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Gear Couplings MZ
Gear Couplings MZ – are mechanical devices designed for connecting horizontal shafts. The company “Gruzopodyom” manufactures gear couplings for reliable operation of bridge, gantry, and jib cranes. In particular, MZ couplings are used in crane travel and hoisting drives to transmit torque up to 5400 Nm (and higher upon request). Gear couplings are applied in crane mechanisms to connect the motor shaft with the gearbox input shaft, as well as to connect the gearbox output shaft with the drive wheel shaft. The design of the couplings allows for compensation of angular and radial shaft misalignments, ensuring stable operation even with slight deviations.
The company produces flexible couplings of types MZ-1, MZ-2, MZ-3, and MZ-4, with specifications and dimensions listed in Tables 1–4, made of 40X steel, known for its high strength and wear resistance. Couplings are manufactured in accordance with the company’s internal technical specifications, while main sizes and parameters comply with GOST 5006-55.
An MZ coupling consists of a toothed sleeve and brake pulley/rigid half-coupling, connected with bolts, and a toothed hub inserted into the sleeve. The hub teeth engage with the sleeve teeth. A cover with a seal is mounted on the sleeve. Thanks to the spherical shape of the teeth heads, misalignment compensation is achieved up to 0°30′.
Figure. 1. Drawing of a gear coupling in the МЗ version with a matching rigid half-coupling.
The couplings are equipped with grease fittings for lubrication. They are designed to be filled with oil to ensure proper and long-lasting performance. During operation, the oil level should cover the full height of the teeth. According to regulations, a full oil change is carried out after 100–150 hours of operation for new couplings, and after 2000–2500 hours during further use. The type of oil must be selected according to the temperature conditions.
Gear couplings are available in a standard version and with a brake pulley, which ensures efficient shaft stopping and fixation when the motor is switched off. The brake pulley is installed on the gearbox shaft.
The company manufactures couplings with the following configurations:
Version with a rigid half-coupling
Version with a brake pulley
Version with a gear half-coupling
Fig. 2. Drawing of the MZ coupling with a brake pulley.
Table 1. Specifications of MZ couplings with brake pulley
Тип | m | z | Мкр, кгс∙м | D1* | D2 | D3 | D4 | D5* | D6 | D7 | D8 | D9 | L1* | L2 |
МЗ-1 | 2,5 | 30 | 71 | 36 | 55 | 110 | 160 | 35 | 100 | 170 | 200 | 140 | 86 | 18 |
МЗ-2 | 2,5 | 38 | 140 | 40 | 70 | 125 | 185 | 50 | 125 | 270 | 300 | 160 | 112 | 21 |
МЗ-3 | 3 | 40 | 315 | 55 | 90 | 160 | 225 | 65 | 140 | 270 | 300 | 195 | 112 | 21 |
МЗ-4 | 3 | 48 | 560 | 75 | 110 | 185 | 265 | 90 | 180 | 360 | 400 | 230 | 143 | 21 |
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|
| ||||||||||||
| L3* | L4* | L5 | L6 | L7 | L8* | L9 | L10* | DБ | n | DБ | Масса, кг |
|
|
МЗ-1 | 60 | 60 | 15 | 26 | 20 | 60 | 100 | 216 | 12 | 4 | 12 | 19 |
|
|
МЗ-2 | 84 | 84 | 23 | 29 | 30 | 74 | 150 | 224 | 12 | 4 | 12 | 43 |
|
|
МЗ-3 | 84 | 112 | 30 | 28 | 30 | 99 | 150 | 270 | 16 | 6 | 16 | 52 |
|
|
МЗ-4 | 107 | 107 | 38 | 36 | 40 | 142 | 190 | 322 | 16 | 6 | 16 | 108 |
|
|
By agreement with the customer, it is possible to manufacture MZ-1 with a Ø160 mm brake pulley and MZ-4 with a Ø500 mm brake pulley.
Fig. 3. Drawing of the MZ coupling in the form of a gear half-coupling.
Table 2. Specifications of MZ couplings without brake pulley
Тип
m
z
Мк,
кгс∙м
N,
об/мин
d1
d2
D1
D2
D3
L1
L2
L3
L4
L5
L6
L7
L8
DБ
nБ
Масса,
кг
МЗ-1
2,5
30
71
6300
36
55
110
160
140
60
12
15
26
18
20
86
112,5
12
4
5
МЗ-2
2,5
38
140
5000
40
70
125
185
160
84
15
23
29
21
30
112
147,5
12
4
8
МЗ-3
3
40
315
4000
55
90
160
225
195
84
20
30
28
21
30
112
147,5
16
6
13
МЗ-4
3
48
560
3350
75
110
185
265
230
107
25
38
36
21
30
143
180,5
16
6
20
Fig. 4. Drawing of a reciprocal rigid half-coupling.
Table 3. Specifications of MZ couplings without mating half-coupling
Тип
D1min
D1max
D2
D3
D4
D5
L1*
L2*
L3*
nБ
Масса,
кг
МЗ-1
30
50
100
160
140
13
60
20
132
4
8
МЗ-2
30
55
125
185
160
13
107
30
137
4
13
МЗ-3
50
75
140
225
195
17
107
30
150
6
18
МЗ-4
65
90
180
265
230
17
230
107
150
6
39
Fig. 5. Brake pulley drawing.
Table 4. Specifications of MZ couplings with mating half-coupling
Тип
D1
D2
D3
D4min
D4max
D5
D6
L1*
L2*
L3
L4*
nБ
Масса,
кг
МЗ-1
200
170
100
30
50
140
13
60
60
100
110
4
14
МЗ-2
300
270
125
30
55
160
13
107
74
150
165
4
35
МЗ-3
300
270
140
50
75
195
17
107
99
150
171
6
39
МЗ-4
400
360
180
65
90
230
17
230
142
190
200
6
78
* subject to customer agreement
Also, by customer agreement, it is possible to manufacture MZ-1 half-coupling with Ø160 mm brake pulley and MZ-4 with Ø500 mm brake pulley.
The final stage of coupling production is through hardening of the gear rims of hubs and sleeves to a hardness of 42 … 51 HRC.
Our company manufactures gear couplings with straight-line tooth generatrix, and the outer teeth of the bushings have a spherical surface. Such coupling design allows to compensate for axial and radial displacement of mating shafts. The mounting holes for the shaft ends are cylindrical or conical in shape.
We produce couplings with an involute tooth profile and a pressure angle α = 20°, with normal accuracy grade, for circumferential speeds at the pitch circle of less than 15 m/s.
The “Gruzopodyom” plant manufactures gear couplings with the following design features:
Tooth flank roughness Ra 2.5, reducing friction, ensuring uniform load distribution, and increasing service life.
Shaft bores are cylindrical or conical; after machining to the required diameter, keyways or splines are cut according to the customer drawing.
The design includes grease fittings to supply lubrication to the gear mesh, and seals protect working surfaces from contamination and leaks.
Couplings can be made with or without brake pulley, and with or without mating half-coupling.
Teeth are heat-treated to increase load-bearing capacity, ensuring durable operation under high loads and frequent start-stop cycles.
It is important to note that during operation, possible deviations in the hub and sleeve construction may cause uneven load distribution among teeth, leading to bending loads on shafts. Additionally, when the shaft axes are misaligned or radially displaced, friction forces arise on tooth flanks, creating bending moments in the misalignment plane. Therefore, we recommend ordering this product from companies with extensive experience and qualified engineering staff.
Since 2008, “Gruzopodyom” has been designing and manufacturing crane equipment. We have the necessary competencies to produce gear couplings. Our production is equipped with modern CNC machines, allowing high-precision manufacturing in a short time. Each order comes with detailed drawings indicating dimensions of all parts, steel grade, and product weight.