Step motor and indicator instrument for vehicle

Patent metadata

Field	Value
Publication number	US-11274730-B2
Application number	US-201916566125-A
Country	US
Kind code	B2
Filing date	Sep 10, 2019
Priority date	Apr 13, 2017
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A step motor that rotationally drives a rotating body includes: an output gear having an output shaft that rotates around a rotation center line together with the rotating body, and a final gear extending radially outward from the output shaft; a radial bearing having an inner circumference side that radially supports the output shaft, on one side of the final gear in an axial direction; a reduction gear mechanism having a first reduction gear meshed with the final gear, and a second reduction gear meshed with the first reduction gear on the one side of the final gear in the axial direction; and a protrusion protruding from the radial bearing toward the other side in the axial direction, in a specific area extending from a longitudinal cross section of the output gear including the rotation center line to an opposite side away from the first reduction gear.

First claim

What is claimed is:

1. A step motor that rotationally drives a rotating body having a rotation shaft, comprising:
an output gear having an output shaft formed in a cylindrical shape surrounding the rotation shaft to rotate around a rotation center line together with the rotating body, and a final gear extending radially outward from the output shaft;
a radial bearing having an inner circumference side that radially supports the output shaft, on one side of the final gear in an axial direction;
a reduction gear mechanism having a first reduction gear meshed with the final gear, and a second reduction gear meshed with the first reduction gear on the one side of the final gear in the axial direction; and
a protrusion protruding from the radial bearing toward the other side in the axial direction, in a specific area extending from a longitudinal cross section of the output gear including the rotation center line to an opposite side away from the first reduction gear, wherein
the protrusion is provided at least at a position, in the specific area, opposite to the first reduction gear through the rotation center line in a radial direction, and
a radial gap is defined between the protrusion and the output shaft inserted in the radial bearing.

2. The step motor according to claim 1 , wherein
the protrusion is provided to spread over an entire area around the rotation center line in the specific area.

3. The step motor according to claim 1 , wherein
the protrusion is one of a plurality of protrusions provided dispersedly around the rotation center line in the specific area.

4. The step motor according to claim 1 , wherein
the protrusion radially supports an outer circumference side of the output shaft inserted in the radial bearing.

5. An indicator instrument for a vehicle comprising:
the step motor according to claim 1 ; and
a rotation indicator that indicates a vehicle state value as the rotating body.

6. The step motor according to claim 1 , wherein the protrusion is provided within a range less than or equal to 180 degrees around the rotation center line in the specific area.

Assignees

• Denso Corp

Inventors

• Sasaki Tatsuya

Classifications

• B60K35/23

  Head-up displays [HUD] (optical aspects of head-up displays G02B27/01) · CPC title

• B60K35/60

  Instruments characterised by their location or relative disposition in or on vehicles (arrangements of lighting devices on dashboards B60Q3/10) · CPC title

• F16H1/20 Primary

  involving more than two intermeshing members · CPC title

• H02K37/10

  of permanent magnet type (H02K37/02 takes precedence) · CPC title

• H02K7/116 Primary

  with gears · CPC title