US20100031529A1

US20100031529A1 - Clothes dryer motor with broken belt switch

Info

Publication number: US20100031529A1
Application number: US12/579,090
Authority: US
Inventors: Philip S. Johnson; Marshall J. Huggins; Michael Peebles; John R. Holden
Original assignee: Emerson Electric Co; BSH Home Appliances Corp
Current assignee: Emerson Electric Co; BSH Home Appliances Corp
Priority date: 2006-10-13
Filing date: 2009-10-14
Publication date: 2010-02-11
Also published as: US20080088989A1; US7609491B2

Abstract

A clothes dryer includes a motor adapted to be mounted on a frame of the dryer for driving a dryer belt to rotate a drum of the dryer. The motor includes a rotor adapted to rotate the belt, at least one winding energizable to cause rotation of the rotor, and a first switch operable to control energization of the winding. A second switch has a sensor for sensing belt breakage. The second switch is mounted on the first switch and is electrically connected to the winding so that when the belt is no longer sensed, the second switch stops operation of the winding and thereby stops rotation of the rotor.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of co-pending U.S. patent application Ser. No. 11/549,192 filed Oct. 13, 2006, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to electric appliances such as clothes dryers, and more particularly to motors and drive belts for use in clothes dryers.

BACKGROUND OF THE INVENTION

Conventional clothes dryers generally include a drum for receiving clothes therein, a heater, and a drive belt and motor for turning the drum to facilitate clothes drying. It is well known that the dryer should automatically turn off the heater and the motor when the belt breaks. A variety of conventional systems sense belt breakage and turn off the heater and motor. Some include a switch, separate from a switch in the motor, e.g., mounted on the dryer frame, that is operable to sense belt breakage and is wired into the dryer to turn off the heater and motor. Although these prior art systems are generally satisfactory, applicants have discovered a better system to sense belt breakage and to turn off the heater and motor.

SUMMARY OF THE INVENTION

In one aspect of the invention, a clothes dryer motor is adapted to be mounted on a frame of the dryer for driving a dryer belt to rotate a drum of the dryer. The motor includes a rotor adapted to rotate the belt, at least one winding energizable to cause rotation of the rotor, and a first switch operable to control energization of the winding. A second switch has a sensor for sensing belt breakage. The second switch is mounted on the first switch and is electrically connected to the winding so that when the belt is no longer sensed, the second switch stops operation of the winding and thereby stops rotation of the rotor.
In another aspect, the motor includes a motor frame mountable on the dryer frame and has an outwardly facing surface. A belt break switch is mounted on the surface of the motor frame adjacent the belt and having an arm disposed to sense dryer belt breakage, the switch operable to inhibit power to the motor when the dryer belt breaks.
In another aspect, the clothes dryer motor includes a main winding, a start winding operable to cause rotation of the rotor at motor start-up, and a protector assembly electrically connected to the main and start windings. A main switch is operable to stop operation of the start winding at a predetermined rotor speed. A frame mounts the rotor, the windings, the protector assembly and the main switch, and the frame has an outwardly facing surface. The protector assembly includes a belt switch mounted on the outwardly facing surface of the frame and operable to stop operation of the motor in response to arm movement indicating a belt malfunction.
In other aspects, a clothes dryer includes one of the above-described motors. Also, various refinements exist of the features noted in relation to the above-mentioned aspects of the present invention. Further features may also be incorporated in the above-mentioned aspects of the present invention as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments of the present invention may be incorporated into any of the above-described aspects of the present invention, alone or in any combination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of a dryer including a motor of one embodiment of the invention.

FIG. 2 is an enlarged perspective of the motor of FIG. 1.

FIG. 3 is like FIG. 2 but showing a broken belt condition.

FIG. 4 is an electrical schematic of the components connected to main and start windings of the motor.

Corresponding reference characters indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1-2, a motor of one embodiment of the invention is generally designated by 11. The motor 11 is mounted in a dryer 13 having a dryer frame generally designated by 15. The motor 11 generally includes a stator 17 having windings 19 and a stator core 21 including laminations. A rotor generally designated by 23 is magnetically coupled to the stator 17 and has a rotor core and a rotor shaft 25. In this embodiment, the windings 19 include a main winding (27 in FIG. 4) generally operable to cause rotation of the rotor 23 and a start winding 29 generally operable to cause rotation of the rotor at motor start-up. The motor 11 also includes a motor frame 31 including endshields 33 secured to the stator core 21.
In this embodiment, one end of the rotor shaft 25 has a grooved pulley 35 on which a belt 36 is mounted for rotating a dryer drum 37. The belt 36 extends partially around an idler pulley 39 that is rotatably mounted on an idler arm and thereby mounted on the dryer frame 15. In this embodiment, as is conventional, the belt 36 is biased by a spring 41 to tension the belt. Note that the belt 36 extends around the drum 37 as is conventional, but may be otherwise connected to rotate or drive the drum.
Referring to FIG. 4, a schematic shows wiring of the components of this embodiment. A first or main switch 51 is operable to control energization of the main windings 27, and includes a centrifugal actuator 53 to control energization of the start winding 29. A motor protector 55 is electrically connected to the main and start windings 27, 29. The main switch 51, centrifugal actuator 53, protector 55, and the remainder of the components may be conventional, including an optional customer circuit and an optional push-to-start feature.
A second or belt break switch 59 has a sensor generally for sensing the belt 36. The break switch 59 is electrically connected in series with the main and start windings 27, 29 via the protector 55.
The sensor of the break switch 59 is an arm 61 extending from the break switch and disposed for contact with the belt 36. The belt break switch 59 is electrically connected to the winding so that when the belt is no longer sensed, the break switch open circuits the main and start windings 27, 29 to stop energization of the windings and thereby stop rotation of the rotor 23. The break switch 59 is physically mounted on an outwardly facing surface of the motor frame 31. In this embodiment, the outwardly facing surface is that of a mounting plate 63 that is mounted on the main switch 51. Note that the break switch 59 can be mounted differently on the motor 11 without departing from the scope of this invention. In one embodiment, the break switch 59, the main switch 51, and the motor frame 31 are provided as an integral unit and the connections between the second switch and the main switch are pre-wired, e.g., using a jumper as shown. This arrangement eliminates the need for a separate harness to connect the main switch 51 to the break switch 59.
The break switch 59 is a normally closed (NC) microswitch adapted for automatic reset, so that the switch automatically resets after replacement of the broken belt. However, many other types of switches are contemplated as being within the scope of the invention.
When the belt 36 breaks, the idler pulley 39 moves due to the spring 41 and triggers the arm of the break switch 59 to open the switch. Opening the switch causes power to be cut or inhibited to the windings, and thus the motor is stopped.
The dryer 13 also includes a heater that is wired into the “customer circuit” shown in FIG. 4. The motor and dryer are wired together such that opening of the break switch causes the heater operation to cease along with the motor.
When introducing elements of various aspects of the present invention or embodiments thereof, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, the use of “top” and “bottom”, “front” and “rear”, “above” and “below”, and variations of these and other terms of orientation is made for convenience, but does not require any particular orientation of the components.
As various changes could be made in the above constructions, methods and products without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. A clothes dryer motor adapted to be mounted on a frame of a dryer for driving a dryer belt to rotate a drum of the dryer, the motor comprising:

a motor frame mountable on the dryer frame having an outward facing surface;

a stator mounted on the motor frame;

a rotor rotatably mounted for rotation within the stator;

a belt break switch mounted on the surface of the motor frame adjacent the belt and having an arm disposed to sense dryer belt breakage, the switch operable to inhibit power to the motor whenever the dryer belt is broken.

2. The dryer motor of claim 1 further comprising a main switch, wherein the break switch and the main switch are provided as an integral unit with connections between the break switch and the main switch being pre-wired.

3. The dryer motor of claim 1 wherein the break switch cuts power to the motor in response to movement of the arm.

4. The dryer motor of claim 3 wherein the arm is disposed to be moved by an idler arm of the dryer frame, the idler arm moving in response to belt breakage.

5. The dryer motor of claim 1 wherein the switch is an automatic reset switch so that the switch automatically resets after the broken belt is replaced.

6. A clothes dryer motor for rotating a drum of a dryer via a dryer belt, the motor comprising:

a rotor adapted to rotate the belt;

a main winding operably connected to the rotor to cause rotation of the rotor;

a start winding operably connected to the rotor to cause rotation of the rotor at motor start-up;

a protector assembly electrically connected to the main winding and the start winding;

a main switch operably connected to the start winding to stop the start winding from operating when the rotor reaches a predetermined speed; and

a motor frame for mounting the rotor, the main winding, the start winding, the protector assembly, and the main switch, the frame having a surface, the protector assembly including a belt switch having an arm, the belt switch being mounted on the surface of the frame and operable to stop operation of the motor whenever a belt malfunction occurs.

7. The dryer motor of claim 6 wherein the protector assembly is in series with the main winding and the start winding.

8. The dryer motor of claim 6 wherein the belt switch, the main switch, and the motor frame are provided as an integral unit and connections between the belt switch and the main switch are pre-wired.

9. A clothes dryer comprising:

a dryer frame;

a drum rotatably mounted on the dryer frame;

a belt connected to the dryer frame for rotation thereof; and

a motor mounted on the dryer frame and connected to the belt to rotate the belt and drum, the motor including:

a motor frame mounted on the dryer frame and having an outward facing surface; and

a belt break switch mounted on the surface of the motor frame adjacent the belt and having an arm disposed to sense belt breakage, the switch being operable to inhibit power to the motor whenever the dryer belt is broken.

10. The dryer of claim 9 wherein:

the motor further comprises a main switch; and

the break switch, the main switch, and the motor frame are provided as an integral unit with connections between the break switch and the main switch being pre-wired.

11. The dryer motor of claim 10 wherein the break switch cuts power to the motor in response to movement of the arm.

12. The dryer motor of claim 11 wherein:

the arm is disposed to be moved by an idler arm of the dryer frame; and

the idler arm moves in response to belt breakage.