CN110817465B - Pitching system and bucket wheel stacker reclaimer - Google Patents

Abstract

The invention belongs to the technical field of bucket-wheel stacker-reclaimers, and relates to a pitching system and a bucket-wheel stacker-reclaimer. The pitching system comprises a rotary upright post, a cantilever, a bucket wheel mechanism and a pitching mechanism, wherein the first end of the cantilever is hinged to the rotary upright post, the bucket wheel mechanism is hinged to the second end of the cantilever, and the bucket wheel mechanism is used for taking materials; the pitching mechanism comprises a pitching driving assembly, a gear transmission assembly and a pull rod, wherein the gear transmission assembly is hinged to the rotary upright post, a first end of the pull rod is hinged to the gear transmission assembly, and a second end of the pull rod is hinged to a second end of the cantilever; the pitching driving assembly is fixedly connected to the rotary upright post and used for driving the gear transmission assembly to rotate, so that the pull rod hinged with the gear transmission assembly drives the cantilever to swing up and down. The pitching system adopts a gear transmission amplitude-variable pitching structure.

Description

Pitching system and bucket wheel stacker reclaimer

Technical Field

The invention belongs to the technical field of bucket wheel stacker reclaimers, and in particular relates to a pitching system and a bucket wheel stacker reclaimer.

Background technique

Arm-type bucket wheel stacker-reclaimer is a large-scale key equipment widely used in bulk material stacking and reclaiming operations in large and medium-sized storage yards such as metallurgy, electric power, ports, and coking. It has the advantages of large stacking and reclaiming capacity, small yard footprint, easy operation, and high degree of automation control.

The working principle of the bucket wheel stacker and reclaimer is as follows: the traveling mechanism travels along the track, the pitching drive mechanism supports the weight of the bucket wheel and the cantilever, and by changing the height of the bucket wheel, the bucket wheel can stack and reclaim materials at different heights. The slewing mechanism drives the slewing column and the front arm frame to slew and swing, and the bucket wheel stacker and reclaimer can realize the full range of stacking and reclaiming operations through power drive and communication control.

At present, the pitching mechanism of arm-type bucket wheel stacker reclaimer is divided into integral balance and non-integral balance structure. Non-integral balance luffing mechanism has two forms: mechanical and hydraulic: hydraulic cylinder and wire rope pitching.

In the hydraulic cylinder pitch system, the load of the hydraulic system is constantly changing due to the continuous change of the angle of the bucket wheel arm during operation. Especially for double-acting cylinders, from compression to tension, the system needs to solve problems such as speed control and vibration. Therefore, the structure of the hydraulic cylinder pitch system is complex and the manufacturing cost is high. In addition, the manufacturing and installation of domestic hydraulic stations and hydraulic pipelines are prone to oil leakage, pressure relief and asynchronism. Therefore, a lot of maintenance costs are required during the use of the hydraulic cylinder pitch system.

In the wire rope luffing and pitching system, it is necessary to ensure that the front arm has a forward tilting moment so that the front of the bucket wheel machine always maintains a certain ground force. As a result, the overall eccentricity of the bucket wheel machine becomes larger, and protective structures such as rope breakage, overload or mechanism failure must be added to prevent equipment tipping accidents, which will inevitably increase the manufacturing and operation and maintenance costs of the equipment. In addition, after a long period of operation, the dirt load in various parts of the bucket wheel stacker and reclaimer will change according to the specific operating conditions, mainly distributed on the bucket, bucket wheel mechanism surface and cantilever frame, causing the overall center of gravity of the bucket wheel stacker and reclaimer to continue to move forward, and the stability of the equipment will deteriorate.

Summary of the invention

The technical problem to be solved by the present invention is: to provide a pitching system and a bucket wheel stacker and reclaimer in view of the technical problem that the hydraulic cylinder pitching system of the existing bucket wheel stacker and reclaimer is prone to leakage.

In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides a pitch system, comprising a slewing column, a cantilever, a bucket wheel mechanism and a pitch mechanism, wherein the first end of the cantilever is hinged on the slewing column, the bucket wheel mechanism is hinged on the second end of the cantilever, and the bucket wheel mechanism is used for taking materials;

The pitch mechanism comprises a pitch drive assembly, a gear transmission assembly and a pull rod, wherein the gear transmission assembly is hinged on the slewing column, the first end of the pull rod is hinged on the gear transmission assembly, and the second end of the pull rod is hinged on the second end of the cantilever;

The pitch drive assembly is fixedly connected to the slewing column, and is used to drive the gear transmission assembly to rotate, so that the pull rod hinged to the gear transmission assembly drives the cantilever to swing up and down.

According to the pitch system of the embodiment of the present invention, the pitch drive assembly is fixedly connected to the slewing column, and the gear transmission assembly is driven to rotate by the pitch drive assembly, so that the pull rod hinged to the gear transmission assembly drives the cantilever to swing up and down to change the amplitude of the cantilever. The pitch system overcomes the problems of high cost, leakage and asynchronism of the hydraulic cylinder system by adopting a gear transmission variable amplitude pitch structure, and solves the hidden dangers of overall stability change in the wire rope pitch system equipment. In addition, the pitch system has the characteristics of stable transmission, low processing cost, long trouble-free working cycle and convenient maintenance.

Optionally, the gear transmission assembly includes a transmission gear shaft, a transmission gear and a tower, the transmission gear shaft is mounted on the rotary column, the transmission gear and the tower are hinged on the transmission gear shaft, the tower can rotate with the transmission gear, and the first end of the pull rod is hinged on the tower;

The pitch driving assembly is used to drive the transmission gear to rotate.

Optionally, the tower is provided with a first connecting end, a second connecting end and a third connecting end, the first end of the pull rod is hinged to the first connecting end, the second connecting end is hinged to the transmission gear shaft, and the third connecting end is located at a side of the second connecting end facing away from the bucket wheel mechanism;

A gear connecting portion is provided between the second connecting end portion and the third connecting end portion, and the gear connecting portion is hinged to a side of the transmission gear away from the bucket wheel mechanism.

Optionally, the gear transmission assembly further includes a counterweight, and the counterweight is fixedly connected to the third connecting end.

Optionally, the transmission gear and the tower are located in the same plane, and the axis of the transmission gear shaft is perpendicular to the plane where the transmission gear is located.

Optionally, the pitch drive assembly includes a drive motor, a gear reduction box and a drive gear, the output shaft of the drive motor is fixedly connected to the input shaft of the gear reduction box, the output shaft of the gear reduction box is fixedly connected to the drive gear shaft of the drive gear, and the drive gear is meshed with the transmission gear;

The gear reduction box is used to reduce the rotation speed output by the drive motor.

Optionally, a first gear and a second gear meshing with the first gear are provided in the gear reduction box, the output shaft of the drive motor is fixedly connected to the gear shaft of the first gear, and the gear shaft of the second gear is fixedly connected to the driving gear shaft of the driving gear.

Optionally, the pitch drive assembly also includes a bearing seat, a high-speed coupling and a low-speed coupling, the driving gear shaft of the driving gear is rotatably connected to the bearing seat, the high-speed coupling is fixedly connected between the output shaft of the driving motor and the input shaft of the gear reduction box, and the low-speed coupling is fixedly connected between the output shaft of the gear reduction box and the driving gear shaft of the driving gear.

Optionally, the rotary column includes a column upper portion and a column lower portion fixedly connected below the column upper portion, the first end of the cantilever is hinged to the column lower portion, and the gear transmission assembly is hinged to the column upper portion.

Optionally, the bucket wheel mechanism comprises a bucket wheel shaft, a bucket wheel body, a bucket and a bucket wheel driving device, the bucket wheel shaft is rotatably connected to the second end of the cantilever, the bucket wheel body is fixedly connected to the bucket wheel shaft, and the bucket is fixedly connected to the outer side of the bucket wheel body;

The bucket wheel driving device is fixedly connected to the second end of the cantilever, and the bucket wheel driving device is used to drive the bucket wheel shaft to rotate.

On the other hand, an embodiment of the present invention provides a bucket wheel stacker and reclaimer, which includes a pitch system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a pitch system provided by an embodiment of the present invention;

FIG2 is a partial schematic diagram of a pitch mechanism of a pitch system provided by an embodiment of the present invention;

Fig. 3 is a partial cross-sectional view taken along line A-A in Fig. 2;

Fig. 4 is a partial cross-sectional view taken along line B-B in Fig. 2;

FIG. 5 is a schematic diagram of a pitch drive assembly of a pitch system provided in an embodiment of the present invention.

The reference numerals in the specification are as follows:

1. Rotating column; 11. Upper part of column; 12. Lower part of column;

2. Cantilever;

3. bucket wheel mechanism; 31. bucket wheel shaft; 32. bucket wheel body; 33. bucket;

4. Pitch mechanism; 41. Pitch drive assembly; 411. Drive motor; 412. Gear reduction box; 413. Drive gear; 414. Bearing seat; 415. High-speed coupling; 416. Low-speed coupling; 42. Gear transmission assembly; 421. Transmission gear shaft; 422. Transmission gear; 423. Tower; 4231. First connecting end; 4232. Second connecting end; 4233. Third connecting end; 4234. Gear connecting part; 424. Counterweight; 43. Pull rod;

5. Radial spherical plain bearing; 6. Spherical roller bearing; 7. Three-row cylindrical roller slewing bearing; 8. Door seat; 9. Pinion gear.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

As shown in Figures 1 to 5, the pitch system provided in an embodiment of the present invention includes a rotating column 1, a cantilever 2, a bucket wheel mechanism 3 and a pitch mechanism 4. The first end of the cantilever 2 is hinged to the rotating column 1, the bucket wheel mechanism 3 is hinged to the second end of the cantilever 2, and the bucket wheel mechanism 3 is used for taking materials.

The pitch mechanism 4 includes a pitch drive assembly 41, a gear transmission assembly 42 and a pull rod 43. The gear transmission assembly 42 is hinged on the rotating column 1, the first end of the pull rod 43 is hinged on the gear transmission assembly 42, and the second end of the pull rod 43 is hinged on the second end of the cantilever 2.

The pitch driving assembly 41 is fixedly connected to the slewing column 1 , and is used to drive the gear transmission assembly 42 to rotate, so that the pull rod 43 hinged to the gear transmission assembly 42 drives the cantilever 2 to swing up and down.

The pitch system provided by the embodiment of the present invention fixes the pitch drive assembly 41 to the slewing column 1, and drives the gear transmission assembly 42 to rotate through the pitch drive assembly 41, so that the pull rod 43 hinged to the gear transmission assembly 42 drives the cantilever 2 to swing up and down, so as to change the amplitude of the cantilever 2. The pitch system overcomes the problems of high cost, leakage and asynchronism of the hydraulic cylinder system by adopting the gear transmission variable amplitude pitch structure, and solves the hidden dangers of overall stability change in the wire rope pitch system equipment. In addition, the pitch system has the characteristics of stable transmission, low processing cost, long trouble-free working cycle and convenient maintenance.

In one embodiment, the first end of the cantilever 2 is hinged to the slewing column 1 through a self-lubricating spherical bearing, the first end of the cantilever 2 is a fixed hinge, and the second end of the cantilever 2 is a floating hinge. The cantilever 2 swings up and down around the hinge axis a (as shown in FIG. 1 ) through the sliding of the inner and outer rings of the radial spherical bearing in the hinge axis.

In one embodiment, as shown in FIG. 1 and FIG. 2 , the gear transmission assembly 42 includes a transmission gear shaft 421, a transmission gear 422 and a tower 423. The transmission gear shaft 421 is mounted on the slewing column 1. The transmission gear 422 and the tower 423 are hinged on the transmission gear shaft 421. The tower 423 can rotate with the transmission gear 422. The first end of the pull rod 43 is hinged on the tower 423. The pitch drive assembly 41 is used to drive the transmission gear 422 to rotate.

When the pitch driving assembly 41 drives the transmission gear 422 to rotate, the tower 423 rotates along with the transmission gear 422 to drive the pull rod 43 to move, so that the cantilever 2 swings up and down.

In one embodiment, as shown in Fig. 1, Fig. 2 and Fig. 4, the transmission gear 422 is fixed to both sides of the transmission gear shaft 421 through double-row spherical roller bearings. The first end of the pull rod 43 is hinged to the tower 423 through a spherical roller bearing, and the hinge axis is c (as shown in Fig. 1), and the second end of the pull rod 43 is hinged to the cantilever 2 through a joint bearing, and the hinge axis is d (as shown in Fig. 1).

In one embodiment, as shown in FIG. 1 and FIG. 2 , the tower 423 is provided with a first connection end 4231, a second connection end 4232 and a third connection end 4233, and the first end of the pull rod 43 is hinged on the first connection end 4231 to connect the pull rod 43 and the tower 423. The second connection end 4232 is hinged on the transmission gear shaft 421 to connect the pull rod 43 and the transmission gear shaft 421. The third connection end 4233 is located on the side of the second connection end 4232 facing away from the bucket wheel mechanism 3 to form the tower 423.

A gear connection portion 4234 is provided between the second connection end portion 4232 and the third connection end portion 4233 . The gear connection portion 4234 is hinged to a side of the transmission gear 422 away from the bucket wheel mechanism 3 to connect the tower 423 and the transmission gear 422 .

In one embodiment, as shown in FIG. 2 and FIG. 3 , the transmission gear 422 is connected to the tower 423 via a radial spherical bearing 5 .

In one embodiment, as shown in Fig. 1, the gear transmission assembly 42 further comprises a counterweight 424, and the counterweight 424 is fixedly connected to the third connection end 4233, so as to fix the counterweight 424 to the tower 423. The counterweight 424 has an adjustable counterweight installed therein.

In one embodiment, as shown in Figures 1 and 2, the transmission gear 422 and the tower 423 are located in the same plane, and the axis of the transmission gear shaft 421 is perpendicular to the plane where the transmission gear 422 is located, so that when the tower 423 rotates with the transmission gear 422, the pull rod 43 can pull the cantilever 2 to swing up and down around the hinge axis a (as shown in Figure 1) as the center.

In one embodiment, as shown in Figures 2 and 5, the pitch drive assembly 41 includes a drive motor 411, a gear reduction box 412 and a drive gear 413, the output shaft of the drive motor 411 is fixedly connected to the input shaft of the gear reduction box 412, the output shaft of the gear reduction box 412 is fixedly connected to the drive gear shaft of the drive gear 413, and the drive gear 413 is meshed with the transmission gear 422.

The gear reduction box 412 is used to reduce the rotation speed output by the driving motor 411 .

The rotation speed output by the driving motor 411 is reduced by the gear reduction box 412 and then transmitted to the driving gear shaft of the driving gear 413. Since the driving gear 413 is meshed with the transmission gear 422, the rotation of the driving gear 413 can drive the transmission gear 422 to rotate, thereby driving the pull rod 43 to move.

In one embodiment, as shown in Fig. 5, the pitch drive assembly 41 further includes a bearing seat 414, a high-speed coupling 415 and a low-speed coupling 416, and the driving gear shaft of the driving gear 413 is rotatably connected to the bearing seat 414 to install the driving gear 413. The high-speed coupling 415 is fixedly connected between the output shaft of the driving motor 411 and the input shaft of the gear reduction box 412, and the low-speed coupling 416 is fixedly connected between the output shaft of the gear reduction box 412 and the driving gear shaft of the driving gear 413 to achieve the transmission of the rotation speed.

In one embodiment, a brake is provided on the high-speed coupling 415 .

In one embodiment, the gear reduction box 412 is provided with a first gear and a second gear meshing with the first gear, the output shaft of the drive motor 411 is fixedly connected to the gear shaft of the first gear, and the gear shaft of the second gear is fixedly connected to the driving gear shaft of the driving gear 413 to achieve the reduction and transmission of the rotation speed.

In one embodiment, as shown in Figures 1 and 2, the slewing column 1 includes a column upper portion 11 and a column lower portion 12 fixedly connected to the bottom of the column upper portion 11, the first end of the cantilever 2 is hinged to the column lower portion 12, and the gear transmission assembly 42 is hinged to the column upper portion 11 to achieve the installation between the cantilever 2 and the gear transmission assembly 42 and the slewing column 1.

In one embodiment, as shown in FIG1 , the bucket wheel mechanism 3 includes a bucket wheel shaft 31, a bucket wheel body 32, a bucket 33 and a bucket wheel driving device (not shown), wherein the bucket wheel shaft 31 is rotatably connected to the second end of the cantilever 2, the bucket wheel body 32 is fixedly connected to the bucket wheel shaft 31, and the bucket 33 is fixedly connected to the outer side of the bucket wheel body 32. The bucket wheel driving device is fixedly connected to the second end of the cantilever 2, and the bucket wheel driving device is used to drive the bucket wheel shaft 31 to rotate, so as to drive the bucket wheel body 32 fixedly connected to the bucket wheel shaft 31 and the bucket 33 fixedly connected to the outer side of the bucket wheel body 32 to rotate, so as to realize the material taking operation.

In one embodiment, as shown in FIG. 1 , a plurality of buckets 33 are provided, and the plurality of buckets 33 are evenly distributed on the outer ring of the bucket wheel body 32 . The bucket wheel body 32 is fixed to the bucket wheel shaft 31 by a locking plate, and the bucket wheel shaft 31 is fixed to the second end of the cantilever 2 by a bearing seat.

The working principle of the pitch system provided in the embodiment of the present invention is as follows:

As shown in Fig. 5, the driving motor 411 of the pitch driving assembly 41 is started, and the high-speed coupling 415 with a brake is connected to the input shaft of the gear reduction box 412, and the input shaft of the gear reduction box 412 rotates. The gears in the gear reduction box 412 are meshed and transmitted, and the output shaft of the gear reduction box 412 is connected to the driving gear shaft of the driving gear 413 through the low-speed coupling 416, driving the driving gear 413 to rotate.

When the driving gear 413 rotates, the transmission gear 422 will rotate synchronously with the outer ring of the spherical roller bearing connected between the transmission gear 422 and the transmission gear shaft 421, and the radial spherical bearing between the transmission gear 422 and the tower 423 will rotate, driving the tower 423 to rotate around the transmission gear 422 along the hinge shaft b (as shown in Figure 1).

When the tower 423 rotates, the pull rod 43 and the hinge axis c of the tower 423 will rotate around the hinge axis b of the transmission gear 422, and the pull rod 43 and the hinge axis d of the cantilever 2 will make an up and down amplitude movement around the rotation center of the bucket wheel mechanism 3 (that is, the hinge axis a of the cantilever 2 and the rotating column 1).

Since the cantilever 2 and the tower 423 are non-integrated balanced pitch mechanisms rotating around different rotation centers, the rotation angles of the cantilever 2 and the tower 423 are different. According to the material pile height and bucket wheel diameter, the bucket wheel stacker and reclaimer can achieve normal stacking and reclaiming operation. The cantilever 2 has a variable amplitude angle of +15.2° to -9.6° around the hinge axis a, and the rotation angle of the hinge axis c of the tower 423 around the gear rotation center d is +37.7° to -20.8°.

When the driving motor 411 of the pitch driving assembly 41 rotates forward, the transmission gear 422 drives the tower 423 and the pull rod 43 to rotate clockwise around the hinge axis b, and the cantilever 2 pitches down around the hinge axis a. When the driving motor 411 of the pitch driving assembly 41 reverses, the transmission gear 422, the tower 423 and the pull rod 43 rotate counterclockwise around the hinge axis b, and the cantilever 2 pitches up around the hinge axis a.

The bucket wheel stacker and reclaimer provided in the embodiment of the present invention comprises the above-mentioned pitch system, wherein the slewing column 1 is connected to the gate seat 8 through three rows of cylindrical roller turntable bearings 7, and the inner ring of the turntable bearing is driven to rotate by the pinion 9 of the slewing drive device, so that the slewing column 1 can slew ±120° around the hinge axis a.

The cantilever 2 is evenly distributed with a cantilever belt conveyor, and the belt driving device at the second end of the cantilever 2 drives the driving roller to rotate, and the materials dug by the bucket wheel mechanism 3 are taken away through the operation of the belt, roller group and the redirecting roller installed at the first end of the cantilever 2. At the same time, the incoming materials can also be stored in the material yard through the reverse operation of the arm frame belt conveyor.

In one embodiment, the technical parameters of the bucket wheel stacker and reclaimer provided by the embodiment of the present invention are: stacking capacity is 4000t/h, reclaiming capacity is 3000t/h, the length of the cantilever 2 is 35m, the belt width of the cantilever 2 is 1400mm, the pitch angle is +15.2°～-9.6°, the pitch speed is 12.1m/min, the number of teeth of the driving gear 413 is 14, the number of teeth of the transmission gear 422 is 194, the gear pair module is 25, and the driving power is 2*30Kw.

The working interlocking process of the pitching mechanism of the arm-type bucket wheel stacker and reclaimer provided by the embodiment of the present invention is as follows:

First, the control room starts the working interlock between the operating parts according to the working status of the equipment.

When taking materials, the ground system belt conveyor, the belt conveyor arranged on the cantilever 2, the bucket wheel mechanism, the rotary column, the walking mechanism feeding and the pitching mechanism are started in sequence.

When stacking materials, the belt conveyor, the rotary column, the pitch mechanism, the walking mechanism feeding and the ground system belt conveyor arranged on the cantilever 2 are started in sequence.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (11)

1. The pitching system is characterized by comprising a rotary upright post, a cantilever, a bucket wheel mechanism and a pitching mechanism, wherein the first end of the cantilever is hinged to the rotary upright post, the bucket wheel mechanism is hinged to the second end of the cantilever, and the bucket wheel mechanism is used for taking materials;

The pitching mechanism comprises a pitching driving assembly, a gear transmission assembly and a pull rod, wherein the gear transmission assembly is hinged to the rotary upright post, a first end of the pull rod is hinged to the gear transmission assembly, and a second end of the pull rod is hinged to a second end of the cantilever;

the pitching driving assembly is fixedly connected to the rotary upright post and used for driving the gear transmission assembly to rotate, so that the pull rod hinged with the gear transmission assembly drives the cantilever to swing up and down.

2. The pitch system of claim 1, wherein the gear drive assembly comprises a drive gear shaft, a drive gear, and a pylon, the drive gear shaft mounted on the slewing post, the drive gear and the pylon hinged to the drive gear shaft, the pylon rotatable with the drive gear, the first end of the tie rod hinged to the pylon;

The pitching driving component is used for driving the transmission gear to rotate.

3. The pitch system of claim 2, wherein the tower is provided with a first connection end, a second connection end and a third connection end, the first end of the tie rod being hinged to the first connection end, the second connection end being hinged to the drive gear shaft, the third connection end being located on a side of the second connection end facing away from the bucket wheel mechanism;

A gear connecting part is arranged between the second connecting end part and the third connecting end part, and the gear connecting part is hinged with one side, far away from the bucket wheel mechanism, of the transmission gear.

4. A pitch system according to claim 3, wherein the gear assembly further comprises a weight fixedly connected to the third connection end.

5. The pitch system of claim 2, wherein the drive gear is in the same plane as the tower and the axis of the drive gear shaft is perpendicular to the plane in which the drive gear is located.

6. The pitch system of claim 2, wherein the pitch drive assembly comprises a drive motor, a gear reduction box, and a drive gear, an output shaft of the drive motor is fixedly connected with an input shaft of the gear reduction box, an output shaft of the gear reduction box is fixedly connected with a drive gear shaft of the drive gear, and the drive gear is meshed with the transmission gear;

the gear reduction box is used for reducing the rotation speed output by the driving motor.

7. The pitching system of claim 6, wherein a first gear and a second gear meshed with the first gear are disposed in the gear reduction box, an output shaft of the driving motor is fixedly connected with a gear shaft of the first gear, and a gear shaft of the second gear is fixedly connected with a driving gear shaft of the driving gear.

8. The pitch system of claim 6, wherein the pitch drive assembly further comprises a bearing housing, a high speed coupling and a low speed coupling, the drive gear shaft of the drive gear is rotatably coupled to the bearing housing, the high speed coupling is fixedly coupled between the output shaft of the drive motor and the input shaft of the gear reduction box, and the low speed coupling is fixedly coupled between the output shaft of the gear reduction box and the drive gear shaft of the drive gear.

9. The pitch system of claim 1, wherein the slewing mast comprises a mast upper portion and a mast lower portion fixedly connected below the mast upper portion, the first end of the boom being hinged to the mast lower portion, the gear assembly being hinged to the mast upper portion.

10. The pitch system of claim 1, wherein the bucket wheel mechanism comprises a bucket wheel shaft, a bucket wheel body, a bucket and a bucket wheel driving device, wherein the bucket wheel shaft is rotatably connected to the second end of the cantilever, the bucket wheel body is fixedly connected to the bucket wheel shaft, and the bucket is fixedly connected to the outer side of the bucket wheel body;

the bucket wheel driving device is fixedly connected to the second end of the cantilever, and the bucket wheel driving device is used for driving the bucket wheel shaft to rotate.

11. A bucket wheel stacker reclaimer comprising a pitch system as defined in any of claims 1-10.