Rotary hammer drill - Rotary Drills

SOURCE: hammer drills and rotary hammers comparison

Basically yes. Lower power units are usually titled as "hammer drills." Higher power units, usually labeled "rotary hammers," tend to be larger and provide bigger impact forces. But there are a few differences that are worth knowing: The rotary hammer usually have a chisel only feature, for light chiseling and masonry removal. Rotary hammers also have specially designed chucks that only accept bits specifically designed to fit their chuck. The special chuck on a rotary hammer helps hold the drill bit and prevents it from slipping during use.

SOURCE: i have a bosch rotary hammer 11245evs and it was

They are filled with a special grease that comes from Bosch. It sounds like the impact bolt or the striker pin in the unit are not moving the way they should. These are the pieces that work together to create the hitting action. About all that can be done now is the unit has to be dismantled to get those to pieces moving again. Bosch makes what they call service packs for all thier hammers. They have all the o-rings and grease to get your hammer working again. A Bosch service center can supply you with the kit. Ask for P/N 1617000225, or they can take care of it for you.
Hope this helps

SOURCE: rotary hammer won't rotate, hammers very good

If tool hammers brushes still good. Motor runs hammer action.
Take hammer/ drill switch lever off by removing small plastic plug in center with small screw driver.remove indicator handle off by removing #8 torx screw and lightly pry off. There is a pin and spring that lock tool into hammer or drill.Check for broken spring or binding spring and pin.If binding , clean and grease.

SOURCE: I have a makita hr2455x rotary hammer drill that won't hammer

you need to get that service,
the grease causes the hammering.
and probably too much pressure was applied
to it.

SOURCE: i have a makita hr300c rotary hammer drill.

it sounds like it needs new o rings and serviced. you can go to Makitatools.com and download a breakdown for this tool, If you are handy and take your time they are not that bad to repair. Let me know if you need more assistance.