Electric motor support structure and power equipment unit incorporating same

Patent metadata

Field	Value
Publication number	US-9472992-B2
Application number	US-201313939708-A
Country	US
Kind code	B2
Filing date	Jul 11, 2013
Priority date	Jul 11, 2013
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

An outdoor power equipment unit such as a string trimmer, and an electric motor support structure for use with the same. The structure may form a cage that surrounds the motor and secures the motor in place relative to an outermost shell of a motor housing of the string trimmer. The cage may electrically and/or thermally insulate the outermost shell from the motor.

First claim

What is claimed is:

1. A string trimmer comprising:
a battery;
an elongate shaft having a first end and a second end;
a handle located at the first end of the elongate shaft;
a motor housing secured to the second end of the elongate shaft, the motor housing comprising:
an electric motor having an output shaft, wherein the electric motor is connected to the battery such that the electric motor is powered by the battery;
a metallic outermost shell surrounding the electric motor and comprising one or more vents, wherein the output shaft protrudes outwardly through the outermost shell;
a cutting head attached to the output shaft such that the cutting head is located outside of the outermost shell;
a support cage comprising a plastic material, the support cage located in an annular region between the outermost shell and the electric motor, wherein the support cage is adapted to support the electric motor in spaced-apart relation to the outermost shell and electrically insulate the motor from the outermost shell; and
one or more filter elements to filter air passing through the one or more vents of the metallic outermost shell, wherein the one or more filter elements are disposed between the one or more vents of the metallic outermost shell and the support cage.

2. The trimmer of claim 1 , further comprising resilient pads compressed between the support cage and the electric motor.

3. The trimmer of claim 1 , wherein the handle comprises a trigger switch adapted to energize the electric motor.

4. The trimmer of claim 1 , wherein the handle defines a receptacle adapted to receive the battery.

5. The trimmer of claim 1 , wherein the battery provides a maximum output voltage of 24 volts DC or more.

6. The trimmer of claim 1 , wherein the battery provides a maximum output voltage of 48 volts DC.

7. The trimmer of claim 1 , wherein one or both of the outermost shell and the support cage comprise mating, semi-cylindrical halves.

8. The trimmer of claim 1 , wherein the plastic material comprises a polyimide material.

9. The trimmer of claim 1 , wherein the support cage is further adapted to thermally insulate the electric motor from the outermost shell.

10. The trimmer of claim 1 , wherein the support cage further comprises a plurality of openings passing completely through the support cage, the plurality of openings adapted to permit air flow through the support cage.

11. The trimmer of claim 1 , wherein the support cage comprises inner surfaces defining a shaped interior space, the inner surfaces adapted to receive the motor in a nesting relationship.

12. The trimmer of claim 1 , wherein the outermost shell comprises inner surfaces that define the annular region and are adapted to receive the support cage in a nesting relationship.

13. A motor housing for an electric outdoor power equipment unit, the housing comprising:
a metallic outermost shell comprising one or more vents;
an electric motor surrounded by the outermost shell, the electric motor comprising an output shaft that protrudes outwardly through the outermost shell;
a support cage comprising a rigid material, the support cage contained within the outermost shell within an annular region between the outermost shell and the electric motor, wherein the support cage is adapted to support the electric motor in spaced-apart relation to the outermost shell, and further wherein the support cage comprises a non-conductive material that electrically insulates the motor from the outermost shell; and
one or more filter elements to filter air passing through the one or more vents of the metallic outermost shell, wherein the one or more filter elements are disposed between the one or more vents of the metallic outermost shell and the support cage.

14. The housing of claim 13 , further comprising resilient pads compressed between the support cage and the electric motor.

15. The housing of claim 13 , wherein one or both of the outermost shell and the support cage comprise mating, semi-cylindrical halves.

16. The housing of claim 13 , wherein the support cage comprises a plastic material.

17. The housing of claim 13 , wherein the support cage comprises a plurality of perforations adapted to allow air circulation through the cage.

18. The housing of claim 13 , wherein the support cage is further adapted to thermally insulate the electric motor from the outermost shell.

19. The housing of claim 13 , further comprising an impeller attached to the output shaft, the impeller adapted to draw the air into the outermost shell through the one or more vents and exhaust heated air outwardly through one or more exhaust vents.

20. The housing of claim 13 , wherein the electric motor is a direct current (DC) electric motor.

Assignees

• The Toro Co

Inventors

• Shaffer Chadwick A

Classifications

• H02K5/08 Primary

  Insulating casings · CPC title

• A01D34/416

  Flexible line cutters · CPC title

• A01D34/90

  for carrying by the operator · CPC title

• H02K7/145

  Hand-held machine tool · CPC title

• H02K5/10

  with arrangements for protection from ingress, e.g. water or fingers · CPC title