Volume 04 Issue 06-2024
31
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
04
ISSUE
06
Pages:
31-36
OCLC
–
1121105677
Publisher:
Oscar Publishing Services
Servi
ABSTRACT
In the article, taking into account the increasing wear of the profile, the intensity of wear of the surface of the cam in
contact with talc during operation is studied, and the change in this intensity depending on the pressure angle is
estimated. The effect of chamber profile wear on the gas distribution mechanism (GDM) and engine operation has
been studied. the possibility of a significant improvement in the tribological properties of a cam-pusher pair is analyzed
on the basis of a numerical method for formulating the law of motion of the pusher.
KEYWORDS
Agriculture, cam, pusher, wear, pressure angle, intensity, normal pressure force, strength.
INTRODUCTION
It is highly advantageous to carry out corrosion
resistance testing of engine gas distribution
mechanism details on a special stand. However, due to
the complexity of the geometry of the ash profile and
the complexity of the implementation of the existing
methods used to measure its wear, the results
obtained during the test are not sufficiently accurate.
In addition, the results obtained during experimental
studies can be used only in friction pairs whose
geometric and kinematic indicators are known.
Therefore, as a result of modeling the wear of the
friction pair made of the sleeve profile and the pusher
sleeve with roller analogs, it becomes possible to
speed up the testing process on the friction machine.
MATERIALS AND RESEARCH METHODS
The total rate of friction of the parts that rub against
each other is determined by the sum of the rates of the
Research Article
CALCULATION OF WEAR VELOCITY IN PROFILE PART OF CAM
Submission Date:
June 04, 2024,
Accepted Date:
June 09, 2024,
Published Date:
June 14, 2024
Crossref doi:
https://doi.org/10.37547/ajast/Volume04Issue06-06
Irgashev Amirqul
Doctor Of Technical Sciences, Professor Tashkent State Technical University Uzbekistan, Tashkent City,
Uzbekistan
Qurbonov Behzod Bahodir Ugli
Doctoral Student, Tashkent State Technical University Uzbekistan, Tashkent City, Uzbekistan
Journal
Website:
https://theusajournals.
com/index.php/ajast
Copyright:
Original
content from this work
may be used under the
terms of the creative
commons
attributes
4.0 licence.
Volume 04 Issue 06-2024
32
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
04
ISSUE
06
Pages:
31-36
OCLC
–
1121105677
Publisher:
Oscar Publishing Services
Servi
rate of friction that occurs with the participation of
abrasive particles in the working environment and the
twists and turns of the parts in the joint.
In the grinding process, abrasive particles with larger
sizes are involved. Research studies show that if the
size of the abrasive particles that have not undergone
the grinding process is equal to the size of the abrasive
particles that have been ground, then the grinding of
the particles with this size will practically stop, because
the particles with this size cannot participate in the
grinding process due to the fact that they are not in
contact with the friction pair.
Fig.1. Scheme of placement of the characteristics partspof the cam
In cases 1 and 6, the cam profile has a constant radius
of curvature, the center of which corresponds to the
center of rotation of the bushing, in which the friction
pair consisting of the bushing and the pusher sleeve
receives a constant, minimum load, therefore, the
bending of this part of the bushing profile is the same
as that of the rest of the bushing profile. will have the
smallest value relative to the parts.[3]
Cases 2 and 5 of the cup profile are characterized
by constant radii of curvature, the center of which is
located outside the center of rotation of the cup. In this
case, due to the vertical deformation of the valve
spring, a variable load is applied to each connection
point of the sleeve profile.
RESEARCH RESULTS AND DISCUSSION
The probability that an abrasive particle settles on the
friction surfaces is determined by the movement path
of the abrasive particles that entered the slot-like gap
of the friction surfaces:
the sliding path of the input cam,
𝑆
𝑘
=
𝑠∙𝐻
𝑖
𝐻
𝑖
+𝐻
𝑜
; (1)
Volume 04 Issue 06-2024
33
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
04
ISSUE
06
Pages:
31-36
OCLC
–
1121105677
Publisher:
Oscar Publishing Services
Servi
the sliding path of the output cam,
𝑆
𝑜
=
𝑠∙𝐻
𝑜
𝐻
𝑖
+𝐻
𝑜
;
where s
–
is the total sliding path, which occurs due to the difference between the lengths of the profiles of the input
and output cams; ;
H
i
,
H
o
- the hardness of the input and output cam materials, respectively.
During the operation of the friction pair consisting of the input (output) cam and the pusher sleeve, the abrasive
particles located in its pin-shaped groove are crushed until they touch the friction surfaces, in this case, the depth of
immersion of the abrasive particles located in this slot into the sleeve surface before being crushed, the thickness of
the oil film involved in the friction process taken into account can be determined from the following expression:
h
i,o
=
(d
a
−h
o
)∙σ
a
4H
i,o
, m (2)
In this
d
a
- the average size of the abrasive particle in the oil;
h
o
- the thickness of the oil film that exists between the
cam and the bearing sleeve during friction;
а
- compressive strength of the abrasive particle;
H
i,o
- the hardness of
the material of input (output) cams.
The following expression was proposed to calculate the thickness of the oil film between the input (output) cam and
the abrasive particle [8];
(
)
0
,
,
max
,
4, 6
a p
к ч
к ч
a
м
Tк ч
e
v
v
h
d
c
+
=
, m. (3)
Where,
0
–
the dynamic viscosity of the lubricating material involved in the friction process; а –
Pezo coefficient of
oil viscosity; р –
oil pressure in the friction pair; d
max
–
is the largest size of an abrasive particle in oil;
,
Tк ч
–
the yield
point of the material of the input (output)cam.
k
v
=1.0003 when there is significant sliding in the friction pair (tooth height coefficient k=1), and k
v
=1.103 in the rolling
region (k=0), therefore k
v
=1 in cases where k=1 is close is recommended.
When calculating the abrasion resistance of the cam profile, it is possible to increase the accuracy of the obtained
calculation results by taking into account the recommendations given in solving the problems related to the
determination of the geometric parameters of the abrasive particles involved in the abrasion process.
The amount of immersion of an egg-shaped abrasive particle on the surface of the ash can be determined by the
following expression [9]:
V =
2π∙k
v
∙d
a
2
∙h
i(o)
12
,
mm
3
(4)
Volume 04 Issue 06-2024
34
American Journal Of Applied Science And Technology
(ISSN
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2771-2745)
VOLUME
04
ISSUE
06
Pages:
31-36
OCLC
–
1121105677
Publisher:
Oscar Publishing Services
Servi
Where,
k
v
- the coefficient that takes into account the degree of penetration of the abrasive particle into the pore-like
slot;
h
i(o)
- the depth of immersion of the abrasive particle on the surface of the input (output) cam.
In order to calculate the distance between two adjacent abrasive particles, the following is assumed: the abrasive
particles in the oil are assumed to be evenly distributed over its entire volume, then the calculation expression will
look like this:
L
1L
= L
1h
=
B
n
L
=
0,72∙d
a
∙√γ
a
√ε
k
∙γ
o
,
mm (5)
Where,
ε
k
- the amount of abrasive particles in the oil;
γ
a
- abrasive particle density;
γ
o
- oil density[1,2]:
The number of abrasive particles in the pin-shaped gap between the cam and the pusher sleeve before fragmentation:
n
s
=
S
k
L
1L
(6)
The number of abrasive particles determined by the lengthwise displacement of the abrasive particles located in the
pin-shaped slot between the cam and the pusher sleeve until they are fragmented:
n
s
= 0,5 ∙ n
L
∙ n
s
=
0.237∙B∙s∙σ
a
∙ε
k
∙γ
m
H
k
∙d
a
2
∙γ
a
(7)
The contact area of the cam profile and the pusher bush corresponding to a single abrasive particle:
F
1a
=
0,53∙d
a
2
∙γ
a
ε
k
∙γ
m
,
mm
3
(8)
The diameter of the contact spot of the spherical abrasive particle, which has sunk to the limit before grinding into
the friction surface of the pusher sleeve of the cam profile[4]:
a
p
= 2 ∙ √d
a
∙ h
k
− h
k
2
, mm (9)
At the threshold level, the contact area of a single abrasive particle embedded in the grinding surface of the cam
profile and the pusher sleeve is[10]:
F
1a
= a
p
∙ L
1L
= 0,362 ∙ d
a
∙ √γ
a
∙
√4γ
a
H
k
σ
a
−σ
a
2
H
k
√γ
m
∙ε
k
,
mm
2
(10)
Table 3.1
The possibility of re-deformation of the insertion cam
Volume 04 Issue 06-2024
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American Journal Of Applied Science And Technology
(ISSN
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2771-2745)
VOLUME
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Pages:
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OCLC
–
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The probability of re-deformation shown in table 3.1 is
calculated using the following preliminary data:
𝑑
𝑎
=
15 ∙ 10
−3
𝑚𝑚;
𝛾
𝑎
= 1,9 𝑔𝑚/𝑠𝑚
3
;
; The results of
𝛾
𝑎
=
0,910 𝑔𝑚/𝑠𝑚
3
show that with an increase in the
amount of active abrasive particles involved in the
friction process in the oil, the probability of re-
deformation of the friction pair consisting of the cam
profile and the pusher sleeve increases and the value
of this probability decreases with the increase of the
contact width of the friction pair consisting of the
pusher sleeve[7].
The status
of cam
profile
The
contact
width Vk,
mm
The amount of abrasive particles in the oil,
𝜀
𝑘
0,2
0,3
0,4
0,5
0,6
1
0,508
0,0001232
0,0001848
0,0002464
0,0003080
0,0003696
2
0,709
0,0000883
0,0001325
0,0001766
0,0002207
0,0002650
0,741
0,0000845
0,0001268
0,0001690
0,0002112
0,0002536
0,771
0,0000812
0,0001218
0,0001624
0,0002030
0,0002436
0,799
0,0000783
0,0001174
0,0001566
0,0001958
0,0002348
0,825
0,0000759
0,0001139
0,0001518
0,0001898
0,0002278
0,849
0,0000737
0,0001105
0,0001474
0,0001843
0,0002210
0,872
0,0000718
0,0001077
0,0001436
0,0001795
0,0002154
0,894
0,0000700
0,0001050
0,0001400
0,0001750
0,0002100
0,915
0,0000684
0,0001026
0,0001368
0,0001710
0,0002052
3
0,764
0,0000819
0,0001229
0,0001638
0,0002048
0,0002458
4
0,764
0,0000819
0,0001229
0,0001638
0,0002048
0,0002458
5
0,915
0,0000684
0,0001026
0,0001368
0,0001710
0,0002052
0,894
0,0000700
0,0001050
0,0001400
0,0001750
0,0002100
0,872
0,0000718
0,0001077
0,0001436
0,0001795
0,0002154
0,849
0,0000737
0,0001105
0,0001474
0,0001843
0,0002210
0,825
0,0000759
0,0001139
0,0001518
0,0001898
0,0002278
0,799
0,0000783
0,0001174
0,0001566
0,0001958
0,0002354
0,771
0,0000812
0,0001218
0,0001624
0,0002030
0,0002436
0,741
0,0000845
0,0001268
0,0001690
0,0002112
0,0002536
0,709
0,0000883
0,0001325
0,0001766
0,0002207
0,0002650
6
0,508
0,0001232
0,0001848
0,0002464
0,0003080
0,0003696
Volume 04 Issue 06-2024
36
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
04
ISSUE
06
Pages:
31-36
OCLC
–
1121105677
Publisher:
Oscar Publishing Services
Servi
CONCLUSION
1. In the presence of abrasive particles, the wear rate of
the camshaft bearing profile increases linearly with
respect to the strength of the abrasive particle, the
frequency of rotation of the bearing profile, the
amount of abrasive particles in the oil, and
parabolically with respect to their size. causes a
decrease in the rate of profile eating.
2. The largest value of the coefficient of acceleration of
the corrosion test of sleeve profiles was 1323.3 in the
inlet sleeve and the smallest value was 19.1, and these
values in the outlet sleeve were 821.4 and 16.4
respectively.
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Mirzayev Q Q Irgashev A Journal of Friction and
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Starzhinsky V E Solimterman Y L Tesker E I Goman
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