Temp sensor placement

I've ordered a few DS18B20 (dallas temp sensor) in a TO92 package. I want to
measure the temperature of a DC motor, therefore a contact application.

I was reading the datasheet and it says that the air temperature around the
package affects the temperature reading, which in this application is
undesireable.
I'm thinking about a few alternatives, such as creating a tight casing
around the sensor using epoxy.

Can anybody here share experiences on mounting temp sensors on motors?

Cheers

Padu