Why did my pear trees stop producing fruit?

You apparently pruned the new wood which makes the blooms. It will take two or three years to make fruiting wood. You should have them bloom next year, but don't prune anymore.

Pear Tree No Fruit

How much did you prune them? Cutting branches back so all or most of the small, leaf producing stems are gone will also prevent fruiting. This type of pruning is called topping or heading, and is detrimental when done on larger branches. When the tree begins regrowth it produces a mass of growth at the ends of the branches. Pruning is always better done as thinning. See the links below.

You probably pruned them too much - cutting off the fruit spurs. Last spring in the UK very few pear trees bore fruit, the reason being the late frost. Pear trees are one of the first fruiting trees to bear blossom and are always at risk of a late frost. Keep your fingers crossed that this year they will come good.

You didn't prune correctly.

Pears don't take a lot of pruning and if they get too much, they don't produce well.

LEAVE THEM ALONE and you'll likely get fruit again.

when we moved here 4 years ago the pear tree produced really nice fruit. Last year nothing. This year nothing. No one has touched it at all. Last year and this year we seen tiny little balls come on but they just fell off.