Hi, I have a established pear tree (unknown on the type) in my garden. Problem is i never get an good pears from it. They never look too good and nearly always have maggots in them!

I would like to have a tree where i could simply pull a pear off and eat there and then I've attached some photos. I think it may be a sick tree?

Any help would be great.

Here are the photos:
http://f.cl.ly/items/0v3K011v1p1D2V2G3E0N/photo%201.JPG
http://f.cl.ly/items/2H420X3q1Z0P3e3Q3J40/photo%202.JPG
http://f.cl.ly/items/050i1A1c1P433j2P3F18/photo%203.JPG
http://f.cl.ly/items/3r2k1O2Q0u0X0n0y381v/photo%204.JPG
http://f.cl.ly/items/3K3Z400N1c3Y0H2U0a2W/photo%205.JPG