English

The service life of hydraulic motor mainly depends on the service life of bearing and the wear of working components

Created on 2025.03.26
1.7.10 service life
The service life of hydraulic motor mainly depends on the service life of bearing and the wear of working components. The actual service life of the motor is generally longer than that of the pump of the same specification. Because the hydraulic pump often runs under rated pressure and rated speed, but the motor does not, the actual life of some motors is much longer than the design life according to rated pressure and rated speed.
The actual service life can be roughly calculated as follows:
LM=(p/pM)3(n/nM)L                     (1-39)
Where p, n -- design pressure and design speed;
PM, nm -- converted pressure and speed;
L -- design life.
The conversion pressure PM and the conversion speed nm can be calculated according to the time taken up by different working conditions of the working machine in a working cycle, namely
(1-40)
(1-41)
Where PI, Ni, Ti -- working pressure, speed and duration of a certain working condition.
1.7.11 installation flange and shaft extension dimension series
Like the hydraulic pump, the mounting flange of the hydraulic motor also has diamond, square, polygon (including circle) and other structural forms, such as cylindrical shaft extension, 1:10 conical shaft extension with external thread and involute spline with 30 ° pressure angle. Refer to GB / T 2353.1 and GB / T 2353.2 hydraulic pump and hydraulic motor mounting flange and shaft extension dimension series and marking (1) and (2) for pump and motor mounting flange and shaft extension dimension series and marking.
1.7.12 comparison of main performance and application scope of various hydraulic motors
The main performance comparison, applicable conditions and application scope of various hydraulic motors are shown in the table below.
Main performance comparison of various hydraulic motors
type
Displacement range
/mL·r-1
pressure
/MPa
Speed range / R · MON-1
Volumetric efficiency /%
Total efficiency /%
Starting torque efficiency /%
Noise
Anti pollution ability
Price
Gear pump
External meshing
5.2～160
20~25
150~2500
85~94
77~85
75~80
more
Strong
minimum
Internal cycloid
80~1250
14~20
10~800
ninety-four
seventy-six
seventy-six
less
Strong
low
Vane pump
Single acting
10~200
16~20
100~2000
ninety
seventy-five
eighty
in
difference
Lower
Double action
50~220
16~25
100~2000
ninety
seventy-five
eighty
less
difference
low
Multiple functions
298~9300
21~28
10~400
ninety
seventy-six
80~85
Small
difference
high
Axial piston pump
Swash plate
2.5～3600
31.5～40
100~3000
ninety-five
ninety
85~90
large
in
higher
Inclined axis type
2.5～3600
31.5～40
100~3000
ninety-five
ninety
85~90
large
in
higher
Double oblique axis
36~3150
25～31.5
10~600
ninety-five
ninety
ninety
less
in
high
Ball plunger type
250~600
16~25
10~300
ninety-five
ninety
eighty-five
less
Poor
in
Radial Piston Pump
Single acting
Pin connecting rod
126~5275
25～31.5
5~800
＞95
ninety
＞90
less
Strong
high
Static equilibrium
360~5500
17.5～28.5
3~750
ninety-five
ninety
ninety
less
Strong
higher
Roller type
250~4000
21~30
3~1150
ninety-five
ninety
ninety
less
Strong
higher
Multiple functions
Roller plunger force transmission
215～12500
30～40
1～310
95
90
90
Smaller
powerful
high
Ball plunger force transmission
64～100000
16～25
3～1000
93
85
95
Smaller
middle
Higher
Note: the efficiency performance listed in the table is the rough average value of different roll numbers under rated conditions, not the highest efficiency value of the modified hydraulic motor.
Working condition and application range of various hydraulic motors
Hydraulic motor type
Applicable working conditions
Application
Gear Motor
The structure is simple and easy to manufacture, but the speed pulsation is large, the gear motor load torque is not large, the speed stability requirement is not high, the noise limit is not strict, and it is suitable for high speed and low torque conditions.
Drilling machines, ventilation equipment, etc.
Orbital Motor
Medium load speed and small volume requirement
Plastic machinery, coal mining machinery, excavators, etc.
Vane motor
Compact structure, small size, smooth movement, low noise, small load torque
Grinding machine rotary table, machine tool operating mechanism, etc.
Axial piston motor
Compact structure, small radial size, small moment of inertia, high speed, large load, variable speed requirements, small load torque, high requirements for low-speed stability
Cranes, winches, forklifts, internal combustion forklifts, CNC machine tools, walking machinery, etc.
Crankshaft connecting rod radial piston motor
Large load torque, medium speed, large radial size
Rubber and plastic machinery, walking machinery, etc.
Internal Curve Radial Piston Motor
Large load torque, low speed, high stability
Excavators, tractors, cranes, coal mining machines, etc.
Generally speaking, under the same power, a hydraulic motor with excellent performance should have the following characteristics: high power mass ratio, high rated pressure and speed, low minimum stable speed, high volumetric efficiency and total efficiency, high starting mechanical efficiency, small slip speed, strong ability to bear impact load, low noise, good dynamic characteristics, long service life, etc.
Leave your information and
we will contact you.
Phone
WhatsApp
WeChat