过了一会儿means after a while~过means"经过after"in this sentence,一会儿means a while~过and 了imply sth past,i dont know if u get it now?

take an example: Action 1:A is reading a book. Ten minutes later:A is playing table tennis . After A come back,a friend ask A "what did u do just now?" A said:刚读了会儿书，过了一会儿打乒乓去了。 From a state to anther,must have a time transfer,and 过了一会儿 can describe this,especially the time not long.

Let's explain it in this way: Meaning: In "过了一会“, "过" means time passed by,like 5 minutes passed, whether you spend it or just sitting there doing nothing, time still passed; "一会" means a while, just a short time; After word meaning, it comes to the "Tense": In Chinese, the word "了" has a passed tense (or perfect tense) to show something "was" balabala, rather than "is", or someone "did" or "have done" something rather than "do" or "being to do". It's usually used when you describe something (you experienced, stories) to others. Like: I called tom last night but he's not in (say 9 clock). Then after a while (say 9:15) Tom called me back. Hope you can get the point there!! I called you twice on skype.... SOOOO, "过了一会" literally means after a little while.

过=after ;to spend time; to pass time 了＝auxiliary symbol ，after verb,no meaning 一会儿=in a (little) while; in an instant; presently; soon; awhile; half a minute second tick; in a moment

过了一会儿=a moment later