AU2009100186A4

AU2009100186A4 - Shaft rotating mechanism for mower

Info

Publication number: AU2009100186A4
Application number: AU2009100186A
Authority: AU
Inventors: Hung You-Nan
Original assignee: Shunchi Crankshaft Co Ltd
Current assignee: Shunchi Crankshaft Co Ltd
Priority date: 2009-02-26
Filing date: 2009-02-26
Publication date: 2009-03-26
Anticipated expiration: 2017-02-26

Description

SHAFT ROTATING MECHANISM FOR MOWER ¢4 SBACKGROUND OF THE INVENTION 1. Technical Field 00 oO The present invention relates to mowers, and more particularly, to a shaft rotating mechanism that has simplified structure and improved transmission efficiency for being applied to a mower so as to transmit power from a power source to a shaft, thereby rotating the shaft.

2. Description of Related Art Conventionally, a mower comprises three main portions, namely a mowing mechanism, wheels, and a handle portion. In use, a user holds the handle portion and exerts a forward force thereon to make the mower on the rolling wheels move forward. Meanwhile, a power source of the mowing mechanism drives blades to rotate with high speed so as to mow and the mowings are then expelled from the mower along the rotating direction of the blades.

While such a conventional mower is efficient in mowing, the user thereof nevertheless has to spend energy to advance the mower on the ground, thus making mowing a wide yard a laborious work.

In view of this, US Patent No. 6,679,036, titled "Drive gear shaft 0 structure of a self-moving type mower", having the same assignee of the present invention, disclosed a self-propelled mower wherein two transmission IN taper blocks use their taper surfaces to urge against taper holes of a gear on the drive gear shaft so that friction upon the taper surfaces transmits power and in 00 turn drives the shaft to rotate.

However, after being put into practical application, the high working

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Stemperature caused by the friction upon the taper surfaces, and the side effect of reducing the durability of the components needs to be remedied. Beside, the patented structure is also defective for its inferior transmission efficiency and complex components, thus needing to be improved.

SUMMARY OF THE INVENTION In view of the need, the primary objective of the present invention is to provide a shaft rotating mechanism for a mower so as to eliminate problcms of the prior art, such as the inferior transmission efficiency and component complexity.

The shaft rotating mechanism of the present invention comprises: a housing receiving therein a driving shaft; a driving gear rotatably mounted around the driving shaft and comprising a plurality of first one-way teeth; a shiftable gear unrotatably mounted around the driving shaft and comprising a o plurality of second one-way teeth; a clutch settled on the housing for controlling the driving gear and the shiftable gear to engage or disengage mutually; and a worm piercing into the housing for driving the driving gear to

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rotate. Thereby, when operated, the clutch makes the shiftable gear along the 00 driving shaft move toward and get coupled with the driving gear so that the driving gear driven by the worm rotates the shiftable gear and in turn rotates the driving shaft. Hence, the present invention allows improved power transmission effect and enhanced structural strength.

BRIEF DESCRIPTION OF THE DRAWINGS Further objectives and advantages of the invention as well as a preferred mode of use will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: Fig. 1 is a perspective view of a shaft rotating mechanism of the present invention; Fig. 2 is an exploded view of the shaft rotating mechanism of the present invention; Fig. 3 is a perspective view of a shiftable gear of the shaft rotating mechanism of the present invention; Fig. 4 is an axial plane view of the shiftable gear; Fig. 5 is a perspective view of a driving gear of the shaft rotating O mechanism of the present invention;

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Fig. 6 is an axial plane view of the driving gear;

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00 Fig. 7 is a schematic drawing showing the shaft rotating mechanism in its idling position; and SFig. 8 is a schematic drawing showing the shaft rotating mechanism in its operating position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to Figure 1 for a perspective view of a shaft rotating mechanism for a mower according to the present invention. The shaft rotating mechanism 100 comprises a housing 10, a pulley 20, a driving shaft 30 and a clutch 40. The pulley 20 is connected with and driven by a power source (not shown) of the mower so as to rotate. The clutch 40 allows the pulley 20 to mechanically connect and rotate the driving shaft Fig. 2 is an exploded view of the shaft rotating mechanism of the present invention. As can be seen therein, the housing 10 comprises an upper member and a lower member 10b. The upper member 10a is formed with an installation hole 11. A closed accommodating space 13 is formed between the assembled upper and lower members 10a, 10b for receiving lubricant, which takes 40% of capacity of the accommodating space 13 and functions for IND thermal dispersion, lubrication, and component cleaning. Besides, a pedestal 14 is raised from a bottom of the accommodating space 13.

00 The pulley 20 is rotatably mounted onto the upper member 10a. The pulley 20 is so connected with a worm 21 that the worm 21 is driven by the 0q pulley 20 to rotate.

The driving shaft 30 is settled between the upper and lower members 10 Oa, A plurality of fastening holes 31 are provided at predetermined locations on the driving shaft 30. In the present invention, two said fastening holes 31 are formed on the driving shaft 30. Two U-shaped retainers 32 have legs thereof fixed in the fastening holes 31 by a mechanical means or any equivalent means.

The clutch 40 includes a pulling rod 41, a wing 44, and an extension spring 42. The extension spring 42 has one end connected with the upper member 10a and an opposite end connected with the pulling rod 41. A sleeve 43 assembled to one end of the pulling rod 41 is retained in the installation hole 11 of the upper member 1 Oa. Moreover, the sleeve 43 is formed with a slot 431.

The wing 44 includes a lower salient 443 formed at a lower edge thereof for being inserted into the pedestal 14 of the lower member O10b, and includes an upper salient 441 formed at an upper edge thereof for being inserted into the sleeve 43 on the pulling rod 41 so that the wing 44 is fixedly positioned with respect to the pulling rod 41. That is, the wing 44 and the pulling rod 41, when IDassembled, move as an integral piece.

The wing 44 has a substantially C-shaped body with an opened side 00 formed with a pair of arms 422 that jointly hold a shiftable gear 50. The shiftable gear 50 comprises an annular groove 51 for partially receiving the Swing 44 and thus gets retained by the arms 442. Thereby, the pulling rod 41 drives the wing 44 to swing when pulled, and returns to its initial position due to resilience of the extension spring 42 when released.

Fig. 3 is a perspective view of the shiftable gear of the shaft rotating mechanism of the present invention. The shiftable gear 50 comprises an axial hole 52 so that the shiftable gear 50 is unrotatably yet shiftably mounted around the driving shaft 30. Four second one-way teeth 53 are provided at one side of the shiftable gear 50. Each said one-way tooth 53 has a higher end and a lower end, and has a plurality of vents 54.

Fig. 4 is a plane view of the shiftable gear 50. The axial hole 52 of the shiftable gear 50 is flanked by and intercommunicated with two positioning slots 55. Besides, a plurality of recesses 56 are arranged around the axial hole 52. Therein, when the wing 44 is swung, due to the fact that the retainers 32 of the driving shaft 30 are retained by the positioning slots 55, the shiftable gear moves axially along the driving shaft 30 while retaining from rotation.

Additionally, a driving gear 60 is rotatably provided around the driving IDshaft 30 and aligned with the shiftable gear 50. The driving gear 60 is engaged

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with and driven by the worm 21.

00 Figure 5 is a perspective view of the driving gear 60 of the shaft rotating mechanism of the present invention. The driving gear 60 has an axial hole 61 c so that the driving gear 60 is rotatably mounted around the driving shaft The driving gear 60 has peripherally a worm gear portion 62 for engaging with the worm 21 and a side of the driving gear 60 is integrally formed with four first one-way teeth 64 each having a plurality of vents Fig. 6 is a plane view of the driving gear 60 showing a plurality of recesses 63 provided on an opposite side of the driving gear The first one-way teeth 64 of the driving gear 60 face the second one-way teeth 53 of the shiftable gear 50 so that when the shiftable gear 50 moves toward the driving gear 60, the first and second one-way teeth 64, 53 come to couple with each other. Consequently, the shiftable gear 50 can be driven by the driving gear 60, and in turn the driving shaft 30 can be driven to rotate.

It is to be noted that both the shiftable gear 50 and the driving gear 60 are made of a compound material containing 70%-80% nylon and 30%-20% fiber through an injection molding process so that the shiftable gear 50 and the 0 driving gear 60 possess the characters of high-heat resistance and high strength.

Meanwhile, provision of the recesses 56, 63 and the vents 54, 65 facilitates not Ionly saving the material, reducing overall weight of the components, and

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increasing overall thermal dispersion surface area, but also preventing 00 deformation of the components under cool contraction or uneven thermal dispersion.

SFig. 7 is a schematic drawing showing the shaft rotating mechanism in its idling position. As can be seen therein, the wing 44 is now placed such that the shiftable gear 50 and the driving gear 60 are separated by a predetermined distance. At this time, the driving gear 60 is idling, as indicated by the dotted arrow in the drawing, and the driving shaft 30 being independent from the driving gear 60 now stays still.

Fig. 8 is a schematic drawing showing the shaft rotating mechanism in its operating position. As can be seen therein, at this time, the wing 44 is placed such that the shiftable gear 50 moves along the driving shaft 30 and gets engaged with the driving gear 60. Thus, the driving gear 60 is now capable of transmitting power to the shiftable gear 50, so that the shiftable gear 50 in turn drives the driving shaft 30 to rotate, as indicated by the dotted arrows in the drawing.

Therefore, the simplified power transmission path, from the worm 21, the o driving gear 60, the shiftable gear 50 through the driving shaft 30, realizes more direct power transmission and reduces power loss.

To sum up, the shaft rotating mechanism of the present invention has the

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driving gear 60 composed of the integrally formed worm gear portion 62 and 00

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the first one-way teeth 64, so as to accomplish a simplified transmission 0 mechanism. In operation, power is transmitted from the worm 21, the driving 0 gear 60, and the shiftable gear 50 to the driving shaft 30, thereby making power transmission more direct and reducing power loss.

Since the shiftable gear 50 and the driving gear 60 are made of the compound material containing nylon and fiber in proper proportion and formed with the vents 54, 65 and recesses 56, 63, they have all the advantages related to light weight, high-heat resistance, and high strength.

The present invention has been described with reference to the preferred embodiment and it is understood that the embodiment is not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.

Claims

1. A shaft rotating mechanism for a mower, the shaft rotating mechanism IDcomprising: (N a housing comprising an upper member and a lower member; 00 a driving shaft settled between the upper and lower members; a driving gear rotatably mounted around the driving shaft and comprising a worm gear portion and a plurality of first one-way teeth that are integrally formed on the driving gear; a shiftable gear unrotatably yet shiftably mounted around the driving shaft and comprising an annular groove and a plurality of second one-way teeth, wherein the annular groove and the plurality of second one-way teeth are integrally formed on the shiftable gear and the second one- way teeth face the first one-way teeth; a clutch settled on the housing for engaging or disengaging the shiftable gear with or from the driving gear; and a worm having one end connected with a power source of the mower and an opposite end coupled with the worm gear portion of the driving gear for driving the driving gear to rotate; whereby, the clutch, when operated, moves the shiftable gear along the driving shaft to make the shiftable gear couple with the driving gear so 0 that the driving shaft is driven by the driving gear to rotate.

2. The shaft rotating mechanism of Claim 1, wherein two retainers are provided on the driving shaft and the axial hole of the shiftable gear is flanked by two positioning slots so that when the shiftable gear is mounted around the driving 00 shaft, the shiftable gear is axially movable with respect to the driving shaft and retained from rotating with respect to the driving shaft.

S3. The shaft rotating mechanism of either one of Claim 1 and Claim 2, wherein the clutch includes a pulling rod, a wing, and an extension spring, in which the pulling rod has one end controlling the wing to swing, and the wing is retained in the annular groove of the shiftable gear so that when the wing is swung, it moves the shiftable gear along the driving shaft to make the shiftable gear get coupled with the driving gear, and in which the shiftable gear and the driving gear are normally separated due to the extension spring.

4. The shaft rotating mechanism of Claim 3, wherein a sleeve is assembled to the pulling rod, the sleeve having a slot and the pulling rod having an upper salient formed at a top thereof for being inserted into the sleeve, wherein the wing includes a lower salient while a pedestal is formed at an inner surface of the lower member of the housing so that the lower salient is retained by the pedestal, and wherein the wing has a C-shaped body with an opened side formed with a pair of arms to be received in the annular groove of the 0 shiftable gear so that the wing is capable of pushing the shiftable gear to o move axially.

5. The shaft rotating mechanism of any one of Claim 1 to Claim 4, wherein a (N closed accommodating space is formed between the assembled upper and 00 lower members for receiving lubricant. Shunchi Crankshaft Co., Ltd. By their Attorneys M. J. Service Associates