Linear motor device and machine tool having the same mounted thereon

• US 20080079319A1
• Filed: 09/25/2007
• Published: 04/03/2008
• Est. Priority Date: 09/28/2006
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: GMC Hillstone Co., Ltd., Murata Machinery Limited (Muratec)
• Inventors: Ishiyama, Noritaka, Okada, Takuya
• Granted Patent: US 7,906,877 B2
• Time in Patent Office: Days
• US Class Current: 310/12
• CPC Class Codes: B30B 1/42 by magnetic means, e.g. electromagnetic
• CPC Class Codes: H02K 11/21 Devices for sensing speed or position, or actuated thereby specially adapted for machines having non-mechanical commutating devices H02K29/06, H02K29/14
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information
• CPC Class Codes: H02K 41/031 of the permanent magnet type
• CPC Class Codes: H02K 7/106 with dynamo-electric brakes
• CPC Class Codes: H02K 7/1185 with a mechanical one-way direction control, i.e. with means for reversing the direction of rotation of the rotor
• CPC Class Codes: Y10T 83/9476 Tool is single element with continuous cutting edge [e.g., punch, etc.]

Abstract

The present invention provides a linear motor device that can reduce a variation in thrust caused by a variation in attractive force. The linear motor device includes a linear motor 1 and a control section 30 that controls the linear motor 1. The linear motor 1 includes a magnet member 2 composed of permanent magnets having respective N poles and S poles alternately arranged in an axial direction, and a coil member 3 which is located orthogonally to the axial direction with respect to the magnet member 2 and through which the magnet member 2 is movable in the axial direction relative to the coil member 3. The control section 30 controls current conducted through the coil member 3 so that a moving one of the magnet member 2 and the coil member 3 reciprocates within a use range L corresponding to a part of a pitch p between the magnetic poles N and S in the magnet member 2.

Claims

1. A linear motor device characterized by comprising a linear motor and a control section that controls the linear motor, the linear motor comprising a magnet member composed of permanent magnets having respective N poles and S poles alternately arranged in an axial direction, and a coil member which is located orthogonally to said axial direction with respect to the magnet member and through which said magnet member is movable in the axial direction relative to the coil member, said control section controlling current conducted through said coil member so that a moving one of said magnet member and said coil member reciprocates within a part of a range between magnetic poles in the magnet member.

2. A machine tool having a linear motor device mounted thereon, comprising processing means for processing a workpiece and a drive means for reciprocating the processing means, said machine tool being characterized in that said drive means comprises a linear motor and a control section that controls the linear motor, and said linear motor comprises a magnet member composed of permanent magnets having respective N poles and S poles alternately arranged in an axial direction, and a coil member which is located orthogonally to said axial direction with respect to the magnet member and through which said magnet member is movable in the axial direction relative to the coil member, and in that said control section controls current conducted through said coil member so that a moving one of said magnet member and said coil member which is combined to said processing means reciprocates within a part of a range between magnetic poles in the magnet member.

3. A press machine having a linear motor device mounted thereon, comprising a press processing means for executing processing such as punching or forming on a plate material and a drive means for driving the press processing means, said press machine being characterized in that said drive means comprises a linear motor and a control section that controls the linear motor, and said linear motor comprises a magnet member composed of permanent magnets having respective N poles and S poles alternately arranged in an axial direction, and a coil member which is located orthogonally to said axial direction with respect to the magnet member and through which said magnet member is movable in the axial direction relative to the coil member, and in that said control section controls current conducted through said coil member so that a moving one of said magnet member and said coil member which is combined to said press processing means reciprocates within a part of a range between magnetic poles in the magnet member.