SU1732214A1 - Method for testing mechanical transmissions - Google Patents

Abstract

The invention relates to the field of testing various structures and devices, and more specifically to methods of technical diagnostics and determining the technical condition of gear mechanisms. The purpose of the invention is to improve the accuracy and differentiated determination of the angular gaps of each of the gear teeth of mechanical gears. This is achieved by loading the input shaft with a moment, turning the shafts, determining the moments of selecting the gap, measuring the angle of rotation of the input shaft and determining the angular gaps according to the angle of rotation of the input shaft between the moments of selecting the angular gap, while the input shaft loading electric machine, not exceeding the time, causing the output shaft to start off, the current load of the electric machine is recorded depending on the angle of rotation of the input shaft, and the moments of the choice of the gap are determined by the break of the curve t okay load. The obtained values are compared with the angles of rotation of the respective shafts of the standard mechanical transmission 1 sludge (L s

Description

The invention relates to the field of testing various structures and devices, in particular, to methods for determining the technical condition and technical diagnostics of gear mechanisms.

There is a method for evaluating the technical condition of transmission units by the total angular clearance Јfj.

However, it does not involve the use of accurate means of control, as a result of which it has not found wide distribution.

The closest to the present invention is a method for determining the technical condition of mechanical gears without disassembling the method. The method consists in determining the shaft twist angles under torque loading, the load being provided in the range from nominal to the limit value and comparing the obtained values with the twist angle values of the reference mechanical gears 2.

The disadvantages of this method are the impossibility of a differentiated determination of the angular gaps of each of the gears of multiple mechanical gears, CHHJ 1

with to

one

accuracy of determining the technical condition of mechanical gears based on the total angular clearance, the impossibility of determining the moment of occurrence of elastic and plastic deformations of the shafts and teeth of gear wheels, etc.

The purpose of the invention is to improve the accuracy and differential determination of the angular gaps of each of the gears.

This goal is achieved by loading the input shaft of the mechanical transmission with torque, turning the shafts, determining the moments of selecting the gap, measuring the angle of rotation of the input shaft, and determining the angular gaps according to the angle of rotation of the input shaft between the moments of selecting the angular gap, while the input shaft is immersed from the electric machine, not exceeding the moment, causing the output shaft to break, current is recorded, the load of the electric machine depending on the angle of rotation of the input shaft, and the moments of the choice of the gap is determined from the kink of the current load curve. The transmitted values are compared with the angles of rotation of the respective shafts of the reference mechanical transmission o.

The proposed method is characterized in that the shaft is loaded without braking the output shaft outside the limits of Hooke's law (i.e. the action of elastic deformations), and the angular gaps are determined differentially and the angles of rotation of the shafts about

Below is an analysis of one of the component errors of the angular clearance along the diameter of the mechanical transmission shaft.

From the theory of resistance of materials it is known

(one)

MRpMKL with m wp L

the loading shaft is twisting

moment;

W. is the polar moment of the shaft resistance; 3 Permissible stresses for the shaft twist.55 Within the limits of the Hooke's law for twisting the shaft, the torque is proportional to the angle of twist of the shaft

calf -

(2)

where G is the angular stiffness of the shaft; UU is the twist angle.

Polar moment of shaft resistance

W

R

L

32

where d is the diameter of the shaft

Substituting the expression of Wp and the value of M kr from formula (2) in formula (1) receive

Sh

(3)

20

From here

/

(I

And ----- d3

WITH

25

By colarifying the expression get

WITH,

In DS |

, Number 3

 1p CT32

+ 3 In d. (five)

After differentiating expression (5) and replacing infinitely small quantities with finite increments, the functions are

35

 , & d

c 5

(6)

From the expression (6) it follows that for a known method, the component of the relative error of the twisting angle does not significantly depend on the relative error of the shaft diameter, while with the proposed method, the shaft twisting practically does not occur and the component

DCH5ravna

relative error -, -

to zero. This confirms the increase. accuracy of measurement of angular gaps.

The proposed method provides the simplicity of the structural implementation, the absence of mechanical deformation of the elements of the diagnosed mechanical gears, as well as the reduction of power consumption and electric motor power

The drawing shows a principal on the block diagram of a device for carrying out the proposed method.

uh

The implementation of the method is carried out by a device which comprises an electric machine i direct current connected by a rigid coupling 2 to an input shaft 3 of a multi-shaft mechanical transmission k having an output shaft 5, an output current load sensor 7 is connected to the motor power circuit 6, which is connected the input of the registering device 80 A rotation angle sensor 9 is installed on the input shaft 3, the output of which is connected with the other input of the recording device 8 o

The input shaft 3 of the diagnosed mechanical transmission k is connected via a rigid coupling 2 to the electric motor 1, the signals from the sensors 7 and 9 are fed to the inputs of the recording device 8, the drive so that the rotation of the electric motor shaft 1 and the input shaft 3 of the transmission k loads the motor 1 sufficient to turn the shafts of the mechanical transmission k without braking the output shaft 5. During the period from the beginning of the supply of current to the electric motor 1 to the beginning of the rotation of the output shaft 5, the recording device 8 records the current load of the electric motor 1 as a function of the angle of rotation of the input shaft 3. The angles of rotation are fixed at the characteristic break points of the current load curve. The total angular clearance in the gears of the shafts is determined to be the abscissa of the last break point of the current load curve.

Alternately, the angular clearance in each of the gears is determined.

0

five

0

22

five

0

five

0

five

I6

consecutive shafts, equal to the abscissa difference of the corresponding neighboring break points of the current load curve.

The obtained angular clearances, characteristic for the diagnosed gear, are compared with the corresponding angular clearances of the reference mechanical gear. According to the difference between the corresponding clearances, characteristic for the test and the reference gear, the technical condition of the test gear is judged.

Claims (1)

Invention Formula The method of determining the technical condition of mechanical gears is that the input shaft is loaded with a moment, the shafts are turned, the moments for selecting the gap are determined, the angle of rotation of the input shaft is measured, and the angular gaps are determined by the angle of rotation of the input shaft, between By the fact that, in order to increase the accuracy and differentiated determination of the angular gaps of each gearing, the input shaft is loaded with a torque from an electric machine not exceeding the torque causing The output shaft is recorded, the current load of the electric machine is recorded depending on the angle of rotation of the input shaft, and the moments of the choice of the gap are determined from the break of the current load curve.