Bramley is a type of apple called a triploid. This means that it is self sterile, so its flowers won't pollinate each other. Not only that, it is a useless pollinator for other varieties. Not only that, but to get a really good crop you need two other varieties, not just one, to pollinate your Bramley.
Another thing to take into account is that it produces quite a few of its fruits, but not all, at the ends of its branches. So if you have been pruning it in summer you may well have cut off some of your flower buds.
Here is a list of apple trees which are known to be good pollinators of Bramley. As you have had some fruit in the past, rather than no fruit at all, there must be suitable trees in the area. This can be up to two miles away. But by all means plant another tree. Why not?
Bramley is a very poor pollinator it needs at least two other apple trees for decent pollinatio. Don't forget they must be different kinds of apples and blossom at the same time.
Pansy face you beat me to it.
Quick draw McGraw