GB2032703A - Rotary drum device - Google Patents

Abstract

A rotary drum device comprises a drum assembly including a drum 1, a motor 12, 13 within the drum and gearing 32, 41-43 which is within and which is drivably connected to the drum, the drive also including a fluid clutch 18 external to the drum. A fixed member 4 carries the stator 12, and the rotor 13 drives a hollow shaft 17 connected to clutch member 19. The driven clutch member 21 drives an inner shaft 22 carrying a first gear element, a sun pinion 31. This, together with ring gear 32, acts to drive a planet gear 34 whose rotating carrier 35 carries a pinion 41. This pinion 41 engages idler gear 42 which drives the drum. A brake comprises a disc 46 engaged by spring-loaded pads 48, the brake being released by fluid in tube 52. <IMAGE>

Description

SPECIFICATION Rotary drum device This invention relates to a rotary drum device.

Such a rotary drum device may be used, for example, for driving a belt conveyor. When so used the external surface of the drum of the device transmits a driving force to a conveyor belt by means of friction. It may also be used, by way of further example, for driving a scraper chain conveyor and, when so used, the external surface of the drum will be provided with chain-engaging teeth.

Such a drum is customarily driven by a motor through gearing.

In order to cater for the starting characteristics of a conveyor driven by such a rotary drum device, it is desirable gradually to accelerate the device to its full running speed. To that end a clutch has been interposed between the motor and the gearing. The motor, the clutch and the gearing have all been external of the drum.

A drum with its external motor, clutch and gearing occupy a large amount of space, and the space in a coal mine where such a device is located is at a premium.

It is an object of this invention to provide a more compact rotary drum device.

A rotary drum device in accordance with the invention comprises a drum assembly including a drum, a motor within the drum, and gearing within, and drivably connected to, the drum, a clutch, a first shaft extending from the motor through an end of the drum assembly to the clutch, and a second shaft extending from the clutch through that end of the drum assembly to the gearing, the drum, the first shaft and the second shaft being substantially coaxial.

Where the rotary drum device is used with a conveyor in which the conveying run is inclined, it may have a shaft, preferably, but not necessarily, coaxial with the first and second shafts, extending beyond the other end of the drum assembly to connect the gearing to a brake external to the drum assembly. This shaft and the second shaft can be one and the same shaft.

The rotary drum device is more compact than previous devices and yet the clutch, which may require frequent attention, in contrast to that needed by the motor and the gearing, is readily accessible at all times.

A rotary drum device in accordance with one embodiment of the invention will now be described, by way of example, with reference to the accompanying cross-sectional drawing.

Referring to the drawing, the driving surface is formed by the exterior of a drum 1.

The drum is supported for rotation by main brackets 2 and 3 which will be mounted, in use, on a fixed member, not shown. The bracket 2 carries a hollow fixed support 4 of cylindrical shape, fitting mainly within the drum 1 and having a hollow cylindrical extension 5 of smaller diameter by which bracket 2 is connected to the support 4. The extension 5 carries a roller bearing 6, on which an end wall 7 of the drum 1 is rotatably mounted.

The bracket 3 carries a cylindrical extension 8 having a roller bearing 9 for the other end wall 11 of the drum 1.

Internally of the support 4 the stator 1 2 of an electric induction motor is fixed. Within the stator a rotor 1 3 is rotatably mounted by means of bearings 14, such bearings being carried by end walls 1 5 and 1 6 of the support 4.

The end wall 1 6 is secured to the extension 5. The rotor 1 3 drives a first shaft 1 7 which is tubular and which extends through the end 7 of the drum 1.

Within the bracket 2, extension 5 and end wall 1 6 a passage 25 is provided for electrical conductors connected to the stator 1 2 of the electric motor.

On the side of the bracket 2 remote from the drum 1 a clutch 1 8 is located, this being external to the drum. The clutch 1 8 is of the hydro-dynamic kind and has two rotary members 19 and 21. The rotary member 19 encloses the member 21, and in the conventional way rotation of the member 1 9 will cause rotation of the member 21 but with a degree of relative slip, depending on the speed of rotation and the applied torque. The member 1 9 is carried at the end of the shaft 17, whilst the member 21 is connected to a second shaft 22 which extends back through the end 7 of the drum 1 and rotor 13, its opposite end terminating in a head 23 located for rotation by bearing 24 in the end wall 1 5.

The drum, the first shaft and the second shaft are substantially coaxial.

A splined socket 26 is formed in head 23 to receive the splined end 27 of a shaft 28 substantially coaxial with the drum axis. Shaft 28 extends through a bearing 29 within cylindrical extension 8 from bracket 3. Shaft 28 has a pinion 31 formed thereon which forms the sun pinion of an epicyclic reduction gear 32. This reduction gear includes a ring gear 33, a planet pinion 34 and a planet carrier 35. The planet carrier has a stub shaft 36 on which the planet pinion 34 is mounted. The planet carrier itself is supported for rotation by a bearing 37 within the extension 8 and a bearing 38 on the shaft 28. Although only one planet pinion 34 has been shown it will be appreciated that a plurality of planet pinions 34 may be provided on the carrier 35 in the conventional way.The ring gear 33 is securely fixed by means of an end wall 39 to the cylindrical extension 8, whereby rotation of the pinion 31 will produce rotation at reduced speed of the planet carrier 35.

The planet carrier 35 is connected to a second sun pinion 41 which surrounds shaft 28. The pinion 41 engages an idler gear 42 which, in turn, engages within a ring gear 43 secured internally to the drum 1. The idler gear 42 is rotatably mounted on a stub shaft 44 secured to the fixed support 4. A plurality of such idler gears 42 may be secured around the sun pinion 41 to stub shafts 44 extending from the fixed support 4. Rotation of sun pinion 41 will cause rotation of ring gear 43 and drum 1 at a reduced speed.

If the rotary drum device is to be used with a conveyor in which the conveying run is inclined it may be desirable to use a brake to prevent "run-back" of the conveyor when the drum is not being rotated. To that end, a brake 45 is mounted on the bracket 3. This brake comprises a disc 46, carried by a shaft which in this embodiment is an extension of the shaft 28, fixed friction pads 47 and moving friction pads 48. The pads 48 are carried by a member 49 urged by springs (only one of which is shown) 51 so that these pads press against disc 46 urging it against the pads 47 to lock the disc and shaft 28 against rotation.For the purpose of releasing the brake a flexible tube 52 is provided which, when supplied with hydraulic liquid under pressure, will move the member 49 away from disc 46, thereby compressing springs 51 and releasing the brake so that disc 46 and shaft 28 may rotate.

For operation, electric power is supplied to the stator 1 2 to cause rotation of the rotor 1 3. Initially, rotor 1 3 will rotate clutch member 1 9 which, on attainment of a predetermined speed, will start to apply driving torque to clutch member 21, such torque being transmitted through shaft 22 and shaft 28 to the pinion 31. Pinion 31 in rotation will carry the planet pinion 34 around on its carrier 35, thus causing rotation of the pinion 41. Rotation of carrier 35 results from the fact that the ring gear 33 is fixed against rotation. Rotation of pinion 41 will cause rotation of the idler gear 42 which, in turn, will transmit rotational drive to ring gear 43 and drum 1.In order to brake the drum the hydraulic pressure is removed from the flexible tube 52 allowing springs 51 to cause pads 47 and 48 to grip disc 46, thus locking the pinion 31 against rotation and preventing the drum from rotating.

Whilst the drum, the motor and the reduction gear form a compact drum assembly, the clutch 1 8 is external to the drum assembly so that servicing easily may be carried out. The brake 45 is also external to the drum assembly and again easily may be serviced.

In order to provide liquid cooling in the interior of the drum, a cooling device 53 may be provided within the drum which is fed with water or other liquid through passage 54 passing through the extension 8. The device 53 may be located in any position or positions, where generation of heat may occur.

In another embodiment, not illustrated, the diameter of the extension 5 (shown in the drawing) is substantially the same as the diameter of the support 4 and the bearing 6 is of much greater diameter.

In yet another embodiment, not illustrated, the diameter of the extension 8 (shown in the drawing) is substantially the same as the diameter of the support 4 and the bearing 9 is of much greater diameter.

Claims (9)

1. A rotary drum device comprising a drum assembly which includes a drum, a motor within the drum, and gearing within, and drivably connected to, the drum, a clutch, a first shaft extending from the motor through an end of the drum assembly to the clutch, and a second shaft extending from the clutch through that end of the drum assembly to the gearing, the drum, the first shaft and the second shaft being substantially coaxial.

2. A device as claimed in Claim 1, wherein a third shaft is provided substantially coaxial with said first and said second shafts and extending beyond the other end of said drum assembly to connect said gearing to a brake disposed externally of the drum assembly.

3. A device as claimed in either Claim 1 or Claim 2, wherein said clutch is of the hydrodynamic kind.

4. A device as claimed in any one of the preceding claims, wherein said gearing is of speed-reduction type.

5. A device as claimed in Claim 4, wherein said gearing includes a sun pinion, which is in mesh with at least one planet pinion supported upon a planet carrier rotatable with respect to first fixed structure, part of which is disposed within said drum, and a further pinion, carried by said planet carrier, which is in mesh with at least one idler gear mounted upon a support which is fast with respect to further fixed structure.

6. A device as claimed in Claim 5, wherein the or each planet pinion is in mesh with a first ring gear which is fast with respect to said first fixed structure, and the or each idler gear is in mesh with a further ring gear which is secured internally to said drum.

7. A device as claimed in any one of the preceding claims, wherein said motor is an electric motor.

8. A device as claimed in Claim 7 when dependent upon either Claim 5 or Claim 6, wherein said support is hollow and houses the stator and the rotor of said electric motor, the stator being fast with a wall of said support, and the rotor being carried by said first shaft.

9. A rotary drum device substantially as hereinbefore described with reference to the accompanying drawing.