Note: Descriptions are shown in the official language in which they were submitted.
Description
DEVICE AND METHOD FOR TESTING LOAD-CARRYING PROPERTIES OF WIRE ROPE
FOR FRICTION HOIST
Technical Field
The present invention relates to a device and method for testing load-carrying
properties of wire rope,
in particular to a device and method for testing load-carrying properties of
wire rope for friction hoist.
Background Art
As the main mine hoisting equipment, vertical shaft hoists undertake important
tasks of coal gangue
hoisting, material lowering, and personnel and equipment lifting, and is the
linking hub between the
underground coal mine and the ground. Among vertical shaft hoists, friction
hoists take a dominant
position. The bearing capacity of the steel wire rope, which is the key
component for load bearing
and power transfer, has direct influence on the safety of mine hoisting.
According to the "Safety
Regulations in Coal Mine", usually the hoisting steel wire rope shall be
discarded and replaced once
two years, but must be replaced immediately once the number of broken wires is
increased suddenly
or the elongation is accelerated suddenly. Before a new steel wire rope is
installed, the new steel wire
rope shall be verified, in order to avoid degradation of the bearing capacity
of the hoist caused by the
new steel wire rope, which may lead to a severe potential safety hazard. In
addition, the vertical shaft
hoister is key equipment that operates continuously in a long time in the coal
mine, but the coal
hoisting operation has to be stopped when the steel wire rope is to be
replaced. Severe economic
losses may be resulted if it is found that reparation is necessary after the
rope is replaced. Therefore,
it is necessary to carry out strict load-carrying property test on the new
steel wire rope before the new
steel wire rope can be installed.
Presently, the researches on steel wire rope tests mainly focus on the
detection of defects of steel wire
ropes in service in mines. For example, the novel non-destructive testing
device for steel wire ropes
disclosed in the Chinese Patent Application No. CN201710462492.X utilizes a
magnetic flux leakage
detection method to detect the defects of steel wire ropes. Besides, some
researchers have set up
various test stands to test a specific property of steel wire ropes. For
example, the high-speed and
fretting friction testing device for steel wire ropes disclosed in the Patent
No. CN201410728384.9
can simulate the friction behavior between steel wire ropes and analyze the
friction state of steel wire
ropes under different sliding speed and fretting friction conditions. However,
based on the above
researches, it is unable to test the friction hoists of different
specifications uniformly. Therefore, it is
necessary to develop a testing device that can be used to uniformly test the
load-carrying capacity of
the steel wire ropes of friction hoists in vertical shafts with different drum
diameters and drum wrap
angles, so as to uniformly check different types of steel wire ropes produced
by various manufacturers
before field installation, avoid repeated testing investment for large-scale
production enterprises,
improve the manufacturing quality of small-scale production enterprises, set
standard for the market
of hoisting steel wire ropes, and ensure the load-carrying capacity of
hoisting steel wire ropes.
Developing such a testing device is of great significance for ensuring the
safety of vertical shaft
hoisting. However, at present, such a testing device is unavailable.
Date Recue/Date Received 2022-06-09
Contents of the Invention
Technical Problem: the object of the present invention is to overcome the
drawbacks in the prior art,
and the present invention provides a device and method for testing load-
carrying properties of wire
rope for friction hoist. The device has a simple structure, and is reliable
and practical.
Technical Solution: a device for testing load-carrying properties of wire rope
for friction hoist of
the present invention, comprising loading hydraulic cylinders connected to a
tested steel wire rope,
a hydraulic cylinder positioning platform, a wrap angle positioning device,
several steel wire rope
positioning devices and a steel wire rope positioning platform, wherein the
hydraulic cylinder
positioning platform is arranged in the vertical direction and provided with
several rows of
hydraulic cylinder positioning holes arranged in parallel thereon; the steel
wire rope positioning
platform is in an arc shape, located in the same plane as the hydraulic
cylinder positioning platform
and is arranged opposite to the hydraulic cylinder positioning platform, and
provided with several
rows of positioning holes arranged circumferentially thereon; two loading
hydraulic cylinders are
provided and arranged side by side on the hydraulic cylinder positioning
platform in the horizontal
direction through the hydraulic cylinder positioning holes; the wrap angle
positioning device is
arranged on a linear section of the steel wire rope positioning platform in
the vertical direction
through the positioning holes; several steel wire rope positioning devices are
arranged on an arc
section of the steel wire rope positioning platform in the radial direction
through the positioning
holes.
The wrap angle positioning device comprises a positioning telescopic sleeve, a
wrap angle positioning
slide table, a wrap angle positioning lead screw, a wrap angle positioning
lead screw nut, a positioning
telescopic rod, wrap angle positioning rollers, a wrap angle positioning
friction liners, a wrap angle
positioning support table, a wrap angle positioning pedestal, and a wrap angle
positioning hand wheel,
wherein the wrap angle positioning support table is arranged on the wrap angle
positioning pedestal;
the wrap angle positioning lead screw, the wrap angle positioning lead screw
nut and the wrap angle
positioning hand wheel are arranged coaxially; the wrap angle positioning hand
wheel rotates to drive
the wrap angle positioning lead screw to rotate, thereby pushing the wrap
angle positioning lead screw
nut to move back and forth; the wrap angle positioning slide table is fixed to
the wrap angle
positioning lead screw nut and can slide axially on the top surface of the
wrap angle positioning
support table; the positioning telescopic sleeve is arranged on the wrap angle
positioning slide table
axially; the wrap angle positioning roller is arranged on the top end of the
positioning telescopic rod,
and the rim of the wrap angle positioning roller is provided with a groove in
which the wrap angle
positioning friction liner is installed; the wrap angle positioning friction
liner is provided with a rope
groove.
The steel wire rope positioning device comprises a steel wire rope positioning
support table, a two-
way hydraulic pump, a steel wire rope positioning lead screw, a steel wire
rope positioning pedestal,
hydraulic pump positioning bolts, a main shaft of hydraulic pump, main steel
wire rope positioning
rollers, a main steel wire rope positioning slide table, steel wire rope
positioning friction liners, steel
wire rope clamping bolts, auxiliary steel wire rope positioning rollers, a
auxiliary steel wire rope
positioning slide table, a steel wire rope positioning lead screw nut, steel
wire rope clamping nuts,
and a steel wire rope positioning hand wheel, wherein the steel wire rope
positioning support table is
arranged on the steel wire rope positioning pedestal; the steel wire rope
positioning lead screw, the
steel wire rope positioning lead screw nut and the steel wire rope positioning
hand wheel are arranged
coaxially; the steel wire rope positioning hand wheel rotates to drive the
steel wire rope positioning
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Date Recue/Date Received 2022-06-09
lead screw to rotate, thereby pushing the steel wire rope positioning lead
screw nut to move back and
forth; the main steel wire rope positioning slide table is fixed to the steel
wire rope positioning lead
screw nut, and can slide axially on the top surface of the steel wire rope
positioning support table; the
hydraulic pump positioning bolts fix the two-way hydraulic pump and the main
steel wire rope
positioning rollers coaxially on the main steel wire rope positioning slide
table, and the main steel
wire rope positioning rollers drive the main shaft of hydraulic pump to rotate
synchronously; the
auxiliary steel wire rope positioning slide table is arranged on the top
surface of the steel wire rope
positioning support table, the auxiliary steel wire rope positioning rollers
are arranged on the auxiliary
steel wire rope positioning slide table, and the axis of the main steel wire
rope positioning rollers is
in the same line as the axis of the auxiliary steel wire rope positioning
rollers; the main steel wire
rope positioning slide table and the auxiliary steel wire rope positioning
slide table are provided with
collinear through-holes in the two sides respectively, the steel wire rope
clamping bolts penetrate
through the through-holes from one end to connect the main steel wire rope
positioning slide table
and the auxiliary steel wire rope positioning slide table together, and are
tightened up at the other end
by means of the steel wire rope clamping nuts, so that the main steel wire
rope positioning rollers and
the auxiliary steel wire rope positioning rollers can clamp the tested steel
wire rope under the action
of squeezing force; the rims of the main steel wire rope positioning rollers
and the rims of the auxiliary
steel wire rope positioning rollers are provided with a groove respectively,
in which the steel wire
rope positioning friction liner is installed, and the steel wire rope
positioning friction liner is provided
with a rope groove.
The loading hydraulic cylinder is a double-acting hydraulic cylinder
comprising a loading hydraulic
cylinder jacket, a loading hydraulic cylinder pedestal, and a loading
hydraulic cylinder piston rod; the
front end of each loading hydraulic cylinder piston rod is provided with a
steel wire rope lock sleeve,
the two end pigtails of the tested steel wire rope connected with the loading
hydraulic cylinders are
clamped in the steel wire rope lock sleeves via installing steel wire rope
locks, and pulling force is
exerted on the tested steel wire rope via the loading hydraulic cylinders; the
two loading hydraulic
cylinders serve as a driving side and a load side for each other, the
hydraulic cylinder at the driving
side drives its loading hydraulic cylinder piston rod by adjusting the oil
pressure at the oil inlet to pull
the tested steel wire rope, while the hydraulic cylinder at the load side
inhibit the tested steel wire
rope from pulling its loading hydraulic cylinder piston rod by adjusting the
oil pressure at the oil
outlet.
The length of the loading hydraulic cylinder piston rod is greater than the
circumference of the friction
hoist with maximum diameter.
The number of the steel wire rope positioning devices depends on the testing
accuracy of the friction
hoist with different diameter.
The hole density of the hydraulic cylinder positioning holes in the vertical
direction depends on the
testing requirement for adaptation of the vertical distance clamped by the two
loading hydraulic
cylinders to the friction hoist with different diameter.
The hole density of the positioning holes in the circumferential direction
depends on the testing
requirement for adaptation of the arc enclosed by the wrap angle positioning
device and the steel wire
rope positioning devices to the friction hoist with different diameter and
wrap angle.
A testing method by using the above-mentioned device for testing load-carrying
properties of wire
rope for friction hoist, comprising the following steps:
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Date Recue/Date Received 2022-06-09
(a) installing the wrap angle positioning support table on the wrap angle
positioning pedestal,
installing the wrap angle positioning lead screw, the wrap angle positioning
lead screw nut and
the wrap angle positioning hand wheel coaxially, fixing the wrap angle
positioning slide table to
the wrap angle positioning lead screw nut, installing the positioning
telescopic sleeve axially on
the wrap angle positioning slide table, installing the wrap angle positioning
friction liners in the
groove of the wrap angle positioning roller, and installing the wrap angle
positioning roller on
the top end of the positioning telescopic rod, to assemble a wrap angle
positioning device;
(b) installing the steel wire rope positioning support table on the steel
wire rope positioning pedestal,
installing the steel wire rope positioning lead screw, the steel wire rope
positioning lead screw
nut and the steel wire rope positioning hand wheel coaxially, fixing the main
steel wire rope
positioning slide table to the steel wire rope positioning lead screw nut,
installing the steel wire
rope positioning friction liners in the grooves of the main steel wire rope
positioning rollers and
the auxiliary steel wire rope positioning rollers, fixing the two-way
hydraulic pump and the main
steel wire rope positioning rollers coaxially on the main steel wire rope
positioning slide table
with the hydraulic pump positioning bolts, inserting the steel wire rope
clamping bolts from one
end of the slide table though the through-holes to connect the main steel wire
rope positioning
slide table and the auxiliary steel wire rope positioning slide table
together, and tightening the
steel wire rope clamping bolts with the steel wire rope clamping nuts at the
other end of the slide
table, to assemble several steel wire rope positioning devices;
(c) based on the diameter D and wrap angle a of the friction hoist to which
the tested steel wire rope
belongs, installing the wrap angle positioning device in the vertical
direction on the linear section
of the steel wire rope positioning platform according to the positioning holes
at preset positions,
installing several steel wire rope positioning devices at an interval in the
radial direction on the
arc section of the steel wire rope positioning platform, turning the steel
wire rope positioning
hand wheel to push the steel wire rope positioning lead screw nut to move back
and forth, turning
the wrap angle positioning hand wheel to push the wrap angle positioning lead
screw nut to
move back and forth, trimming the telescopic length of the positioning
telescopic rod to push
the wrap angle positioning rollers to move back and forth in a small field,
till the diameter of the
arc enclosed by the rims of the wrap angle positioning rollers and the rims of
the main steel wire
rope positioning rollers is equal to the diameter D of the friction hoist and
the angle of the arc is
equal to the wrap angle a of the friction hoist finally, then arranging the
two loading hydraulic
cylinders side by side in the horizontal direction on the hydraulic cylinder
positioning platform
via the hydraulic cylinder positioning holes, with the vertical distance
between the two hydraulic
cylinders expressed as follows:
D
Dl= ¨(1+ cos (a ¨ 70)
2
(d) cutting the tested steel wire rope in required length according to the
telescopic length of the
loading hydraulic cylinder piston rod and the diameter D of the friction
hoist, installing the steel
wire rope locks on the two end pigtails of the tested steel wire rope,
clamping the steel wire rope
locks in the steel wire rope lock sleeves, and embedding the arc part of the
tested steel wire rope
in the rope grooves of the wrap angle positioning friction liners and the
steel wire rope
positioning friction liners;
(e) adjusting the oil pressure at the oil inlet of the hydraulic cylinder
at the driving side and the oil
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Date Recue/Date Received 2022-06-09
pressure at the oil outlet of the hydraulic cylinder at the load side, and
actuating the loading
hydraulic cylinders at low oil pressure, so that the tested steel wire rope is
tensioned up;
tightening up the steel wire rope clamping nuts so that the steel wire rope
positioning friction
liners clamp the steel wire rope tightly to avoid any relative slip between
the steel wire rope
positioning friction liners and the tested steel wire rope;
(f) simulating a load FL] at the heavy load side and a load FL2 at the no-load
side during actual
friction hoisting according to the diameter D and wrap angle a of the friction
hoist, and obtaining
tangential force distributionfe on the tested steel wire rope (3) within the
range of the wrap angle
a with the following formula:
{ 2Ft 2e'
I! h9
_ ' 0 5 0 5 aR
f60 - BD ,
0 an5095a
wherein, 0 is the circumferential coordinate with the separation point of the
steel wire rope at
the driving side and the friction wheel as the origin and the counterclockwise
direction as the
positive direction, B is the width of the actual friction liner of the hoist,
y is the friction
ln(FL, I F,2)
coefficient of the actual friction liner, 12K¨ is the creeping arc angle
within the
Al
wrap arc under the action of FL] and FL2;
thus, obtaining the tangential forces fl, f2, f3, f4, fs, f6 and f7 on the
tested steel wire rope at the
main steel wire rope positioning rollers, adjusting the oil pressure at the
oil discharge outlet of
the two-way hydraulic pump accordingly, and adding additional rotation damping
to the main
steel wire rope positioning rollers according to the following formula:
k= _______________________________
fi+f2+f3+4+f5+4+fy ,
mi=kfir,M2 = kf2r,M3 = kf3r,M4 = kf4r,M 5 = kf5r,M6 =k-f6r,M7 =kf7r
wherein, M1,M2,M3,M4,M5,M6,M7 are the simulated load torque at each two-way
hydraulic
pump (5-b), k is a compensation coefficient, and r is the radius of the main
steel wire rope
positioning roller (5-g),
when the loading hydraulic cylinders pull the tested steel wire rope,
FLI¨kfi+kf2+kf3+kfi+kfs-hkf6+kf7+F.L2; thus, simulating the actual steel wire
rope pulling
process of the friction hoist and the creeping process of the steel wire rope
within the wrap arc
in the friction hoisting process;
to test the tensile strength of the tested steel wire rope, the oil pressures
of the loading hydraulic
cylinders and the two-way hydraulic pump may be adjusted, so that the
hydraulic cylinder at the
driving side and the hydraulic cylinder at the load side pull the tested steel
wire rope, so as to
simulate the actual overload and secondary loading conditions of the friction
hoist; at that point,
whether the tested steel wire rope meets the requirement for tensile strength
can be judged by
detecting whether the unit elongation of the steel wire rope is within an
allowable threshold;
Date Recue/Date Received 2022-06-09
to test the fatigue life of the tested steel wire rope, the oil pressures of
the loading hydraulic
cylinders and the two-way hydraulic pump may be adjusted, so that the
hydraulic cylinder at the
driving side and the hydraulic cylinder at the load side pull the tested steel
wire rope alternately
and cyclically, so as to simulate the actual coal hoisting process of the
friction hoist; at that point,
whether the tested steel wire rope meets the requirement for fatigue life can
be judged by
detecting whether the percentage of broken wires and unit elongation of the
steel wire rope in
multiple cycles are within allowable thresholds; in addition, since there is
no time limitation on
the actual coal loafing and unloading process, the testing process can be
accelerated greatly by
adjusting the flow rates through the loading hydraulic cylinders and the two-
way hydraulic pump.
Beneficial effects: the device for testing the load-carrying capacity of the
steel wire rope for a friction
hoist provided by the present invention can be used to uniformly test the load-
carrying capacity of
steel wire ropes for friction hoists in vertical shafts with different drum
diameters and drum wrap
angles, and uniformly check different types of steel wire ropes produced by
various manufacturers
before field installation, thereby avoides repeated test investment for large-
scale production
enterprises and improves the manufacturing quality of small-scale production
enterprises, and sets
standard for the market of hoisting steel wire ropes and ensures the load-
carrying capacity of hoisting
steel wire ropes. In the present invention, the actual friction hoisting
process is simulated on the basis
of a principle that the double-acting hydraulic cylinders drive the steel wire
rope and the two-way
hydraulic pump provides load damping, and steel wire rope positioning device
and the wrap angle
positioning device that are based on lead screw transmission are employed, so
that the present
invention is applicable to steel wire ropes of friction hoists with different
drum diameters and different
wrap angles. Harsh working conditions such as overload and secondary loading,
etc. can be simulated
by utilizing hydraulic cylinder loading, so as to test the tensile strength of
the steel wire rope under
extremity working conditions; the actual tangential force distribution of the
steel wire rope along the
drum can be simulated by utilizing the hydraulic pump to provide load damping,
thereby the creeping
process of the steel wire rope within the wrap arc can be simulated, so as to
accurately test the fatigue
life of the steel wire rope and accurately test the load-carrying capacity of
the steel wire rope. The
device provided by the present invention can meet the requirements for testing
friction hoists with
different drum diameters and different wrap angles, has a simple structure,
high reliability, and high
versatility, and is of great significance for ensuring the load-carrying
capacity of hoisting steel wire
ropes and ensuring safe friction hoisting.
Description of Drawings
Fig. 1 is a schematic structural diagram of the device provided in the present
invention;
Fig. 2 is a schematic structural diagram of the wrap angle positioning device
in the present invention;
Fig. 3 is a schematic structural diagram of the steel wire rope positioning
and loading device in the
present invention;
Fig. 4 is a schematic installation diagram of the loading hydraulic cylinders
and steel wire rope in the
present invention;
Fig. 5 is a schematic diagram illustrating the testing principle of the device
in the present invention.
In the figures: 1 - loading hydraulic cylinder, 1-a - loading hydraulic
cylinder jacket, 1-b - loading
hydraulic cylinder pedestal, 1-c - loading hydraulic cylinder piston rod, 1-d -
steel wire rope lock
sleeve, 2 - hydraulic cylinder positioning platform, 2-a - hydraulic cylinder
positioning hole, 3 - steel
6
Date Recue/Date Received 2022-06-09
wire rope, 3-a - steel wire rope lock, 4 - wrap angle positioning device, 4-a -
positioning telescopic
sleeve, 4-b - wrap angle positioning slide table, 4-c - wrap angle positioning
lead screw, 4-d - wrap
angle positioning lead screw nut, 4-e - positioning telescopic rod, 4-f - wrap
angle positioning roller,
4-g - wrap angle positioning friction liner, 4-h - wrap angle positioning
support table, 4-i - wrap angle
positioning pedestal, 4-j - wrap angle positioning hand wheel, 5 - steel wire
rope positioning device,
5-a - steel wire rope positioning support table, 5-b - two-way hydraulic pump,
5-c - steel wire rope
positioning lead screw, 5-d - steel wire rope positioning pedestal, 5-e -
hydraulic pump positioning
bolt, 5-f- main shaft of the hydraulic pump, 5-g - main steel wire rope
positioning roller, 5-h - main
steel wire rope positioning slide table, 5-i - steel wire rope positioning
friction liner, 5-j - steel wire
rope clamping bolt, 5-k - auxiliary steel wire rope positioning roller, 5-1 -
auxiliary steel wire rope
positioning slide table, 5-m - steel wire rope positioning lead screw nut, 5-n
- steel wire rope clamping
nut, 5-o - steel wire rope positioning hand wheel, 6 - steel wire rope
positioning platform, 6-a -
positioning hole.
Embodiments
Hereunder the present invention will be further detailed in embodiments with
reference to the
accompanying drawings.
As shown in Fig. 1, a device for testing load-carrying properties of steel
wire rope for friction hoist
according to the present invention mainly comprises two loading hydraulic
cylinders 1, a hydraulic
cylinder positioning platform 2, a wrap angle positioning device 4, several
steel wire rope positioning
devices 5 and a steel wire rope positioning platform 6, wherein the hydraulic
cylinder positioning
platform 2 is arranged in the vertical direction, located in the same plane as
the steel wire rope
positioning platform 6 and is arranged opposite to the steel wire rope
positioning platform 6, and
provided with several rows of hydraulic cylinder positioning holes 2-a
arranged in parallel thereon;
the steel wire rope positioning platform 6 is provided with several rows of
positioning holes 6-a
arranged circumferentially thereon; the two loading hydraulic cylinders 1 are
arranged side by side
in the horizontal direction on the hydraulic cylinder positioning platform 2
via the hydraulic cylinder
positioning holes 2-a; the wrap angle positioning device 4 is arranged on a
linear section of the steel
wire rope positioning platform 6 in the vertical direction through the
positioning holes 6-a; the several
steel wire rope positioning devices 5 are arranged on an arc section of the
steel wire rope positioning
platform 6 in the radial direction through the positioning holes 6-a.
As shown in Fig. 2, the wrap angle positioning device 4 comprises a
positioning telescopic sleeve 4-
a, a wrap angle positioning slide table 4-b, a wrap angle positioning lead
screw 4-c, a wrap angle
positioning lead screw nut 4-d, a positioning telescopic rod 4-e, wrap angle
positioning rollers 4-f, a
wrap angle positioning friction liners 4-g, a wrap angle positioning support
table 4-h, a wrap angle
positioning pedestal 4-i, and a wrap angle positioning hand wheel 4-j, wherein
the wrap angle
positioning support table 4-h is arranged on the wrap angle positioning
pedestal 4-i; the wrap angle
positioning lead screw 4-c, the wrap angle positioning lead screw nut 4-d and
the wrap angle
positioning hand wheel 4-j are arranged coaxially; the wrap angle positioning
hand wheel 4-j rotates
to drive the wrap angle positioning lead screw 4-c to rotate, thereby pushing
the wrap angle
positioning lead screw nut 4-d to move back and forth; the wrap angle
positioning slide table 4-b is
fixed to the wrap angle positioning lead screw nut 4-d and can slide axially
on the top surface of the
wrap angle positioning support table 4-h; the positioning telescopic sleeve 4-
a is arranged on the wrap
angle positioning slide table 4-b axially; the wrap angle positioning roller 4-
f is arranged on the top
end of the positioning telescopic rod 4-e, and the rim of the wrap angle
positioning roller 4-f is
7
Date Recue/Date Received 2022-06-09
provided with a groove in which the wrap angle positioning friction liner 4-g
is installed; the wrap
angle positioning friction liner 4-g is provided with a rope groove.
As shown in Fig. 3, the steel wire rope positioning device 5 comprises a steel
wire rope positioning
support table 5-a, a two-way hydraulic pump 5-b, a steel wire rope positioning
lead screw 5-c, a steel
wire rope positioning pedestal 5-d, hydraulic pump positioning bolts 5-e, a
main shaft 5-f of the
hydraulic pump , main steel wire rope positioning rollers 5-g, a main steel
wire rope positioning slide
table 5-h, steel wire rope positioning friction liners 5-i, steel wire rope
clamping bolts 5-j, secondary
steel wire rope positioning rollers 5-k, a secondary steel wire rope
positioning slide table 5-1, a steel
wire rope positioning lead screw nut 5-m, steel wire rope clamping nuts 5-n,
and a steel wire rope
positioning hand wheel 5-o, wherein the steel wire rope positioning support
table 5-a is arranged on
the steel wire rope positioning pedestal 5-d; the steel wire rope positioning
lead screw 5-c, the steel
wire rope positioning lead screw nut 5-m and the steel wire rope positioning
hand wheel 5-o are
arranged coaxially; the steel wire rope positioning hand wheel 5-o rotates to
drive the steel wire rope
positioning lead screw 5-c to rotate, thereby pushing the steel wire rope
positioning lead screw nut 5-
m to move back and forth; the main steel wire rope positioning slide table 5-h
is fixed to the steel
wire rope positioning lead screw nut 5-m, and can slide axially on the top
surface of the steel wire
rope positioning support table 5-a; the hydraulic pump positioning bolts 5-e
fix the two-way hydraulic
pump 5-b and the main steel wire rope positioning rollers 5-g coaxially on the
main steel wire rope
positioning slide table 5-h, and the main steel wire rope positioning rollers
5-g drive the main shaft
5-f of the hydraulic pump to rotate synchronously; the auxiliary steel wire
rope positioning slide table
5-1 is arranged on the top surface of the steel wire rope positioning support
table 5-a, the auxiliary
steel wire rope positioning rollers 5-k are arranged on the auxiliary steel
wire rope positioning slide
table 5-1, and the axis of the main steel wire rope positioning rollers 5-g is
in the same line as the axis
of the auxiliary steel wire rope positioning rollers 5-k; the main steel wire
rope positioning slide table
5-h and the auxiliary steel wire rope positioning slide table 5-1 are provided
with collinear through-
holes in the two sides respectively, the steel wire rope clamping bolts 5-j
penetrate through the
through-holes from one end to connect the main steel wire rope positioning
slide table 5-h and the
auxiliary steel wire rope positioning slide table 5-1 together, and are
tightened up at the other end by
means of the steel wire rope clamping nuts 5-n, so that the main steel wire
rope positioning rollers 5-
g and the auxiliary steel wire rope positioning rollers 5-k can clamp the
tested steel wire rope 3 under
the action of certain squeezing force; the rims of the main steel wire rope
positioning rollers 5-g and
the rims of the auxiliary steel wire rope positioning rollers 5-k are provided
with a groove respectively,
in which the steel wire rope positioning friction liner 5-i is installed, and
the steel wire rope
positioning friction liner 5-i is provided with a rope groove.
As shown in Fig. 4, the loading hydraulic cylinder 1 is a double-acting
hydraulic cylinder comprising
a loading hydraulic cylinder jacket 1-a, a loading hydraulic cylinder pedestal
1-b, and a loading
hydraulic cylinder piston rod 1-c, and a steel wire rope lock sleeve 1-d; the
front end of each loading
hydraulic cylinder piston rod 1-c is provided with a steel wire rope lock
sleeve 1-d, the steel wire rope
locks 3-a are clamped in the steel wire rope lock sleeves 1-d after steel wire
rope locks 3-a are installed
on the two end pigtails of the steel wire rope 3, thus pulling force can be
exerted on the tested steel
wire rope 3 via the loading hydraulic cylinders 1; the two loading hydraulic
cylinders 1 serve as a
driving side and a load side for each other, the hydraulic cylinder at the
driving side drives its loading
hydraulic cylinder piston rod 1-c by adjusting the oil pressure at the oil
inlet to pull the tested steel
wire rope 3, while the hydraulic cylinder at the load side inhibit the tested
steel wire rope 3 from
pulling its loading hydraulic cylinder piston rod 1-c by adjusting the oil
pressure at the oil outlet.
8
Date Recue/Date Received 2022-06-09
The length of the loading hydraulic cylinder piston rod 1-c shall be greater
than the circumference of
the friction hoist with maximum diameter; the number of the steel wire rope
positioning devices 5
depends on the testing accuracy of the friction hoist with different diameter;
the hole density of the
hydraulic cylinder positioning holes 2-a in the vertical direction meets the
testing requirement for
adaptation of the vertical distance clamped by the two loading hydraulic
cylinders 1 to the friction
hoist with different diameter; the hole density of the positioning holes 6-a
in the circumferential
direction meets the testing requirement for adaptation of the arc enclosed by
the wrap angle
positioning device 4 and several steel wire rope positioning devices 5 to the
friction hoist with
different diameter and wrap angle.
As shown in Fig. 5, the method for testing the load-carrying capacity of the
steel wire rope for a
friction hoist in the present invention comprises the following specific
steps:
(a) installing the wrap angle positioning support table 4-h on the wrap angle
positioning pedestal 4-
i, installing the wrap angle positioning lead screw 4-c, the wrap angle
positioning lead screw nut
4-d and the wrap angle positioning hand wheel 4-j coaxially, fixing the wrap
angle positioning
slide table 4-b to the wrap angle positioning lead screw nut 4-d, installing
the positioning
telescopic sleeve 4-a axially on the wrap angle positioning slide table 4-b,
installing the wrap
angle positioning friction liners 4-g in the groove of the wrap angle
positioning roller 4-f, and
installing the wrap angle positioning roller 4-f on the top end of the
positioning telescopic rod
4-e, to assemble a wrap angle positioning device 4;
(b) installing the steel wire rope positioning support table 5-a on the steel
wire rope positioning
pedestal 5-d, installing the steel wire rope positioning lead screw 5-c, the
steel wire rope
positioning lead screw nut 5-m and the steel wire rope positioning hand wheel
5-o coaxially,
fixing the main steel wire rope positioning slide table 5-h to the steel wire
rope positioning lead
screw nut 5-m, installing the steel wire rope positioning friction liners 5-i
in the grooves of the
main steel wire rope positioning rollers 5-g and the auxiliary steel wire rope
positioning rollers
5-k, fixing the two-way hydraulic pump 5-b and the main steel wire rope
positioning rollers 5-g
coaxially on the main steel wire rope positioning slide table 5-h with the
hydraulic pump
positioning bolts 5-e, inserting the steel wire rope clamping bolts 5-j from
one end of the slide
table though the through-holes to connect the main steel wire rope positioning
slide table 5-h
and the auxiliary steel wire rope positioning slide table 5-1 together, and
tightening the steel wire
rope clamping bolts 5-j with the steel wire rope clamping nuts 5-n at the
other end of the slide
table, to assemble several steel wire rope positioning devices 5;
(c) based on the diameter D and wrap angle a of the friction hoist to
which the tested steel wire rope
belongs, installing the wrap angle positioning device 4 in the vertical
direction on the linear
section of the steel wire rope positioning platform 6 according to the
positioning holes 6-a at
selected positions, installing several steel wire rope positioning devices 5
at an interval in the
radial direction on the arc section of the steel wire rope positioning
platform 6, turning the steel
wire rope positioning hand wheel 5-o to push the steel wire rope positioning
lead screw nut 5-m
to move back and forth, turning the wrap angle positioning hand wheel 4-j to
push the wrap
angle positioning lead screw nut 4-d to move back and forth, trimming the
telescopic length of
the positioning telescopic rod 4-e to push the wrap angle positioning rollers
4-f to move back
and forth in a small field, till the diameter of the arc enclosed by the rims
of the wrap angle
positioning rollers 4-f and the rims of the main steel wire rope positioning
rollers 5-g is equal to
the diameter D of the friction hoist and the angle of the arc is equal to the
wrap angle a of the
9
Date Recue/Date Received 2022-06-09
friction hoist finally, then arranging the two loading hydraulic cylinders 1
side by side in the
horizontal direction on the hydraulic cylinder positioning platform 2 via the
hydraulic cylinder
positioning holes 2-a, with the vertical distance between the two hydraulic
cylinders expressed
as follows:
,
D1¨ ¨D(1+ cos(a ¨ 70)
2
(d) cutting the tested steel wire rope 3 in appropriate length according to
the telescopic length of the
loading hydraulic cylinder piston rod 1-c and the diameter D of the friction
hoist, installing the
steel wire rope locks 3-a on the two end pigtails of the tested steel wire
rope 3, clamping the
steel wire rope locks 3-a in the steel wire rope lock sleeves 1-d, and
embedding the arc part of
the tested steel wire rope 3 in the rope grooves of the wrap angle positioning
friction liners 4-g
and the steel wire rope positioning friction liners 5-i;
(e) adjusting the oil pressure at the oil inlet of the hydraulic cylinder
at the driving side and the oil
pressure at the oil outlet of the hydraulic cylinder at the load side, and
actuating the loading
hydraulic cylinders 1 at low oil pressure, so that the tested steel wire rope
3 is tensioned up;
tightening up the steel wire rope clamping nuts 5-n so that the steel wire
rope positioning friction
liners 5-i clamp the steel wire rope 3 tightly to avoid any relative slip
between the steel wire rope
positioning friction liners 5-i and the tested steel wire rope 3;
(f) simulating a load FL] at the heavy load side and a load FL2 at the no-load
side during actual
friction hoisting according to the diameter D and wrap angle a of the friction
hoist, and obtaining
tangential force distribution on the tested steel wire rope 3 within the range
of the wrap angle a
with the following formula:
2F e'
1.2
1-1 (.195ceR
fe = 4 BD ,
0 ceR a
wherein, 0 is the circumferential coordinate with the separation point of the
steel wire rope at the
driving side and the friction wheel as the origin and the counterclockwise
direction as the positive
direction, B is the width of the actual friction liner of the hoist, it is the
friction coefficient of the
In(Fri I Fiz)
actual friction liner, a R ¨ is the creeping arc angle within the wrap arc
under the
It
action of FL] and FL2; thus, obtaining the tangential forces fi, f2, f3, f I,
fs, f6 and f7 on the tested steel
wire rope 3 at the main steel wire rope positioning rollers 5-g, adjusting the
oil pressure at the oil
discharge outlet of the two-way hydraulic pump 5-b accordingly, and adding
additional rotation
damping to the main steel wire rope positioning rollers 5-g according to the
following formula:
n .1.2
fl-Ff2+fl+f4+A-i-f6+f,
m1= kfir,M 2 = k12r,M 3 = 1cf3r,M 4 = k14r,M 5 = kf5r,M 6 = kf6r ,M 7 = kl,r'
{
Date Recue/Date Received 2022-06-09
wherein, MI, M2,M3,M4,M5,M6,M7 are the simulated load torque at each two-way
hydraulic
pump (5-b), k is a compensation coefficient, and r is the radius of the main
steel wire rope positioning
roller 5-g, when the loading hydraulic cylinders 1 pull the tested steel wire
rope 3,
FL/ ¨Iffi +kf2+kf3+kf4+kfs+kf6+kf7+F.L2; thus, simulating the actual steel
wire rope pulling process of
the friction hoist and the creeping process of the steel wire rope within the
wrap arc in the friction
hoisting process;
(g)
adjusting the oil pressures of the loading hydraulic cylinders 1 and the two-
way hydraulic pump
5-b:
to test the tensile strength of the steel wire rope 3, the hydraulic cylinder
at the driving side and the
hydraulic cylinder at the load side pull the tested steel wire rope 3, so as
to simulate the actual overload
and secondary loading conditions of the friction hoist; at that point, whether
the tested steel wire rope
3 meets the requirement for tensile strength can be judged by detecting
whether the unit elongation
of the steel wire rope 3 is within an allowable threshold;
to test the fatigue life of the steel wire rope 3, the hydraulic cylinder at
the driving side and the
hydraulic cylinder at the load side pull the tested steel wire rope 3
alternately and cyclically, so as to
simulate the actual coal hoisting process of the friction hoist; at that
point, whether the tested steel
wire rope 3 meets the requirement for fatigue life can be judged by detecting
whether the percentage
of broken wires and unit elongation of the steel wire rope 3 in a certain
number of cycles are within
allowable thresholds; in addition, since there is no time limitation on the
actual coal loading and
unloading process, the testing process can be accelerated greatly by adjusting
the flow rates through
the loading hydraulic cylinders 1 and the two-way hydraulic pump 5-b.
11
Date Recue/Date Received 2022-06-09
