Pulsar ring, magnetizing device and magnetizing method for pulsar ring-use magnetized member, and bearing unit having pulsar ring

Abstract

A pulsar ring is provided with a ring-shaped supporting member and a magnetized member formed into a strip shape and secured to a circumferential face of the supporting member so that N-poles and S-poles are arranged alternately with equal pitches. The length of the circumferential face of the supporting member is set so as to correspond to the length of the magnetized member so that the end portions of the magnetized member are butted to each other without any gap with the magnetic property in the butted portion being maintained to have equal pitches. The magnetized member is magnetized by a magnetizing device, and then affixed to the supporting member.

1 - 14 . (canceled)  
     
     
         15 . A pulsar ring, comprising: 
 a ring-shaped supporting member and a magnetized member, wherein    the magnetized member comprises a plurality of plate-shaped magnets which are secured to the supporting member so that magnetic poles on a face of the supporting member are arranged with N-poles and S-poles being alternately placed with equal pitches.    
     
     
         16 . The pulsar ring according to  claim 15 , wherein 
 concave portions in which magnets are placed are formed on the face of the supporting member to which the magnets are secured.    
     
     
         17 . The pulsar ring according to  claim 15 , wherein 
 the number of magnets is determined in accordance with the circumferential length of the supporting member.    
     
     
         18 . The pulsar ring according to  claim 17 , wherein 
 a gap between the magnets is determined so that magnetic poles are arranged with equal pitches.    
     
     
         19 . The pulsar ring according to  claim 15 , wherein 
 the supporting member comprises a cylinder portion and an inward or outward flange portion provided on one end thereof, and the plurality of plate-shaped magnets are provided on a circumferential face of the cylinder portion and on a side face of the flange portion.    
     
     
         20 . The pulsar ring according to  claim 15 , wherein 
 the supporting member comprises a cylinder portion and an inward or outward flange portion provided on one end thereof, and concave portions in which magnets are placed are formed on a side face of the flange portion with equal pitches.    
     
     
         21 . The pulsar ring according to  claim 15 , wherein 
 the plurality of plate-shaped magnets are arranged so that equal pitches are not given in the magnetic property at only one portion per one rotation.    
     
     
         22 . The pulsar ring according to  claim 15 , wherein 
 after the plurality of plate-shaped magnets are secured to the supporting member, the supporting member is divided into two portions.    
     
     
         23 . A bearing unit comprising: 
 a pulsar ring according to  claim 21  which outputs a rotation signal; and    a sensor device having a magnetic sensor configured to face the pulsar ring and signal processing means for carrying out signal processing based upon an output from the magnetic sensor, said pulsar ring and said sensor device being rotated relatively, wherein    the one portion of the pulsar ring at which equal pitches are not given in the magnetic property serves as a detected part for a reference position signal detection which provides an output signal having a small bottom value at a peak portion, and    the signal processing means of the sensor device comprises a reference position signal detection unit for detecting the detected part for a reference position signal detection of the pulsar ring.    
     
     
         24 . The bearing unit according to  claim 23 , wherein 
 the signal processing means has a first threshold value which is smaller than the small bottom value of the output signal from the detected part for a reference position signal detection and a second threshold value which is greater than the small bottom value of the output signal from the detected part for a reference position signal detection and also smaller than the output peak of the detected part for a reference position signal detection, and when the input signal exceeds the first threshold value, the rotation signal is outputted while, when the input value, after having become smaller than the second threshold value, again exceeds the second threshold value before reaching the first threshold value, the reference position signal is outputted.    
     
     
         25 . A magnetizing device, comprising: 
 a first magnetizing unit comprising a first magnetic pole array in which N-poles and S-poles are alternately arranged; and    a second magnetizing unit having a second magnetic pole array which faces the first magnetizing unit with a gap for arranging a member to be magnetized, and having S-poles and N-poles that are arranged in a manner reversed to the first magnetic pole array, wherein    a magnetizing process is carried out with the member to be magnetized being sandwiched by the first magnetizing unit and the second magnetizing unit.    
     
     
         26 . The magnetizing device according to  claim 25 , wherein 
 the first and second magnetic pole arrays are aligned in a linear shape.    
     
     
         27 . The magnetizing device according to  claim 25 , wherein each of the first and second magnetizing units further comprises: 
 a yoke unit comprising coil element housing concave portions placed in predetermined gaps; and    a coil formed by allowing a wire to successively pass through the respective coil element housing concave portions of the yoke unit.    
     
     
         28 . The magnetizing device according to  claim 26 , wherein each of the first and second magnetizing units further comprises: 
 a yoke unit comprising coil element housing concave portions placed in predetermined gaps; and    a coil formed by allowing a wire to successively pass through the respective coil element housing concave portions of the yoke unit.    
     
     
         29 . The magnetizing device according to  claim 26 , wherein 
 the first and second magnetizing units and the member to be magnetized make contact with each other.    
     
     
         30 . The magnetizing device according to  claim 25 , wherein 
 after a wire is wound on the first magnetizing unit from one end to the other end in a winding manner, the coil is wound from the other end of the first magnetized member to one end of the second magnetizing unit facing the other end so that the wire is wound toward the end of the second magnetizing unit which faces the one end of the first magnetizing unit in a winding manner, thus forming both of the magnetizing unit-use coils by one wire.    
     
     
         31 . The magnetizing device according to  claim 25 , wherein 
 the member to be magnetized is contact with at least one of the first magnetizing unit and the second magnetizing unit.    
     
     
         32 . The magnetizing device according to  claim 25 , wherein 
 each magnetic pole array of the first and second magnetizing units is formed into a ring shape and a member to be magnetized has a ring shape.    
     
     
         33 . The magnetizing device according to  claim 27 , wherein 
 each of the yokes is formed into a disc shape with a hole so that a ring-shaped magnetized member is obtained.    
     
     
         34 . A magnetizing method, comprising 
 sandwiching a member to be magnetized with a first magnetizing unit having a first magnetic pole array in which N-poles and S-poles are alternately arranged and a second magnetizing unit having a second magnetic pole array which faces the first magnetizing unit with a gap for arranging a member to be magnetized, and has S-poles and N-poles that are arranged in a manner reversed to the first magnetic pole array.    
     
     
         35 . The magnetizing method according to  claim 34 , wherein 
 the first and second magnetic pole arrays are aligned in a linear shape and the magnetized member has a strip shape.