CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/KR2018/004769, filed Apr. 25, 2018, which claims priority to Korean Patent Application No. 10-2017-0052956, filed Apr. 25, 2017, whose entire disclosures are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a sensing device.

BACKGROUND ART

Electronic Power Steering Systems (hereinafter, referred to as ‘EPS’) allow an electronic control unit (ECU) to drive a motor according to driving conditions to secure turning stability and provide quick resilience so as to allow a driver to safely drive a vehicle.

To provide appropriate torque, an EPS includes a torque sensor that measures torque of a steering shaft. The steering shaft may include an input shaft connected with a steering wheel and an output shaft connected with power transfer components of wheels.

The torque sensor measures a degree of distortion between the input shaft and the output shaft to measure torque being applied to the steering shaft. The torque sensor may include a housing, a rotor, a stator, and a sensor part.

In this case, the stator may include a stator ring and a stator holder to which the stator ring is fixed.

According to the rotation of the steering wheel, the stator holder connected with the output shaft is also rotated.

Further, as a rotating force is continuously applied to the stator holder, a gap between the stator ring and the stator holder, which are coupled, increases. Therefore, a problem occurs in that the stator ring moves in a circumferential direction.

Particularly, since an R-type EPS is installed in an engine room, the R-type EPS requires a higher mechanical condition than a C-type EPS. For example, the C-type EPS requires a temperature condition of 40 to 85° C., but the R-type EPS requires a temperature condition of −40 to 125° C.

Therefore, to satisfy enhanced reliability requirements, a coupling force between the stator holder and the stator ring is increased, and thus an increase in gap due to a continuous rotating force can be prevented.

DISCLOSURE

Technical Problem

The present invention is directed to providing a sensing device which increases a coupling force between a stator holder and a stator ring to prevent a gap between the stator holder and the stator ring due to a rotation of the stator holder.

Particularly, the present invention is directed to providing a sensing device which increases a caulking force in a rotation direction using at least two protrusions formed in the stator ring.

The problem to be solved by the present invention is not limited to the above-described problem, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following descriptions.

Technical Solution

One aspect of the present invention provides a sensing device which includes a rotor and a stator disposed on an outside of the rotor, wherein the stator includes a stator holder and a stator ring disposed in the stator holder, the stator ring includes a body, a plurality of teeth formed to protrude from an inner circumferential surface of the body, and a protrusion part formed to protrude from an outer circumferential surface of the body, and the protrusion part is disposed between the teeth when viewed in a radial direction and is provided as two or more protrusions disposed to be spaced apart from each other.

The stator holder may include a stator ring-fixing part and a shaft-fixing part, and the protrusions may be coupled to an outer surface of the stator ring-fixing part in a caulking manner.

The stator ring-fixing part may be formed of a synthetic resin.

The stator holder may include a stator ring-fixing part and a shaft-fixing part, the stator ring-fixing part may include a fixing part-main body and a flange that protrudes from an outer circumferential surface of the fixing part-main body in the radial direction, and the protrusions may be fixed to the flange in a caulking manner.

Grooves may be formed in the flange by the caulking, and the protrusions may be supported by holding-protrusion surfaces formed in the grooves.

The stator holder may include a stator ring-fixing part and a shaft-fixing part, wherein the stator ring-fixing part may include the fixing part-main body and the flange that protrudes from an outer circumferential surface of the fixing part-main body in the radial direction, and the protrusions may be bent and disposed in the grooves of the flange.

A ratio of a distance (d) between the protrusions to a width (W) of the protrusion may be 1:1.5.

One surface of the protrusion may be formed to be inclined from a virtual line (L), which passes through a center of the protrusion, at a predetermined angle (θ).

A width of the protrusion may increase in a direction away from the body.

The protrusion may be formed in a trapezoid form.

The body, the teeth, and the protrusions may be integrally formed, and the teeth and the protrusions may protrude in the same direction.

A height of the protrusion may be smaller than that of the tooth.

The sensing device may further include a sensing unit configured to measure a magnetic field generated between the rotor and a stator assembly.

Advantageous Effects

A sensing device according to embodiments can increase a coupling force between a stator holder and a stator ring using a protrusion part that includes two or more protrusions spaced apart from each other.

In this case, contact areas and a coupling force in a rotation direction between the protrusions and the stator holder is increased using a caulking method, and thus movement of the stator ring due to a rotation of the stator holder can be prevented or minimized.

That is, when a caulking force between the stator ring and the stator holder is increased, the protrusions of the stator ring are fixed to the stator holder, and thus movement of the stator ring due to the rotation of the stator holder can be prevented.

Various and advantageous advantages and effects of the embodiments are not limited to the above descriptions and will be more easily understood in a process of describing specific embodiments of the present invention.

