Bloodhound LSR Thread As Requested...

Bloodhound LSR Thread As Requested...

Author
Discussion

Greg_D

6,542 posts

246 months

Thursday 19th February 2015
quotequote all
Ha, gotcha

I've finally seen a zip tie!!!!

I can now continue to say that all the best race vehicles are held together with zip ties and duck tape

please provide a picture of some duck tape on the vehicle by return!!! biggrin

Storer

5,024 posts

215 months

Thursday 19th February 2015
quotequote all
That is one hell of a stand!

Was it a bridge in a previous life......



Paul

PS.
I am booked to come and have a look around a little later in the year. Can't wait.

IN51GHT

Original Poster:

8,779 posts

210 months

Friday 20th February 2015
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As it's Friday morning & people may need a little cheering up at the end of a long week I'm just going to leave this here for now.


yorkieboy

1,845 posts

175 months

Friday 20th February 2015
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OOOOOOOOOOOOOOFFFFFFFFFFFFFFFFFFFFFFFFFFFF Damn sexy sound 'tis that!!

Hooli

32,278 posts

200 months

Friday 20th February 2015
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IN51GHT said:
Baron Greenback said:
Great news but how far does the water go when pointing straight up!?
I'd love to know that too.

ETA....

I've asked the team in Newquay the question, head of systems says I'm a tw@t, but then added "doesn't mean we won't try it though".........
We they are there for testing & it's an important test hehe

160

239 posts

145 months

Monday 23rd February 2015
quotequote all
IN51GHT said:
Baron Greenback said:
Great news but how far does the water go when pointing straight up!?
I'd love to know that too.

ETA....

I've asked the team in Newquay the question, head of systems says I'm a tw@t, but then added "doesn't mean we won't try it though".........


Edited by IN51GHT on Tuesday 17th February 14:37
any luck, how high did it go?

IN51GHT

Original Poster:

8,779 posts

210 months

Tuesday 24th February 2015
quotequote all
Pump back & stripped down, all not happy in the rear bearing. We think the damage to the bearing is caused by the end float in the output of the road car gearbox we are using as an interim way to drive the pump. This is not a part that will be on the car.

We plan to test with the proper car gearbox on the rig to prove this theory.









anonymous-user

54 months

Tuesday 24th February 2015
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How does end float in the shaft cause bearing failure in the pump? Or do you mean a lack of end float means gear axial loads are being transferred to the pump bearing? Presumably the pump runs back to back axial contact bearings to offset the impeller axial loadings? Something like a pair of CV joints back to back would decouple the two parts and allow for mounting misalignment, thermal movement etc?


(also, 10.5krpm on a bearing that size must be getting close to the CF limits, so perhaps you need more preload to avoid rolling element scuffing/slip?)

Edited by anonymous-user on Tuesday 24th February 10:54

IN51GHT

Original Poster:

8,779 posts

210 months

Tuesday 24th February 2015
quotequote all
The gearbox loads are getting transferred into the pump,also the way the pump is mounted means there can be a small amount of rocking between the gearbox & we didn't envisage it being a problem.

Scuffers

20,887 posts

274 months

Tuesday 24th February 2015
quotequote all
IN51GHT said:
The gearbox loads are getting transferred into the pump,also the way the pump is mounted means there can be a small amount of rocking between the gearbox & we didn't envisage it being a problem.
are you not looking to put a coupler (or the like) in the drivetrain?

you're always going to have some axial loads (and thus movement) to deal with, the pump itself will have significant axial loading.

IN51GHT

Original Poster:

8,779 posts

210 months

Tuesday 24th February 2015
quotequote all
Scuffers said:
are you not looking to put a coupler (or the like) in the drivetrain?

you're always going to have some axial loads (and thus movement) to deal with, the pump itself will have significant axial loading.
No, because on the car installation we have a sliding spline to effectively decouple any axial load.

Scuffers

20,887 posts

274 months

Tuesday 24th February 2015
quotequote all
IN51GHT said:
No, because on the car installation we have a sliding spline to effectively decouple any axial load.
OK, but surely that's going to bind-up under torque loads? (much like old sliding spline driveshafts do).

McWigglebum4th

32,414 posts

204 months

Tuesday 24th February 2015
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If you pull the bearing and send the dead bits to SKF they should have experts who could read the failure.

Before you pull it ensure you mark it so you know which way round it is.

SKF condition monitoring in Aberdeen has a guy from Zimbabwe who was a genius at it but i have no idea what his name is


Also the pump impeller didn't look hydraulically balanced so it would be pulling towards the suction. but i guess your pump designers would know this.

anonymous-user

54 months

Tuesday 24th February 2015
quotequote all
McWigglebum4th said:
If you pull the bearing and send the dead bits to SKF they should have experts who could read the failure.

Before you pull it ensure you mark it so you know which way round it is.

SKF condition monitoring in Aberdeen has a guy from Zimbabwe who was a genius at it but i have no idea what his name is


Also the pump impeller didn't look hydraulically balanced so it would be pulling towards the suction. but i guess your pump designers would know this.
ime, it's pretty difficult to establish the pressure distribution across the "back" side of a fixed flow centrifugal impeller, as tiny clearance differences make big differences in pressure loadings etc.


The interesting thing about those pics of the damaged bearings is that they don't show significant overheating (little/no dis-colouration), which you might expect, although the pump housing is obviously well cooled by the pumped media (water for these tests). That's why i wondered about rolling element slip due to CF forces. Once you get a single element in the race to slide, then it rapidly wears and the loadings are shared around the remaining elements, which wear one at a time in short succession. I'm sure whoever designed this pump has done best practice on the bearing solution though!

IN51GHT

Original Poster:

8,779 posts

210 months

Tuesday 24th February 2015
quotequote all
McWigglebum4th said:
Also the pump impeller didn't look hydraulically balanced so it would be pulling towards the suction. but i guess your pump designers would know this.
Yes I do!!!!

McWigglebum4th

32,414 posts

204 months

Tuesday 24th February 2015
quotequote all
Max_Torque said:
The interesting thing about those pics of the damaged bearings is that they don't show significant overheating (little/no dis-colouration), which you might expect, although the pump housing is obviously well cooled by the pumped media (water for these tests). That's why i wondered about rolling element slip due to CF forces. Once you get a single element in the race to slide, then it rapidly wears and the loadings are shared around the remaining elements, which wear one at a time in short succession. I'm sure whoever designed this pump has done best practice on the bearing solution though!
Yep looking again there is no sign of cooking as nothing is blue

Can jag tell you how much load comes out of the end of the gearbox?


robinessex

11,059 posts

181 months

Tuesday 24th February 2015
quotequote all
Did you have the pump input shaft strain gauged up as a load cell, and monitor the loading(s)? I've seen a similar bearing failure on a ball bearing that couldn't take the axial load being applied. Is the aluminium housing scrap now ?

anonymous-user

54 months

Tuesday 24th February 2015
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Nice to see the Bloodhound team gathering another award!

(Semta Engineering Hall of Fame investee is Mark Chapman ;-)

IN51GHT

Original Poster:

8,779 posts

210 months

Wednesday 25th February 2015
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Tufty started cutting the access hole in the Ti upper chassis skins this week

IN51GHT

Original Poster:

8,779 posts

210 months

Monday 2nd March 2015
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Starting to fit front bodywork.....