Electropneumatic rotary actuator having proportional fluid valving

Double acting electric solenoid apparatus comprising:

• a generally cup-shaped housing of magnetically permeable material having a side wall, an end wall, and a transverse wall spaced from said end wall and cooperating therewith and with said side wall to define an elongate axially extending chamber within said housing, one of said transverse wall and said end wall defining an annular pole piece portion extending axially toward the other of said transverse wall and end wall,
• an axially elongate annular armature member of magnetically permeable material movably received in said chamber, said armature member defining a side surface and a pair of oppositely axially disposed end surfaces and in a first centered position thereof being substantially equally spaced both from said pole piece and from the other of said transverse wall and end wall thereby to define at said pair of end surfaces a respective pair of axially extending annular active magnetic air gaps expanding and contracting in opposition in response to axial movement of said armature member:
• resilient means yieldably urging said armature member to said first centered position;
• an elongate annular axially polarized permanent magnet member circumscribing said pole piece, and at one pole thereof in magnetic contract with the one of said transverse wall and end wall:
• an annular magnetically permeable flux conductor member in magnetic contact with the other pole of said permanent magnet member, said flux conductor member further being disposed in radially spaced relation adjacent said side surface of said armature member intermediate said end surfaces thereof to define a radially extending annular inactive magnetic air gap, one of said pair of active magnetic air gaps further being disposed axially intermediate of the poles of said permanent magnet member, whereby said permanent magnet provides static flux in said pair of air gaps and balanced magnetic forces urging said armature in opposite axial directions from said centered position:
• coil means disposed in said chamber and circumscribing said armature member, said permanent magnet member, and said flux conductor member for providing a control flux superimposed at said pair of active air gaps upon said static flux to selectively increase the magnetic force at one of said pair of air gaps while simultaneously decreasing said force at the other of said air gaps, thereby moving said armature from said centered position selectively to one of opposite second and third positions dependent upon electrical polarity applied to said coil means.

Double acting electric solenoid apparatus comprising:

• a generally cup-shaped housing of magnetically permeable material having a side wall, an end wall, and a transverse wall spaced from said end wall and cooperating therewith and with said side wall to define an elongate axially extending chamber within said housing, one of said transverse wall and said end wall defining an annular axially pole piece portion extending axially toward the other of said transverse wall and end wall,
• an axially elongate annular armature member of magnetically permeable material movably received in said chamber said armature member defining a side surface and a pair of oppositely axially disposed end surfaces, thereby to define at said end surfaces a pair of axially extending annular active magnetic air gaps expanding and contracting in opposition in response to axial movement of said armature member;
• an elongate annular axially polarized permanent magnet member circumscribing said pole piece, and at one pole thereof in magnetic contact with the one of said transverse wall and end wall:
• an annular magnetically permeable flux conductor member in magnetic contact with the other pole of said permanent magnet member, said flux conductor member further being disposed in radially spaced relation adjacent said side surface of said armature member intermediate said end surfaces thereof to define a radially extending annular inactive magnetic air gap, one of said pair of active magnetic air gaps further being disposed axially intermediate of the poles of said permanent magnet member, whereby said permanent magnet provides static flux in said pair of air gaps and balanced magnetic forces urging said armature in opposite axial directions from said centered position;
• coil means disposed in said chamber and circumscribing said armature member, said permanent magnet member, and said flux conductor member for providing a control flux superimposed at said pair of air gaps upon said static flux to selectively increase the magnetic force at one of said pair of air gaps while simultaneously decreasing said force at the other of said air gaps thereby moving said armature from said centered position selectively to one of opposite second and third positions dependent upon electrical polarity applied to said coil means.

The method of pivotally moving a load member comprising the steps of:

• providing a housing;
• defining a plurality of elongate bores opening outwardly upon said housing:
• disposing a like plurality of piston members sealingly and reciprocably each in a respective one of said plurality of bores:
• closing said outward opening of said plurality of bores with a like plurality of closed-centered three-way solenoid valves each sealingly received in a respective one of said plurality of bores:
• rotatably journaling a shaft within said housing;
• interconnecting said shaft and said plurality of piston members with rotary motion conversion means for sequentially reciprocating the latter in response to shaft rotation, and rotating said shaft in response to said reciprocation:
• defining a like plurality of variable-volume chambers within said bores by the cooperation of said housing, solenoid valves and piston members, which chambers sequentially expand and contract in response to said reciprocation of said piston members:
• sequentially communicating to and venting from said plurality of variable-volume chambers a flow of pressurized elastic fluid from a source thereof via said like plurality of solenoid valves:
• reciprocating said plurality of piston members sequentially in response to said flow of pressurized fluid:
• rotating said shaft in response to said sequential reciprocation of said plurality of piston members;
• and
• pivoting said load member at a relatively reduced speed in response to rotation of said shaft.

Rotary servo motor apparatus of the elastic fluid expanding type comprising:

• a housing defining a plurality of bores opening outwardly thereon;
• a like plurality of piston members sealingly and reciprocably received each in a respective one of said bores;
• a shaft member rotatably journaled by said housing:
• motion conversion means for sequentially reciprocating each one of said plurality of piston members in response to rotation of said shaft and rotating said shaft in response to sequential reciprocation of said piston members:
• a like plurality of closed-centered three-way solenoid valves respectively received each in a respective one of said plurality of bores to sealingly close said outward opening thereof, and cooperating with said housing and piston members to define a like plurality of variable-volume chambers expanding and contracting sequentially, and command means for controlling said plurality of solenoid valves to sequentially introduce to and vent from said plurality of variable-volume chambers a flow of pressurized elastic fluid.

Linear force motor apparatus comprising:

• an axially elongate annular magnetically permeable armature member having a radially outer side surface and a pair of opposite axially disposed annular end surfaces:
• a cup-like housing member of magnetically permeable material defining a chamber reciprocably receiving said armature member and having an end wall, a transverse wall spaced from said end wall, and a circumferentially extending side wall extending between and interconnecting said end wall and transverse wall, said end wall and said transverse wall sandwiching said armature member therebetween and cooperating therewith to define a pair of axially extending annular active air gaps expanding and contracting in opposition in response to axial reciprocation of said armature member:
• an axially polarized and elongate annular permanent magnet member circumscribing said armature member;
• means for introducing static flux from said permanent magnet member into one of said end wall and transverse wall and into said armature member side wall via a radially extending inactive air gap defined thereby intermediate of said end surfaces, thereby to create a pair of oppositely extending flux loop paths each including only one of said pair of active air gaps:
• and coil means within said housing and circumscribing said armature member, said permanent magnet, and said flux introducing means for selectively inducing a control flux of alternatively opposite polarity in said housing and armature and superimposed upon said static flux to, on the one hand increase the net flux at one of said pair of active air gaps and, on the other hand to decrease the net flux at the other of said pair of air gaps, whereby said armature member is subject to a linear axial magnetic force dependent upon the polarity of said control flux.