1. Spring cone crusher
Figure 1 is the structure diagram of the 1750 type spring cone crusher produced by Henan Deya Machinery Co., Ltd.
The working mechanism is composed of movable cone with manganese steel liner and fixed cone (adjustment ring 10). The cone of the movable cone is press-fitted to the main shaft (vertical shaft). One end of the main shaft is inserted into the tapered hole of the eccentric bushing. A bronze bushing or MC-6 nylon bushing is installed in the tapered hole of the eccentric bushing. When the eccentric sleeve rotates, it drives the movable cone to make a swinging motion. In order to ensure that the movable cone for the requirements of the rotary motion, the lower surface of the movable cone to be made into a spherical surface, and supported on the spherical bearing. All the weight of the movable cone and the main shaft are borne by the spherical bearing and the frame.
B. Adjustment device
The adjustment device and locking mechanism of cone crusher are actually part of the fixed cone, mainly composed of adjustment ring 10, support ring 8, locking nut 18), push cylinder 9 and locking cylinder. Among them, the adjusting ring and the supporting ring constitute the adjustment device of the size of the discharge opening. The support ring is installed in the upper part of the frame and is tightened to the frame 7 by the spring 6 around the crusher. The upper part of the support ring is equipped with locking cylinders and pistons (1750 type cone crusher is equipped with 12 cylinders, 2200 type cone crusher is equipped with 16 cylinders), and the contact surface of the support ring and the adjustment ring are engraved with serrated threads. Two pairs of paddle claws and a pair of push cylinders are mounted on the support ring. When the crusher is working, high pressure oil is passed into the locking cylinder to make the piston rise, and the locking nut and the adjusting ring are slightly jacked up, so that the serrated threads of both are beveled to fit closely. When adjusting the discharge opening, the locking cylinder should be unloaded to relax the serrated thread, and then the hydraulic system should be operated to push the cylinder, which will drive the adjusting ring to turn to the right or left, and make the fixed cone rise or fall with the help of the serrated thread transmission, so as to realize the adjustment of the discharge opening.
C. Insurance device
This kind of crusher’s safety protection measure is to use the spring installed around the frame as an insurance device. When a non-crushing object enters the crushing chamber, the supporting ring and adjusting ring above the spring are forced to lift up and compress the spring, thus increasing the distance between the movable cone and the fixed cone, increasing the size of the discharge opening and discharging the non-crushed object to avoid damage to the machine. Then, under the influence of the spring’s elasticity, the supporting ring and the adjusting ring will quickly return to their original positions and crush the ore again.
It should be seen that the spring is both a safety device and causes crushing force during normal operation, so its tensioning plays an important role in the normal operation of the crusher. When tightening the spring, appropriate compression allowance should be considered, at least 90 mm for 2200 type cone crusher, about 75 mm for 1750 type crusher, and about 56 mm for 1200 type crusher.
2. Hydraulic cone crusher
The above spring cone crusher discharge adjustment, although it has been changed to hydraulic operation, the structure is still serrated thread adjustment device, the work of the thread is often blocked by dust, adjustment is more laborious and time-consuming, and the crusher must stop; at the same time in the removal of non-crushing objects stuck in the crushing chamber is also very inconvenient. In addition, this kind of insurance device is not perfect, even when the machine suffers from the threat of serious overload, and does not play the role of insurance and other shortcomings. For this reason, at home and abroad are vigorously producing and promoting the application of hydraulic cone crusher, this kind of crusher is not only easy and convenient to adjust the discharge opening, and overload insurance is very high, completely eliminating the shortcomings of the spring cone crusher in this regard.
According to the hydraulic cylinder in the cone crusher placement and the number of devices, can be divided into the top single cylinder, bottom single cylinder and the body around the multi-cylinder type. Although the number of cylinders and installation position are different, their basic principles and hydraulic system are similar. The current application of China’s more bottom single-cylinder hydraulic cone crusher as an example. The working principle of this crusher is the same as the spring cone crusher, but in the structure of the spring cone crusher cancellation of the adjustment ring, support ring and locking device and spherical bearings and other parts. The hydraulic adjusting device and hydraulic safety device of this crusher are realized by the hydraulic cylinder and hydraulic pressure system at the bottom of the main shaft which is supported by the movable cone. The structure of the bottom single-cylinder hydraulic cone crusher is shown in Figure 2. The lower end of the main shaft of the movable cone is inserted into the eccentric bushing and supported on the spherical disc above the piston of the cylinder, and high pressure oil is passed under the piston to support the piston. Due to the rotation of the eccentric sleeve, the movable cone makes a tapered motion.
The hydraulic system of this crusher is composed of oil tank, oil pump, check valve, high pressure relief valve, manual reversing valve, shut-off valve, accumulator, one-way throttle valve, bleeder valve and hydraulic cylinder. Figure 3 shows the schematic diagram of the hydraulic system of this machine.
The adjustment of the discharge opening of the crusher is to use the manual reversing valve to make the increase or decrease of the oil volume through the oil cylinder, which causes the movable cone to rise or fall, so as to achieve the purpose of the discharge opening adjustment. When the hydraulic oil is pressed from the tank into the cylinder piston below, the movable cone rises and the discharge port shrinks (Figure 4 a); if the hydraulic oil below the cylinder piston is put into the tank, the movable cone falls and the discharge port increases (Figure 4 b). The actual size of the discharge port can be seen directly from the oil level indicator.
The overload insurance effect of the machine is achieved by an accumulator with an inactive gas (e.g. nitrogen, etc.) in the hydraulic system. The accumulator is filled with nitrogen gas at a pressure of 50 kg/cm², which is slightly higher than the oil pressure in the hydraulic cylinder, and under normal operating conditions, the hydraulic oil cannot enter the accumulator. When a non-crushing object enters the crushing chamber, the vertical force of the movable cone increases and immediately squeezes the piston, then the oil pressure in the oil circuit is greater than the nitrogen pressure in the accumulator, so the hydraulic oil enters the accumulator, at this time, the piston and the movable cone in the cylinder fall at the same time, and the discharge port increases (Figure 4 c), which excludes the non-crushing object and realizes the insurance function. After the non-crushing objects are excluded, the pressure of nitrogen is higher than the normal working oil pressure, and the hydraulic oil entering the accumulator is pressed back into the hydraulic cylinder, prompting the piston to rise, and the movable cone immediately resumes its normal working position.
If the crushing cavity is blocked, the blockage can be eliminated by using the hydraulic adjustment method to change the size of the oil volume in the cylinder, so that the movable cone rises and falls repeatedly several times.
The bottom single-cylinder hydraulic cone crusher is still in the industrial test stage in China. Production practice has proved that this crusher has a simple structure, no spring cone crusher adjustment ring, support ring and spherical bearings and other complex parts; manufacturing is relatively easy to produce a single-cylinder hydraulic cone crusher of the same specifications of the processing time, only equivalent to 60% of the spring cone crusher; easy to operate, a hydraulic cylinder, while playing the role of adjusting the discharge port and overload protection; hydraulic system action The hydraulic system is sensitive and reliable; the overload protection is highly reliable; the discharge opening is easy to adjust; the crushing cavity is easy to eliminate the phenomenon of ore blockage and the crushing product size is more uniform, and other outstanding advantages. However, the oil cylinder of this crusher is located at the bottom of the machine, resulting in a small working space, which causes certain difficulties for the maintenance of the equipment. Nonetheless, domestic now still prefer to use the bottom single-cylinder hydraulic cone crusher. From the current point of view, single-cylinder hydraulic cone crusher will still be the development direction of hydraulic cone crusher in China.
Multi-cylinder hydraulic cone crusher retains the working characteristics of the spring cone crusher, the main structure is the use of hydraulic insurance device, that is, the spring cone crusher spring insurance to hydraulic cylinder insurance, to replace each group of springs with a cylinder. The adjustment of the discharge opening of the crusher is made by using the hydraulic locking and hydraulic push cylinder adjustment mechanism, instead of the mechanical adjustment device of the spring cone crusher, so the adjustment of the discharge opening is simplified. The structure of the crusher is more complex, high manufacturing cost, high maintenance workload, and oil leakage phenomenon. However, it has a certain role in the transformation of the spring cone crusher, because as long as the cone crusher spring insurance replaced by hydraulic cylinders, other parts basically do not need to change, each plant can be solved locally.