LU80007A1 - ROLL BREAKER - Google Patents

Description

T

A 524

V

Patent application

Applicant: A R B E D S.A.

Avenue de la Liberté, Luxembourg

Roll crusher

The present invention relates to a roll crusher, in particular a toothed two-roll crusher.

Roller crushers are generally used for breaking fragile or medium-hard material. Roll crushers are mainly used in the metallurgical industry for primary and secondary crushing of ores, in the coal mine for crushing hard coal, slate and coal sandstone, in pits for crushing iron ore, and in quarries for crushing limestone for lime kilns, lime for blast furnaces and chalk, limestone and marl used in cement works.

The two rollers of such crushers usually consist of a steel or cast iron core, on which the teeth are either welded on individually or attached in the form of interchangeable sets consisting of rings or segments.

There are roller crushers in which one roller is fixed and the other is loosely mounted: The loose bearing enables this roller to avoid any occasional peak loads caused by particularly hard foreign bodies in the material to be crushed. Roll breaker types in which both rolls have a loose bearing or both rolls have a fixed bearing are also known.

In this context, when designing the roller drive, not only must continuous operating power be provided for the smooth breaking process, but also preventive measures in the form of a supply of kinetic energy for the above-mentioned loads and those occurring with very large blocks. For this reason, it is common to support the drive of roller crushers by using at least one flywheel.

The rollers can be driven on the one hand by means of a single motor which drives the fixed roller by means of a V-belt via a flywheel, the two rollers being connected via a gear transmission. On the other hand, two motors can be provided, each of which drives the flywheels attached to the shaft ends of each roller via a V-belt drive.

The use of centrifugal masses demonstrably has the advantage of having a store of stored kinetic energy, which can be used sensibly when peak loads occur. Unfortunately, parallel to the said advantage, there are several disadvantages that are serious in nature. The acquisition costs for flywheels are considerable. In fact, such parts, which usually have a diameter "î - 3 - of about 3 m and masses of about 8 t and can reach speeds of up to about 100 rpm, must be carefully machined, due to the high number of grooves with a large diameter, is associated with high costs. Furthermore, flywheels are voluminous according to their task and, depending on the location of the roller crusher, create problems of a spatial nature. It should also be noted that due to the so-called gyroscopic effect, the resetting of flywheels to operating speed v becomes problematic as a result the fact that the peak load loads the flywheel from one side and the return drive from the opposite side, which in the long run can lead to malfunctions in the bearings.

The aim of the present invention was therefore to develop a roll crusher that avoids the disadvantages mentioned.

According to the invention, this aim is achieved in a crusher with two rollers in that each of the two rollers consists of a hollow body, primarily of cast steel, which is supported by two roller bearings at the ends of a fixed central shaft, the inner wall of the hollow body with the rotor and the fixed central shaft is equipped with the stator of a three-phase motor.

The idea on which the invention is based is therefore not to transmit the amounts of energy required for crushing crushed material to the rollers by means of motors mounted outside the rollers via V-belts and flywheels, but rather to design the rollers themselves as motors and energy stores. Since the required mass moment of the rollers remains the same in any case, the design according to the invention is in any case superior to the conventional roller crushers, which understand expensive and bulky flywheels. Further advantages of the roll crusher according to the invention result from the fact that the energy required for breaking in the roll itself, i.e. exactly in the actual effective zone - 4 - arises; all traditional elements that are responsible for friction-related energy loss, such as gears, belt slip and the like, are eliminated. Furthermore, the flywheel masses and the belt drives eliminate a serious source of accidents.

In a further development of the roller design according to the invention, it is provided that the fixed central shaft of the roller has an axial bore on both sides. Each ► of these bores opening into a continuous radial bore is connected to a ventilation unit and can accommodate the electrical cable feed and the lubricant lines.

Furthermore, the housings of the roller bearings have a plurality of through-holes in the axial direction.

Is this simple measure effective cooling of the motor windings? however, the occasional very strong heat emission from the windings makes it necessary to use particularly powerful ventilation units.

The compact construction of the roller crusher according to the invention leads to a noticeably reduced space requirement due to the elimination of the conventional motors with V-belt drive, which are arranged outside the rollers, the tensioning devices and the bulky flywheel masses, which comes into its own in mining operations, mobile crushers and separating crusher systems, as well as lower production costs .

For explanation, reference is made to the attached drawing, in which

1 shows a side view of the roll crusher according to the invention.

From the drawing it can be seen how the fixed central shaft (10) one of the two rollers is supported in the support frame (1). The roller itself grasps the hollow body (20), - 5 - which usually consists of cast steel and is equipped with the breaking teeth (22) on its outer surface, while the inner surface is connected to the rotor (21) of a three-phase motor. The stator (11) of this three-phase motor is mounted on the fixed central shaft (10). To ventilate and cool the windings of the rotor (21) and the stator (11) that form the three-phase motor, the fixed central shaft (10) is provided with an axial bore (12), which is connected via a line »(13) is connected to a ventilation unit, not shown. The axial bore (12) opens into the radial bore (14), which serves as a cooling air supply line. The opposite bore (15) is used for the introduction of the electrical supply lines, or possibly the lubricant lines.

A plurality of bores (25) which are continuous in the axial direction are provided in the housing (24) of the roller bearings (23) to discharge the heated cooling air.

The roller bearings are provided on both sides with labyrinth seals that retain the lubricant in the storage room and protect the latter from the cooling air. Since there is overpressure in the roller itself, the bearings are largely protected against the ingress of dust particles.

To increase the cooling effect, the rotor (21) is provided with blades (26), which force the introduced cooling air into a swirling motion.

41

Claims (5)

1. Roll crusher, in particular toothed two-roll crusher, characterized in that each of the two rolls consists of a hollow body, mainly made of cast steel, which is supported by two roller bearings at the ends of a fixed central shaft, the inner wall of the hollow body with the rotor and the fixed one central shaft are equipped with the stator of a three-phase motor. 2. Roll crusher according to claim 1, characterized in that the fixed central shaft has an axial bore on both sides which opens into a continuous radial bore. 3. Roll crusher according to claims 1-2, characterized in that at least one hole is connected to a ventilation unit. 4. Roll crusher according to claims 1-3, characterized in that the housing of the roller bearings have a plurality of through holes in the axial direction *. « 5. Roll crusher according to claims 1-4, characterized in that the rotor is provided with blades on the inner surface of the hollow body.