SU33787A1 - Speed Box for Metalworking Machines - Google Patents

Description

The rational use of machines and other machines requires the ability to control the speeds of rotation of their working bodies (spindle, feed mechanism, etc.) in relation to the work being done. Most of the speed boxes used for this purpose do not fully solve this problem, since they have only a limited set of speeds, and it is not always possible to select the required number of revolutions.

The increase in the number of possible speeds leads to a strong complication of the boxes, increases the number of gears, complicates the control mechanism, etc., and yet does not give absolutely stepless adjustment.

The desire to obtain the possibility of continuous (infinitely variable) speeds has led to the emergence in recent times of boxes with hydraulic transmission, as well as the use of adjustable electric motors of direct current. However, the complexity and number of other drawbacks of these structures makes them not always cost-effective. it

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Seemingly from the fact that still most modern machines are built without the use of hydraulic transmissions.

In all machines scheduled for production in the near future in the USSR, there are also no hydraulic gears. However, in order to increase the number of possible speeds, the machines are equipped with highly complex gear boxes. Thus, a universal milling machine of the type Cincinnati, produced by the Gorky plant of milling machines, has a gearbox consisting of J8 gears, which gives 12 different speeds; Warner Turret & Swase, manufactured by the Moscow plant of revolving machines, also has a number of gears in the gearbox, which gives several speeds; radial drilling machine type Cincinnati Biecord, manufactured by Kharkov machine-tool plant, has a box of 22 gears, which gives 36 speeds, etc.

Such a large number of gears also entails the complication of the switching mechanisms

and control, and generally an increase in the cost of the whole structure, without at the same time giving the benefits of stepless adjustment.

All of the above also applies to feed boxes.

The proposed gearbox device is intended to solve the problem of infinitely variable regulation by purely mechanical means, i.e. without the use of hydraulic or adjustable electric drives. This is achieved by using a receive; its swing of a lever acting on a mechanism for converting a swinging movement of a lever into a rotational movement of a spindle. The rotational speed of the spindle is controlled by moving the lever's swing axis.

The drawing of FIG. 1 depicts a velocity box in a perspective view; FIG. 2 is a cross-section of the mechanism for moving the axle; FIG. 3 is the same, top view; FIG. 4-friction scene; FIG. 5 is a schematic of the speed box design for reversing spindle rotation, and FIG. b-modified device gear box, equipped with two levers.

The proposed gearbox, designed for metalworking machines, consists of a drum 2 mounted on the drive shaft 7, which rotates the lever 3 and the gear 6 coupled to it 6. The gear W is stuck on the spindle 77 and carries gear 8 on its sleeve. 8 clockwise, the rollers 72 are wedged in the wedge notches of the pinion of the gear JO and bind the two gears together. However, when rotated counter-clockwise, gear 8 rotates on the sleeve idly. Gears 7 and 9 are connected in the same way. Rollers 72 are pressed by springs toward the tapering part of the wedge space. Consequently, when the b-pinch is rotated clockwise, the gear goes through the pinions b, 7, 9, 10 and the spindle rotates clockwise. When the gear 6 is rotated counterclockwise, the gear goes through gears 6, 5 and the spindle rotates again in the clockwise direction.

Thus, the oscillating movement of the arm 3 and gear 6 is converted into a continuous rotational movement of the spindles in one direction. A change in the spindle speed is achieved by changing the swing angle. For this purpose, the axis 5 of the swing of the lever 3 can move along the lever, thereby changing the ratio of the shoulders. The box can be adapted to any range of speeds. It is enough for this that the number of revolutions of the shaft 7 is equal to the maximum number of revolutions of the spindle.

FIG. 4 shows a variant of the friction connection of the gear 7 with the sleeve of the gear 10. In this case, the rollers 72 are replaced by an internal wedge friction dog. This option, although more expensive, is more reliable in transmitting large torques.

To move the axis 5 when installing the arms of the lever 5 (Figs. 2 and 3), it is enclosed in the cage 13, moving in the guide groove of the box lid using the handwheel 75 and screw 14. associated with the transfer of the machine body, the position of which should depend on the number of revolutions (for example, alternate support in a cutting machine, etc.).

If reversal of the spindle rotation is required, the box design should be changed as shown in FIG. 5. To do this, it is enough to add two gears 77 and 18. At the same time, gear 18 must move along the spindle. Then, when connected to gear 10, gear 18, and, consequently, the spindle also rotates clockwise, when connected to the wheel 17-b in the opposite direction. By appropriate selection of the number of teeth of the gears 10 and 77, it is possible to achieve accelerated reversal. If the gear 18 is moved to the middle position, the machine will be turned off.

In order to eliminate the small stops of rotation of the spindle 77 at the time of changing the direction of swing of the lever 3, it is proposed to use two levers 3 and 19 articulated instead of one lever