Abstract: A rotor blade for a compressor of a gas turbine engine includes an airfoil. The airfoil has a span that extends from 0% at the root to 100% at the tip and a mean camber line that extends from a leading edge to a trailing edge. The airfoil has a location of local maximum thickness defined as a ratio of a first arc distance along the mean camber line between the leading edge and a position of the local maximum thickness to a total arc distance along the mean camber line from the leading edge to the trailing edge. A value of the ratio increases from the root to a first position value, decreases from the first position value to a second position value and increases from the second position value to the tip. The first position value is at a spanwise location within 20% to 50% of the span.

Abstract: A rotor blade for a compressor of a gas turbine engine includes an airfoil. The airfoil has a span that extends from 0% at the root to 100% at the tip and a mean camber line that extends from a leading edge to a trailing edge. The airfoil has a location of local maximum thickness defined as a ratio of a first arc distance along the mean camber line between the leading edge and a position of the local maximum thickness to a total arc distance along the mean camber line from the leading edge to the trailing edge. A value of the ratio increases from the root to a first position value, decreases from the first position value to a second position value and increases from the second position value to the tip. The first position value is at a spanwise location within 20% to 50% of the span.

Abstract: The present invention provides a very compact, lightweight, turbomolecular pump for evacuating a chamber at volumetric flowrates of less than 10 liters per second. In one embodiment a turbomolecular pump is provided having a bladed rotor disposed within a housing, and mounted for rotation at one end on a passive magnetic main bearing and at the other end on a ball bearing. The pump is configured such that the magnetic bearing carries a majority of the rotor unbalance load. The rotor may be beneficially tapered from a larger diameter at the high vacuum end to a smaller diameter at the low vacuum end. The invention also provides a method of machining the blades of the rotor from a rotor blank using a single point tool in a two-step numerical control lathe operation. In another method of the invention, the rotor blades are individually cut using a high speed circular slitting saw by plunging the saw radially into the rotor blank.