A compressor and oil blocking device therefor are provided which are capable of preventing oil from spreading onto, for example, a balance weight, which are capable of preventing oil from being excessively sucked into a compression device by a separating device disposed between a driving motor and the compression device, and which are capable of constantly maintaining a predetermined amount of oil in compression chambers regardless of a rotational speed of the driving motor by directly supplying oil to a bearing surface and the compression chambers and by easily discharging gas from an oil drain passage. A trochoid gear pump may be used to smoothly supply oil to the compression device. Further, a synchronous reluctance motor may be used to enhance a performance of the compressor and to expand a driving region of the compressor.