It could be the heating element, a safety limit, a control problem, or an electrical problem. A heating coil is used to warm the clothes as they get tossed gently inside the drum. A blower mounted on the motor pulls air through the heating element into the drum and out the exhaust. The element gets old and brittle with use and eventually needs replacement. That is what you check first.
On gas dryers vibration and age will cause the igniter to crumble and fail.
If it turns out the element is fine then one of the safety's might be blown. These safety's are set to a certain temperature
for the dryer to operate safely. The drum temp control (7) for cotton is 160f. A limit on the heater housing is 250f.(3) If it fails another smaller limit is mounted nearby that blows at 300f.(1) If that temp exceeds 350f a duct fuse mounted on the blower housing opens and kills most dryers.(5) On gas dryers the duct fuse will kill the gas assembly but the dryer will still run. If all of those safetys are good the timer could be the problem. The timer has a terminal on it that runs down to the heating element. If you suspect it is bad you can check it with a meter. That leg of the timer should have continuity with other terminals on the timer at different spots on the timer.
Turning the timer and checking for continuity will give a clue. If you cannot get continuity with any other terminal on the timer at any position on the dial then you have a burned contact in the timer. If that turns out to be good, you would need to inspect the electrical outlet for proper power to the machine.
On American models the motor runs on 120 volts but the heating element must have 240 volts. If you have more questions just post a comment. Good luck on repairing your machine. I have some repair photos: HERE