Board mounted microelectromechanic system (MEMS) sensors for motor diagnostics and analytics

Patent metadata

Field	Value
Publication number	US-10717643-B2
Application number	US-201715716977-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Sep 27, 2017
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

A motor having a circuit board including at least two MEMS sensors. The circuit board is mounted within a housing of the motor using the same fasteners as an encoder of the motor. Mounting the MEMS sensors to the circuit board simplifies assembly of the motor and standardizes the positioning of the MEMS sensors within the housing, while the overall motor footprint is unaffected.

First claim

The following is claimed:

1. A motor assembly comprising: a housing; an output shaft supported by the housing; and a circuit board at least partially surrounding opposite sides of the output shaft and having at least two MEMS sensors mounted thereto, wherein the circuit board has at least a partial annular shape and the at least two MEMS sensors are mounted at approximately diametrically opposed locations on the circuit board, and wherein the circuit board is mounted within the housing with the at least two MEMS sensors and an axis of rotation of the output shaft being approximately collinear.

2. The motor assembly of claim 1 , wherein the circuit board is secured to the housing at first and second locations, said first and second locations being approximately collinear with the at least two MEMS sensors.

3. The motor assembly of claim 2 , wherein first and second fasteners are used to secure the circuit board to the housing at the respective first and second locations.

4. The motor assembly of claim 3 , further comprising an encoder, wherein said encoder is secured to the housing with the first and second fasteners.

5. The motor assembly of claim 4 , wherein the circuit board at least partially surrounds at least one of the output shaft or a shaft of the encoder.

6. The motor assembly of claim 4 , wherein the circuit board and encoder are mounted in a common compartment within the housing.

7. The motor assembly of claim 2 , further comprising a third mounting location, the third mounting location providing a ground path for grounding the circuit board.

8. The motor assembly of claim 1 , wherein the at least two MEMS sensors are multi-axis MEMS sensors mounted to the circuit board with at least one axis oriented in opposite directions.

9. A circuit board mountable concentrically with an axis of rotation of an associated shaft, the circuit board comprising a substrate and first and second MEMS sensors mounted on the substrate, wherein the substrate has a semi-annular shape having an outer circumferential curved edge having a first radius of curvature, an inner circumferential curved edge having a second radius of curvature, and first and second edges extending between the outer circumferential curved edge and the inner circumferential curved edge, wherein the outer circumferential edge and inner circumferential edge have a common point of curvature, and wherein the MEMS sensors are mounted to the substrate at diametrically opposed locations such that a centerline between the MEMS sensors extends through the point of curvature.

10. The circuit board of claim 9 , wherein the first and second edges delimit slot in the circuit board for receiving an associated shaft such that the substrate can be positioned about the associated shaft with the axis of rotation of the associated shaft centered between and collinear with the first and second MEMS sensors.

11. The circuit board of claim 9 , further comprising first and second mounting holes, the mounting holes being in line with the first and second MEMS sensors.

12. The circuit board of claim 11 , wherein the first mounting hole is located radially inwardly from the first MEMS sensor and the second mounting hole is located radially inwardly from the second MEMS sensor.

13. The circuit board of claim 12 , wherein the mounting holes are diametrically opposed from each other.

14. The circuit board of claim 11 , further comprising a third mounting hole located equidistant from the first and second mounting holes.

15. A method of assembling a motor comprising:
providing a circuit board having a substrate and first and second MEMS sensors mounted on the substrate, wherein the substrate has a semi-annular shape having an outer circumferential curved edge having a first radius of curvature, an inner circumferential curved edge having a second radius of curvature, and first and second edges extending between the outer circumferential curved edge and the inner circumferential curved edge, wherein the outer circumferential edge and inner circumferential edge have a common point of curvature, and wherein the MEMS sensors are mounted to the substrate at diametrically opposed locations such that a centerline between the MEMS sensors extends through the point of curvature, positioning the circuit board in a compartment of a housing of the motor such that the MEMS sensors are collinear with an axis of rotation of an output shaft of the motor, positioning an encoder in the compartment, and securing the circuit board and the encoder to the housing using at least one common fastener.

Assignees

• Rockwell Automation Tech Inc

Inventors

• Yee Kristin N
• Melfi Michael J
• Yuan Zhenhuan
• Balcerak John A
• Guru Arun K

Classifications

• G01D11/24 Primary

  Housings {; Casings for instruments} · CPC title

• G01D11/30

  Supports specially adapted for an instrument; Supports specially adapted for a set of instruments · CPC title

• G01D11/245

  Housings for sensors · CPC title

• H02P1/02

  Details {of starting control} · CPC title

• B81B3/0075 Primary

  For improving wear resistance · CPC title