Интернаука - Интернаука №16 (часть3) 2020

MAZ 642208-020

Name of parts and as-

№

Number

Specific

Nature of

Number of

Specific

Character

semblies

of failures

weight%

failure

failures

weight%

rejection

1 Sleeve

11

14 , 7

wear

16

11.3

wear

2

Piston

8

10.6

wear

11

7.7

wear

3 Loose leaf

7

9.3

wear

15

10, 5

wear

4 Connecting rod

7

9.3

wear

15

10.5

wear

5 Set of rings

11

14.7

wear

14

9.8

wear

6 Oil pump

-

wear

1

0.7

wear

7 Head gasket

11

14.7

burnout

14

9.8

burnout

8

Connecting rod

-

wear

4

2,8

wear

9

Head cover gasket

11

14.7

burnout

15

10.5

burnout

10 Pusher

-

wear

3

2,3

wear

11 Yoke

-

wear

3

2,3

wear

12

Barbell

-

wear

6

4.3

wear

13

Crankshaft

1

1.3

wear

1

0.7

wear

35

Журнал «Интернаука»

№ 16 (145), часть 3, 2020 г.

14

Exhaust manifold gasket

5

6.6

burnout

15

10.5

burnout

1 5 Piston pin

-

wear

4

2,8

wear

1 6 ICE pillow

3

4.1

wear

5

3,5

wear

Total

75

100

142

100

Bus operating conditions in Tashkent. The tempera-

 Service by year (once a year, three years 1 time,

ture of the air - a maximum of + 44 ° ,minimum, -29 °

five years 1 time)

C , , average - 14.8 ° C .Humidity air : - in the period of In order to determine the reliability indicators of

time is hot - 21%, - a cold time - 55%. About 429 mm Mercedes-Benz O 405 buses in hot climates and heavy

of precipitation falls annually. Barometric pressure

traffic in a big city, taking into account the specific con-

is 1.0 kg per 1 cm 2 . The average annual wind speedis ditions of operation on the city routes , Mercedes-Benz 1.4 m/s.

O 405 buses were tested

The reliability of buses for specific operating condi-

A study was conducted to select the equivalent of

tions largely depends on the accepted modes of bus ser-

motor oils for Mercedes-Benz and Otayul buses from

vice, which characterizes the frequency, list of opera-local production instead of imported ones and establish

tions, and their complexity.

the optimal timing for their replacement. [1 9 ]

The system of service for specific maintenance

Was conducted controlled operation of 40 buses,

conditions buses designed with buses Guidance Docu-

"Mercedes-Benz O 405" 8 - the bus fleet of the city of ment "Mercedes-Benz" joint analysis of the operating Tashkent . Units and parts critical to reliability have experience of the service station, chronometry results been identified [ 20 ].

data and expert evaluation specialists [1 5 16,17,18 ] .

Reliability maps of Mercedes-Benz O 405 buses

After-sales service of Mercedes-Benz buses is di-

have been developed, which are necessary for improv-

vided into the following types:

ing the design, production and operation of buses [ 21 ].

 daily maintenance (performed in the ATP).

Were first identified indicators buses reliability

 after-sales service with a frequency of 15.0

properties of the "Mercedes-Benz O 405" for the com-thousand km (S-15000km.)

plete life cycle, which amounted to 1,250,000

 After-sales service with a frequency of 30.0

km, significantly more resources 1 000 000 km, set by

thousand km (S-30000km.)

the manufacturer! [ 22 ] .

 after-sales service with a frequency of 45.0

In

[ 22] shows a detailed

information

about

thousand km (S-45000km.)

the district aspredelenie failures buses Mercedes-Benz

 After-sales service with a frequency of 90.0

O 405 for systems and units on the run 0 ÷

thousand km (S-90000km.)

1250 you s.km (tablitsa №3)

Table 3.

Distribution of failures of Mercedes-Benz O 405 buses by systems and aggregates at a range of 0 ÷ 1250 thousand km

The

f

il-

s

ce

o

it

Total

amount of

s

un

ic

f fa

bu

ic

%

№

Name of units and

er

if

ht,

o

expense failure

if

costs per

rt

un

te

ht

parts

l bo

ec

%

er

ec

pa

ra

repair parts ,

bus ,

per

ta

Sp

weig

Numb

o

thousand soums

Sp

weig

thousand

T

ures per

Numb

soums

Suspension and

1

8

3455

15.7

86.4

3234058,0

25.8

80851.5

suspension

Electrical

2

25

2622

11.9

65.6

1280,170.4

10,2

32004.3

equipmente

Engine cooling

3

16

1847

8.4

46.2

771802.1

6.2

19,295.1

system

4

Engine OM 447 N

12

1860

8.5

46.5

739 625.6

5.9

18,490.6

Automatic gearbox

5

21

1801

8.2

45.0

556,143.1

4.6

13903.6

ZF 4 HP 500

Reliability-limited reliability

52.7

Chassis, bodywork

6

27

1807

8.2

45,2

1696536,4

13.6

42,413.4

and superstructure

7

Brake system

20

1362

6.2

34.1

859935.2

6.9

21498.4

Heatingis,

8

17

1364

6.2

34.1

770737.7

6.2

19268.4

and circulation

36

Журнал «Интернаука»

№ 16 (145), часть 3, 2020 г.

Serviceability Limit Reliability

79,4

9

Front axle

16

1035

4.7

25.9

534,726.4

4.3

13368.2

10 Rear axle

27

1094

5,0

27.4

571,869.7

4.6

14,296.7

11 Steering

7

802

3.6

20.1

468,990.8

3,7

11724.8

Fuel system

12

22

499

2,3

12.5

385,402.4

3,1

9635.1

Fuel pump

13 Compressor

fifteen

621

2,8

15,5

328,116.7

2.6

8202.9

14 Cardan drive

2

46

0.2

1,2

43055.8

0.3

1076.4

Electrical

15 equipmente

12

1558

7.1

39.0

196674,2

1,6

4916.9

Body

16 Engine mount

4

200

0.9

5

74,597.7

0.6

1864,943

Total

251

21974

100

549.3

12512442.1

100

312811,1

Source: calculated by the author based on data from

For

example , for reliability of

the

en-

the Mercedes-Benz service in Tashkent

gine I ( (table № 4) on the reliability of the engine cool-

Reliability and maintainability indicators were de-

ing system ( (table № 5)

termined for all units of Mercedes-Benz O 405 buses, at

a range of 0 ÷ 1250 thousand km .

Table 4.

Engine Reliability

The

ce

ht,

Total

s

amount of

Name kt s and

er

s ,

it

un

Number

costs on Spare

ic

rt

if

costs per

No.

details s /

te

weig

ht%

un

of failures

parts to the elimi-

l bo

ra

ic

%

ec

bus ,

Detail number

pa

Numb

if

of

in

ta

per bus

nation of failures ,

Sp

o

ec

weig

thousand

T

thousand soums

Sp

soums

Sleeve , piston

1

group A 447 030

6

347

18.6

8.7

215447.6

29.1

5386.2

09 37

2

Insert kit t

6

520

27.9

13.0

107144.4

14.5

2678.6

Piston ring A

3

6

347

18.6

8.7

87025,2

11.8

2175.6

422 030 01 24

Reliability-limited reliability

65.1

Cylinder block A

4

1

6

0.3

0.2

72,577.4

9.8

1814.4

447 010 07 08

Crankshaft A

5

1

17

0.9

0.4

58815.2

8

1470.4

496 030 02 01

Serviceability Limit Reliability

73.2

Camshaft

6

1

25

1.3

0.6

62840.3

8.5

1571.0

A 447 050 11 01

Connecting Rod A

7

6

132

7.1

3.3

54043,7

7.3

1351.1

447 030 04 20

Set gasket set A

8

1

79

4.3

2.0

35871.6

4.8

896.8

427 010 00 05

Oil pump A

9

2

31

1.7

0.8

19321.8

2.6

483.0

403 180 27 01

Inlet and outlet

10

valve A 442 050 05

12

336

18.1

8.4

14127.4

1.9

353.2

26

Oil cooler A

11

1

13

1.7

0.3

8383.7

1,1

209.6

001 188 31 01

Cylinder head A

12

6

8

0.4