This invention relates to jaw rock crushers. In such known crushers, eccentrics or unbalanced rotors drive one or two oppositely situated swing jaws. The disadvantage of the known jaw rock crushers in comparison with known gyratory crushers lies in their cyclical work. i.e. the jaw makes one power stroke and one idle stroke during one revolution of the eccentric shaft. That requires higher strength of construction, balancing and a more powerful mechanical drive. Also, in the conventional jaw crushers, the axle of the swing jaw is situated in its rear part, the power stroke of the jaw providing a force component acting in anti-gravitational direction and braking the material.
The objectives of the present invention is to increase the efficiency of above crushers, decrease their mass and requirements to the construction strength, balancing and mechanical drive, to simplify the construction, and to reduce the drive to easily accessible and interchangeable conventional relatively cheap units.
Above objectives are achieved by executing the drive in form of hydraulic cylinder acting on the swing jaw and connected to a hydraulic pulser. The latter is made as a hydraulic reciprocating cylinder with its plunger actuated by a displacer, such as radial or axial cam, eccentrics, cranks and the like. This simplifies the drive by eliminating heavy components of the known mechanical drives and reduces it to easily accessible and interchangeable hydraulic units with lesser masses and cost.
Above cyclical work is eliminated by dividing the swing jaw into separate sections interacting with hydraulic cylinders connected to a multi-plunger hydraulic pulser. The plungers of the latter are spaced equally apart from each other and relatively to the displacer.
Such a rock crusher squeezes treated materials continuously since the jaw sections work in turn, the more sections, the more uniformly the crusher works. The different jaw sections squeeze and release the materials simultaneously. Such uniform work lessens the horsepower, dynamic load and the crusher’s mass and foundation. Besides, the efficiency of the breaking down of rocks is elevated since the transverse (bending) load on rocks between the different sections is probable.
Still better balancing is achieved providing opposite swings of the synchronized swing jaws, instead of the stationary one. Besides, the opposite swing counterbalanced jaws increase the crusher’s throughput.
To facilitate the gravitational movement of the material and to provide the possibility of a much lower headroom construction (e.g. for portable crushers of underground mining), the jaws form an inclined crushing chamber. It slops downwardly from the inlet to the discharge, with the swing jaw being lower and having frontal ears for its swing axle. Such a low-profiling crusher with its dramatically reduced mass and easily disconnected hydraulic drive makes it suitable for underground mine applications.
Similar to the hydraulic cone and gyratory crushers of the previous chapter, this invention can be also made in line with the author’s earlier hydraulic shock impact applications. Therein an impulse exciter/pulser of hydraulic shocks is installed in the pipeline with its length greater than a half product of the sound velocity and the impulse time.
Fig. 1 is a side elevation view of the present crusher with a stationary jaw and a double-acting hydraulic cylinder.
Fig. 2 is a top plan view of the crusher with two-sectional swing jaws.
Fig. 3 is a hydraulic diagram of the crusher of Fig. 2.
Fig. 4 is a kinematic diagram of a hydraulic pulser of a crank type.
Fig. 5 is the same as above of a radial eccentric (cam) type with parallel rocks between the different sections is probable.
Fig. 6 is the same as above of an axial cam type.
Fig. 7 is the same as in Fig. 1, with a single-acting hydraulic cylinder.
Fig. 8 is above crusher’s hydraulic diagram.
Fig. 9 is the same of the crusher of Fig. 1 with two opposite synchronized swing jaws.
Fig. 10 is the same as above, a swing jaw having frontal ears.
A hydraulic rock crusher of the present invention consists of a swing jaw 1 swung on an axle 2 mounted on a frame 3 (Fig. 1 and 2). An opposite jaw can be a stationary one 4 fixed to the frame 3 (Fig. 1 – 3. 7 and 8) or a synchronized jaw 5 swim on an axle 6 mounted either on the frame 3 (Fig. 9) or on the same axle 2 (Fig. 10). To eliminate the cyclical work of the crusher, the swing jaw 1 is divided into separate sections 7 (two such sections are shown in Fig. 2 only in way of illustration, but not in a limiting sense). The hydraulic drive consists of hydraulic cylinders 8 swung in axles 9 mounted on the frame 3 and acting upon the swing sections. The cylinders of different sections are connected to a multi¬plunger hydraulic pulser 10.
In double-acting cylinders (Fig. 1, 3, 9 and 10), their rods are hinged to the sections with axes 11. In single-acting cylinders (Fig. 7 and 8), their rods are provided with spherical supports 12 fixed to the sections, although hinges can be also used as above. With single-acting cylinders, tension rods 13 are mounted on the frame 3 and have threaded ends carrying springs 14 and nuts 15. Said ends extend through suitable holes in the frame 3. The springs 14 provide the backstroke. Such a tension arrangement holds a single-acting cylinder with an unhinged rod in place. The hydraulic pulser 10 consists of a rotating member 16. such as a radial eccentric (Fig. 3, 5 and 8) or a cam (not shown), a crank, an axial cam, (Fig. 6) and the like, acting on plungers 17.
To replenish leakages, the cylinders are connected to a hydraulic accumulator 18 via a two-way valve 19 and non-return valves 20. The pressure chambers of the cylinders have safety valves 21. To adjust the positions of jaws, (to vary the discharge opening between them) and to release trapped unbreakable materials, the cylinders are connected to pressure and drain lines by four-way valves 22 (Fig. 3) or three-way valves 23 (Fig. 8).
In the rock crushers with both swing jaws Fig. 9 arid 10), the cylinders of the opposite sections have parallel connections to the pulser 10. To provide a downward component of the power stroke, the lower swing jaw has frontal ears 24 for its swing axle (Fig. 10).
Rocks are fed from the top crushed by the jaw sections moving to the opposite jaw and fall down when the sections are moved back. The rocks are crushed again by the next power stroke until they drop through the discharge opening. The resistance of the motion of the moving section increases sharply on the power stroke and diminishes on the return one. That is why the sections of the present crusher distribute the load on the mechanical drive of the pulser, frame and foundation more uniformly and ensure the smooth running. For assistance to the distribution, a hydraulic accumulator can be used in a conventional manner (not shown), storing the surplus energy during the idle stroke and releasing it for crushing on the power stroke.
Big rocks are subjected to transverse (bending) load between sections. That elevates the efficiency still more. The crusher with oppositely swing jaws is counterbalanced almost completely and therefore, its dynamic load on the foundation is considerably decreased. Since the pulser serves as an intensifier too, the hydraulic drive of the present crusher is not as cumbersome as the conventional eccentric drive of the known crushers.