Abstract: Coil assemblies (2) of electric motors (1) produce heat that can be a disadvantage when needing the electric motor (1) for high precision positioning applications. To reduce the negative impact of the heat, the coils (26a, 26b, 26c) are arranged in an internally cooled housing (21). The housing (21) has an outermost layer (25) at least on the side lacing the magnet assembly (3) of the electric motor (1), the outermost layer (25) being made of low or non-electrically conductive, non-magnetic or nearly non-magnetic material. The outermost layer (25) prevents heat radiation to the environment.

Abstract: A coil for use in an actuator in a lithographic projection apparatus. The coil is formed of a strip of electrically conducting sheet-material that is wound round a winding axis. Respective turns of the strip of sheet-material are separated by an electrically non-conducting layer.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Abstract: A coil for use in an actuator in a lithographic projection apparatus. The coil is formed of a strip of electrically conducting sheet-material that is wound round a winding axis. Respective turns of the strip of sheet-material are separated by an electrically non-conducting layer.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.