Rotation detector,wheel bearing equipped therewith and process for manufacturing the same

Abstract

A sensor assembly ( 3 ) is sandwiched together with a rubber material ( 11 ) mixed with a vulcanizing agent in a mold assembly ( 2 ) including an upper mold ( 9 ) and a lower mold ( 10 ). The upper and lower molds ( 9, 10 ), while completely sandwiching the sensor assembly ( 3 ), are heated for a predetermined length of time, and a pressure is then applied to the sensor assembly ( 3 ) to complete a compressive molding.

1 . A rotation detecting device which comprises:
 a magnetic sensor arranged in face-to-face relation with a metallic body or magnet body provided in a rotational member; and   peripheral component parts electrically or mechanically connected with the magnetic sensor;   in which the magnetic sensor and the peripheral component parts are molded together so as to be covered by a thermoplastic elastomer or a material capable of exhibiting a rubber elasticity.   
   
   
       2 . The rotation detecting device as claimed in  claim 1 , wherein an electric terminal of the magnetic sensor or a metallic electrode, which is one of the peripheral component parts electrically connected with the electric terminal, and the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity are sealingly bonded together by the molding. 
   
   
       3 . The rotation detecting device as claimed in  claim 1 , further comprising a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts, and in which the magnetic sensor, the peripheral component parts and the fixture are molded together so as to be covered by the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity. 
   
   
       4 . The rotation detecting device as claimed in  claim 1 , further comprising:
 a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts; and   a connecting member for integrally connecting the magnetic sensor and the fixture together,   wherein the magnetic sensor, the peripheral component parts, the fixture and the connecting member are molded together so as to be covered by the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity.   
   
   
       5 . The rotation detecting device as claimed in  claim 1 , further comprising:
 a fixture, made of a metallic material, for positioning the magnetic sensor; and the peripheral component parts; and   a cable clamp affixed to the fixture for holding a metallic cable forming a part of the peripheral component parts and electrically connected with the magnetic sensor,   wherein the magnetic sensor, the peripheral component parts and the cable clamp are molded together so as to be covered by the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity.   
   
   
       6 . The rotation detecting device as claimed in  claim 1 , in which the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity for covering the cable forming a part of the peripheral component parts and electrically connected with the magnetic sensor is externally pressed so that the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity and an outer skin of the cable are tightly sealed together. 
   
   
       7 . The rotation detecting device as claimed in  claim 6 , further comprising a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts and a press-fixing member for externally pressing the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity, which covers the cable. 
   
   
       8 . The rotation detecting device as claimed in  claim 1 , further comprising:
 a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts; and   an annular cable sealing member capable of being plastically deformed in a direction radially inwardly thereof and provided on an outer periphery of a cable, which is one of the peripheral components, electrically connected with the magnetic sensor with a gap intervening therebetween;   wherein the magnetic sensor, the peripheral component parts, the fixture and the cable sealing member are molded together so as to be covered by the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity, and   wherein the cable sealing member is plastically deformed in a direction radially inwardly thereof together with a portion of the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity, which portion covers an outer peripheral portion of the cable.   
   
   
       9 . The rotation detecting device as claimed in  claim 1 , further comprising:
 a cable covering member covering a cable, which is one of the peripheral components, electrically connected with the magnetic sensor; and   a ring member, provided on an outer periphery of the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity, for holding the thermoplastic elastomer or said material and the cable covering member in a fastened condition.   
   
   
       10 . A method of manufacturing a rotation detecting device, which method comprises the steps of:
 loading a magnetic sensor to be arranged in face-to-face relation with a magnet body or a metallic body provided on a rotational member, peripheral component parts electrically or mechanically connected with the magnetic sensor and a thermoplastic elastomer or a material capable of exhibiting a rubber elasticity into a mold assembly; and   compressive molding the magnetic sensor and the peripheral component parts so as to be covered by the thermoplastic elastomer or said material within the mold assembly.   
   
   
       11 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , in which the mold assembly includes an upper mold and a lower mold and in which the compressive molding step comprises the substeps of:
 intervening and sandwiching the magnetic sensor, the peripheral component parts and the rubber material mixed with a vulcanizing agent between the upper mold and the lower mold;   heating at least one of the upper mold and the lower mold; and   subsequent to the previous substep, applying a pressure between the upper mold and the lower mold.   
   
   
       12 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , in which the mold assembly includes an upper mold and a lower mold and in which the compressive molding step comprises the substeps of:
 intervening and sandwiching the magnetic sensor, the peripheral component parts and the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity between the upper mold and the lower mold;   heating at least one of the upper mold and the lower mold; and+   subsequent to the previous substep, applying a pressure between the upper mold and the lower mold to allow the following three elements to be sealingly bonded together by vulcanization,   an electric terminal of the magnetic sensor or a metallic electrode forming one of the peripheral component parts and electrically connected with the electric terminal,   the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity, or a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts, and   the material capable of exhibiting the rubber elasticity.   
   
   
       13 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , in which the compressive molding step comprises loading, in addition to the magnetic sensor and the peripheral component parts, a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts, and the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity into the mold assembly so that the magnetic sensor and the peripheral component parts may be integrally compressive molded together so as to be covered by the thermoplastic elastomer or said material. 
   
   
       14 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , in which the compressive molding step comprises loading, in addition to the magnetic sensor and the peripheral component parts,
 a connecting member connecting the magnetic sensor and a fixture, made of a metallic material, for positioning the magnetic sensor and the peripheral component parts, and   the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity,   into the mold assembly so that the magnetic sensor and the peripheral component parts are integrally compressive molded together so as to be covered by the thermoplastic elastomer or said material.   
   
   
       15 . The method of manufacturing the rotation detecting device as claimed in  claim 14 , in which the mold assembly includes an upper mold and a lower mold and in which during the step of applying the pressure for the compressive molding step, an excessive portion of the material is expelled to the outside of the mold assembly through a gap formed beforehand between the upper mold and the lower mold. 
   
   
       16 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , in which the compressive molding step comprises the substeps of:
 loading, in addition to the magnetic sensor and the peripheral component parts,   a cable clamp affixed to a fixture made of a metallic material for positioning the magnetic sensor and the peripheral component parts, the cable clamp being made of a metallic material and capable of holding a cable connected electrically with the magnetic sensor which cable is one of the peripheral component parts, and   the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity,   into the mold assembly so that the magnetic sensor and the peripheral component part are integrally molded together within the mold assembly so as to be covered by the thermoplastic elastomer or said material.   
   
   
       17 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , further comprising, subsequent to the compressive molding step, a step of sealing the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity and an outer skin of a cable, which is one of the peripheral component parts and is electrically connected with the magnetic sensor, tightly together by pressing from outside the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity then covering the cable. 
   
   
       18 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , in which the mold assembly includes an upper mold and a lower mold and in which the compressive molding step executes compressively molding within the mold assembly, in addition to the magnetic sensor and the peripheral component parts, an annular cable sealing member spacedly provided on an outer periphery of a cable, which is one of the peripheral component parts and electrically connected with the magnetic sensor, the cable seal member being capable of undergoing a plastic deformation in a radially inward direction, together with the thermoplastic elastomer or the material capable of exhibiting the rubber elasticity so as to be covered by the thermoplastic elastomer or said material; and
 the method further comprises the step of, subsequent to the preceding substep, plastically deforming the cable sealing member together with a portion of a covering material including the thermoplastic elastomer or said material, which portion covers an outer peripheral portion of the cable, in a direction radially inwardly thereof.   
   
   
       19 . The method of manufacturing the rotation detecting device as claimed in  claim 10 , further comprising, subsequent to the compressive molding step, a step of providing a ring member for holding a covering material and a cable covering member in a fastened condition in the covering material,
 wherein the covering material includes the material capable of exhibiting the rubber elasticity or the thermoplastic elastomer, and   wherein the cable covering member covers an outer portion of a cable connected electrically with the magnetic sensor, which cable is one of the peripheral component parts.   
   
   
       20 . A wheel support bearing assembly for supporting a vehicle wheel rotatably relative to a vehicle body structure, which assembly comprises:
 an outer member having double row rolling surfaces formed in an inner periphery thereof;   an inner member having an outer periphery formed with rolling surfaces in face-to-face relation with the rolling surfaces in the outer member;   double row rolling elements interposed between the opposed rolling surfaces; and   a rotation detecting device of a structure as defined in  claim 1 , which is fitted to one of the outer and inner members which serves as a stationary member,   wherein the magnet body or the metallic body confronting the magnetic sensor of the rotation detecting device is fitted to the other of the outer and inner members which serves as a rotational member.