Shaft having a magnetostrictive torque sensor and a method for making same

• US 5,585,574 A
• Filed: 02/14/1994
• Issued: 12/17/1996
• Est. Priority Date: 02/02/1993
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Materials Corporation
• Original Assignee: Mitsubishi Materials Corporation
• Inventors: Suzuki, Isao, Yoshida, Kazushi, Inoue, Kazutoshi, Yang, Ji-bin, Sugihara, Tadashi
• Primary Examiner(s): Chilcot, Richard
• Assistant Examiner(s): Biegel, Ronald
• Application Number:
  US08/195,375
• Time in Patent Office: 1,037 Days
• Field of Search: 73/862.333, 73/862.334, 73/862.335, 73/862.336
• US Class Current: 73/862.334
• CPC Class Codes: G01L 3/102 involving magnetostrictive means magnetostrictive sensors H10N35/101
• CPC Class Codes: G01L 3/103 Details about the magnetic material used
• CPC Class Codes: G01L 3/105 involving inductive means G01L3/102, G01L3/104 take precedence
• CPC Class Codes: H10N 35/101 with mechanical input and electrical output, e.g. generators, sensors

Abstract

A shaft having a magnetostrictive sensor measures torque applied to a shaft, as a shaft, without contact and utilizing reverse-magnetostrictive properties of magnetic alloys. The shaft includes a plurality of magnetic alloy layers, and the magnetosensitive torque detector is variously formed by diffusion bonding a magnetostrictive layer with a high magnetostrictive constant onto the shaft surface, by heat treating, adhesive fixation or the like bonding means. Methods for making the shaft are disclosed.

Claims

1. A shaft with a magnetostrictive torque detector comprising:

an inner shaft with a circumferential surface;

a layer of magnetostrictive magnetic alloy, wherein said magnetic alloy layer is diffusion-bonded onto said circumferential surface;

wherein

an intermediate layer is formed between said inner shaft and said layer of magnetostrictive magnetic alloy.

2. The shaft with a magnetostrictive torque detector of claim 1, wherein said magnetic alloy layer is crystallized.

3. The shaft with a magnetostrictive torque detector of claim 1, wherein said magnetic alloy layer is non-crystallized.

4. The shaft with a magnetostrictive torque detector of claim 1, wherein said magnetic alloy layer has a magnetostrictive constant greater than 5×

10^-6.

5. The shaft of claim 1,

wherein said intermediate layer contains at least one of the following:

Ni, Nb, Mo, Zn, Fe, Y, Sc, Ti, Hf, Ta, W, Co, Rh, Ir, Pd, Pt, and Ni--P.

6. The shaft of claim 5 wherein:

said intermediate layer is at least one of nickel and an Ni--P alloy.

7. A shaft having a magnetostrictive torque detector as described in claim 1 wherein:

said intermediate layer has a thickness of 10-100 micrometers.

8. The shaft with a magnetostrictive torque detector of claim 1, wherein said intermediate layer has melting point greater than melting point of said layer of magnetostrictive magnetic alloy.

9. A shaft with a magnetostrictive torque detector comprising:

an inner shaft with a circumferential surface;

a layer of magnetostrictive magnetic alloy, wherein said magnetic alloy layer is diffusion-bonded onto said circumferential surface;

wherein said magnetic alloy includes at least one alloy selected from the group consisting of and represented by the formula;

Fe_X B_m Si_n, wherein X+m+n=1.0, and 0.65<

X<

0.80, 0.20<

m+n<

0.350.02<

m<

0.33;

(Fe₀.9 Co₀.1)₀.78 Si_X B_Y wherein X+Y=0.22;

(Fe_X Ni_Y)Mo_m B_n wherein X+Y+m+n=1.0, and wherein 0.70<

X+Y<

0.80, 0.30<

X<

0.50, 0.20<

m+n<

0.30, 0.02<

m<

0.10;

(Fe₀.9 Co₀.1)_X (Si_m B_n)_Y wherein X+Y=1.0, and where 0.75<

X<

0.90, 0.10<

Y<

0.25 and m+n=1, where 0.2<

m<

0.80, 0.2<

n<

0.81];

Co-40% Fe;

Fe-13% Al;

TbFe₂ ;

Tb-30% Fe;

Tb (CoFe)₂ ;

Tb(NiFe)₂ ;

TbFe₃

Fe₃ O₄ ; and

DyFe₂.

10. The shaft with a magnetostrictive torque detector of claim 9, wherein said magnetic alloy layer is crystallized.

11. The shaft with a magnetostrictive torque detector of claim 9, wherein said magnetic alloy layer is non-crystallized.

12. The shaft with a magnetostrictive torque detector of claim 9, wherein said magnetic alloy layer has a magnetostrictive constant greater than 5×

10^-6.

13. The shaft of claim 9, further comprising:

an intermediate layer between said shaft and said magnetic alloy layer;

wherein said intermediate layer contains at least one of the following;

Ni, Nb, Mo, Zn, Fe, Y, Sc, Ti, Hf, Ta, W, Co, Rh, Ir, Pd, Pt, and Ni--P.

14. The shaft of claim 13 wherein:

said intermediate layer is at least one of nickel and an Ni--P alloy.

15. A shaft having a magnetostrictive torque detector as described in claim 13 wherein:

said intermediate layer has a thickness of 10-100 micrometers.

16. The shaft with a magnetostrictive torque detector of claim 13, wherein said intermediate layer has melting point greater than melting point of said layer of magnetostrictive magnetic alloy.