Torque detecting apparatus
First Claim
1. A torque detecting apparatus comprising:
- a driving shaft and a driven shaft connected coaxially with said driving shaft by a torsion bar;
a first drum fitted on said driving shaft and a second drum fitted on said driven shaft;
magnetic signals recorded on the surface of said first and second drums; and
a magnetic sensor for detecting the rotational angles of said first and second drums in a non-contact manner, said apparatus detecting a torque from a difference of rotational angles of said first and second drums, wherein said driving shaft and driven shaft are connected at free end portions thereof by a coupling bearing so that said shafts are allowed to have a relative rotation, and wherein said first and second drums are fitted on the external circumference of free ends of said driving shaft and driven shaft.
1 Assignment
0 Petitions
Accused Products
Abstract
A device for detecting a load torque using angle detectors fitted with a certain spacing on a shaft which is rotated by a drive source and on the basis of a relative angular difference of angles detected by the angle detectors. The device includes two rotary drums or discs fitted with a certain spacing on the drive side and load side of the shaft, with a plurality of magnetic poles for generating magnetic signals being formed on the surface thereof, and a magnetic sensor disposed to confront the surface of the rotary drums or discs, with magnetic resistance effect elements which vary in internal resistance in response to the magnetism of the magnetic poles being provided thereon. The amount of torsion created by the load on the load side of the rotary shaft is measured as a phase difference of outputs of the magnetic sensor, and the torque is detected in terms of the angular difference between the magnetic drums or discs. The device is operative to detect a torque in both storage and rotation, and capable of detection within a period of magnetic signal, whereby high-accuracy, high-resolution torque detection is made possible.
-
Citations
35 Claims
-
1. A torque detecting apparatus comprising:
-
a driving shaft and a driven shaft connected coaxially with said driving shaft by a torsion bar; a first drum fitted on said driving shaft and a second drum fitted on said driven shaft; magnetic signals recorded on the surface of said first and second drums; and a magnetic sensor for detecting the rotational angles of said first and second drums in a non-contact manner, said apparatus detecting a torque from a difference of rotational angles of said first and second drums, wherein said driving shaft and driven shaft are connected at free end portions thereof by a coupling bearing so that said shafts are allowed to have a relative rotation, and wherein said first and second drums are fitted on the external circumference of free ends of said driving shaft and driven shaft. - View Dependent Claims (2)
-
-
3. A torque detecting apparatus comprising rotary members, with magnetic members of a plurality of poles being provided thereon, fitted on both ends of a torsion bar;
- electromagnetic transducer elements disposed to confront said rotary members for detecting a relative displacement of said magnetic members; and
a signal processing circuit for measuring a torque from a signal detected by said electromagnetic transducer elements, said signal processing circuit comprising a waveform shaping circuit which produces pulses in response to the rotation of the magnetic members of one rotary member on the basis of the signal detected by said electromagnetic transducer elements, a differential voltage detecting circuit which produces a differential voltage from a relative displacement of both rotary members on the basis of the signal detected by said electromagnetic transducer elements, and an arithmetic circuit which evaluates a rotational angle and torque on the basis of signals provided by said circuits.
- electromagnetic transducer elements disposed to confront said rotary members for detecting a relative displacement of said magnetic members; and
-
4. A torque detecting apparatus designed to detect a torque transmitted along a certain rotary shaft and applied to the control of an assisting torque to be added to the torque output side of said rotary shaft in response to the result of detection, said apparatus comprising:
-
a non-contact sensor means comprising magnetic resistance effect elements for detecting said torque and producing a output waveform indicative thereof; a sensor signal processing means mounted on a base for processing said output waveform of said non-contact sensor means; and an electronic control means for controlling said assisting torque based on an output of said sensor signal processing means, said electronic control means being formed integrally with said sensor means and said sensor signal processing means as one control unit and fitted on a fixture for supporting said rotary shaft. - View Dependent Claims (5, 6, 7, 35)
-
- 8. A torque detecting apparatus for detecting a load torque from a relative angular difference of angles detected by angle detectors fitted at a certain interval on a shaft rotated by a drive source, said apparatus comprising two rotary drums or rotary discs with a plurality of magnetic poles for generating magnetic signals being provided on the surface thereof, and magnetic sensors disposed to confront said surface of said rotary drums or discs, with magnetic resistance effect elements which varies in internal resistance in response to the magnetism of said magnetic poles being provided thereon, a relative angular position of said rotary drums or rotary discs being taken out as a resistance variation of said magnetic resistance effect elements.
-
16. A torque detecting apparatus comprising a plurality of rotary drums fitted with a certain spacing on the drive side and load side of a rotary shaft, with signal tracks with a record of magnetic signals being formed on the surface thereof, and magnetic resistance effect elements disposed on a fixed portion which confront each of said drums, a relative displacement created by a torsion of rotational axis between said rotary drums being taken out as a resistance variation of said magnetic resistance effect elements, wherein one of said rotary drums is formed in a cup shape, and wherein said drums are fitted on said rotary shaft to meet a relation of Ld>
- Ls where Ld is a distance between positions on the shaft where said drums are fitted and Ls is a distance between the signal tracks, and wherein said plurality of magnetic resistance effect elements for detecting the magnetic signals on both rotary drums are formed by evaporative deposition or etching on a single substrate to form a single-chip magnetic sensor.
- 17. A torque detecting apparatus comprising a plurality of angle detectors fitted with a certain spacing on a rotational shaft which connects a load with a drive source and operates to detect a load torque from a relative angular difference of angles detected by said angle detectors, said apparatus comprising a plurality of rotary drums or rotary discs fitted with a certain spacing on the drive side and load side of said rotary shaft, with a plurality of magnetic poles for generating magnetic signals being formed on the surface thereof, and a magnetic sensor disposed to confront said surface of said rotary drums or discs, with magnetic resistance effect elements which vary in internal resistance in response to the magnetism of said magnetic poles being provided thereon, said magnetic sensor producing two sets of outputs with a virtually sinusoidal waveform in correspondence to angles of said rotary drums or discs, an angular difference of the two set of sinusoidal outputs being calculated to detect a torque.
- 23. A torque detecting apparatus comprising a plurality of angle detectors fitted with a certain spacing on a rotational shaft which connects a load with a drive source and operates to detect a load torque from a relative angular difference of angles detected by said angle detectors, said apparatus comprising a plurality of rotary drums or rotary discs fitted with a certain spacing on the drive side and load side of said rotary shaft, with a plurality of magnetic poles for generating magnetic signals being formed on the surface thereof, and a magnetic sensor disposed to confront said surface of said rotary drums or discs, with magnetic resistance effect elements which vary in internal resistance in response to the magnetism of said magnetic poles being provided thereon, said magnetic sensor producing two sets of outputs with a virtually triangular waveform in correspondence to angles of said rotary drums or discs, an angular difference of the two sets of triangular outputs being calculated to detect a torque.
- 29. A torque detecting apparatus comprising a plurality of angle detectors fitted with a certain spacing on a rotational shaft which connects a load with a drive source and operates to detect a load torque from a relative angular difference of angles detected by said angle detectors, said apparatus comprising a plurality of rotary drums or rotary discs fitted with a certain spacing on the drive side and load side of said rotary shaft, with a plurality of magnetic poles for generating magnetic signals being formed on the surface thereof, and a magnetic sensor disposed to confront said surface of said rotary drums or discs, with magnetic resistance effect elements which vary in internal resistance in response to the magnetism of said magnetic poles being provided thereon, said magnetic sensor producing two sets of outputs in correspondence to angles of said rotary drums or discs, and apparatus further comprising a ROM (memory) which stores angles corresponding to the waveform of the outputs, the angular difference of the two sets of outputs being calculated from the output of said ROM.
Specification