Transmission cover with improved airflow

Patent metadata

Field	Value
Publication number	US-10738876-B2
Application number	US-201916401771-A
Country	US
Kind code	B2
Filing date	May 2, 2019
Priority date	Jul 22, 2013
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A cover for a transmission having improved airflow path is disclosed. The interior of the cover has a progressively narrowing airflow path to reduce pressure drop through the cover, thereby improving the cooling efficiency of the airflow through the cover. The cover includes a diverter sheltering the air inlet to the cover to prevent air in the cover from exerting outward pressure on the incoming air.

First claim

The invention claimed is:

1. An off-road vehicle for traversing a surface, comprising:
surface engaging members;
an engine that generates power;
a transmission coupled between the engine and the surface engaging members for transferring power from the engine to the surface engaging members; the transmission comprising:
a drive clutch that receives at least a portion of the generated power from the engine, the drive clutch being driven by an input shaft, the drive clutch having a first side from which the input shaft extends and a second side opposite the first side;
a driven clutch that is offset from the drive clutch in a first direction of the vehicle, the driven clutch having an output shaft to send power to the surface engaging members;
a belt that transmits at least a portion of the received portion of the power from the drive clutch to the driven clutch; and
a clutch cover that covers at least a portion of the drive clutch and at least a portion of the driven clutch, the cover having a first side through which the input shaft extends and a second side opposite the first side of the cover, wherein the cover includes:
an air inlet on the first side of the cover adjacent the drive clutch,
an air outlet adjacent the driven clutch,
a deep region adjacent the air inlet,
a shallow region adjacent the air outlet, and
a ramp region defined between a ramp surface and the second side of the cover having a longitudinal dimension and a lateral dimension, the lateral dimension decreasing along an entirety of the longitudinal dimension in the direction of the deep region toward the shallow region.

2. The vehicle of claim 1 , wherein at least a portion of the ramp region is a semi-circular region.

3. The vehicle of claim 1 , further including an air channeling structure adjacent the air inlet.

4. The vehicle of claim 1 , further including a diversion wall adjacent the air outlet.

5. The vehicle of claim 1 , wherein the cover further includes:
a high region that extends from the air outlet to the air inlet on the cover; and
a ridge that separates the high region from the deep region, the ramp region, and the shallow region.

6. The vehicle of claim 5 , wherein the first side of the cover further includes:
a first hole that receives a drive shaft coupled to the drive clutch;
a second hole that receives a driven shaft coupled to the driven clutch; and
wherein the ridge extends generally tangentially from the first hole towards an approximate midpoint of the second hole.

7. The vehicle of claim 5 , wherein the high region includes:
a divider positioned at a perimeter of the first side of the cover adjacent the air inlet, wherein the divider longitudinally extends a portion of a distance between the perimeter of the cover and the first hole.

8. A vehicle comprising an engine and a transmission; the transmission comprising a drive clutch with a drive shaft and a driven clutch with a driven shaft, a cover at least partially surrounding the drive clutch and the driven clutch, the cover having a first side and a second side, the cover comprising:
a first hole adapted to receive the drive shaft on the first side of the cover;
a second hole adapted to receive the driven shaft on the first side of the cover;
an interior within which the drive clutch and driven clutch are positioned;
at least one air inlet adapted to provide air from an exterior of the cover to the interior; and
at least one air outlet adapted to provide air from the interior to the exterior;
wherein the interior of the cover includes:
a deep region adjacent the air inlet on the first side of the cover, wherein the deep region includes a first lateral dimension;
a shallow region adjacent the second hole and the air outlet, wherein the shallow region includes a second lateral dimension that is less than the first lateral dimension, wherein the deep region and the shallow region form at least one portion of an airflow channel that guides air flowing from the at least one air inlet to the at least one air outlet; and
a ramp region that extends from the deep region to the shallow region, the ramp region having a longitudinal dimension and a third lateral dimension that continuously decreases along an entirety of the longitudinal dimension.

9. The vehicle of claim 8 , further comprising a diversion ridge extending adjacent at least a portion of the ramp region.

10. The vehicle of claim 8 , wherein the ramp region forms another portion of the air channel, and the ramp region has a transverse dimension that is substantially perpendicular to the third lateral dimension and that continuously increases along a longitudinal direction intermediate the deep region and the shallow region.

11. The vehicle of claim 10 , wherein a transverse slope of the ramp region is between 0 degrees and 20 degrees.

12. The vehicle of claim 8 , further including a first cover portion and a second cover portion that is separate from and laterally offset from the first cover portion, and the first and the second cover portions are coupled together to form the interior.

13. The vehicle of claim 12 , wherein each of the air inlet and the air outlet are positioned entirely on the first cover portion.

14. The vehicle of claim 13 , wherein the first cover portion is laterally intermediate the second cover portion and the engine of the vehicle.

15. The vehicle of claim 13 , wherein the first cover portion being on the first side of the cover.

16. The vehicle of claim 8 , further including an air channeling structure adjacent the air inlet.

17. The vehicle of claim 8 , further including a diversion wall adjacent the air outlet.

18. A transmission for a vehicle that includes at least a drive shaft and a driven shaft that is offset in a longitudinal direction, wherein each of the drive and the driven shafts extend in a lateral direction that is transverse to the longitudinal direction, and a vertical direction is transverse to each of the longitudinal direction and the lateral direction, the transmission comprising:
a drive clutch held by the drive shaft;
a driven clutch held by the driven shaft; and
a case including:
a first lateral portion;
a second lateral portion;
an air inlet extending through at least one of the first lateral portion of the case or the second lateral portion of the case;
an air outlet extending through at least one of the first lateral portion of the case or the second lateral portion of the case; and
an airflow channel within the case that guides at least a portion of flowing air from the air inlet downstream to the air outlet, wherein the airflow channel has a deep region that is downstream from the air inlet and upstream from the air outlet, a ramp region that is downstream from the deep region and upstream from the air outlet, and a shallow region that is downstream from the ramp region and upstream from the air outlet, the ramp region extending from the deep region to the shallow region, the ramp region defined between a ramp surface and the second lateral portion of the case having a longitudinal dimension and a lateral dimension, the lateral dimension decreasing along an entirety of the longitudinal dimension in the direction of the deep region toward the shallow region.

19. The transmission of claim 18 , wherein each of the air inlet and the air outlet extend through the first lateral portion of the case.

20. The transmission of claim 18 , wherein the case further includes a drop wall extending from an upper portion of the first latera

Assignees

• Arctic Cat Inc

Inventors

• Eberhardt Ryan

Classifications

• F16H57/0489

  with endless flexible members, e.g. belt CVTs · CPC title

• F16H57/0416 Primary

  Air cooling or ventilation · CPC title

• F16H57/035

  Gearboxes for gearing with endless flexible members · CPC title

• F16H9/12

  engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members · CPC title

• F16H57/031

  characterised by covers or lids for gearboxes · CPC title