponding to the current value r ((b (), the total tangent tt to the dividing surfaces is inclined to the axis of rotation of the worm 2 at an angle y. Then the normal pnn point P is tilted to the axis o also at an angle V. The pusher 12 of the cam mechanism is located at the distance e from the end of the screw 2. In view of this, as well as the constructions in Fig. 4, dependences (2) are obtained

x - r2 sinf + b, + 1 (3) y 1g cosj- t r, (b,).

Dependencies (3) make it possible to take into account the specific design of the gear: the value e takes into account the length of the elements connecting the plug 10 with the pusher 12, as well as the distance between the end face of the worm 2 and the fork 10.

Worm chna transmission works as follows.

The transfer of rotation from the worm 2 to the worm wheel 3 is carried out in

the screw 8. In this case, the frame 6 moves together with the shaft 5 and the screw 2 along the guides 7. Due to the fact that the guides 7 are located in the housing 1 parallel to the central transmission plane, there is a change in the center distance.

When moving the worm 2 with the shaft 5, the pusher 12 moves through the cam 11, since the pusher 12 is connected to the plug 10, which is connected to the worm hub 2. Due to the shape of the cam described by dependencies (2), the worm to 2 is connected through the file 10 and the pusher 12 with the cam 11, and the longitudinal axis of the fork 10 coincides with the axis of rotation of the screw 2, the screw 2 is displaced along the shaft 5

by an amount which ensures the contacting of the dividing surfaces of the worm 2 and the worm gear 3 for different values of the center distance of the transmission.

5 Performing a radius R of grooves of the surfaces of the tops of the teeth of the worm gear 3 according to the relation (1) ensures correct engagement (no edge contact) in the case of a maximum center distance when the worm to 2 contacts the worm gear 3 with its maximum division radius Cj.

The constancy of the steps of the turns of the worm 2 along the dividing surface forming it ensures normal engagement between the teeth of the worm gear 3 and the turns of the worm 2 at different positions of the latter. Thanks to this, a change in the center distance of the transmission occurs during operation at high gear ratios.

five

45

Claims (1)

Invention Formula A worm gear, comprising a housing, guided rails with a frame, a worm to, mounted in a frame with the possibility of axial movement, a worm wheel fixed on the shaft, and an actuator associated with the worm shaft, which in order to expand the result of the engagement of the working surface jj of the operational capabilities due to the bones of the turns of the worm 2 and the teeth of the cogging of the axial distance of the gear wheel 3, which are compatible with the gearbox, is equipped with a fork connected the same. If it is necessary to change the axial distance, rotate the hub bearing of the screw, the longitudinal axis of which coincides with the axis of the screw ,. hcg functional capabilities by changing the center distance, the transmission is equipped with a plug connected with the hub of the screw, the longitudinal axis of which coincides with the axis of the screw ,. hcg The cam mechanism, the cam of which is fixedly mounted in the housing, and the pusher is connected to the fork, the guides are located in the housing perpendicular to the axis of rotation of the screw and the screw, the radius of the wedge surface of the screw is variable, the dividing pitch of turns of the screw is constant, the radius R of grooves on the surfaces of the tops of the teeth of the worm gear is chosen from the ratio g "max Rfc t  Max the maximum radius of the dividing surface of the screw; VO is the angle of inclination of the tangent to the generatrix of the dividing surface Q of the screw at the point with r 4 / iax and coordinates of cam profile points selected from ratios 0 Q X Where x r2 sin yy cosj + b. + e + g , (B,), y - Cartesian coordinates with the origin of coordinates in the center of the worm gear; -radius of the dividing surface of the screw at the point of contact; -radius of the worm wheel at the point of contact; | - the angle of inclination of the tangent to the generator of the dividing surface of the screw at the point of contact; - distance from the point of contact to the larger end of the screw; distance from the larger end of the screw to the pusher. 25 Aa Phi2.2