EP3205944A1

EP3205944A1 - Convection fan

Info

Publication number: EP3205944A1
Application number: EP16205732.7A
Authority: EP
Inventors: David Mark Cink
Original assignee: Wolf Appliance Inc
Current assignee: Wolf Appliance Inc
Priority date: 2016-02-09
Filing date: 2016-12-21
Publication date: 2017-08-16
Also published as: US20170227238A1; AU2016277534A1

Abstract

A convection fan includes a plurality of blades mounted for rotation with a shaft, a guiding plate mounted to partially surround the plurality of blades, and a fan-motor mount. The fan-motor mount includes a top plate and a bottom plate through which the shaft extends, a motor fastener that mounts a motor to the bottom plate in isolation from the top plate, a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate, an insulator between the top plate and the bottom plate, and a plate fastener that mounts the top plate to the bottom plate. The plate fastener includes a fastener and a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break.

Description

BACKGROUND

A cross-flow or tangential fan is usually long in relation to its diameter, so the flow approximately remains two-dimensional away from its ends. The cross-flow fan uses an impeller with forward curved blades, placed in a housing consisting of a rear wall and a vortex wall. The cross-flow fan may be used in a convection oven where it is exposed to high temperatures sometimes exceeding 400 degrees Centigrade (800 degrees Fahrenheit).

SUMMARY

In an example embodiment, a convection fan is provided. The convection fan may include, but is not limited to, a plurality of blades mounted to a shaft to rotate when the shaft rotates, a guiding plate mounted to partially surround the plurality of blades, and a fan-motor mount. The fan-motor mount may include, but is not limited to, a top plate through which the shaft extends, a bottom plate through which the shaft extends, a motor fastener that mounts a motor to the bottom plate in isolation from the top plate, a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate, an insulator between the top plate and the bottom plate, and a plate fastener that mounts the top plate to the bottom plate. The plate fastener may include, but is not limited to, a fastener, and a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break.
In an example embodiment, a convection fan assembly is provided. The convection fan assembly may include, but is not limited to, a motor, a shaft connected to the motor, and a fan. The motor is configured to rotate the shaft. The fan may include, but is not limited to, a plurality of blades mounted to the shaft to rotate when the shaft rotates, a guiding plate mounted to partially surround the plurality of blades, and a fan-motor mount. The fan-motor mount may include, but is not limited to, a top plate through which the shaft extends, a bottom plate through which the shaft extends, a motor fastener that mounts the motor to the bottom plate in isolation from the top plate, a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate, an insulator between the top plate and the bottom plate, and a plate fastener that mounts the top plate to the bottom plate. The plate fastener may include, but is not limited to, a fastener, and a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break.
In another example embodiment, a convection oven is provided. The convection oven may include, but is not limited to, the convection fan, a plurality of walls that form an enclosure in which the convection fan is at least partially mounted, and a control to control operation of the convection fan.
Other principal features of the disclosed subject matter will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the disclosed subject matter will hereafter be described referring to the accompanying drawings, wherein like numerals denote like elements.

Fig. 1 depicts a front perspective view of a convection fan in accordance with an illustrative embodiment.
Fig. 2 depicts a front view of the convection fan of Fig. 1 in accordance with an illustrative embodiment.
Fig. 3 depicts a top, front perspective view of the convection fan of Fig. 1 in accordance with an illustrative embodiment.
Fig. 4 depicts a zoomed front view showing a motor mounting portion of the convection fan of Fig. 1 in accordance with an illustrative embodiment.
Fig. 5 depicts the zoomed front view of Fig. 4 with an insulator removed in accordance with an illustrative embodiment.
Fig. 6 depicts a top, back perspective view of a bottom flank and a motor mount and fasteners of the convection fan of Fig. 1 in accordance with an illustrative embodiment.
Fig. 7 depicts a top perspective view of the bottom flank of Fig. 6 in accordance with an illustrative embodiment.
Fig. 8 depicts a top perspective view of the motor mount of Fig. 6 in accordance with an illustrative embodiment.
Fig. 9 depicts a side perspective view of a standoff of a fan fastener in accordance with an illustrative embodiment.
Fig. 10 depicts a bottom perspective view of the standoff of Fig. 9 in accordance with an illustrative embodiment.
Fig. 11 depicts a front view of the motor mount and fasteners of Fig. 6 in accordance with an illustrative embodiment.
Fig. 12 depicts a zoomed front perspective view showing the motor mounting portion of the convection fan of Fig. 1 in accordance with an illustrative embodiment.
Fig. 13 depicts a bottom perspective view of the motor mount of Fig. 6 including the fan fastener in accordance with an illustrative embodiment.
Fig. 14 depicts a front perspective view of fasteners of the bottom flank and the motor mount of Fig. 6 in accordance with an illustrative embodiment.
Fig. 15 depicts a front perspective view of a convection oven with the convection fan of Fig. 1 in accordance with an illustrative embodiment.

DETAILED DESCRIPTION

Referring to Fig. 1, a front perspective view of a convection fan 100 is shown in accordance with an illustrative embodiment. Referring to Fig. 2, a front view of convection fan 100 is shown in accordance with an illustrative embodiment. Referring to Fig. 3, a top, front perspective view of convection fan 100 is shown in accordance with an illustrative embodiment. In the illustrative embodiment, convection fan 100 is a cross flow fan 100 that may be mounted in a convection oven to provide convective heat to items to be cooked.
For example, Fig. 15 shows a front perspective view of a convection oven 1500 with convection fan 100 in accordance with an illustrative embodiment. Convection oven 1500 may include a plurality of walls that define an enclosure in which the items to be cooked are placed as understood by a person of skill in the art. One or more controls 1504 of various types may be used to control operation of convection fan 100 as understood by a person of skill in the art. Illustrative controls include a knob or other user interface electrically, mechanically, or electromechanically connected to receive a user input as to a desired operation of convection oven 1500 and to control an operation of one or more heating elements, convection fan 100, and other components to achieve operation of convection oven 1500.
In the illustrative embodiment of Fig. 15, convection oven 1500 may include a first convection fan 1506 and a second convection fan 1508 mounted adjacent to two rear corners of the enclosure of convection oven 1500. A fewer or a greater number of convection fans may be included in convection oven 1500 and may be mounted in various locations and with different orientations than that shown as needed to achieve a desired convective heat distribution in the enclosure as understood by a person of skill in the art.
As used herein, the term "mount" includes join, unite, connect, couple, associate, insert, hang, hold, affix, attach, fasten, bind, paste, secure, hinge, bolt, screw, rivet, solder, weld, glue, form over, form in, layer, mold, rest on, rest against, abut, and other like terms. The phrases "mounted on", "mounted to", and equivalent phrases indicate any interior or exterior portion of the element referenced. These phrases also encompass direct mounting (in which the referenced elements are in direct contact) and indirect mounting (in which the referenced elements are not in direct contact, but are connected through an intermediate element) unless specified otherwise. Elements referenced as mounted to each other herein may further be integrally formed together, for example, using a molding or thermoforming process as understood by a person of skill in the art. As a result, elements described herein as being mounted to each other need not be discrete structural elements unless specified otherwise. The elements may be mounted permanently, removably, or releasably unless specified otherwise.
Use of directional terms, such as top, bottom, right, left, front, back, upper, lower, horizontal, vertical, behind, etc. are merely intended to facilitate reference to the various surfaces of the described structures relative to the orientations introduced in the drawings and are not intended to be limiting in any manner unless otherwise indicated.
Referring again to Figs. 1, 2, and 3, convection fan 100 may include a fan 102, a motor 104, and an electrical connector 106. Electrical connector 106 is connected to an electrical power source (not shown) to provide power to motor 104. Motor 104 is mounted to fan 102 to rotate a shaft 208 to circulate heated air in convection oven 1500. Motor 104 may be a direct current (DC) or an alternating current (AC) motor of a variety of different types including a stepper motor, an induction motor, etc.
Fan 102 may include shaft 208, a bearing housing 110, a top flank 112, a guiding plate 114, a vortex structure 116, a fan-motor mount 118, blades 200, one or more body disks 202, a top disk 204, and a bottom disk 206. A plurality of plate fasteners 308 mount fan 102 to motor 104. Fan 102 may include a greater or a fewer number of components. The one or more components of fan 102 may be formed of one or more materials, such as various metals (i.e., galvanized steel, stainless steel, aluminum, etc.), glass, and/or plastics having a sufficient strength and rigidity as well as thermal and permeability properties sufficient to support the described application.
The blades 200 may be forward curved blades. The blades 200 are elongated and mounted to each other to form a cylinder resulting in a long cylindrical impeller. The blades 200 are inserted through holes in the one or more body disks 202, in top disk 204, and in bottom disk 206. The one or more body disks 202, top disk 204, and bottom disk 206 provide stability to the blades 200. In an alternative embodiment, fan 102 may not include any of the one or more body disks 202.
Shaft 208 extends from motor 104 through fan-motor mount 118 and top flank 112 and into bearing housing 110 at a top of convection fan 100. The bearing housing 110 includes a bearing and associated elements that mount shaft 208 for rotation with a minimum of axial movement. The blades 200 are mounted for rotation with shaft 208.
A housing of fan 102 includes guiding plate 114, fan-motor mount 118, and top flank 112. Guiding plate 114 is mounted between fan-motor mount 118 and top flank 112. Guiding plate 114 may include a curved wall 300, a first mounting flange 210, and a second mounting flange 212. Curved wall 300 partially surrounds the blades 200 to direct air flow generated by rotation of the blades 200. First mounting flange 210 and second mounting flange 212 extend from curved wall 300 and are configured to provide surfaces through which convection fan 100 may be mounted to one or more of the walls of convection oven 1500. For example, first mounting flange 210 and second mounting flange 212 may include holes through which one or more fasteners may be used to mount convection fan 100 to convection oven 1500.
Vortex structure 116 also mounts between fan-motor mount 118 and top flank 112 and is positioned and shaped to direct air flow. Vortex structure 116 may include a bottom vortex flange 302, a first vortex wall 304, a second vortex wall 306, a bottom vortex fastener 214, a bottom screw 216, a top vortex flange (not shown), a top vortex fastener 218, and a top screw 220. First vortex wall 304 and second vortex wall 306 are mounted to each other to form a v-shape that opens outward though other shapes, numbers of walls, orientations, etc. may be used depending on a mounting location and a desired airflow within the enclosure of convection oven 1500. Bottom vortex fastener 214 and bottom screw 216 are mounted to bottom vortex flange 302 to mount first vortex wall 304 and second vortex wall 306 to fan-motor mount 118. Top vortex fastener 218 and top screw 220 are mounted to the top vortex flange to mount first vortex wall 304 and second vortex wall 306 to top flank 112. A fewer or a greater number of fasteners of various types may be used to mount first vortex wall 304 and second vortex wall 306 to top flank 112 and to fan-motor mount 118.
In a cross flow fan, air is drawn in over the entire length of the blades 200. The airflow is diverted and accelerated by first vortex wall 304 and second vortex wall 306. An area between first mounting flange 210 and second vortex wall 306 defines an airflow intake side of convection fan 100. An area between second mounting flange 212 and first vortex wall 304 defines an airflow discharge side of convection fan 100. The airflow also exits over the entire length of the blades 200. First vortex wall 304 directs an approximately uniform laminar airflow out of convection fan 100.
Referring to Fig. 4, a zoomed front view showing a motor mounting portion of convection fan 100 is shown in accordance with an illustrative embodiment. Referring to Fig. 5, the zoomed front view of Fig. 4 with an insulator 404 removed is shown in accordance with an illustrative embodiment. Fan-motor mount 118 may include a bottom flank 400, a motor mount 402, an insulator 404, the plurality of plate fasteners 308, and a plurality of motor mount housings 406. Insulator 404 fills a space between bottom flank 400 and motor mount 402. Insulator 404 is formed of an insulating material such as mica plate, insulation fiber, ceramic, glass, etc. In an alternative embodiment, no insulation may be provided between bottom flank 400 and motor mount 402 such that the space is filled with air. A distance between bottom flank 400 and motor mount 402 may be determined based on a space within which convection fan 100 is mounted and a thickness of insulator 404, if any.
Bottom vortex fastener 214 may include a screw 408 and a bottom nut 410 mounted to screw 408 to insure that bottom vortex flange 302 abuts a top surface of bottom flank 400. A nut may similarly be mounted to bottom screw 216. Bottom screw 216 and screw 408 may be identical. The plurality of plate fasteners 308 may each include a standoff 500 and a screw 502 that is inserted through standoff 500 to extend partially from a bottom of motor mount 402. The plurality of plate fasteners 308 mount bottom flank 400 to motor mount 402. The plurality of motor mount housings 406 each cover a motor fastener of a plurality of motor fasteners 504. The plurality of motor fasteners 504 mount motor 104 to motor mount 402 in isolation from bottom flank 400 that may be exposed to a heat within the enclosure of convection oven 1500. A plurality of guiding plate fasteners 506 mount guiding plate 114 to bottom flank 400.
Referring to Fig. 6, a top, back perspective view of bottom flank 400 and motor mount 402 are shown in accordance with an illustrative embodiment. Referring to Fig. 7, a top perspective view of bottom flank 400 is shown in accordance with an illustrative embodiment. Top flank 112 may include a plate similar to bottom flank 400. Bottom flank 400 may include a top plate 600, a first shaft aperture wall 602, a plurality of guiding plate fastener aperture walls 700, a plurality of fan fastener aperture walls 702, and a plurality of vortex fastener aperture walls 704. Top plate 600 is generally flat on both sides and is sized and shaped based on the arrangement of vortex structure 116 and guiding plate 114.
First shaft aperture wall 602, the plurality of guiding plate fastener aperture walls 700, the plurality of fan fastener aperture walls 702, and the plurality of vortex fastener aperture walls 704 form openings through top plate 600. First shaft aperture wall 602 is sized, shaped, and positioned to accommodate shaft 208. The plurality of guiding plate fastener aperture walls 700 are each sized, shaped, and positioned to accommodate a fastener shaft 1400 (shown referring to Fig 14) of a guiding plate fastener of the plurality of guiding plate fasteners 506 such that a head 1402 (shown referring to Fig 14) of the guiding plate fastener abuts a bottom surface of top plate 600. The plurality of fan fastener aperture walls 702 are each sized, shaped, and positioned to accommodate a fastener shaft 1408 (shown referring to Fig 14) of screw 502 such that a head 1410 (shown referring to Fig 14) of screw 502 abuts a top surface of top plate 600. The plurality of vortex fastener aperture walls 704 are each sized, shaped, and positioned to accommodate a fastener shaft 1412 (shown referring to Fig 14) of bottom screw 216 and of screw 408 of bottom vortex fastener 214 such that a head 1414 (shown referring to Fig 14) of bottom screw 216 and of screw 408 abuts a bottom surface of top plate 600.
Referring to Fig. 8, a top perspective view of motor mount 402 is shown in accordance with an illustrative embodiment. Motor mount 402 may include a bottom plate 604, a second shaft aperture wall 606, a plurality of standoff aperture walls 800, and a plurality of motor fastener aperture walls 802. Second shaft aperture wall 606 is sized, shaped, and positioned to accommodate shaft 208. The plurality of standoff aperture walls 800 are each sized, shaped, and positioned to accommodate a head 900 (shown referring to Fig. 9) of standoff 500. The plurality of motor fastener aperture walls 802 are each sized, shaped, and positioned to accommodate a fastener shaft 1404 (shown referring to Fig 14) of a motor fastener of the plurality of motor fasteners 504 such that a head 1406 (shown referring to Fig 14) of the motor fastener abuts a top surface of bottom plate 604 without contacting top plate 600.
Referring to Fig. 9, a side perspective view of standoff 500 is shown in accordance with an illustrative embodiment. Referring to Fig. 10, a bottom perspective view of standoff 500 is shown in accordance with an illustrative embodiment. Standoff 500 may include a head 900 and a body 902. For illustration, standoff 500 may be formed any metal or hard material such as steel, stainless steel, zinc, ceramic, glass, copper, etc. Standoff 500 is pressed into place, for example, using a pneumatic press.
Head 900 may include a bottom surface 1000, a side wall 904, and a top surface 906. Side wall 904 extends between bottom surface 1000 and top surface 906. Head 900 may form a hexagon though head 900 may have other shapes in other embodiments. For example, head 900 may form another polygon, a circle, an ellipse, etc.
Body 902 may include a first cylinder wall 908, a second cylinder wall 910, a wall outer surface 912, an inner aperture wall 914, and a score 916. In the illustrative embodiment, body 902 is generally cylindrical though body 902 may have other shapes in other embodiments. For example, body 902 may form a polygon, an ellipse, etc. First cylinder wall 908 extends from and is generally perpendicular to top surface 906. Second cylinder wall 910 extends from first cylinder wall 908. First cylinder wall 908 and second cylinder wall 910 form a cylinder with an inner aperture wall 914 though first cylinder wall 908 has a smaller circumference than second cylinder wall 910. As a result, a shelf (not shown) provides a transition between first cylinder wall 908 and second cylinder wall 910.
Inner aperture wall 914 also extends through head 900 to allow insertion of screw 502 through standoff 500. Outer surface 912 extends between an outer surface of second cylinder wall 910 and inner aperture wall 914. A score 916 is formed as a u-shaped valley in the outer surface of second cylinder wall 910.
Referring to Fig. 11, a front view of motor mount 402 is shown in accordance with an illustrative embodiment. Motor mount 402 is shown transparent so that standoff 500 extending through motor mount 402 is visible. Referring to Fig. 12, a zoomed front perspective view showing the motor mounting portion of convection fan 100 is shown in accordance with an illustrative embodiment. Referring to Fig. 13, a bottom perspective view of motor mount 402 is shown including fan fastener 308 in accordance with an illustrative embodiment. Referring to Fig. 14, a front perspective view of fasteners of bottom flank 400 and motor mount 402 are shown in accordance with an illustrative embodiment.
Head 900 is pressed into bottom plate 604 of motor mount 402 until the shelf formed between first cylinder wall 908 and second cylinder wall 910 abuts a top surface of bottom plate 604 of motor mount 402. Fastener shaft 1408 of screw 502 is inserted within inner aperture wall 914 until screw head 1410 of screw 502 abuts a top surface of top plate 600 of bottom flank 400.
The plurality of plate fasteners 308 are the only components that contact both bottom plate 604 and top plate 600. Top plate 600, bottom vortex fastener 214, bottom screw 216, and the plurality of plurality of guiding plate fasteners 506 are exposed to the potentially high temperatures attained within the enclosure of convection oven 1500. In contrast, motor mount 402 and the plurality of motor fasteners 504 are insulated by insulator 404 from bottom flank 400, and standoff 500 of each of the plurality of plate fasteners 308 provide a thermal break between top plate 600 and bottom plate 604. Motor 104 is thereby protected from the high temperatures and remains cool supporting a longer motor life and an improved motor performance. Additionally, motor 104 may be less expensive because it is not required to tolerate the high temperatures attained within the enclosure of convection oven 1500.
Various types of fasteners may be used to mount the components of convection 100 together. A fewer or a greater number of fasteners further may be used.

PREFERRED FEATURES

1. A convection fan comprising: a plurality of blades mounted to a shaft to rotate when the shaft rotates; a guiding plate mounted to partially surround the plurality of blades; and a fan-motor mount comprising a top plate through which the shaft extends; a bottom plate through which the shaft extends; a motor fastener that mounts a motor to the bottom plate in isolation from the top plate; a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate; an insulator between the top plate and the bottom plate; and a plate fastener that mounts the top plate to the bottom plate, the plate fastener comprising a fastener; and a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break.
2. The convection fan of feature 1, wherein the insulator is air.
3. The convection fan of feature 1, wherein the insulator is formed of an insulating material.
4. The convection fan of feature 3, wherein the insulating material is selected from the group consisting of a mica plate, an insulation fiber, a ceramic, and glass.
5. The convection fan of feature 1, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body.
6. The convection fan of feature 5, wherein the head mounts within the bottom plate.
7. The convection fan of feature 6, wherein the fastener extends below the bottom plate.
8. The convection fan of feature 5, wherein a head of the fastener mounts above the top plate.
9. The convection fan of feature 8, wherein the top plate is positioned between an end of the body of the standoff opposite the head of the standoff and the head of the fastener.
10. The convection fan of feature 1, wherein the fastener extends through the standoff.
11. A convection fan assembly comprising: a motor; a shaft connected to the motor, wherein the motor is configured to rotate the shaft; and a fan comprising a plurality of blades mounted to the shaft to rotate when the shaft rotates; a guiding plate mounted to partially surround the plurality of blades; and a fan-motor mount comprising a top plate through which the shaft extends; a bottom plate through which the shaft extends; a motor fastener that mounts the motor to the bottom plate in isolation from the top plate; a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate; an insulator between the top plate and the bottom plate; and a plate fastener that mounts the top plate to the bottom plate, the plate fastener comprising a fastener; and a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break.
12. The convection fan assembly of feature 11, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body.
13. The convection fan assembly of feature 12, wherein the head mounts within the bottom plate.
14. The convection fan assembly of feature 13, wherein the fastener extends below the bottom plate.
15. The convection fan assembly of feature 12, wherein a head of the fastener mounts above the top plate.
16. The convection fan assembly of feature 15, wherein the top plate is positioned between an end of the body of the standoff opposite the head of the standoff and the head of the fastener.
17. The convection fan of assembly feature 11, wherein the fastener extends through the standoff.
18. A convection oven comprising: a plurality of walls that form an enclosure; a convection fan at least partially mounted within the enclosure, the convection fan comprising a motor; a shaft connected to the motor, wherein the motor is configured to rotate the shaft; and a fan comprising a plurality of blades mounted to the shaft to rotate when the shaft rotates; a guiding plate mounted to partially surround the plurality of blades; and a fan-motor mount comprising a top plate through which the shaft extends; a bottom plate through which the shaft extends; a motor fastener that mounts the motor to the bottom plate in isolation from the top plate; a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate; an insulator between the top plate and the bottom plate; and a plate fastener that mounts the top plate to the bottom plate, the plate fastener comprising a fastener; and a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break; and a control to control operation of the convection fan.
19. The convection oven of feature 18, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body, wherein the head mounts within the bottom plate.
20. The convection oven of feature 18, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body, wherein a head of the fastener mounts above the top plate.

The word "illustrative" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "illustrative" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for the purposes of this disclosure and unless otherwise specified, "a" or "an" means "one or more". Still further, using "and" or "or" in the detailed description is intended to include "and/or" unless specifically indicated otherwise.
The foregoing description of illustrative embodiments of the disclosed subject matter has been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the disclosed subject matter to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosed subject matter. The embodiments were chosen and described in order to explain the principles of the disclosed subject matter and as practical applications of the disclosed subject matter to enable one skilled in the art to utilize the disclosed subject matter in various embodiments and with various modifications as suited to the particular use contemplated.
When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

A convection fan comprising:
a plurality of blades mounted to a shaft to rotate when the shaft rotates;

a guiding plate mounted to partially surround the plurality of blades; and

a fan-motor mount comprising
a top plate through which the shaft extends;

a bottom plate through which the shaft extends;

a motor fastener that mounts a motor to the bottom plate in isolation from the top plate;

a guiding plate fastener that mounts the guiding plate to the top plate in isolation from the bottom plate;

an insulator between the top plate and the bottom plate; and

a plate fastener that mounts the top plate to the bottom plate, the plate fastener comprising
a fastener; and

a standoff that surrounds a portion of the fastener between the top plate and the bottom plate and within the bottom plate to provide a thermal break.
The convection fan of claim 1, wherein the insulator is air.
The convection fan of claim 1, wherein the insulator is formed of an insulating material.
The convection fan of claim 3, wherein the insulating material is selected from the group consisting of a mica plate, an insulation fiber, a ceramic, and glass.
The convection fan of claim 1, wherein the fastener extends through the standoff.
A convection fan assembly comprising:
the convention fan of claim 1;

a motor; and

the shaft connected to the motor, wherein the motor is configured to rotate the shaft.
The convection fan of claim 1 or the convention fan assembly of claim 6, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body.
The convection fan or the convection fan assembly of claim 7, wherein the head mounts within the bottom plate.
The convection fan or the convection fan assembly of claim 8, wherein the fastener extends below the bottom plate.
The convection fan or the convection fan assembly of claim 7, wherein a head of the fastener mounts above the top plate.
The convection fan or the convection fan assembly of claim 10, wherein the top plate is positioned between an end of the body of the standoff opposite the head of the standoff and the head of the fastener.
The convection fan of assembly claim 6, wherein the fastener extends through the standoff.
A convection oven comprising:
a plurality of walls that form an enclosure;

the convection fan assembly of claim 11, at least partially mounted within the enclosure; and

a control to control operation of the convection fan.
The convection oven of claim 13, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body, wherein the head mounts within the bottom plate.
The convection oven of claim 13, wherein the standoff includes a head and a body that extends from the head, wherein a shaft of the fastener fits within an aperture formed through the head and the body, wherein a head of the fastener