60Hz to 50Hz frequency transformer/inverter?
Both your machines use transformers inside to create the required working voltage. Using transformers at 60Hz designed for 50Hz will be no problem. Using one at 50Hz when designed for 60Hz is more troublesome, as the max flux inside the core will be greater than designed.

So for you 60Hz 220-230V is fine.
But the electronics inside that measure time were built for 50Hz, so at 60Hz they will run faster. Many electronic clocks use industry standard chips which can be set to either 50 or 60 Hz by soldering a certain pin to ground or not.

Use them, don't worry, just don't trust the clocks.