Systems and methods for reducing cutting blade noise
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
A01D-034/82
A01D-034/73
A01D-101/00
출원번호
US-0156016
(2016-05-16)
등록번호
US-10117380
(2018-11-06)
발명자
/ 주소
Kaukler, William
Thompson, Wayne
출원인 / 주소
Board of Trustees of the University of Alabama, for and on behalf of the University of Alabama in Huntsville
대리인 / 주소
Maynard Cooper & Gale, P.C.
인용정보
피인용 횟수 :
0인용 특허 :
11
초록▼
A cutting blade for use in a lawnmower or other cutting device has a contoured leading edge profile that forms a series of protrusions and contoured notches. Each contoured notch has a surface that is smooth and contoured such that air is funneled through the contoured notch by the adjacent protrusi
A cutting blade for use in a lawnmower or other cutting device has a contoured leading edge profile that forms a series of protrusions and contoured notches. Each contoured notch has a surface that is smooth and contoured such that air is funneled through the contoured notch by the adjacent protrusions, thereby causing the air to form vortices at the surface of the blade. The formation of the vortices helps the airflow to adhere to the blade surface rather than separate from it, thereby creating a more laminar streamlined flow that merges with air flowing over the opposite side of the blade at the trailing edge. By preventing the airflow from separating from the blade surface over a substantial portion of the blade, turbulence is significantly reduced. Thus, noise generated by the blade is significantly reduced as well. In addition, the blade experiences less drag, and the performance of the blade and lawnmower is generally increased.
대표청구항▼
1. A cutting blade for use with a lawnmower to reduce sound emitted from the lawnmower, comprising: an elongated body having a top face, a bottom face, a first leading edge, a second leading edge, and a trailing edge, wherein the first leading edge is a first side of the elongated body and is notche
1. A cutting blade for use with a lawnmower to reduce sound emitted from the lawnmower, comprising: an elongated body having a top face, a bottom face, a first leading edge, a second leading edge, and a trailing edge, wherein the first leading edge is a first side of the elongated body and is notched thereby forming a plurality of contoured notches and a plurality of protrusions in the first leading edge, the plurality of protrusions including an adjacent pair of protrusions with one of the contoured notches located between the adjacent pair of protrusions, wherein the second leading edge is on a second side of the elongated body, wherein the second side is opposite of the first side, wherein the first leading edge forms a sharp tip along the top face for cutting, wherein a cross-sectional profile of the first leading edge is rounded from the tip to the bottom face, wherein the one contoured notch is shaped such that an airflow induced by movement of the elongated body is channeled through the one contoured notch thereby generating at least one vortex within the airflow such that turbulence in the airflow is reduced, and wherein the elongated body has a hole for receiving a spindle of the lawnmower between the first side and the second side. 2. The cutting blade of claim 1, wherein the first leading edge forms a first sinusoid defining the protrusions and the contoured notches. 3. The cutting blade of claim 2, wherein the body has an edge forming a second sinusoid, and wherein a surface of the one contoured notch slopes from the second sinusoid to the first sinusoid. 4. The cutting blade of claim 3, wherein the first sinusoid has a first amplitude, and wherein the second sinusoid has a second amplitude different than the first amplitude. 5. The cutting blade of claim 1, wherein the trailing edge is beveled. 6. The cutting blade of claim 1, wherein the cutting blade is attached to the lawnmower by the spindle, and wherein the spindle passes through the hole. 7. The cutting blade of claim 1, wherein the at least one vortex is sufficient for preventing the airflow from separating from a surface of the blade between the first leading edge and the trailing edge. 8. A lawnmower, comprising: a deck housing;a spindle coupled to the deck housing; anda blade coupled to the spindle, wherein the blade has a top face, a bottom face, a leading edge and a trailing edge, wherein the leading edge is notched thereby forming a plurality of contoured notches and a plurality of protrusions in the leading edge, wherein the leading edge forms a sharp tip along the top face for cutting, wherein a cross-sectional profile of the leading edge is rounded from the tip to the bottom face, and wherein the spindle is configured to rotate the blade such that airflow is induced across a surface of the blade, and wherein the contoured notches are shaped such that the airflow is channeled through the contoured notches to form a plurality of vortices in the airflow such that turbulence in the airflow is reduced thereby reducing sound emitted from the lawnmower. 9. The lawnmower of claim 8, wherein the vortices are sufficient for preventing the airflow from separating from a surface of the blade between the leading edge and the trailing edge. 10. The lawnmower of claim 8, wherein the leading edge forms a first sinusoid defining the protrusions and the contoured notches. 11. The lawnmower of claim 10, wherein the blade has an edge forming a second sinusoid, and wherein a surface of one of the contoured notches slopes from the second sinusoid to the first sinusoid. 12. The lawnmower of claim 11, wherein the first sinusoid has a first amplitude, and wherein the second sinusoid has a second amplitude different than the first amplitude. 13. The lawnmower of claim 8, wherein the trailing edge is beveled. 14. The lawnmower of claim 8, wherein at least one of the vortices extends from the leading edge to the trailing edge thereby interfering with spanwise pumping induced by rotation of the blade. 15. A method for reducing sound emitted from a lawnmower, comprising: rotating a lawnmower blade about a spindle coupled to the lawnmower blade, thereby generating an airflow around the lawnmower blade, wherein the lawnmower blade has a top face, a bottom face, a leading edge and a trailing edge, wherein the leading edge is shaped to form a plurality of protrusions and a plurality of contoured notches in the leading edge, wherein the leading edge forms a sharp tip along the top face, wherein a cross-sectional profile of the leading edge is rounded from the tip to the bottom face, and wherein the contoured notches are shaped such that the airflow is channeled through the contoured notches, thereby forming a plurality of vortices in the airflow such that turbulence in the airflow is reduced; andcutting grass with the tip. 16. The method of claim 15, wherein the vortices are sufficient for preventing the airflow from separating from a surface of the blade between the leading edge and the trailing edge. 17. The method of claim 15, where at least one of the vortices extends from the leading edge to the trailing edge thereby interfering with spanwise pumping induced by the rotating. 18. The method of claim 15, wherein the leading edge forms a first sinusoid defining the protrusions and the contoured notches. 19. The method of claim 18, wherein the lawnmower blade has an edge forming a second sinusoid, and wherein a surface of one of the contoured notches slopes from the second sinusoid to the first sinusoid. 20. The method of claim 19, wherein the first sinusoid has a first amplitude, and wherein the second sinusoid has a second amplitude different than the first amplitude. 21. The method of claim 15 wherein the trailing edge is beveled. 22. The method of claim 15, wherein the face of the leading edge has a bullnose profile. 23. The method of claim 21, wherein the lawnmower blade is twisted such that an angle of attack of the leading edge changes along the leading edge. 24. The method of claim 23, wherein the angle of attack of the leading edge at an end of the elongated body is greater than 0 degrees. 25. The method of claim 15, wherein the leading edge is a first leading edge on a first side of the lawnmower blade, wherein the lawnmower blade has a second leading edge on a second side of the lawnmower blade, wherein the second side is opposite of the first side, and wherein the lawnmower blade is twisted such that each of the first leading edge and the second leading edge has a positive angle of attack. 26. The cutting blade of claim 1, wherein the face of the first leading edge has a bullnose profile. 27. The cutting blade of claim 5, wherein the elongated body is twisted such that an angle of attack of the first leading edge changes along the first leading edge. 28. The cutting blade of claim 27, wherein the angle of attack of the first leading edge at an end of the elongated body is greater than 0 degrees. 29. The cutting blade of claim 1, wherein the elongated body is twisted such that each of the first leading edge and the second leading edge has a positive angle of attack. 30. The lawnmower of claim 8, wherein the top face faces the deck housing, and wherein the bottom face is opposite of the top face. 31. The lawnmower of claim 8, wherein the face of the leading edge has a bullnose profile. 32. The lawnmower of claim 13, wherein the blade is twisted such that an angle of attack of the leading edge changes along the leading edge. 33. The lawnmower of claim 32, wherein the angle of attack of the leading edge at an end of the blade is greater than 0 degrees. 34. The lawnmower of claim 8, wherein the leading edge is a first leading edge on a first side of the blade, wherein the blade has a second leading edge on a second side of the blade, wherein the second side is opposite of the first side, and wherein the blade is twisted such that each of the first leading edge and the second leading edge has a positive angle of attack.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (11)
Tutschka Alfred,DEX, Blade for a rotary mower and rotary mower.
White ; III Donald M. (Chanhassen MN) Tonsager Gregory P. (Plymouth MN) Thorud Richard A. (Bloomington MN), Mulching mower with improved mulching blade.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.