A thermal energy transfer device for use with an x-ray generating device or x-ray system including an anode assembly having a target, a cathode assembly positioned at a distance from the anode assembly configured to emit electrons that strike the target producing x-rays and residual energy in the form of heat, and a rotatable shaft supported by a bearing assembly. The thermal energy transfer device including a thermal gradient device positioned adjacent to and in thermal communication with one end of the shaft, the thermal gradient device operable for transferring heat away from that end of the shaft, and a fin structure positioned adjacent to and in thermal communication with the thermal gradient device, the fin structure operable for convectively cooling the thermal gradient device.