Views: 53 Author: Site Editor Publish Time: 2018-06-05 Origin: www.fuchun-casting.com
Do you know how long any hydraulic pump should last? In this industry, using past experience might not always deliver the answers you were hoping for, and are likely to give you answers that are actually no better than guessing.
Disappointingly, there is no dependable approach to determine how long your hydraulic pump will last. Using historical data is perhaps something that will give you the best indicator, but if it’s a new pump and you have no data – that’s where the guessing game beings. Fortunately, there are a number of factors that determine how long any pump will last and using these can give you an estimate that is more informed.
For example, let’s consider your hydraulic system. The type of application it is will make a different to the pump life and so will the temperature. Using pumps that are graded as ‘industrial grade’ will deliver a better lifespan than those that are not. Using auxiliary information can also help. For example, an axial piston design pump has less heavily loaded shaft bearings and therefore are not at a great risk of premature failure.
Of course, roller type bearings in this type of piston design can fail prematurely due to brinelling. That’s why it’s better to use shell-type bearings as they are more like a bushing than a bearing.
Another major consideration is the type and grade of oil being used. If it’s ‘special purpose’ and is fire resistant then it won’t always have a positive influence on the service life. However, it will run cool which could help with its lifespan as there will be less temperature related lubrication issues.
Keeping a high level of oil cleanliness will also work well in extending the life of any hydraulic component.
Another point to ponder is how hard the pump is working. This is about how fast it’s spinning and under what pressure –how much of each hour is the pump under load? If they are under load for 55 minutes of every hour, then that’s going to be a 90% duty cycle, which is a lot to maintain compared to being under load for say 42 minutes of every hour. Under ideal conditions such as a duty cycle of 70% or less, 1200 rpm spinning with clean oil, you can hope an industrial grade hydraulic pump would last 20,000 hours or more. However, if you’ve got a 90% load with special purpose oil and 1800 rpm then you are more likely to get something in the arena of 10,000 hours of service life.
There’s no doubt that these are only informed estimates using the information that we have about the pump and how it’s being used. Of course, if there are any hidden design flaws then the lifespan of the pump could be drastically compromised. For example, if there are pressure spikes that are caused by rapid valve shifts, then over time this could lead to a pump failure.
To continue to run a hydraulic pump until it fails is not a good idea. Its failure could cause consequential damage to other components. The cost of the rebuild of the pump will increase. Changing a pump before its life expires should be managed, whilst historical data is collected.
So if it’s looking like 20,000 hours is a strong lifespan possibility for any pump, then it’s wise to pull it out at 12,000 hours. It can be inspected and put back into service until say 15,000 hours. Then run to 17,500 hours and if all is well, then run until 20,000 hours. Getting too greedy will put the pump into the correct timeframe for a failure, so it’s not wise to push it too far.
Using this approach can provide information to make informed decisions on realistic expectations for component lifespan without putting the hydraulic system at great risk.