SU1203259A1 - Slipping clutch - Google Patents

Description

I

The invention relates to mechanical engineering and can be used in F drives of machines subjected to frequent torque pulsations and in drives that require protection of drive parts from destruction depending on the duration of the application of torque.

The aim of the invention is to improve the reliability of operation and service life by completely disconnecting the clutch during prolonged overloads.

FIG. schematically shows a functional safety clutch, a slit; FIG. 2 shows the ball screw mechanism of the clutch in the process of long slipping.

The clutch consists of the leading I and the slave 2 coupling halves, which have the ability to interact between themselves through a package of friction disks 3 and 4, respectively, of the leader 1 and the slave 2 floor: / clutch. The clutch is turned on and off by pressing the disk 5, dinner through elastic elements b relative to coupling half 2. The driving and driven coupling half 1 and 2 are also interconnected by means of a planetary row, one element of which, for example, the sun wheel 7, is mounted on the follower. shaft 8 through one-way clutch 9 freewheel. The crown wheel 10 is mounted on the drive, half-1uf hei i coaxially with it, and the carrier 11 is mounted on the driven shaft 8 with the possibility of relative rotation.

On the driven floor, the coupling 2 is installed with the possibility of joint rotation and axial movement of the flange 12, for example by means of fingers P, pressed around the circumference in the flange 12, the flange 12 is spring-loaded relative to the driven floor;) of the coupling 2 by means of elastic elements 14, the preliminary compression of which is carried out adjustable with 1 screw and 15, and is installed with a gap D relative to the pressure plate 5,

The clutch control mechanism is made in the form of a ball screw of a new mechanism, screw 16 of which is usan: tang .n freely on the driven shaft 8 concentric 5 and the nut 17 is connected to the flange 12. Sharg-psi are placed between the screw 16 and the nut 1 7 1 8. Last-HJ-M screw turn 16 vertical032592

chickpea groove 19, and the edge 20 of the working surface is located at an angle smaller. 90, to facilitate the entry of the ball 18 when the mechanism is rotated

5 starting position.

During operation, the coupling is permanently closed. In this case, there are two cases of exploitation1 |; the mode of short-time slip of the disks 3 and 4, when

0 the angle of relative rotation of the discs 3 and 4 is less than some previously selected value, which determines the thermal load of the friction surfaces and their wear, within

5 of this angle, the elastic-damping properties of the friction springs are retained; the mode of long slip of the discs 3 and 4, when the angle is greater than the selected value

0 reason for the sharp increase in the moment on the driven half coupling 2,

Work during the first mode is carried out as follows.

The moment of slipping of the friction discs 3 and 4 is transmitted to the driven shaft 8. The angular speed of the driven shaft 8 is less than the half coupling 1 and the crown wheel 10 respectively. causes the latter to rotate synchronously with the driven half coupling 2 and the shaft 8, But as the driving shaft 21 rotates faster, in the relative movement of the clutch 9 and shaft 8 the power circuit closes on the driven shaft 8, the sun wheel 7 and the shaft 8 is connected. Upon further slipping, the moment is transmitted to the carrier 1 I, turning it relative to the shaft 8. This movement is transformed by the screw Mechanism 16-18 into the forward movement of the flange 12. At the same time, the elastic elements 14 are compressed. If the slipping has stopped, the flange 12 will move within the maximum gap L between it and the pressure disk 5.

When the slipping is stopped, the compressive force of the elastic elements i 4 acts on the screw pair 16-17 and acts on the carrier i1. But since the angular velocities of the slave 2 and the master 1 half coupling were equalized, the clutch 9 opens and the whole system assumes the initial position.

five

0

five

3

If the slip has not stopped (the second case), the flange 12 fully selects the gap D between it and the compression disk and then the elastic elements 6. At this, the torque transmitted by the clutch begins to decrease, and the further rotation of the carrier 11 depends on the magnitude of the resistance moment on the driven shaft 8,

If the torque is still high (within the limits of the reduced transmitted frictional moment), then the ball 18 escapes into the vertical groove 19 (the case of unexpected jamming of the driven shaft 8),

If the torque is sufficient to overcome the resistance forces, the skidding is stopped (also the case of a complete stop of the drive) and the system is brought to its original position by the force of the elastic elements 6 and 14.

The determination of the size of the gap D must be solved for each case based on the service life of the coupling and can be determined for different actuators in different ways, namely: to improve the safety properties of the coupling (fast control mechanism) the size of the gap & should tend to zero. To increase its elastic-damping properties, the & should be chosen greater than some optimal value, which can be calculated outcome of the following ratio.

1d1-h -4r-ck

-one

L

. .1 -r

Vb.

()

de. D - the gap between the flange 12 and the pressure disk -5;

.h Zt,

hereinafter, the ratio of the number of teeth of the crown wheel 10 to the number of teeth of the sun wheel 7, the sign (-) indicates that with the retarded carrier 11, these links rotate in different directions for this type of mechanism;

V scs - the angle of the screw

screw line 16; 4; p is the average diameter of the helix of the screw 16; full angle of slipping friction discs 3 and 4.

The pitch of the helix of the screw 16 is selected from the condition that the control mechanism fully operates according to the ratio.

; B

Ihu

2TG () (Su-1)

U7; h To - LC, (,

where n

0

five

- screw surface pitch

screws 16;

B - the minimum clearance to start shutting off the friction discs 3 and 4; D - the gap between the flange 12 and

pressure disk 5; f - the full angle of the slipping of the disks 3 and 4

The stiffness of the elastic elements 14 between the flange 12 and the pressure disk 5 should be chosen from the ratio

thirty

35

WITH

where C is the stiffness of the elastic elements 14;

.) gp is the average diameter of the friction surfaces of the disks 3 and 4; JU - friction coefficient of disks

3 and 4; stiffness of elastic elements

b;

a (- the angle of inclination of the helix of the screw 16;

B - the minimum clearance to start shutting down the friction discs 3 and 4;

4tp is the average diameter of the screw. screws 16.

" five

r in

1W

fff

/ J

F1. f

/eight

Editor A ,. Thieves ich

Compiled by I.Lukina Tehred Z.Kastelevich Proofreader T.Kolb

Order 8400/39 Circulation 897 Subscription

VNSHSHI USSR State Committee

for inventions and discoveries 113035, Moscow, F-33, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

FIG. 2

Claims (1)

FRICTIONAL SAFETY COUPLING, comprising a driving and driven coupling half with driving and driven shafts, a spring-loaded pressure plate mounted to rotate together with the driven coupling coupling, a screw control mechanism with a screw and nut mounted to rotate together with the driven coupling coupling and having a flange located with the possibility of interaction in the axial direction with the pressure plate. planetary gear with two links, one of which is made in the form of a sun wheel and kinetically connected to a driven shaft, and the other - in the form of satellites with axes connected to a screw, characterized in that, in order to increase reliability and service life by completely shutting down the clutch during prolonged overloads, it is equipped with a third link of the planetary gear, made in the form of a crown wheel and connected to the drive coupling half, and a freewheel installed between. the sun wheel and the driven shaft and having a jamming direction identical with the direction of rotation of the drive coupling half, the screw control mechanism is made in the form of a ball screw mechanism, the screw of which is mounted loosely on the driven shaft concentrically to it, and the nut is spring-loaded to the driven coupling half and installed with a gap between the flange and the pressure disk, while the satellites are mounted rotatably on the axes, the axis of the last turn is perpendicular to the axis of rotation of the coupling, and the edge of its working surface positioned at an angle less than 90 °.