GB2153018A

GB2153018A - Rotary drum with grease lubricating apparatus

Info

Publication number: GB2153018A
Application number: GB08401122A
Authority: GB
Inventors: Per Birch
Original assignee: FLSmidth and Co AS
Current assignee: FLSmidth and Co AS
Priority date: 1984-01-17
Filing date: 1984-01-17
Publication date: 1985-08-14
Also published as: GB8401122D0

Abstract

The drive gearing (2,3) of a rotary drum, such as a kiln (1), is spray lubricated by two separate lubrication circuits with nozzles (12,22), which are operated independently. The two sets of nozzles are directed at the same zone (7) and are fed with compressed air and grease via respective air pipes (13,23) and lubricant pipes (14,24). A central control unit (9. Fig.2) monitors and controls the operation of the separate lubrication circuits. <IMAGE>

Description

SPECIFICATION Rotary drum with grease lubricating apparatus The invention relates to apparatus for automatically grease lubricating drive gearing of a rotary drum, particularly the pinion and gear rim of a rotary kiln or tube mill.

It is known, for instance from the disclosures in the monthly publication ZEMENT-KALK-GIPS, Nos. 5 and 12, 1980 (Volume 33) to use a spray lubricating apparatus for grease lubrication of the pinion and gear rim of a rotary drum. Such an apparatus often comprises one or more nozzles, dependent on the width of the pinion and gear rim, the nozzle or nozzles being directed against the pressure flank of the teeth of either the pinion or the gear rim.

Such spray lubricating apparatus usually function in spray cycles durng which each nozzle receives a lubricant dose according to the immediate lubricating requirements, which dose is forced out as a spray through the nozzle by compressed air, the dose being suspended in the air flow, whereafter the nozzle receives a fresh lubricant dose for the next cycle.

During normal operation, for instance of a rotary kiln, i.e. the kiln is rotating continuously, the lubricating apparatus may be preset to give e.g. a number of short lasting sprays (i.e. < 2 secs.) at short intervals (i.e. < 10 secs.) followed by a longer lasting pause of say 10 minutes before a new spray cycle is initiated. The number of lubricating sprays from a nozzle and the length of the intervals between the sprays and of the pauses between the cycles are preset so as to ensure that the entire pinion and gear rim are lubricated sufficiently and without overdosing during the operation of the kiln.

However, such a periodic spraying does not provide for a sufficient and complete lubrication of the pinion and the gear rim during barring of the kiln where the kiln is only barred a part of a full rotation with a longer lasting, intervening pause, say 45 minutes, before the next part of a rotation is made, e.g. in connection with heating during kiln start-up or cooling during kiln stoppage. Under such circumstances the known lubricating apparatus, during the lubricating cycle, cannot guarantee the lubrication of each pressure flank owing to the fact that a certain minimum span of time is necessary for the loading of the apparatus with lubricant before the next cycle. During this span of time one or more teeth may have passed the lubrication zone without receiving any lubricant.This may entail risk of damage to the teeth of the pinion and gear rim which are both often exposed to very heavy loads, as the kiln, during such operations, tends to warp.

In case of failure of a spray lubricating apparatus and a subsequent longer lasting cessation of the lubrication of the kiln, the rotation of the kiln has to be interrupted to avoid damage to the gearing teeth. This may entail undesired interruption of the kiln production, and also risk of damage to the kiln lining caused by uneven cooling of the kiln shell.

It is therefore the object of the invention to reduce or eliminate the above drawbacks of the known spray lubricating apparatus.

According to the invention a rotary drum has drive gearing and spray lubricating apparatus for automatically grease lubricating the gearing, the spray lubricating apparatus being characterised by at least two separate sets of spray nozzles, each set being connected to its separate lubricating circuit and covering the same lubrication zone of the gearing, and a control unit for controlling and monitoring operation of the different lubricating circuits.

During barring and start-up the spray lubricating circuits may be utilised in such a way that the lubrication is made continuously by successively spraying of lubricant from the different lubricating circuits. Thus ensuring that all teeth of, e.g. the pinion and the gear rim, are lubricated evenly and sufficiently even during a partial kiln rotation.

Thus, the lubricating apparatus may include means which ensure that the pressure flank of each single tooth of the gearing is lubricated in succession during any rotation of the drum.

During normal kiln operation where periodic spraying by only one set of nozzles is satisfactory, as mentioned above, the lubrication may advantageously be performed by a preset number of sprays from the one lubricating circuit succeeded by at least one spray from the other lubricating circuit.

There is thus achieved the desired efficient lubrication, without overdosing of lubricant, and simultaneously a constant check of the operability of both lubricating circuits so that without changing the lubricating pattern and the amount of lubricant one of the lubricating circuits may always be ready for taking over the entire lubricating function should the other lubricating circuit fail.

By means of the control unit controlling the two or more lubricating circuits, there is achieved both the desired alternating operation, and that one of the lubricating circuits instantaneously and automatically can replace the other circuit if necessary.

The apparatus may, in known manner, produce a longer lasting spray of a length of 4 seconds or more per cycle which ensures that the lubrication zone is completely covered by evenly distributed lubricant.

The control unit may be provided in known manner with means for giving an alarm if one of the lubricating circuits fails for some reason, and the use of at least two lubricating circuits renders superfluous a permanent control of the lubricating apparatus by the operating personnel.

To secure the reliability of the entire spray lubricating apparatus, it is expedient that each lubricating circuit has its own lubricant source thus ensuring that it is possible during kiln operation in a simple way to supply the lubricant. This may be of particular importance when using new gearing, when etching or abrasive means are added to the lubricant during the running in operation of the teeth, and which means may only be used for a short span of time for etching or abrasing the teeth.

The invention is explained in more detail by means of an example of a spray lubricating apparatus, illustrated diagrammatically in the accompanying drawings, in which: Figure 1 is a side view of a drive gearing of a rotary kiln; and, Figure 2 shows an apparatus for lubricating the gearing of Figure 1.

On the outside of the kiln shell 1 of a rotary kiln is mounted a gear rim 2 which is engaged by a pinion 3 to rotate the kiln. The pinion 3 is mounted in bearings on brackets 4 and driven by a motor (not shown) by means of a shaft 5.

On a frame 6 are mounted two sets of spray lubricating nozzles 11, 12 and 21, 22, mounted at substantially the same distance from and directed at the same lubrication zone 7 on the pinion 3.

The two sets of nozzles are in known manner fed with compressed air and lubricating via their separate sets of air pipes 13 and 23 and lubricant pipes 14 and 24.

The supply of air and lubrication respectively to the first set of nozzles 11, 12 is, via a control panel 15, fed with compressed air from an air pipe 16 and lubricant from a lubricant pipe 17, while the supply of compressed air and lubricant to the other set of nozzles 21, 22, via a control panel 25, is fed through air pipe 26 and lubricant pipe 27.

The two sets of pipes 16 and 26 are connected to a common compressed air source (not shown) by means of a common air pipe 8. The lubricant pipe 17 of the first spray lubricating circuit 11-15 is, via a pump 18, connected to a lubricant container 19 while the lubricant pipe 27 of the second spray lubricating circuit 21-25 is connected, via a pump 28, to a second lubricant container 29.

A control unit 9 (Figure 2) monitors and controls, via connections 20 and 30, the mutual alternating operation of the two control panels 15 and 25 and the nozzles 11, 12, 21 and 22 connected thereto.

The control unit 9 further monitors and controls, via connections 31 and 32, the pumps 18 and 28 and also the lubricant level in each of the containers 19 and 29.

During barring of the kiln, calling for a lubrication of each tooth flank of the pinion 3, because of the above mentioned heavy and uneven, loads on the teeth flanks of the pinion, the control unit 9 controls the two periodically and alternatingly operating spray lubrication circuits 11-19 and 21-29 in such a way that the two sets of nozzles together lubricate continuously.

As previously explained, the hitherto known lubricating apparatus is not able to provide for continuous lubrication, which means that when the pressure flank of say the tooth 33 (Figure 1) is lubricated the lubricating cycle does not guarantee the lubrication of the next tooth 34 passing the lubricating zone. The illustrated apparatus in accordance with the invention guarantees continuous lubrication of all the teeth 33, 34, and 35 etc. in succession.

During normal kiln operation, for which a periodc spraying is satisfatory for sufficient lubrication, the control unit 9 controls the two sprays lubricating circuits to the effect that one of the lubricating circuits sprays e.g. eight times in series while the other lubricating circuit sprays only once whereafter there is a pause before the next spray cycle starts. It is thus possible to check whether both lubricating circuits are constantly operational.

The fact that the two circuits do not provide for the same number of sprays entails that the life of one of the lubricating circuits may be significantly longer than that of the other circuit whereby the probability of both circuits being worn down to the same degree, and failing at the same time, is reduced. Thus, a worn circuit can be replaced while the other is operating intact.

The control unit 9 may be provided with suitable alarm systems to indicate interruptions in operation in one of the spray lubricating circuits.

Claims

1. A rotary drum having drive gearing and spray lubricating apparatus for automatically grease lubricating the gearing, the spray lubricating apparatus being characterised by at least two separate sets of spray nozzles, each set being connected to its separate lubricating circuit and covering the same lubrication zone of the gearing, and a control unit for controlling and monitoring operation of the different lubricating circuits.

2. A drum according to claim 1, wherein the lubricating apparatus includes means which ensure that the pressure flank of each single tooth of the gearing is lubricated in succession during any rotation of the drum.

3. A drum according to claim 1 or 2, characterised in that each lubricating circuit has its own lubricant source.

4. A rotary drum with associated drive gearing and spray lubricating apparatus for the gearing, substantially as described with reference to the accompanying drawings.