Self guided linear induction motor system and method
A polyphase linear induction motor including a movable primary member ( 100 ), the primary member ( 100 ) including a magnetic material ( 110 ), a polyphase winding ( 120 ) arranged around the magnetic material, and a stationary longitudinally-extending secondary member ( 150 ) separated from the primary member ( 100 ) by a gap, the secondary member ( 150 ) including an electrically-conductive reaction plate ( 200 ) and a backing magnetic material ( 300 ), wherein the secondary member includes a middle section ( 205 ) and two outer sections ( 210.1, 210.2 ), the middle section ( 205 ) and the two outer sections ( 210.1, 210.2 ) arranged next to each other in parallel to an axis of longitudinal extension of the reaction plate ( 200 ).
1 . A polyphase linear induction motor comprising:
a movable primary member ( 100 ), the primary member ( 100 ) including a magnetic material ( 110 ), a polyphase winding ( 120 ) arranged around the magnetic material; and
a stationary longitudinally-extending secondary member ( 150 ) separated from the primary member ( 100 ) by a controlled gap, the secondary member ( 150 ) including an electrically-conductive reaction plate ( 200 ) and a backing magnetic material ( 300 ),
wherein the electrically-conductive reaction plate ( 200 ) includes a middle section ( 205 ) and two outer sections ( 210 . 1 , 210 . 2 ) having an increased electric conductivity as compared to an electric conductivity of the middle section ( 205 ) wherein at least one winding of the polyphase winding ( 120 ) of the movable primary member ( 100 ) includes windings arranged to support the operation of the primary member in a trapezoidal shape; and
wherein an angle of inclination between the outer sections ( 210 . 1 , 210 . 2 ) and the middle section ( 205 ) is different at a first section and a second section along the axis of longitudinal extension of the reaction plate ( 200 ), the first section being located at a different location than the second section.
2 . The polyphase linear induction motor according to claim 1 , wherein the magnetic material ( 110 ) of the movable primary member ( 100 ) includes a middle section ( 130 ) and two outer sections ( 140 . 1 , 140 . 2 ), the middle section ( 130 ) and the two outer sections ( 140 . 1 , 140 . 2 ) facing the middle section ( 205 ) and the two outer sections ( 210 . 1 , 210 . 2 ) of the reaction plate ( 200 ), respectively, via a gap.
3 . The polyphase linear induction motor according to claim 2 , wherein a cross-sectional shape of the magnetic material ( 110 ) of the movable primary member ( 100 ) has a trapezoidal shape, when viewed in a direction of the axis of longitudinal extension, with surfaces of the two outer sections ( 140 . 1 , 140 . 2 ) forming side legs of the trapezoidal shape, wherein the angle of inclination between the two outer sections ( 140 . 1 , 140 . 2 ) and the middle section ( 130 ) of the movable primary member ( 100 ) are oblique when viewed in a direction of the axis of longitudinal extension.
4 . The polyphase linear induction motor according to claim 2 , wherein the two outer sections ( 140 . 1 , 140 . 2 ) of the movable primary member ( 100 ) and the two outer sections ( 210 . 1 , 210 . 2 ) of the reaction plate ( 200 ) are arranged to be parallel to each other, respectively.
5 . The polyphase linear induction motor according to claim 2 , wherein the two outer sections ( 140 . 1 , 140 . 2 ) of the movable primary member ( 100 ) can be subdivided and arranged to be parallel to the two outer sections ( 210 . 1 , 210 . 2 ) and ( 210 . 3 , 210 . 4 ) of the reaction plate ( 200 ), respectively.
6 . The polyphase linear induction motor according to claim 1 , wherein the electrically-conductive reaction plate comprises variable stacked electrically-conductive layers wherein the electrical conductivity of the said layers on the stack can change from layer to layer.
7 . A polyphase linear induction motor comprising:
a movable primary member ( 100 ), the primary member ( 100 ) including a magnetic material ( 110 ), a polyphase winding ( 120 ) arranged around the magnetic material; and
a stationary longitudinally-extending secondary member ( 150 ) separated from the primary member ( 100 ) by a gap, the secondary member ( 150 ) including variable stacked electrically-conductive layers to form a reaction plate ( 200 ), and a backing magnetic material ( 300 ) wherein the reaction plate ( 200 ) comprises a middle section ( 205 ) and two outer sections ( 210 . 1 , 210 . 2 ) and wherein an angle of inclination between outer sections ( 210 . 1 , 210 . 2 ) and middle section ( 205 ) is different at a first section and a second section along the axis of longitudinal extension of the reaction plate ( 200 ), the first section being located at a different location than the second section.
8 . The polyphase linear induction motor according to claim 7 , wherein the reaction plate comprising the variable stacked electrically-conductive layers ( 200 ) includes a variation of the materials used along the axis of longitudinal extension to provide for an effective variability of the electrical conductivity of the reaction plate ( 200 ) along an axis of longitudinal extension of the secondary member ( 150 ).
9 . The polyphase linear induction motor according to claim 7 , wherein the reaction plate comprising the variable stacked electrically-conductive layers ( 200 ) includes a stack of layers ( 210 , 220 ), the first layer ( 210 ) and the second layer ( 220 ) of the stack of layers ( 210 , 220 ) made of different material compositions providing for a different electrical conductivity.
10 . The polyphase linear induction motor according to claim 9 , wherein a thickness of a first layer ( 210 ) of the stack of layers ( 210 , 220 ) is different from a thickness of a second layer ( 220 ) of the stack of layers ( 210 , 220 ).
11 . The polyphase linear induction motor according to claim 9 , wherein a thickness of at least one of the layers of the stack of layers ( 210 , 220 ) is variable when measured at different positions along the axis of longitudinal extension, to provide for the variability of the electrical conductivity of the reaction plate ( 200 ) by an increased cross-section of at least one of the layers of the stack of layers ( 210 , 220 ).
12 . The polyphase linear induction motor according to claim 9 , wherein the first layer ( 210 ) includes a first substack of layers ( 212 , 214 , 216 ) and the second layer ( 220 ) includes a second substack of layers ( 222 , 224 , 226 ), each layer of the first and second substack of layers having a different thickness resulting in an increased thrust force to the primary member ( 100 ).
13 . The polyphase linear induction motor according to claim 7 , wherein the reaction plate comprising the variable stacked electrically-conductive layers ( 200 ) is lower at a first section at a first location along the axis of longitudinal extension of the secondary member ( 150 ) as compared to a second section at a second location along the axis of longitudinal extension of the secondary member ( 150 ), the first and second locations being different.
14 . The polyphase linear induction motor according to claim 7 , wherein the first section of the reaction plate ( 200 ) is located at an area designated for a higher relative speed of the movable primary member ( 100 ) relative to the secondary member ( 200 ) as compared to the second section.