This invention relates to a cone crusher for crushable material and which comprises a stationary bowl, a conical head which is capable of carrying out gyra_tory movement within the bowl, and a drive train coupled with the head to apply gyratory movement thereto.

Usually, the stationary bowl has a concave liner, and the head carries a mantle which is capable of carrying out gyratory movement within the bowl so that ttie concave liner and the mantel cooperate to exert crushing action on material therebetween.

It is usual to drive a cone crusher by a drive train comprising a single bevel gear drive, supported by bearings and driven by an arrangement of belts and pulley wheels.

It is the case that, when driving large capacity crushers, high power is required to operate the machine. While it is desirable to vary the speed of the crusher, this can only be achieved with an electric or diesel prime mover by changing the size of the belt and pulley wheel, which is costly and time consuming. Also, provision of variable speed electric drives, or varying engine speed, would both result in loss of maximum power and which would be undesirable.

The most practical means of achieving variable speed drive would be by using variable displacement hydraulic pumps or motors, which can operate up to their maximum power limit, regardless of the set flow, providing no operational parameters are exceeded.

However, a potential problem which would be faced by driving large cone crushers with hydraulic motors is that the maximum power of such variable pumps or motors is limited, and greater power ratings are not regularly available.

The present invention seeks to solve this problem by providing a novel arrangement of drive train to operate a cone crusher, using more than one hydraulic motor to drive the head of the cone crusher. According to the invention there is provided a cone crusher which comprises: a bowl; a conical head which is capable of carrying out gyratory movement within the bowl in order to exert a crushing action on crushable material present between the outer surface of the head and the bowl; and a drive train coupled with the conical head and operative to apply gyratory movement thereto; in which the drive train comprises: an upright main mounting shaft; an eccentric mounted on and arranged to be rotated about the axis of the shaft, said head being mounted on the eccentric in such a way that the head is driven to carry out gyratory movement within the bowl; and two hydraulic motors diametrically opposed to each other with respect to the axis of the shaft, and each coupled drivingly with the eccentric via a respective input gear .

Preferably, each hydraulic motor applies drive input to a main bevel gear on which the eccentric is mounted via a respective bevel spur gear.

Preferably, two hydraulic motors and respective bevel spur gears are provided, arranged diametrically opposed to each other with respect to the axis of the shaft. However, it is within the scope of the invention for more than two hydraulic motors and respective bevel spur gear drives to be provided, to apply drive input to the main bevel gear.

To facilitate maintenance work, preferably the entire drive assemblies are removable through apertures provided in the side of the frames.

With use of at least two hydraulic motors, to apply drive directly to small opposed bevelled gears, the following technical advantages can be achieved: motors and pumps are more readily available in the sub-200kw power range and are consequently cheaper. The necessary control valves are also smaller, cheaper and may be multi-sourced; the bevel gears to carry fractional machine power are smaller diameter, which allows greater reduction ratios. This permits higher motor speeds which better use the full power ratings; replacement of the massive shaft, bearings, bevel gears and pulleys present in existing drive trains to cone crushers, reduce the overall weight and size of the crusher assembly. Unlike jaw crushers, the motion in a cone crusher is cyclic, ie not reciprocating, so that massive fly wheels are not required to store inertial energy; and the motor mounts and gear housings may be constructed within the "envelope" of the crusher frame in the form of "plug-in components". This will make on-site maintenance and replacement much easier.

Manufacturing implications

Any existing style or design of cone crusher can be adapted, using a drive train according to the invention by redesign of the main frame to accommodate the drive gear bearing housings and motor mountings. The main shaft assembly, bearings and pulleys of the existing cone crusher will then not be required. The external space occupied by such drives will be released for other purposes.

The drive train of the invention may be easily applied to long shaft "gyratory" style crushers.

A preferred embodiment of cone crusher according to the invention will now be described in detail, by way of example only, with reference to Figure 1 of the accompanying drawings.

A cone crusher according to the invention, having an improved drive train, is designated generally by reference 10, and has a stationary bowl 11 which will be provided with a concave liner (not shown) within which a conical head 3 (provided with a mantle not shown) is capable of carrying out gyratory movement. The conical head 3 is mounted on an eccentric 2, which is rotatably mounted on a stationary main shaft 8 such that, upon application of drive to the eccentric 2, the conical head 3 is caused to undergo gyratory movement within the bowl 11.

A main horizontal bevel gear 4 is mounted on the lower end of the eccentric 2, and drive input to the main bevel gear 4 results in rotation of the eccentric 2 about the axis of the main shaft 8.

A drive train to apply drive input to the bevel gear 4 comprises at least two input gears 7, and in the preferred arrangement, as illustrated, two bevel spur gears 7 are arranged at diametrically opposed positions with respect to the axis of the shaft 8. The gears 7 are each driven by a respective hydraulic motor 5 fixed at a bearing carrier 6.

The entire drive assemblies may be removed, eg for maintenance, through apertures (not shown in detail) in the side of the frame of the crusher for maintenance.