Design rules for rope groove rotation and wire rope selection of single rope winding hoist

Single rope #drumwinder is the most widely used hoist in small and medium-sized mines. Its principle is: one end of the #wirerope is fixed on the drum, and the other end is connected with the lifting container. The lifting or lowering of the lifting container is realized by winding or releasing the wire rope on the drum.

The single rope drum winder?has many structural factors related to the rope groove and wire rope, including the laying direction of the wire rope itself (left laying or right laying), the winding direction of the wire rope on the drum (left rotation or right rotation) and the rope outlet direction (upper rope outlet or lower rope outlet), the fixed position of the wire rope head on the drum (which side of the drum), the number of winding layers (1 layer, 2 layers, 3 layers), etc. To ensure the best use effect of steel wire rope, it is necessary to know the design rules of the hoist manufacturer on the direction of rotation of rope groove and the selection of steel wire rope.

1 Lay direction of wire rope

Steel wire rope is made of steel wire twisted according to certain rules, and the twisting direction can be divided into left twisting and right twisting. To facilitate understanding, a simple twist direction judgment rule is introduced: erect the wire rope along the axis, and if the left side of the rope strand is high, it is left twist, as shown in Figure 1 (a); If the right side of the strand is high, it is right lay, as shown in Figure 1 (b).

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Figure 1 Twisting Direction of Wire Rope

2 Winding direction of wire rope on drum (direction of rope groove rotation)

The steel wire rope of the single rope drum winder?is wound on the drum according to a certain winding direction (the specific winding forms are spiral winding and parallel broken line winding), and its direction is divided into left rotation and right rotation. For easy understanding, it is assumed that the axis of the drum is erected vertically. If the left side of the wire rope is high, it is left handed, as shown in Figure 2 (a); If the right side of the wire rope is high, it is right-handed, as shown in Figure 2 (b).

Fig. 2 Winding direction of wire rope (rope groove rotation direction)

3 Wire rope outlet direction on the drum

The wire rope on the drum has upper rope and lower rope. From the driver's position, when the wire rope goes out from the top of the drum, it is the upper rope, as shown in Figure 3 (a); The rope coming out from the lower part of the drum is the lower rope, as shown in Figure 3 (b).

Fig. 3 Wire rope outlet direction

For single drum hoist, if single hook hoisting is adopted, the rope outlet direction of wire rope on the drum is generally set as upper rope outlet, as shown in Figure 4 (a); If double hook lifting is adopted (there are few cases at present), from the driver's direction, the left steel rope is the lower rope, and the right steel rope is the upper rope, as shown in Figure 4 (b).

For double drum hoist, the wire ropes set on the traveling drum and fixed drum are opposite to each other. Generally, the steel rope on the left drum of the double drum hoist is the lower outgoing rope, and the steel rope on the right drum is the upper outgoing rope, as shown in Figure 4 (c). The outgoing direction of the wire rope is independent of the relative positions of the fixed drum and the traveling drum.

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Fig. 4 Rules of wire rope outgoing direction

The relative positions of the traveling drum and the fixed drum of different series of single rope winding mine hoists are different. The conventional right installation method is adopted (the motor is on the right when viewed from the driver's position). For double drum single rope drum winders of XKT, XKTB, JK/A, JK/E and other series, the traveling drum is on the non drive side (far from the motor side), and the fixed drum is on the drive side (near the motor side). The wire rope exits from the lower part of the left drum and from the upper part of the right drum, as shown in Figure 5.

Fig. 5 Wire Rope Outgoing Direction of XKT, XKTB, JK/A, JK/E Series Hoists

Right installation method: For the imitation Su, KJ, JKA series hoists, the traveling drum is on the drive side (near the motor side), and the fixed drum is on the non drive side (far away from the motor side). The steel wire rope exits from the bottom on the left side and from the top on the right side, as shown in Figure 6.

Fig. 6 Wire Rope Outgoing Direction of Sugarlike, KJ, JKA Series Hoists

Although Sugarlike, KJ and JKA series elevators are still used, the number is very small, so the following description is only for newly designed elevators. If the left mounting arrangement is adopted (the motor is on the left side when viewed from the driver's position), the fixed drum is on the left side and the traveling drum is on the right side. The steel wire rope exits from the bottom on the left side and from the top on the right side, as shown in Figure 7.

Photo 7 Wire rope outlet direction of left double drum hoist

4 Fixed position of wire rope end

The wire rope end is fixed on the web plate of the drum with a holder, and the wire rope is wound on the drum after passing through the rope outlet hole on the drum shell. In order to avoid bending of the steel wire rope, the steel wire rope fixed by the holder moves almost along the tangent direction of the cylinder shell, so the direction of the steel wire rope passing through the cylinder shell is unique, as shown in Figure 8.

1. Shell 2. Wire rope holder 3. Wire rope

Fig. 8 Fixation of Wire Rope Head and Rope Outgoing Direction

4.1 Single drum drum winder

The rope head fixing position is set on both sides of the drum of the single drum drum winder?to meet the requirement that the steel wire rope is still on the upper rope when it is arranged on the left. According to the actual situation, only one of the rope head fixing positions can be selected, as shown in Figure 9. The arrow in Figure 9 indicates the travel direction of the wire rope after it passes through the rope outlet hole of the cylinder shell.

Photo 9 Fixing position of rope head of single drum elevator

4.2 Double drum drum winder

For easy understanding, Fig. 10 shows the schematic marks of each part of the double drum hoist.

1. Brake disc 2. Rope guard 3. Rope outlet 4. Low speed coupling 5. Reducer 6. High speed coupling 7. Motor

Figure 10 Structural Diagram of Double drum Hoist

The drum at the non drive end of the double drum drum winder?is set with a fixed rope head near the brake disc. The drive end drum shall be set with fixed rope head positions near the brake disc and the middle rope guard plate to adapt to the different winding layers and installation forms, and always ensure that the rope goes out under the left drum and on the right drum. According to the actual situation, only one rope head fixed position can be selected for each drum, as shown in Figure 11.

Photo 11 Fixing position of rope head of double drum elevator

5. The relationship between the fixed position of wire rope head and the number of winding layers

5.1 Single drum elevator

When the single drum hoist is installed on the right side, the rope head is fixed on the right side, the steel wire rope is wound on the right side, and the rope is pulled out, as shown in Figure 12; When it is installed on the left, the rope head is fixed on the left side, and the steel wire rope is wound on the left side, which is still the upper rope, as shown in Figure 13.

Photo 12 Fixed position of rope head of single drum elevator during right installation

Photo 13 Fixed position of rope head of single drum elevator during left installation

5.2 Double drum elevator

The reason why two fixed rope head positions are set on the drum on the drive side of the double drum drum winder?is to adapt to the different winding layers and installation methods of the steel wire rope. According to the Coal Mine Safety Regulations, the maximum number of winding layers is 3, and the installation methods of hoist are divided into left installation and right installation. When selecting the fixed position of the rope head of the steel wire rope, the principle of "parallel and equidistant rope arrangement" of the two steel wire ropes traveling and fixing the drum shall be followed to avoid "opposite rope arrangement", so as to prevent the two ropes from converging together, which will cause the most adverse impact on the force on the main shaft. Therefore, the fixed position of wire rope head is closely related to the number of winding layers and installation mode of wire rope. The author takes the right installation mode as an example to explain.

5.2.1 1-layer winding

When the number of winding layers is 1, the rope head position of the traveling drum and the rope head position of the fixed drum are close to the brake disc; The wire rope of the left drum (traveling drum) is the right down rope, and the wire rope of the right drum (fixed drum) is the right up rope. As shown in Figure 14.

Photo 14 Rope head position of double drum elevator during 1st layer winding

5.2.2 2-layer winding

When the number of winding layers is 2, the rope head of the traveling drum is close to the brake disc, and the rope head of the fixed drum is close to the middle rope guard; The wire rope of the left drum (traveling drum) is the right down rope, and the wire rope of the right drum (fixed drum) is the left up rope. As shown in Figure 15.

Photo 15 Rope head position of double drum elevator during 2-layer winding

5.2.3 Three layer winding

When the number of winding layers is 3, the rope head of traveling drum and fixed drum is close to the brake disc; The wire rope of the left drum (traveling drum) is the right down rope, and the wire rope of the right drum (fixed drum) is the right up rope. As shown in Figure 16.

Photo 16 Rope head position of double drum elevator during 3 layers winding

5.2.4 Number of other winding layers

If the number of wire rope winding layers is not an integer, the manufacturer shall determine the reasonable rope head position after accounting according to the aforementioned principle of "avoiding the convergence of two ropes", which will not be repeated here.

If the double drum hoist is installed on the left, the fixed drum is on the left and the traveling drum is on the right. When winding layer 1, the rope ends of the traveling drum and fixed drum are close to the brake disc. The fixed drum is right handed down and the traveling drum is right handed up; During 2-layer winding, the rope head of the fixed drum is close to the middle rope guard plate, the rope head of the traveling drum is close to the brake disc, the fixed drum is left-handed to lower the rope, and the traveling drum is right-handed to upper the rope; During the winding of the third layer, the rope ends of the traveling drum and the fixed drum are located close to the brake disc. The fixed drum is used for right-handed down rope delivery, and the traveling drum is used for right-handed up rope delivery. This is not illustrated here, but readers can analyze it by themselves.

6. The relationship between the twist direction of wire rope winding on the drum and its own twist direction

In order to avoid loose twisting of wire rope, the wire rope must be wound in the direction of tight twisting rather than loose twisting. If the tightening direction of the wire rope is from left to right, the wire rope shall be wound from left to right. At this time, the winding direction is left and the wire rope is right, as shown in Figure 17 (a). If the tightening direction of the wire rope is from right to left, the wire rope shall be wound from right to left. At this time, the winding direction is right, and the wire rope is left, as shown in Figure 17 (b). Therefore, the principle of "the winding direction of wire rope is opposite to its own" shall be followed. The user shall select the corresponding wire rope according to the winding direction (rotation direction) of the wire rope on the drum.

Fig. 17 Relationship between the winding direction of steel wire rope and its own twisting direction

7 Conclusion

The above rules are not only applicable to spiral rope grooves, but also to parallel broken line rope grooves. They are general rules and can cover most cases. In case of special requirements or individual cases, the manufacturer will consider adjustment.

When the hoist is selected, designed or ordered, the number of steel wire rope winding layers (or lifting height), the hoist installation form (left and right), and the hoisting system layout (reflecting the position relationship between the crown wheel and the drum) shall be indicated. If there are special requirements for the rope outlet direction, they shall be clearly stated. According to these parameters, the manufacturer determines the winding direction and the fixed position of the rope head of the wire rope on the two drums, and indicates them on the general drawing of the equipment. Users can purchase the wire rope correctly according to the above rules.