Bicycle rear sprocket assembly
[technical field]
The present invention relates to a kind of chain wheel assembly that is used on the bicycle, more particularly, be meant the rear sprocket assembly of bicycle.
[background technology]
Social in modern times, cycle racing is more and more popularized with popular.No matter be amateurish jockey or professional jockey, also become for the pursuit of speed and thirst for more that therefore, the speed change quantity in the transmission mechanism of bicycle is in continuous increase, the sprocket wheel quantity that is contained in the chain wheel assembly on the bicycle rear drum also is increased to ten or more.Along with the increase of sprocket wheel quantity, the weight of whole chain wheel assembly also increases.In order in expendable weight, not influence speed changing effect again, a lot of this type design-calculated products have appearred on the market.
The patent No. is that the patent of ZL96119886.9 discloses sprocket wheel load module after a kind of carriage class; Each sprocket bearing carriage has a plurality of supporting arms that radially extend; Two relative attachment faces are arranged on each supporting arm; Two different sprocket wheels of the number of teeth are installed on two attachment faces through a shared attaching parts, and height between two attachment faces has been confirmed the distance between two sprocket wheels.In the centre of frame support bracket the splined hole that assembles with the bicycle rear drum is arranged, each frame support bracket can be installed on the bicycle rear drum independently.For expendable weight, generally the carriage of this type all is to adopt with the material of sprocket wheel material compared lightweight such as aluminum alloy etc. to process, so the intensity of sprocket wheel load module behind this type, and especially the intensity at attachment face place just becomes extremely important on each radial support arm.When the sprocket wheel quantity of rear sprocket assembly is increased to ten when above; Distance between two sprocket wheels just becomes very little; Therefore the thickness that is in the attachment face between the two also diminishes accordingly, particularly for the bigger sprocket wheel of ratio of number of teeth, when the big torsion that bears that chain applies; Can cause the distortion or the fracture of Support bracket, influence the speed changing effect of rear sprocket assembly.
Patent ZL 200310121557.2 has disclosed another kind of chain sprocket structure, and the rear sprocket assembly of this structure comprises at least three sprocket wheel and frame support brackets that have two relative attachment faces that the number of teeth is different.First sprocket wheel is installed on first attachment face, and second sprocket wheel is installed on second attachment face, and the 3rd sprocket wheel is installed on second sprocket wheel through connecting element and distance piece and is placed between first and second sprocket wheels.Because the 3rd sprocket wheel is placed between first and second sprocket wheel; When assembling, must earlier the 3rd sprocket wheel be installed on second sprocket wheel with several connecting elements, and then the assembly set of first sprocket wheel and the second and the 3rd sprocket wheel is installed on the Support bracket; So not only need many one procedure; Need increase some connecting elements simultaneously, through facts have proved, this all has improved space on cost of installation and material.
[summary of the invention]
The objective of the invention is to be to overcome the deficiency of prior art, providing a kind of can gain in strength, and reduces the bicycle rear sprocket assembly of cost of installation and expendable weight.
In order to solve the technical matters of above-mentioned existence, the present invention adopts following technical proposals:
A kind of bicycle rear sprocket assembly; It comprises that quantity is three or the wheel hub of above odd number sprocket wheel and and the assembling of bicycle rear drum; Wherein: each sprocket wheel comprise have one radially a plurality of through holes of inner terminal band the installation lug and radially outermost end have the sprocket of a plurality of teeth; The number of teeth of all sprocket wheels is inequality and by being divided into a pair ofly to chain wheel set toward minispread by big, and the through hole that the every pair of chain wheel set is installed on the lug is corresponding, and last sprocket wheel is the strand wheel; Said wheel hub is along the mounting bracket that stretches out the multi-step formula on its outer end radial direction, and every layer of mounting bracket includes a plurality of hold-down arms that claw type distributes that on circumference, are, and the number of plies of said mounting bracket is that the logarithm of chain wheel set adds one; Be provided with on the hold-down arm of each layer mounting bracket with the respective sprockets group on through hole or strand wheel on the consistent mounting hole of through hole; Be installed on the cooresponding mounting bracket after between each is to the corresponding through hole on the sprocket wheel of chain wheel set, being provided with distance piece and being passed the mounting hole of hold-down arm by fastener, described strand wheel is installed on the cooresponding minimum mounting bracket passed the mounting hole of hold-down arm by fastener after.
In the improvement project to above-mentioned bicycle rear sprocket assembly, described fastener is general-duty rivet or screw.
In the improvement project to above-mentioned bicycle rear sprocket assembly, described distance piece and fastener are one.
In improvement project to above-mentioned bicycle rear sprocket assembly, a sprocket wheel one in the described distance piece and the every pair of chain wheel set.
A kind of bicycle rear sprocket assembly; It includes quantity is four or the wheel hub of above even number sprocket wheel and and the assembling of bicycle rear drum; Wherein: each sprocket wheel comprise have one radially a plurality of through holes of inner terminal band the installation lug and radially outermost end have the sprocket of a plurality of teeth; The number of teeth of all sprocket wheels is inequality and by being divided into a pair ofly to chain wheel set toward minispread by big, and the through hole that the every pair of chain wheel set is installed on the lug is corresponding; Said wheel hub is along the mounting bracket that stretches out the multi-step formula on its outer end radial direction, and every layer of mounting bracket includes a plurality of hold-down arms that claw type distributes that on circumference, are, and the number of plies of said mounting bracket is the logarithm of chain wheel set; Be provided with on the hold-down arm of each layer mounting bracket with the respective sprockets group on the consistent mounting hole of through hole; Be installed on the cooresponding mounting bracket after between each is to the corresponding through hole on the sprocket wheel of chain wheel set, being provided with distance piece and passing the mounting hole of hold-down arm by fastener.
In the improvement project to above-mentioned bicycle rear sprocket assembly, described fastener is general-duty rivet or screw.
In the improvement project to above-mentioned bicycle rear sprocket assembly, described distance piece and fastener are one.
In the improvement project to above-mentioned bicycle rear sprocket assembly, a sprocket wheel in the described distance piece and the every pair of chain wheel set is an one.
Compared with prior art; The invention has the beneficial effects as follows: since it be whole sprocket wheels are divided into a pair of to chain wheel set; And after being separated by distance piece chain wheel set, each is fixed on again on cooresponding mounting bracket one side; The material thickness of mounting bracket does not receive this to the size restriction of the spacing between the sprocket wheel like this, thereby can gain in strength, and comes expendable weight through the thickness that reduces mounting bracket satisfying under the prerequisite of rigidity; In addition; Owing to be installed on the hold-down arm of mounting bracket by same fastener after per two sprocket wheels are formed the pair of sprocket group; Comparatively speaking can reduce the quantity of needed connecting element in the patent that the patent No. is ZL 200310121557.2; Save time of setting up simultaneously, install and productive costs thereby reduce.
Below in conjunction with the accompanying drawing and the specific embodiment the present invention is made further detailed description:
[description of drawings]
Fig. 1 is the structural representation of the embodiment of the invention one;
Fig. 2 is the birds-eye view of Fig. 1;
Fig. 3 is the assembling scheme drawing of the embodiment of the invention one;
Fig. 4 is the assembling scheme drawing of the embodiment of the invention two;
Fig. 5 is the schematic perspective view of the wheel hub holder of the embodiment of the invention.
[specific embodiment]
The present invention is a kind of bicycle rear sprocket assembly, and it includes quantity is three or the wheel hub 2 of above odd number or even number sprocket wheel 1 and and the assembling of bicycle rear drum, wherein:
Each sprocket wheel 1 comprise have one radially a plurality of through holes 11 of inner terminal band installation lug 12 and radially outermost end have the sprocket 13 of a plurality of teeth; The number of teeth of all sprocket wheels 1 is inequality and by being divided into a pair of to chain wheel set G by big toward minispread; The through hole 11 that the every couple of chain wheel set G installs on the lug 12 is corresponding; When sprocket wheel add up to odd number, last sprocket wheel 1 was the strand wheel;
As shown in Figure 5; Said wheel hub 2 is along the mounting bracket 21 that stretches out the multi-step formula on its outer end radial direction; Be that mounting bracket diminishes at circumference last layer one deck; As shown in Figure 5, every layer of mounting bracket 21 includes a plurality of hold-down arms 211 that claw type distributes that on circumference, are, and the number of plies of said mounting bracket 21 is logarithms (when for the even number sprocket wheel) of chain wheel set G or adds one (when for the odd number sprocket wheel) again; Be provided with on the hold-down arm 211 of each layer mounting bracket 21 with respective sprockets group G on through hole 11 or strand wheel on the consistent mounting hole 212 of through hole 11;
Be installed on the cooresponding mounting bracket 21 after between each is to the corresponding through hole 11 on the sprocket wheel 1 of chain wheel set G, being provided with distance piece 3 and passing the mounting hole 212 of hold-down arm 211 by fastener 4; For the rear sprocket assembly of odd number sprocket wheel, its last sprocket wheel---strand wheel is installed on the cooresponding minimum mounting bracket passed the mounting hole 212 of hold-down arm 211 by fastener 4 after.
Owing to be fixed on again on mounting bracket one side after each was opened by distance piece chain wheel set G in 3 minutes; The material thickness of mounting bracket does not receive this to the restriction of the size of the spacing between the sprocket wheel like this; Thereby can gain in strength, and come expendable weight at the thickness that satisfies under the prerequisite of rigidity through reducing mounting bracket; In addition; Owing to be installed on the hold-down arm 211 of mounting bracket 21 by same fastener 4 after per two sprocket wheels are formed the pair of sprocket group; Comparatively speaking can reduce the quantity of needed connecting element in the patent that the patent No. is ZL 200310121557.2; Save time of setting up simultaneously, install and productive costs thereby reduce.
In Fig. 1,2, the embodiment one shown in 3, chain wheel assembly includes 4 sprocket wheels, is divided into two pairs; And in embodiment as shown in Figure 4 two, chain wheel assembly includes 3 sprocket wheels, is divided into pair of sprocket group and a strand wheel.In these two embodiment, mounting bracket all has two-layer, when the sprocket wheel number is 5 or 6, then needs three layers, comes to confirm the number of plies of mounting bracket by that analogy.
Described fastener 4 generally is general-duty rivet or screw, and in embodiment one, two, it is a rivet.Described distance piece 3 can be an one with fastener 4, also can be separately independently, and at this moment distance piece can be independent ferrule arrangement, also can with the sprocket wheel one.Like Fig. 3,4 embodiment one, shown in two, distance piece 3 is what to separate with fastener, and with the hinge wheel moulding of every pair of chain wheel set, more convenient like this installation.
Although describe the present invention, be to be understood that to can in the purport of the present invention design and scope, carrying out multiple improvement with reference to embodiment.Therefore, the invention is not restricted to described embodiment, but by the described four corner of claims.