Motor-fan unit with thermal device
A motor-fan unit includes a thermal device serving to monitor the operating temperature of the motor-fan unit. The thermal device is secured to the motor-fan unit through a frictional fit between the thermal device and a cavity provided in an end plate assembly and the field laminations of the motor-fan unit.
The present invention generally relates to motor-fan units. More particularly, the present invention relates to the placement of a thermal device within a motor-fan unit. Most particularly, the present invention relates to a motor-fan unit having a thermal device assembly that is mounted in a cavity in a motor bracket portion, sandwiched between the motor bracket portion and the field laminations of the motor-fan unit.
BACKGROUND OF THE INVENTIONElectronic motors and generators are well known in the art and have been put to use in a variety of applications. One application is the handling of air by what will be termed herein as a “motor-fan unit.” In these motor-fan units, an electric motor is coupled with a fan to create a flow of air to be employed for any of a number of purposes, for example, to draw a vacuum. Often, the fan is used not only to produce a flow of useful air but also to provide cooling air to the motor. A fan mounted on a shaft driven by the motor draws air into a fan shroud to compress or pressurize the air. The pressurized air is released into the motor housing to flow across the motor windings to draw heat into the flow and exhaust it from the motor housing.
Referring to
Motor assembly 12 is configured with commutator 18 closest to fan assembly 14. Fan assembly 14 of motor-fan unit 10 includes fan 26 coupled to one end 27 of shaft 20, as by nut, such that it rotates therewith. Fan assembly 14 is received by diffuser assembly 28 (a radial diffuser is shown, but other diffuser assemblies, such as a ported diffuser could be employed), and shroud 30 encapsulates both diffuser assembly 35 and fan 26. As known in the art, shroud 30 is provided with axial port 31, coaxial with axis A of shaft 20, through which outside air is drawn by fan 26. As shaft 20 and thus fan 26 is rotated by motor 16, fan 26 draws in air at port 31 and forces the air through diffuser assembly 35, which is configured to distribute air as needed according to the desired use of motor-fan unit 10. The motor assembly 12 includes an end plate assembly, generally indicated by the numeral 35, to enclose the motor and support the brushes. The end plate assembly 35 generally includes a planar plate portion 36, which may be annular as shown, and, a motor bracket portion 37 extending from the plate portion toward the motor 16. The bracket portion 37 is adapted to support the motor assembly 15.
These motor-fan units may be sealed or unsealed systems, and may permit differing degrees of air flow through the system. A more open system, with good air through flow, typically runs at high amps, while a more sealed system, with poorer air through flow, runs at lower amps. In operation, each system builds up heat that can destroy motor parts if permitted to build, and, therefore, thermal devices are often employed to monitor the temperature or amperage or both of a motor-fan unit and shut down the motor when the temperature being monitored rises above a set selected threshold.
As shown in
Thus, there exists a need in the art for a new concept for the placement of a thermal device in a motor-fan unit. The thermal device should monitor an area of the motor-fan unit that more accurately reflects the heat building up in the system, and should be mounted in a manner more easily and inexpensively manufactured.
SUMMARY OF THE INVENTIONA motor-fan unit comprising: an end plate assembly having a motor bracket portion providing a cavity, field laminations axially displaced from and located adjacent said cavity, and a thermal device having a mount end inserted into said cavity, said thermal device being secured to the motor-fan unit through a frictional fit established by the contact between said thermal device and said cavity and said field laminations. Independent claims to be added before filing.
Referring now to
As can be seen, the thermal device 200 is received, at a mount end 202 thereof, in motor bracket portion 137 of end plate assembly 135. More particularly, the motor bracket portion 137 is bowed outwardly as at 138 to provide a cavity 150 that can receive the mount end 202 of the thermal device 200. The remainder of the thermal device 200 extends out of the cavity 150 along side the field laminations 152. Preferably a frictional fit is established between mount end 202 and bowed portion 138 and field laminations 152. A sensor 204 is mounted at the field laminations 152, and is enclosed in a Mylar pocket 206. As seen in
The thermal device 200, particularly the sensor 204, measures the general ambient temperature at the locality where it is place, and does not inappropriately measure the amperage or temperature at the field coil. As a result, it is a more reliable thermal device, because it will not incorrectly process that the motor-fan unit is operating at an acceptable temperature, as it might if it were mounted to the field coil. The thermal device 200 and the adaptation made to motor bracket portion 137 also permit the thermal device 200 to be more easily mounted to a motor-fan unit, negating the need for taping and/or cable ties. This will decrease the cost of manufacture.
In light of the foregoing, it should thus be evident that the process of the present invention, providing a motor-fan unit with a thermal device, substantially improves the art. While, in accordance with the patent statutes, only the preferred embodiments of the present invention have been described in detail herein above, the present invention is not to be limited thereto or thereby. Rather, the scope of the invention shall include all modifications and variations that fall within the scope of the attached claims.
Claims
1. A motor-fan unit comprising:
- an end plate assembly having a motor bracket portion providing a cavity;
- field laminations axially displaced from and located adjacent said cavity; and
- a thermal device having a mount end inserted into said cavity, said thermal device being secured to the motor-fan unit through a frictional fit established by the contact between said thermal device and said cavity and said field laminations.
Type: Application
Filed: Dec 29, 2006
Publication Date: Jul 3, 2008
Inventor: David Finkenbinder (Ravenna, OH)
Application Number: 11/647,951