Rotor and rotor housing for a snowthrower

Patent metadata

Field	Value
Publication number	US-9546462-B2
Application number	US-201414547740-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Nov 19, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

A self-propelled snowthrower wherein, in one embodiment, drive members on each side of the snowthrower provide variable speed propulsion. A transmission that delivers power to the drive members may be adapted to de-clutch one of the two drive wheels when the ground speed of that wheel exceeds the driving speed of the transmission. In other embodiments, the snowthrower includes a rotor having a snow ejection surface forming a negative rake angle. Yet other embodiments include a chute rotation control mechanism that permits manual discharge chute rotation via one-handed input.

First claim

What is claimed is:

1. A snowthrower rotor housing comprising:
two spaced-apart sidewalls connected to one another by a rear wall to define a front-facing collection opening, wherein the rear wall or an upper wall of the housing further defines a discharge outlet; and
a rotor positioned within the housing between the collection opening and the rear wall, the rotor adapted to rotate in a first direction, relative to the housing, about a rotor axis, wherein the rotor comprises:
a rotor shaft;
a collecting portion comprising a helical flyte adapted to collect snow, the helical flyte connected directly to the rotor shaft by one or more radial legs; and
a central discharge portion comprising a paddle that is offset from the rotor axis, the paddle supported in space by connection to the helical flyte such that a gap is formed between the paddle and the rotor shaft, the gap extending along a length of the paddle, wherein the discharge portion receives the snow transported by the collecting portion and ejects it outwardly from the housing through the discharge outlet;
wherein the paddle comprises a snow ejecting surface that is inclined at a rake angle such that an outermost radial edge of the snow ejecting surface lying on a plane normal to the rotor axis trails an innermost radial edge of the snow ejecting surface also lying on the plane when the rotor rotates in the first direction.

2. The rotor housing of claim 1 , wherein the rake angle is −5 to −25 degrees.

3. The rotor housing of claim 1 , wherein a portion of the rear wall of the housing corresponds in shape to, but is offset from, a surface of revolution defined by the helical flyte.

4. The rotor housing of claim 1 , wherein the rear wall is recessed to define a transition zone proximate the paddle.

5. The rotor housing of claim 4 , wherein the transition zone forms an inverted funnel shape that is wide near the paddle and tapers inwardly toward the discharge outlet.

6. The rotor housing of claim 4 , wherein the transition zone comprises one or more transition walls adapted to direct ejected snow.

7. The rotor housing of claim 6 , wherein the one or more transition walls comprise quadrilateral planar surfaces that connect a rear surface of the transition zone to the rear wall.

8. The rotor housing of claim 1 , wherein the helical flyte has a thickness that is 50% or less than a thickness of the paddle.

9. The rotor housing of claim 1 , wherein the housing is adapted to operate upon an operating plane, and wherein a surface of revolution defined by a radially outermost edge of the rotor is offset from the operating plane during operation.

10. The rotor housing of claim 1 , wherein the flyte comprises effective first and second ends, the flyte being defined by a constant helix angle between the first and second ends.

11. The rotor housing of claim 1 , wherein the rotor comprises two collecting portions outboard of the discharge portion, and wherein each collecting portion comprises two flytes.

12. The rotor housing of claim 1 , further comprising a discharge chute attached to the discharge outlet.

13. The rotor housing of claim 12 , further comprising a directional chute attached to the discharge chute.

14. The rotor housing of claim 1 , wherein the snow ejecting surface comprises a concave surface, wherein a midpoint of the snow ejecting surface trails laterally outermost left and right ends of the snow ejecting surface as the rotor rotates in the first direction.

15. A snowthrower rotor housing comprising:
two spaced-apart sidewalls connected to one another by a rear wall to define a front-facing collection opening, wherein the rear wall further defines a discharge outlet; and
a rotor positioned within the housing between the collection opening and the rear wall, the rotor adapted to rotate in a first direction, relative to the housing, about a rotor axis, wherein the rotor comprises:
a rotor shaft
a collecting portion comprising a helical flyte adapted to collect snow, the helical flyte connected directly to the rotor shaft by one or more radial legs, the helical flyte comprising a first thickness; and
a central discharge portion comprising a paddle that is offset from the rotor axis, the paddle supported in space via attachment to the helical flyte such that a gap is formed between the paddle and the rotor shaft, the gap extending along a length of the paddle, wherein the discharge portion receives the snow from the collecting portion and ejects it outwardly from the housing through the discharge outlet as the rotor rotates in the first direction, the paddle comprising a second thickness two or more times greater than the first thickness;
wherein the paddle comprises a snow ejecting surface that is inclined at a rake angle such that an outermost radial edge of the snow ejecting surface lying on a plane normal to the rotor axis trails an innermost radial edge of the snow ejecting surface also lying on the plane when the rotor rotates in the first direction.

16. The rotor housing of claim 15 , wherein the flyte comprises a first material, and the snow ejecting surface comprises a second material of greater compliance than the first material.

17. The rotor housing of claim 15 , wherein the flyte comprises a metallic material and the snow ejecting surface comprises an elastomeric material.

18. The rotor housing of claim 15 , wherein portions of the housing are adapted to rest upon an operating plane, and wherein a surface of revolution defined by the outermost radial edge of the snow ejecting surface is offset from the operating plane.

19. The rotor housing of claim 15 , wherein an internal cross section of the discharge outlet taken perpendicular to an axis of the discharge outlet defines a rectangular cross section.

20. The rotor housing of claim 19 , wherein the rectangular cross section is square.

21. The rotor housing of claim 15 , wherein an internal cross section of the discharge outlet taken perpendicular to an axis of the discharge outlet defines an octagonal cross section.

22. The rotor housing of claim 15 , wherein the flyte comprises effective first and second ends, the flyte being defined by a constant helix angle between the first and second ends.

23. The rotor housing of claim 15 , wherein the rotor comprises two collecting portions outboard of the discharge portion, and wherein each collecting portion comprises two flytes.

24. The rotor housing of claim 15 , wherein portions of the housing are adapted to rest upon an operating plane defined by the ground surface, and wherein an axis of the discharge outlet is perpendicular to the operating plane.

25. The rotor housing of claim 15 , wherein the rear wall is recessed to define an inverted funnel-shaped transition zone proximate the paddle, the transition zone wider near the paddle and narrower near the discharge outlet.

26. The rotor housing of claim 25 , wherein the transition zone comprises one or more transition walls adapted to direct ejected snow.

27. The rotor housing of claim 25 , wherein the snow ejecting surface is narrower in width than a lowermost edge of the transition zone.

28. A snowthrower rotor housing comprising:
two spaced-apart sidewalls connected to one another by a rear wall to define a front-facing collection opening, wherein the rear wall or an upper wall of the housing further defines a discharge outlet; and
a rot

Assignees

• The Toro Co

Inventors

• Friberg Nathan J
• Stalpes Philip G
• Duchscherer Derek S
• Wersal Nicholas J

Classifications

• E01H5/098 Primary

  about horizontal or substantially horizontal axises perpendicular or substantially perpendicular to the direction of clearing · CPC title

• E01H5/12

  Apparatus or implements specially adapted for breaking, disintegrating, or loosening layers of ice or hard snow {with or without clearing or removing (E01H5/10 takes precedence); Roughening ice or hard snow by means of tools (by means of gritting materials E01H10/00; roughening or breaking-up pavements E01C23/08, E01C23/12)} · CPC title

• E01H6/00 Primary

  Apparatus equipped with, or having provisions for equipping with, both elements {for especially} removal of refuse or the like and elements for removal of snow or ice (E01H8/10 takes precedence) · CPC title

• E01H5/045

  Means per se for conveying or discharging the dislodged material, e.g. rotary impellers, discharge chutes (dislodging apparatus provided therewith E01H5/07, E01H5/08, E01H5/104, E01H5/12) · CPC title