Home |
Search |
Today's Posts |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but
I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? Thanks |
#2
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
mark wrote:
I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? Thanks Sounds like a job for opposed angled roller bearings: http://www.mcmaster.com/#ball-and-ro...arings/=5d7yfq --Winston -- Machining can only occur between one Catholic and one Bridgeport. Other people and machines can continue to enjoy their hobby within a Mechanical Partnership but to protect our fine tradition, they must be prevented from actually Machining. To grant them the ability to Machine would ruin this traditional institution for Catholics, Bridgeports and everyone and everything else. Do we think that a Unitarian and her Deckel has any valid claim to the freedom and sanctity of Machining? Of course not! We cannot risk validating this gravely unjust pairing; to recognize it would send the wrong message to our precious youth. Who knows how many young lives have been utterly ruined because of the non-procreative destruction of perfectly acceptable surfaces by non-Catholics using non-Bridgeports? No other form can be considered as an equivalent to this natural relationship between a Catholic and a Bridgeport out of whose love tools are born. Join me to protect the unique social and legal status of Machining for everyone in the 21st century! |
#3
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Wed, 13 Jan 2010 18:42:34 -0800 (PST), mark
wrote: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? Thanks Normal ball bearing pillow block bearings can carry thrust loads. If the thrust is less than 20% of the dynamic load rating of the bearing you probably don't have to worry. If it's more than that you should go thru the procedure in the bearing mfr's catalog to calculate the equivalent load using your anticipated radial and thrust loads. You can get tapered roller bearing pillow blocks, but they're larger and much more expensive. When applying thrust loads to a pillow block you do need to consider the strength of the housing, its mounting, and the means for transferring the thrust between the shaft and bearing. How much load, radial and thrust, are we talking about? -- Ned Simmons |
#4
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Wed, 13 Jan 2010 18:42:34 -0800 (PST), the infamous mark
scrawled the following: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? Thanks Is this loading perpendicular to the shaft? If so, the standard ball bearings in the pillow blocks should handle it easily, if loads are within their normal range. Non-perpendicular loads would require different bearings, maybe tapered rollers like a wheel bearing setup. -- What helps luck is a habit of watching for opportunities, of having a patient, but restless mind, of sacrificing one's ease or vanity, of uniting a love of detail to foresight, and of passing through hard times bravely and cheerfully. -- Charles Victor Cherbuliez |
#5
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Jan 14, 1:44*pm, Larry Jaques
wrote: On Wed, 13 Jan 2010 18:42:34 -0800 (PST), the infamous mark scrawled the following: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? *Thanks Is this loading perpendicular to the shaft? *If so, the standard ball bearings in the pillow blocks should handle it easily, if loads are within their normal range. * Non-perpendicular loads would require different bearings, maybe tapered rollers like a wheel bearing setup. -- What helps luck is a habit of watching for opportunities, of having a patient, but restless mind, of sacrificing one's ease or vanity, of uniting a love of detail to foresight, and of passing through hard times bravely and cheerfully. * * * * * * * * * * * * * * * * -- Charles Victor Cherbuliez I am building an airboat, the prop shaft will be above the engine driven by belts. I was planning on using a 2' long 1.5" shaft supported by 2 1.5" pillow block bearings and then making a hub to mount the prop to on the end of the shaft. The side load of the bearings would come from the prop pushing the shaft. I priced the tapered roller pillow block bearings and they are $350.00 each, not an option. The other idea I thought of was using a 1 piece rear axleshaft from a pick-up as the prop shaft. Make an adapter for the prop to hubface and the tapered rollerbearing on the other side should take the load. Mount the shaft with 2 pillow block bearings. The boat will weigh about 1500lbs and we are using a stock chev 350 at 2500-3000rpm max. |
#6
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Jan 14, 12:37*pm, Ned Simmons wrote:
On Wed, 13 Jan 2010 18:42:34 -0800 (PST), mark wrote: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? *Thanks Normal ball bearing pillow block bearings can carry thrust loads. If the thrust is less than 20% of the dynamic load rating of the bearing you probably don't have to worry. If it's more than that you should go thru the procedure in the bearing mfr's catalog to calculate the equivalent load using your anticipated radial and thrust loads. You can get tapered roller bearing pillow blocks, but they're larger and much more expensive. When applying thrust loads to a pillow block you do need to consider the strength of the housing, its mounting, and the means for transferring the thrust between the shaft and bearing. How much load, radial and thrust, are we talking about? -- Ned Simmons I did some checking and it seems the HC208-24 bearing that these pillow blocks use have a dynamic C load rating of 30000 (N) and a static Co load rating of 20000 (N). What does this mean? |
#7
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Thu, 14 Jan 2010 19:03:03 -0800 (PST), mark
wrote: On Jan 14, 12:37*pm, Ned Simmons wrote: On Wed, 13 Jan 2010 18:42:34 -0800 (PST), mark wrote: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? *Thanks Normal ball bearing pillow block bearings can carry thrust loads. If the thrust is less than 20% of the dynamic load rating of the bearing you probably don't have to worry. If it's more than that you should go thru the procedure in the bearing mfr's catalog to calculate the equivalent load using your anticipated radial and thrust loads. You can get tapered roller bearing pillow blocks, but they're larger and much more expensive. When applying thrust loads to a pillow block you do need to consider the strength of the housing, its mounting, and the means for transferring the thrust between the shaft and bearing. How much load, radial and thrust, are we talking about? -- Ned Simmons I did some checking and it seems the HC208-24 bearing that these pillow blocks use have a dynamic C load rating of 30000 (N) and a static Co load rating of 20000 (N). What does this mean? C is the load that 90% of the bearings in a sample will support for 1 million revolutions before failure. Life and load are linked by an inverse 3rd power relation. In other words, if you reduce the load by half, the life will increase 8 times. (2x2x2=8) Co is the load that will permanently deform the bearing some very small amount. I don't remember the amount off the top of my head. 30000N equals 6700 pounds force. -- Ned Simmons |
#8
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
I for one (and I'm assuming many others here in RCM), would really like to
see some pictures of the project. Thrust bearings can be bought as an assembly, but I've never had a need to find any in the sizes you're needing, so I can't recommend a source. A bearing distributor should be able to help with some recommendations, check your yellow pages to see if there are bearing distributors in your area. Applied Industrial Technologies is a nationwide USA vendor, which I go to locally. http://www.applied.com/site.cfm/bearings_new.cfm There is a Locate Service Centers link at the top of the webpage -- WB .......... metalworking projects www.kwagmire.com/metal_proj.html "mark" wrote in message ... I am building an airboat, the prop shaft will be above the engine driven by belts. I was planning on using a 2' long 1.5" shaft supported by 2 1.5" pillow block bearings and then making a hub to mount the prop to on the end of the shaft. The side load of the bearings would come from the prop pushing the shaft. I priced the tapered roller pillow block bearings and they are $350.00 each, not an option. The other idea I thought of was using a 1 piece rear axleshaft from a pick-up as the prop shaft. Make an adapter for the prop to hubface and the tapered rollerbearing on the other side should take the load. Mount the shaft with 2 pillow block bearings. The boat will weigh about 1500lbs and we are using a stock chev 350 at 2500-3000rpm max. |
#9
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Jan 15, 12:26*am, Ned Simmons wrote:
On Thu, 14 Jan 2010 19:03:03 -0800 (PST), mark wrote: On Jan 14, 12:37*pm, Ned Simmons wrote: On Wed, 13 Jan 2010 18:42:34 -0800 (PST), mark wrote: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? *Thanks Normal ball bearing pillow block bearings can carry thrust loads. If the thrust is less than 20% of the dynamic load rating of the bearing you probably don't have to worry. If it's more than that you should go thru the procedure in the bearing mfr's catalog to calculate the equivalent load using your anticipated radial and thrust loads. You can get tapered roller bearing pillow blocks, but they're larger and much more expensive. When applying thrust loads to a pillow block you do need to consider the strength of the housing, its mounting, and the means for transferring the thrust between the shaft and bearing. How much load, radial and thrust, are we talking about? -- Ned Simmons I did some checking and it seems the HC208-24 bearing that these pillow blocks use have a dynamic C load rating of 30000 (N) and a static Co load rating of 20000 (N). What does this mean? C is the load that 90% of the bearings in a sample will support for 1 million revolutions before failure. Life and load are linked by an inverse 3rd power relation. In other words, if you reduce the load by half, the life will increase 8 times. (2x2x2=8) Co is the load that will permanently deform the bearing some very small amount. I don't remember the amount off the top of my head. 30000N equals 6700 pounds force. -- Ned Simmons- Hide quoted text - - Show quoted text - So if they will handle 6700 lbs of force each then 20% of that as somone above mentioned is acceptable for side load come in at at 2600 lbs side load. That should be fine and I could install a 3rd one for extra strength. |
#10
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
I am building an airboat, the prop shaft will be above the engine driven by belts. I was planning on using a 2' long 1.5" shaft supported by 2 1.5" pillow block bearings and then making a hub to mount the prop to on the end of the shaft. The side load of the bearings would come from the prop pushing the shaft. I priced the tapered roller pillow block bearings and they are $350.00 each, not an option. The other idea I thought of was using a 1 piece rear axleshaft from a pick-up as the prop shaft. Make an adapter for the prop to hubface and the tapered rollerbearing on the other side should take the load. Mount the shaft with 2 pillow block bearings. The boat will weigh about 1500lbs and we are using a stock chev 350 at 2500-3000rpm max. OK so you will have way more thrust load than pillow blocks normally see, but maybe comparable to truck cornering forces, so I like the idea of adapting an axleshaft. But, cornering forces are only intermittent. So I think it might be worth doing some simple design sums. Do you have a prop in mind; if so, presumably you can find out the thrust force at typical revs? Even if you don't have bearing catalogues to hand, post the load and speed here, and someone will help you size your thrust bearing for a given service life. |
#11
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Jan 15, 2:25*am, mark wrote:
On Jan 14, 1:44*pm, Larry Jaques wrote: On Wed, 13 Jan 2010 18:42:34 -0800 (PST), the infamous mark scrawled the following: I want to mount a 2' long 1.5" shaft with 2 pillow block bearings but I would also like to have a thrust bearing because the shaft will have a load from one end. I assume this is not good for the pillow block bearings. How do I go about this. Can you buy off the shelf thrust bearing assemblies the way pillow block bearings are sold? *Thanks Is this loading perpendicular to the shaft? *If so, the standard ball bearings in the pillow blocks should handle it easily, if loads are within their normal range. * Non-perpendicular loads would require different bearings, maybe tapered rollers like a wheel bearing setup. -- What helps luck is a habit of watching for opportunities, of having a patient, but restless mind, of sacrificing one's ease or vanity, of uniting a love of detail to foresight, and of passing through hard times bravely and cheerfully. * * * * * * * * * * * * * * * * -- Charles Victor Cherbuliez I am building an airboat, the prop shaft will be above the engine driven by belts. I was planning on using a 2' long 1.5" shaft supported by 2 *1.5" pillow block bearings and then making a hub to mount the prop to on the end of the shaft. The side load of the bearings would come from the prop pushing the shaft. I priced the tapered roller pillow block bearings and they are $350.00 each, not an option. The other idea I thought of was using a 1 piece rear axleshaft from a pick-up as the prop shaft. Make an adapter for the prop to hubface and the tapered rollerbearing *on the other side should take the load. *Mount the shaft with 2 pillow block bearings. The boat will weigh about 1500lbs and we are using a stock chev 350 at 2500-3000rpm max. Take a look at the W.W. Grainger catalog. Not because it has the best selection of bearings. But because they only stock tapered roller bearings that in common use. And the bearings in common use are less expensive. You might note that they stock 1.375 inch bore, and 1.750 inch bore , but no 1.5 inch bore roller bearings. Dan |
#12
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
On Fri, 15 Jan 2010 05:12:34 -0800 (PST), mark
wrote: So if they will handle 6700 lbs of force each then 20% of that as somone above mentioned is acceptable for side load come in at at 2600 lbs side load. That should be fine and I could install a 3rd one for extra strength. I threw out the 20% figure as a quick and dirty place to start. It's more complicated than that and, now that I see this project involves large objects swinging at high speeds near your head g, I'd urge you to go thru the bearing manufacturer's procedure to calculate the equivalent load for a combined axial and radial load. Once you have the equivalent load you can figure the bearing's predicted life. Do *not* assume that the axial load will be shared by the bearings. Do the calculations assuming that one bearing will carry all the thrust. -- Ned Simmons |
#13
Posted to rec.crafts.metalworking
|
|||
|
|||
thrust bearings
I now have a new idea. Same as above but I will turn down the end of
the shaft (opposite end that the prop is on) from 1.5 to 1.125 and just a bit less than the thickness of a shielded integrated steel ball thrust bearing (mcmaster part # 60715K16) rated at 7000 lbs thrust load. This will be pushing on part of the framework and I was thinking of "bedding the end of the bearing with JB weld or something similar so it will be evenly seated. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Bearings and Thrust Problems... | Metalworking | |||
Looking for Source for small thrust bearings | Metalworking | |||
Kaydon Bearings Ulta slim bearings - cost is prohibitive -Alternative supplier?? | Metalworking | |||
WARNING For Those Using Spaceage Ceramic Thrust Bearings | Woodworking | |||
WARNING for Those Using Spaceage Ceramic Thrust Bearings | Woodturning |