The BM hydraulic motor is an axial porting hydraulic motor. Its housing is cast from ductile iron with sufficient strength, making it suitable for applications with low loads and intermittent operation. The main features of the motor are as follows:
Adopts an axial oil distribution structure, featuring small size, high efficiency, and long service life.
The shaft seal can withstand high pressure and allows series or parallel connection for use.
Enables easy forward and reverse rotation with stable rotational speed.
Compared with other hydraulic motors, it offers high cost-effectiveness.
Type
Displacement (ml/rev)
Ratedpressure (Mpa)
Maxpressure (Mpa)
Speedrange (r/min)
Ratedoutputtorque (N.m)
Maxoutputtorque (N.m)
Maxpower (Kw)
BMR-50
51.7
14
20
10-775
93
135
7
BMR-80
80.5
14
20
10-750
152
216
10
BMR-100
100.5
14
20
10-600
194
270
10
BMR-125
126.3
14
20
10-475
237
338
10
BMR-160
160.8
14
10-375
310
433
10
BMR-200
200.9
14
20
10-300
369
509
8
BMR-250
252.6
11
16
10-240
380
540
6
BMR-315
321.5
9
13
10-190
380
540
5
BMR-400
401.9
7
11
10-160
380
540
4
BM3-80
80.5
17.5
22.5
10-810
194
271
14
BM3-100
100.5
17.5
22.5
10-750
242
318
16
BM3-125
126.3
17.5
22.5
9-600
303
373
16
BM3-160
160.8
16
22.5
7-470
358
459
14
BM3-200
200.9
16
22.5
6-375
438
576
14
BM3-250
252.6
12.5
20
6-300
440
700
11
BM3-315
321.5
12.5
20
5-240
551
831
10
BM3-400
401.9
10
17.5
5-180
560
865
8
BM3-500
471.1
10
17.5
5-155
636
1113
8
BM4-160
158.8
20
28
10-625
450
663
20.1
BM4-200
200.8
20
28
9-500
561
818
25.2
BM4-250
252.2
20
28
8-400
710
1021
25.2
BM4-320
317.5
20
28
7-312
902
1322
25.2
BM4-400
401.6
18
24
6-250
1008
1431
22
BM4-500
535.3
16
21
5-175
1121
1598
21
BM5-315
314.9
20
28
10-475
873
1293
32
BM5-400
399.7
20
28
9-375
1108
1650
32
BM5-500
496.6
20
28
8-300
1385
2060
32
BM5-630
617.8
18
24
6-238
1570
2249
32
BM5-800
787.4
16
21
5-187
1773
2481
32
BM5-985
969.1
14
18
5-154
1900
2399
24
BM6-800
759.6
16
21
5-200
1690
2220
35
BM6-1000
949.5
16
21
5-160
2160
2774
35
BM6-1250
1186.8
16
21
5-130
2650
3469
35
The impact of oil distribution accuracy on the high efficiency of a gerotor hydraulic motor can be compared to the impact of ignition timing on the power output of an internal combustion engine. From the working principle of the gerotor hydraulic motor, it is known that the oil distribution sleeve and the rotor rotate synchronously. The so-called "oil distribution accuracy" refers to the precision with which the oil distribution process coordinates with the rotor’s rotation for oil intake, sealing, and oil discharge.
There are many factors affecting oil distribution accuracy, such as:
The non-parallelism between the rotor’s spline shaft and the gerotor tooth profile;
The positional accuracy of the pin tooth holes on the stator sleeve of the hydraulic slewing device relative to its bolt holes;
The non-parallelism between the pin hole on the output shaft and its internal spline shaft;
The indexing accuracy of the vertical oil grooves on the oil distribution sleeve and their positional accuracy relative to the wedge-shaped grooves;
The non-parallelism of the spline shafts on both ends of the linkage shaft.
For wheel-side hydraulic motors, as long as the above factors are controlled within the tolerance range, their impact on oil distribution accuracy will not be significant—because all machining errors will not be biased to one side. The factor that has the greatest impact on oil distribution accuracy is the fit clearance of the spline shafts at both ends. Next are: the positional accuracy of the housing’s oil distribution holes relative to the bolt holes (used for stator installation), which is difficult to guarantee in the manufacturing process; and the positional accuracy of the stator relative to the housing’s oil distribution holes when the stator is fixed on the housing.
In the meshing pair of the cycloidal pinwheel reducer (used as the power component of the motor), the rotor is the driving part, while the output shaft and the oil distribution sleeve pinned to it are the driven parts. Due to the clearance of the spline shaft, the output shaft and the oil distribution sleeve lag behind the rotor by an angle, causing the oil distribution sleeve to deviate from its correct position.
