GB1570015A

GB1570015A - Gyratory cone crushers

Info

Publication number: GB1570015A
Application number: GB4284677A
Authority: GB
Original assignee: Brown Lenox and Co Ltd
Current assignee: Brown Lenox and Co Ltd
Priority date: 1978-05-23
Filing date: 1978-05-23
Publication date: 1980-06-25

Description

(54) IMPROVEMENTS IN AND RELATING TO GYRATORY CONE CRUSHERS (71) We, BROWN LENOX & COM PANY LIMITED, a British Company of Pontypridd, Glamorgan, South Wales, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to gyratory cone crushers and in particular to improvements to seals used in such crushers.

Gyratory cone crushers for crushing rock have a gyratory head which is generally mushroom-shaped with an upwardly facing conical grinding surface which co-operates with a further spring-loaded downwardly facing conical grinding surface. The gyratory head has a stem or shaft which is located within an eccentric sleeve and the axis of the stem or main shaft as it is sometimes called is off-centre or eccentric to the main frame of the crusher. The under surface of the generally mushroom-shaped gyratory head has a generally part spherical portion which is supported on a stationary thrust support and the arrangement is such that during operation of the crusher the rotary head will gyrate so that a point on its surface at any time will make small circular movements around a larger circular path.

the said point moving towards and away from the spring-loaded conical surface along a line approximately at right angles thereto to produce the necessary crushing force. In order to retain circulating lubricating oil within the crusher and to prevent the ingress of dust. there must be a seal between the gyratory head and the stationary thrust support. In known crushers a special tyre shaped flexible rubber seal requiring special moulds to produce is used in combination with a secondary seal. The secondary seal is required because there has to be not only relative rotational movement between the gyratory head and its stationary thrust support, but also relative vertical movement.

The relative vertical movement takes place between the vertical face of a seal ring connected to the rubber tyre shaped seal and slidable on a seal ring seat and a holder for the secondary seal. This known sealing arrangement is extremely complex and when it is necessary to replace one or other of the seals, this is a very time-consuming and difficult job because all the various relatively movable parts have to fit together very precisely. To change the seals, the gyratory head has to be completely removed from the crusher and it is sometimes extremely difficult to replace it again after replacement of a seal.

According to the present invention, we provide a gyratory crusher which has a gyratory head having a generally conical crushing surface which co-operates with a further generally conical crushing surface and which is supported for gyratory movement on a stationary thrust support, wherein a seal between the gyratory head and the stationary thrust support is provided by an annular device secured to either the head or the thrust support and bearing under its own inbuilt resiliency against whichever of the gyratory head or thrust support to which it is not connected.

Preferably. a seal ring is mounted on the gyratory head and a seal ring seat is mounted on the stationary thrust support and the seal is connected to one or other of the seal ring or the seal ring seat along one edge so that its opposite edge bears against the other.

Preferably, two such seals are provided, one being connected to the seal ring on the gyratory head along one edge, and having its opposite edge bearing against the seal ring seat on the stationary thrust support, and the other being connected to the seal ring seat along one edge so that its other edge bears against the seal ring.

Preferably, the or each seal is provided by a brush made up of a plurality of selflubricating bristles.

The invention is now described by way of example with reference to the accompanying drawings, in which: Figure 1 is a section through the gyratory head and stationary thrust support and associated parts of a known gyratory cone crusher, and Figure 2 is a scrap section showing a seal between the gyratory head and stationary thrust support in accordance with the invention.

Referring to Figure 1, the crusher includes a gyratory head 22 having an upwardly facing conical crushing surface 182 which co-operates with a downwardly facing crushing surface 183 on a spring-loaded bowl 1. The gyratory head 22 has a part spherical lower surface 3 which is supported upon a matching part spherical upwardly facing surface 5 of a stationary thrust support 34. The gyratory head is supported within an eccentric sleeve 13 by means of a shaft 7, the rotational axis of which is indicated at 9. In order to retain circulating lubricating oil within the crusher and to prevent dust from penetrating into the crusher, a tyre shaped flexible rubber seal 41 is provided between the head 22 and thrust support 34.The seal 41 is manufactured in special moulds and is secured to the thrust support 34 along one edge by means of an annular seal ring seat 35 having an arcuate support surface 36. The opposite edge of the seal 41 is secured to a seal ring 40 which has a support surface slidable on the surface 36. Because of the considerable forces on the surfaces 3 and 5. wear can occur which means that the gyratory head can drop relative to the stationary thrust support 34. To allow for this small vertical movement, and since the surface 36 of the seal ring seat 35 and the surface of the seal ring 40 are in contact and gyrate relative to each other, a vertical sliding contact is required between the seal ring 4U and the gyratory head 22.For this purpose a seal holder 39 is secured to the gyratory head, and an internal vertical surface of the seal holder 39 slides against a vertical surface 42 of the seal ring 40. Because of these two relatively slidable vertical faces. a secondary seal 38 is supported on the seal holder 39 and seals against the surface 42.

The above described seal arrangement is obviously difficult to service and repair because of the many different parts and, what is more, the large tyre shaped seal 41.

because it flexes so much, is liable to rupture. Although it is a fairly simple matter to lift the gyratory head out of its stationary support 34, to replace the seal 41. it is an extremely delicate operation to replace the gyratory head due to the close manufacturing tolerances between the parts 40. 39. 35 and 38. It is because of these disadvantages of the known seal arrangement that the seal arrangement shown in Figure 2 was invented.

Referring to Figure 2, a portion of the gyratory head is indicated by the reference 22 and a portion of the stationary thrust support is indicated at 34. Secured to the gyratory head 22 is a two-piece seal ring 660 and secured to the stationary thrust support 34 is a seal ring seat 651. Instead of being in sliding contact with each other, the sealing surfaces 600 and 601 of these two members are spaced apart. An annular oil seal 680 is secured to the seal ring 660 along one edge, the seal 680 having an inbuilt resilience so that its opposite edge frictionally bears against the sealing surface 601. While this seal might be sufficient to maintain circulating oil within the crusher and prevent dust passing into the crusher, it is preferred that a second seal 681 is secured along one edge to the seal ring seat 651.Because of its inbuilt resiliency, the opposite edge of this annular seal bears frictionally against the surface 660 and in practice the arrangement is that the seal 680 keeps the oil within the crusher, whereas the seal 681 prevents ingress of dust.

The seals 680 and 681 are both of the same construction and, as illustrated, are in the form of annular brushes made up of a plurality of self-lubricating bristles. The edges of the seals connected to the parts 660 and 651 respectively are supported in holders 686 and 685 which may be bolted to the parts 660 and 651 respectively, and the holders may have a re-entrant U-shaped portion to receive a beading, e.g. of metal or plastics, holding together the ends of the bristles making up the brush. Although brush type seals are preferred, it is envisaged that ordinary rubber. leather, plastic or felt type seals could be used.

As the seal ring 660 is secured to the gyratory head 22, a secondary seal such as the seal 38 in the known construction is not required.

Furthermore, because faces 600 and 601 are not in contact, this means that greater manufacturing tolerances can be permitted as the seals 680 and 681 take up any discrepancies. Furthermore, the seals can accommodate any vertical downward movement of the gyratory head as wear takes place on the stationary thrust support (sometimes known as a thrust bowl).

Although the seal ring 660 is shown as having been manufactured in two parts welded together. it is envisaged that it could be cast in one piece.

WHAT WE CLAIM IS: 1. A gyratory crusher which has a gyra

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Preferably, the or each seal is provided by a brush made up of a plurality of selflubricating bristles. The invention is now described by way of example with reference to the accompanying drawings, in which: Figure 1 is a section through the gyratory head and stationary thrust support and associated parts of a known gyratory cone crusher, and Figure 2 is a scrap section showing a seal between the gyratory head and stationary thrust support in accordance with the invention. Referring to Figure 1, the crusher includes a gyratory head 22 having an upwardly facing conical crushing surface 182 which co-operates with a downwardly facing crushing surface 183 on a spring-loaded bowl 1. The gyratory head 22 has a part spherical lower surface 3 which is supported upon a matching part spherical upwardly facing surface 5 of a stationary thrust support 34. The gyratory head is supported within an eccentric sleeve 13 by means of a shaft 7, the rotational axis of which is indicated at 9. In order to retain circulating lubricating oil within the crusher and to prevent dust from penetrating into the crusher, a tyre shaped flexible rubber seal 41 is provided between the head 22 and thrust support 34.The seal 41 is manufactured in special moulds and is secured to the thrust support 34 along one edge by means of an annular seal ring seat 35 having an arcuate support surface 36. The opposite edge of the seal 41 is secured to a seal ring 40 which has a support surface slidable on the surface 36. Because of the considerable forces on the surfaces 3 and 5. wear can occur which means that the gyratory head can drop relative to the stationary thrust support 34. To allow for this small vertical movement, and since the surface 36 of the seal ring seat 35 and the surface of the seal ring 40 are in contact and gyrate relative to each other, a vertical sliding contact is required between the seal ring 4U and the gyratory head 22.For this purpose a seal holder 39 is secured to the gyratory head, and an internal vertical surface of the seal holder 39 slides against a vertical surface 42 of the seal ring 40. Because of these two relatively slidable vertical faces. a secondary seal 38 is supported on the seal holder 39 and seals against the surface 42. The above described seal arrangement is obviously difficult to service and repair because of the many different parts and, what is more, the large tyre shaped seal 41. because it flexes so much, is liable to rupture. Although it is a fairly simple matter to lift the gyratory head out of its stationary support 34, to replace the seal 41. it is an extremely delicate operation to replace the gyratory head due to the close manufacturing tolerances between the parts 40. 39. 35 and 38. It is because of these disadvantages of the known seal arrangement that the seal arrangement shown in Figure 2 was invented. Referring to Figure 2, a portion of the gyratory head is indicated by the reference 22 and a portion of the stationary thrust support is indicated at 34. Secured to the gyratory head 22 is a two-piece seal ring 660 and secured to the stationary thrust support 34 is a seal ring seat 651. Instead of being in sliding contact with each other, the sealing surfaces 600 and 601 of these two members are spaced apart. An annular oil seal 680 is secured to the seal ring 660 along one edge, the seal 680 having an inbuilt resilience so that its opposite edge frictionally bears against the sealing surface 601. While this seal might be sufficient to maintain circulating oil within the crusher and prevent dust passing into the crusher, it is preferred that a second seal 681 is secured along one edge to the seal ring seat 651.Because of its inbuilt resiliency, the opposite edge of this annular seal bears frictionally against the surface 660 and in practice the arrangement is that the seal 680 keeps the oil within the crusher, whereas the seal 681 prevents ingress of dust. The seals 680 and 681 are both of the same construction and, as illustrated, are in the form of annular brushes made up of a plurality of self-lubricating bristles. The edges of the seals connected to the parts 660 and 651 respectively are supported in holders 686 and 685 which may be bolted to the parts 660 and 651 respectively, and the holders may have a re-entrant U-shaped portion to receive a beading, e.g. of metal or plastics, holding together the ends of the bristles making up the brush. Although brush type seals are preferred, it is envisaged that ordinary rubber. leather, plastic or felt type seals could be used. As the seal ring 660 is secured to the gyratory head 22, a secondary seal such as the seal 38 in the known construction is not required. Furthermore, because faces 600 and 601 are not in contact, this means that greater manufacturing tolerances can be permitted as the seals 680 and 681 take up any discrepancies. Furthermore, the seals can accommodate any vertical downward movement of the gyratory head as wear takes place on the stationary thrust support (sometimes known as a thrust bowl). Although the seal ring 660 is shown as having been manufactured in two parts welded together. it is envisaged that it could be cast in one piece. WHAT WE CLAIM IS:

1. A gyratory crusher which has a gyra

tory head having a generally conical crushing surface which co-operates with a further generally conical crushing surface and which is supported for gyratory movement on a stationary thrust support, wherein a seal between the gyratory head and the stationary thrust support is provided by an annular device secured to either the head or the thrust support and bearing under its own inbuilt resiliency against whichever of the gyratory head or thrust support to which it is not connected.

2. A gyratory crusher as claimed in claim 1 wherein a seal ring is mounted on the gyratory head and a seal ring seat is mounted on the stationary thrust support and wherein the seal connected to one or the other of the seal ring and the seal ring seat along one edge so that its opposite edge bears against the one of the seal ring and seal ring seat to which it is not connected.

3. A gyratory crusher as claimed in claim 2 wherein two seals are provided, one being connected to the seal ring along one edge and having its opposite edge bearing against the seal ring seat and the other being connected to the seal ring seat along one edge so that its other edge bears against the seal ring.

4. A gyratory crusher as claimed in claim 1, 2 or 3 wherein the or each seal is provided by a brush.

5. A gyratory crusher as claimed in claim 5 in which the brush is made up of a plurality of self-lubricating bristles.

6. A gyratory crusher substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.