US2652985A

US2652985A - Jaw crusher with opposed jaws driven by unbalanced weights

Info

Publication number: US2652985A
Application number: US116997A
Authority: US
Inventors: Linke Gerhard
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-01
Filing date: 1949-09-21
Publication date: 1953-09-22
Anticipated expiration: 1970-09-22

Description

Sept. 22, 1953 G. LINKE 2,652,985

JAW CRUSHER WITH OPPOSED JAWS DRIVEN BY UNBALANCED WEIGHTS Filed Sept. 21, 1949 inrehfor: [fie/L1G! xinke/ Patented Sept. 22, 1953 UNITED STATES PATENT OFFICE JAW CRUSHER WITH OPPOSED JAWS DRIVEN BY UNBALANCED WEIGHTS Gerhard Linke, Mulheim-Ruhr, Germany 6 Claims.

In the known stone crushing and pulverising apparatus the major part of the energy supplied is transformed into heat since the bodies to be pulverised slide under pressure in relation to one another and are thereby elastically or permanently deformed. Only a small part of the material is stressed to the breaking point and pulverised. This is to be ascribed to the fact that during the impact together of the crusher jaws frictional and crushing actions are mainly exerted on the material and not the more favorable impact action. The mean speed of the crusher jaws amounts, in a normal jaw crusher, to about 10-20 cm. per second. This speed is insufficient to achieve an impact action on the material. Consequently, the pulverising efficiency of these crushers is only very small. A comparatively large amount of energy is transformed uselessly into heat so that the power required is very high. In order to improve the efficiency of the crusher, the crushing operation must be so carried out that the bodies to be crushed do not lie close to one another in the mouth of the crusher and that at each working stroke as few grains as possible are subjected to impact at great speed. The mean speed of the oscillating crusher jaws should be about 35-60 cm. per second in order to achieve a sufficient impact action. Jaw crushers are however known in which the mean speed of the crushing jaws is about 40-50 cm. per second, but the peak value of the acceleration in this construction does not exceed about 2.2 to 2.6 times the value of gravity. This construction does not allow of a higher acceleration as the forces produced by the oscillating masses are not com pensated and the driving elements are unable to take up large acceleration forces. To achieve a sufficient efficiency of the crusher at these high impact speeds, it is however necessary that the time of oscillation and the time of fall of the grain held between the crusher jaws and afterwards freed should bear a definite relation to one another. The falling grain should meet the returning crusher jaw at the moment when the jaw, after passing through its outer dead centre, has already reached a substantial speed so that the grain is hurled by the crusher jaw into the mouth of the crusher. This results in the loosening of the material located in the mouth of the crusher and a travelling speed of the material through the mouth of the crusher sufficient for the high speed of oscillation. I

The invention is based on the recognition that time of oscillation and time of fall, and therefore also the efliciency of the jaw crusher, reach favorable values when, at a mean speed of the oscillating crusher jaws of 30-60 cm. per second, the peak value of the acceleration is 3 to 8 times the value of gravity. In the case where the space between the jaws is inclined, the lower values of the acceleration and speed are to be preferred, while the higher values are to be preferred when the space is vertical.

The compensation of the oscillating masses in the jaw crusher according to the invention is conveniently achieved by having the two crushing jaws oscillate in opposed relation to one another and setting them in motion by an out of balance drive whose unbalance wheels are journalled directly on the respective jaw structures. Such a drive makes it possible to achieve a practically complete compensation of all forces and moments and therefore the advantage that the time and stroke of oscillation can be adjusted largely or wholly to suit the requirements of the crushing operation without having to fear dis placement of the foundation of the crusher. The oscillating cruhser jaws and the out of balance drive also relieve the housing of the crushing forces so that the construction can be made con siderably lighter than hitherto.

The use of the out of balance drive gives the further advantage that the forces necessary for moving the crushing jaws are applied directly from the unbalance wheels Where the greatest crushing forces occur. The reserves of power necessary in every crusher are present in a sufficient degree in the oscillating masses of the crushing jaws and of the unbalance wheels and in the rotating mass of the latter. No energy loss occurs by energy flowing to and fro between the flywheel and crank drive, or bell crank drive, as is the case in previous crushers.

The mechanical emciency of the drive can be still further improved by use of resonance. It is advantageous to arrange the springs of the crushing jaws so that their individual period of oscillation conforms approximately with the operating period of oscillation. By a sufficiently progressive characteristic of the springing and blind power of the oscillating masses, a sufriciently constant stroke of the oscillating jaws can he achieved even with variations in the working power required so as to avoid impermissibly large variations in the crushing space.

In order to regulate the speed of oscillation of the crusher jaws sufliciently in accordance with requirements, the jaws are preferably provided with out of balance wheels which have a relative phase displacement of and which are connected with their fixed drive by elastic couplings. It is in this case particularly favorable when the out of balance wheels are mounted on the lower freely oscillating ends of the crusher jaws as here the maximum crushing forces occur.

A torque arises from the oscillation of the out of balance wheels with the jaws. This can be compensated by spring suspension of the whole crusher.

A further way of compensating torque is to pro vide each crusher jaw with two unbalanced wheels runnin in opposite directions which can be coupled together so that they have the same speed.

Furthermore, the torque can be compensated by providing additional unbalanced wheels either at the pivot of the crusher jaws or outside the latter. In the latter case an increase in crushing pressure can be achieved as well as compensation for the torque.

The drawings show examples of the invention.

Fig. l is a part-sectional side view of a jaw crusher, and Fig. 2 a cross-sectional top view of the same crusher, the section being taken through the plane determined by the axes of the two un-- balance wheels of the machine.

Fig. 3 shows a schematic side view of the jaw portion and Fig. 4 is a schematic, part-sectional top view of another crusher.

Fig. 5 is a sectional view and Fig. 6 a partial side view of a jaw pivot and stop mechanism applicable in jaw crushers according to Figs. 1 and 2.

In Figures 1 and 2 the two oscillating crusher jaws I and 2 are suspended by their pivots it from the housing 4 of the crusher. The jaws I and 2 are maintained in their oblique position by springs 5, which are connected at one end to the jaws and at the other to the housing 4. Each jaw is driven by an unbalanced wheel 6, which is rotatably mounted on the lower freely oscillating end of the jaw. The unbalanced wheels 6 of the two jaws I and 2 have their weights displaced in phase by 180. Rotary movement is transmitted from the fixed drive shaft 8 through elastic couplings "I to the oscillating wheel 6.

The oscillating unbalance wheels 5 produce a force couple Pc (Fig. 1). Since this is undesired, means are provided for compensating for this couple. Accordingly, the crusher housing 4, with the jaws I and 2, the unbalance wheels 6, is hung on springs 23 so that the mass of the jaw crusher can execute a torsional oscillation about its centre of gravity. The amplitude of these oscillations is reduced by additional weights 2A to a nondisturbing value. The additional weights 24 are preferably located as far as possible from the centre of gravity of the jaw crusher.

Spur gears l transfer the movement from the drive shaft 8' to the shafts 9. Between the fixed drive shaft 8' and the gears Ii] is provided a reversing spur gear II so that the two gears Ill and therefore the out of balance wheels 6 rotate in the same directions.

Instead of providing an out of balance wheel 6 on each of the crusher jaws I and 2, the couple Pc can be avoided by providing each jaw with out of balance wheels I2 which rotate in opposite directions (Figs. 3 and 4). These out of balance wheels l2. on each jaw I and 2 are coupled together by a spur gear drive I3. Between the fixed drive 8 and the elastic couplings I4, 2. fixed chain gear I can be used to transmit the movement to the out of balance wheels on the jaws l and 2. Instead of the chain drive I5, a gearing, corresponding to Fig. 2 may be used.

It is also possible to drive the out of balance wheels by electric motors which are electrically synchronized in such a way that the speeds of rotation of the out of balance wheels are exactly equal and the phase displacement of the weights is maintained.

In order so to determine the springing of the jaw so that its own period of oscillation agrees approximately with the period of oscillation of the jaws torsion rod springs I'I (Figs. 5, 6) are mounted on the jaws l and 2. The torsion rods fastened by roller wedges in the housing 4 and disposed within the hollow pivot 3. In the hollow of the pivot 3 the springs I! are held by roller wedges I9. On the pivot 3 of each of the jaws I and 2 is provided a spring lever 20 which is attached to the pivot by a roller wedge 2| and due to the springing of the pivot, oscillates between two rubber buffers 22 fixed to the housing 4. Instead of a special drive external to the crusher, a motor with its driving gear may be mounted directly on the jaws I and 2 to move with them. The supply of material to be crushed can be so regulated by an oscillating discharge device that overfilling of the mouth of the crusher is prevented. The crusher is conveniently connected in circuit with a screening device so that the grain size of the crushed material corresponds to desired requirements.

What I claim and desire to secure by Letters Patent is:

1. A jaw crusher, comprising two jaws pivoted for oscillation in opposition to each other, unbalance wheels having wheel bearings rigidly mounted on said jaws remote from the respective jaw pivots to oscillate together with said jaws, said wheels having respective unbalance weights phase displaced relative to each other, a stationary drive, and elastic coupling means conmeeting said drive with said wheels.

2. A jaw crusher, comprising stationary supporting structure, a crusher housing elastically suspended from said structure to be capable of oscillatory motion relative thereto, two crusher jaws each having one end pivoted on said housing for oscillatory movement in opposing relation to corresponding movement of the other jaw, unbalance wheels having respective bearing means rigidly mounted on said jaws near the oscillatory ends respectively of said jaws, said wheels having respective unbalance weights 180 phase displaced relative to each other, a drive stationary with respect to said structure, and elastic transmission means connecting said drive with said unbalance wheels.

3. A jaw crusher, comprising a spring-suspended housing, two crusher jaws each having one end pivoted on said housing for pivotal oscillation in opposition to the other jaw, unbalance wheels having respective bearing means rigidly mounted on said jaws near the oscillatory ends respectively of said jaws, said wheels having respective unbalance weights 180 phase displaced relative to each other, a stationary drive, elastic coupling means connecting said drive with said wheels, and additional weights disposed on said crusher housing for minimizing torsional oscillations of the crusher.

4. A jaw crusher, comprising two jaws pivoted for angular oscillation in, opposition to each other, two first unbalance wheels each having bearing means rigidly mounted on one of said respective jaws near the oscillatory jaw end and having an unbalance weight 180 phase displaced relative to the unbalance weight of the first unbalance wheel on said other jaw, two second unbalance wheels each having bearing means rigidly mounted on one of said respective jaws, spur gear means coupling said second unbalance wheel of each jaw with said first unbalance wheel of the same jaw for rotating them in opposition to each other, stationary drive, and elastic transmission means connecting said drive with said unbalance wheels.

5. A jaw crusher, comprising a housing structure, two opposingly oscillating jaws having respective hollow pivots revolvably pivoted on said structure for oscillation in mutually opposing relation, unbalance wheels having respective bearing means rigidly mounted on said respective jaws remote from the respective jaw pivots to oscillate together with said jaws, said wheels having respective unbalance weights 180 phase displaced relative to each other, a stationary drive connected with said wheels, and torsion rod springs disposed within said respective hollow pivots, each spring having one rod end secured to one of said respective jaws and having the other rod end secured to said structure.

6. A jaw crusher, comprising a housing structure, two opposingly oscillating jaws having respective hollow pivots revolvably pivoted on said structure for oscillation in mutually opposing relation, unbalance wheels having respective bearing means rigidly mounted on said jaws remote from the respective jaw pivots to oscillate together with said jaws, said wheels having respective unbalance weights 180 phase displaced relative to each other, a stationary drive connected with said wheels, and torsion rod springs disposed within said respective hollow pivots, each spring having one rod end non-revolvably secured to one of said jaws, two lever arms having pivot axes substantially coaxial with said respective springs and being joined with the other ends respectively of said springs, and two pairs of mutually spaced buffers of elastically compressible material mounted on said housing structure, each of said lever arms extending between the two bufiers 01 one of said respective pairs.

GERHARD LINKE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 472,367 Knapp Apr. 5, 1892 1,491,430 Stebbins Apr. 22, 1924 1,936,742 Youtsey Nov. 28, 1933 2,170,768 Schieferstein Aug. 22, 1939 2,352,970 Pollitz July 4, 1944 FOREIGN PATENTS Number Country Date 219,137 Germany Feb. 17, 1910 306,017 Germany June 11, 1918 515,819 Germany Jan. 13, 1931 52,728 Norway June 26, 1933 727,417 Germany Nov. 3, 1942 OTHER REFERENCES Serial No. 372,589, Bachmann (A. P. C.), published May 4, 1943.