Housing FEA analysis

[Stressanalyst87]

thread727-250309

Experts,

I have some doubts in doing a FEA analysis of housing with bevel gears.I hav taken the housing along with gears n bearings and applied the resulting radial loads on the bearings as two components one as the horizontal and the other vertical and the axial load of the bevel gear directly on the housing.I have 2 bearings each on the bevel gear.I am facing diffuclty in judgin the horizontal and vertical radial reaction directions which need to b applied on the bearings.(Note this radial reactions r got from some program).I hav attached a picture for reference. My doubt is whether the bearing reaction at location 2 & 3 will be in same or opposite reaction. My guess is it should be in opposite.I would also like to know the direction of reactions at 1 & 4.

Thanks

 

[rb1957]

maybe it's just the way you drew it, but shouldn't the force bisect the angle between the gears ?

remember there are two forces acting along that line of action (force and reaction). how to tell which one applies to which gear ? ... one gear will be driving the other, no? so one gear is loading the other, yes?

as for the reactions, wouldn't they be like a beam with an overhang load ?

 

[Stressanalyst87]

Yup one gear will be driving the other,and assume that one end of the housing is mounted. gear 1 will drive the gear 2.Gear one is trying to drive gear 2,and gear 2 is resisting.Hence the bearing reaction at location 2 & 3 will be equal and in opposite direction.(Assume that bearing mounting locations r uniform for 2 & 3).Is my assumption correct?

 

[rb1957]

sounds reasonable to me ... and reactions 1 and 4 will also be equal and opposite, and 1 will be opposite to 2 so 2 will be bigger than the load.

 

[Stressanalyst87]

Yeah...but i had an argument with one of my friend and he says 2 & 3 will b in same direction,as well as 1 & 4. I dont have a strong methodolgy to support this. Do u have any material from where can i refer.It will be of great help.Thanks in advance.

 

[rb1957]

i'd start with free bodies on loads and reactions ...

one side (1&2) is loading the other (3&4),
so you can draw a free body that shows the loads at 1 & 2 being reacted by the contact force supplied by the other gear (ie reacting the driving force).

now your friend Might be saying that the loads at 1&2 are the same as the loads at 3&4 ... we've been saying that the loads at 1&2 are reacted at 3&4. these are the same thing, only expressed differently !?