CN1027306C

CN1027306C - Gear ratio changeable helical gear transmission

Info

Publication number: CN1027306C
Application number: CN 91110716
Authority: CN
Inventors: 宋振才
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-11-19
Filing date: 1991-11-19
Publication date: 1995-01-04
Anticipated expiration: 2006-11-19
Also published as: CN1072477A

Abstract

The present invention provides a general method for using variable speed ratio helical gear transmission. The method is characterized in that shifting slide gears use helical spline for transmission so that the axial force of gear transmission counteracts the axial force of a spline transmission shaft. The variable speed ratio helical gear transmission can be applied in wide mechanical manufacturing industries of automobiles, ships, machine tools, etc.

Description

Gear ratio changeable helical gear transmission

The present invention relates to transmission device, relate to particularly that be used for can be with the gear drive of gear ratio transferring rotational motion.

Employed variable gear ratio transmission such as automobile, tractor now, be in two parallel axes, have on one can slippage on spline gear, thereby change the secondary speed ratio that changes of institute meshed gears and obtain different output revolutions by stirring shifting slide gear, because shifting slide gear and shift fork can not bear axial force, so can not use the angular gear that produces axial force, can only use straight-tooth gear, the noise of straight-tooth gear is big, intensity is low, and the accuracy of manufacturing and the size that often need to increase gear overcome above-mentioned shortcoming.

The objective of the invention is to overcome the shortcoming of spur gear in the above-mentioned speed change transmission, a kind of screw-wheel gearing of variable gear ratio is provided.

The objective of the invention is to realize by following scheme, adopt helical teeth at two between centers shifting slide gears, and the used spline of slippage simultaneously also adopts helical spline, in a gear ratio changeable helical gear transmission device, comprise housing, gearshift, also comprise driving shaft with helical spline, the driven axle that is parallel to driving shaft, output shaft and gear pair, the angular gear that has the 2-3 of slip to be connected as a single entity on the driving shaft, be fixed on the axle can be respectively and the helical gear of said gear engagement there being 2-3 on the driven axle, also has output gear on the output shaft; The above-mentioned helical spline and the helical teeth of angular gear slidably thereon, and the relation between the centre distance A between the diaxon should satisfy;

1. helical spline equates with the helical pitch L of helical gear helical teeth;

2. helical spline is identical with the Hand of spiral of helical gear helical teeth;

3. tg β _Tooth=(2 π A)/((1+i _Tooth) L)

Wherein: β _Tooth-certain helix angle to angular gear;

I _Tooth-this is to helical gear velocity ratio=(Z _Quilt)/(Z _Main)

=(the number of teeth _Quilt)/(the number of teeth _Main)

Satisfy above-mentioned requirements, the axial force that angular gear produced can be offset by the axial force that helical spline produced.

Referring now to drawings and Examples, describe gear ratio changeable helical gear transmission device of the present invention and computational methods in detail.

Fig. 1 only shows the variable part for gear ratio changeable helical gear transmission device embodiment's of the present invention structural drawing among the figure.

Fig. 1 only shows the embodiment's of variable part relevant with the present invention in the variable speed drive structural drawing, all the other decelerations or drive part, irrelevant with the present invention, so be not shown specifically, but be to be noted that the various forms of transmissions that to continue after the gear ratio changeable helical gear transmission device of the present invention.They can be installed in the same housing, also can be provided with respectively.

Driving shaft 1 has the spline of helical teeth among Fig. 1, be with the angular gear of 2-3 slip on the axle 1, be 2 shown in the figure, 3,4 three, they are assembled into one, stir the position that can on axle 1, slide onto needs by gearshift 16, driven axle 8 is parallel to axle 1, be fixed with the gear 7 that can be meshed on it with gear 2, gear 6 that can be meshed and the gear 5 that can be meshed with gear 4 with gear 3, axle 8 also has helical spline, also has angular gear 9 on it, 10, they also form one, stir the position that can on axle 8, slide onto needs by gearshift 15, axle 8 is fixed with gear 11 that can be meshed with gear 9 and the gear 12 that can be meshed with gear 10 promptly as driving shaft on the driven axle (output shaft) 13 at this moment, so by gearshift 15,16 manipulation, axle 13 can obtain 6 rotating speeds, and by gear 14 outputs.So in the device of present embodiment, has the gear ratio changeable helical gear transmission of the present invention of two covers, i.e.

axle

1,8 and

slip gear

2,3,4,

axle

8,13 and slip gear 9,10.

For helical gear, the axial force F that produces during its engagement _Axle=F _CutTg β.

F _CutThe tangential force that produces during=gear engagement.

F _Cut=(M)/(r)

The M-transmitting torque, r-gear compound graduation circle radius,

Helix angle on β-standard pitch circle,

∵tgβ＝ (2πr)/(L)

The helical gear helical pitch of L-

∴ F _Axle=(M)/(r) (2 π r)/(L)=(2 π M)/(L)

For helical spline, its axial force T _Axle=T _CutTg β ₁

T _CutFootpath r in the-splined shaft ₁Suffered tangential force

T _Cut=(M)/(r ₁)

β ₁The helix angle in footpath in the-spline

∵tgβ ₁＝ (2πr ₁)/(L ₁)

L ₁The helical pitch of-helical spline

∴ T _Axle=(M)/(r ₁) (2 π r ₁)/(L ₁)=(2 π M)/(L ₁)

As make F axle=T axle

Then (2 π M)/(L)=(2 π M)/(L ₁)

So L=L ₁, promptly gear equates to get final product with the helical pitch of spline;

Simultaneously, by analyzing as can be known, when the Hand of spiral of the Hand of spiral of gear and spline was identical, its axial force that is produced on same gear was opposite;

So: the Hand of spiral of gear should be identical with the Hand of spiral of spline.

Here, it should be noted that: though axial force has been offset, do not act on the same radius, by the moment of flexure F of gear axial force generation because of two axial forces _AxleThe moment of flexure T that r can not produce with the spline axial force _Axler ₁Offset, it will make bending shaft, so should check the rigidity of axle, because there is radial clearance in spline, also have the rigidity problem in addition, but in the gap when very little, the rigidity of oil film is enough.Secondly because helix angle is arranged, unfavorable to the slippage of gear, but the helix angle of gear is generally less, if the precision of interior external splines, when degree of finish is better, fork is stirred the gear slippage and is meshed the problem of not having.

The several sliding gears that fuse that axial distance is very little can not be processed with hobboing cutter, so preferably make modular.

Helical spline shaft adds differential hanging gear processing with spline milling machine, and the Turbo Flora keyway is pulled out with helical spline broach.

The base dimension of gear ratio changeable helical gear transmission is calculated as follows:

Being located at has n group helical gear to be meshed on two parallel axes, make that driving shaft is the helical spline axle the present, and driven shaft is for there being the axle of fixed gear on it, and the velocity ratio of gear pair is preface i successively ₁, i ₂..., i _kI _nAnd the number of teeth of gear is Z at driving shaft ₁₁, Z ₂₁Z _N1The number of teeth of the gear on driven shaft is Z ₁₂, Z ₂₂Z _N2, then

i ₁＝ (Z ₁₂)/(Z ₁₁) ，i ₂＝ (Z ₂₂)/(Z ₂₁) ，……

iK＝ (Z _K2)/(Z _K1) ，……in＝ (Z _N2)/(Z _N1) 。

At first calculate decision modulus and centre distance according to common intensity,

Rule of thumb determine helical pitch L again,, the standardization of spline helical pitch can be existed as far as possible for reducing the size of spline broach

40π，50π，63π，80π，100π，

125π，160π，200π，250π，

300π，320π，400π，500π，

630π，800π，1000π，1250π，

1600 π, 2000 π, 2500 π choose among 3200 π.

With K group gear is example

i _k＝ (Z _K2)/(Z _K1) ，Z _k2＝i _kZ _k1……（1）

A＝ (m(Z _K1+Z _K2))/(2cosβ _K) ……（2）

m＝ (2Acosβ _K)/(Z _K1+Z _K2) ……（3）

tgβ _k＝ (πD _K1)/(L) ＝ (πmZ _K1)/(Lcosβ _K) ……（4）

With (3) substitution (4), then

tgβ _k＝ (πZ _K1)/(Lcosβ _K) · (2Acosβ _K)/(Z _K1+Z _K2)

＝ (2πA)/(L) · (Z _K1)/(Z _K1+Z _K2)

＝ (2πA)/((1+i _K)L)

The helixangle tooth that is gear is determined by following formula

Tg β _Tooth=(2 π A)/((1+i _Tooth) L)

For the helical teeth transmission, severally can both satisfy centre distance A to gear, it is the comparison difficulty that the number of teeth is integer, adopts only to change helixangle and utilize displacement to satisfy, and can be calculated by computer-aided equipment and finish.

Two groups of gears, velocity ratio is close more, and the difference of each helix angle is also more little, otherwise, then big more.

Variable gear ratio helical teeth transmission device has following advantage than straight-tooth gear transmission device, allows the rotating speed height; Bearing capacity is big; Stable drive; Noise is little; Velocity ratio allowable is big slightly; Physical dimension is little, for example, the present most of lathe that uses, all used after the belt transmission deceleration, just used the gear ratio transmission, the variable gear ratio gear-box of heavy duty, as automobile, adopt high hardness, high class gear for the bearing capacity that improves gear, the higher lathe noise of some rotating speed is big, some gearbox gear life-span is too short etc., and using the helical gear transmission will have substantial raising to the mechanical property or the index of these equipment:

For example, be the variable ratio part of gear box of tractor as Fig. 1, it reaches the purpose of gear ratio by the transmission of slippage helical gear, can realize 6 grades of rotating speeds.

Be each and gear parameter of drawing label below, wherein, the X-modification coefficient;

1, helical spline axle: outer diameter D=32 helixangles=6 ° 5 ' 18 " helical pitch L=300 π

2, gear m=3 Z=24 β=13 ° of 48 ' 58 " L=300 π X=0

3, gear m=3 Z=29 β=16 ° of 50 ' 41 " L=300 π X=-0.02

4, gear m=3 Z=18 β=10 ° of 15 ' 52 " L=300 π X=0

5, gear m=3 Z=37 β=10 ° of 15 ' 52 " L=300 π X=+0.23

6, gear m=3 Z=24 β=16 ° of 50 ' 41 " L=300 π X=0

7, gear m=3 Z=30 β=13 ° of 48 ' 58 " L=300 π X=-0.14

8, helical spline axle: D=36 β=6 ° 25 ' 7 " L=320 π

9, gear m=3 Z=17 β=9 ° of 9 ' 15 " L=320 π X=0

10, gear m=3 Z=35 β=19 ° of 15 ' 3 " L=320 π X=0

11, gear m=3 Z=43 β=9 ° of 9 ' 15 " L=320 π X=-0.05

12, gear m=3 Z=22 β=19 ° of 15 ' 3 " L=320 π X=+0.14

13, driven axle

14, output gear

Axle 1 and axle 8 centre distance A=83mm,

Axle 8 and axle 13 centre distance A=91mm.

Claims

1, a kind of gear ratio changeable helical gear transmission device, comprise housing and gearshift, also comprise driving shaft, driven axle, output shaft and gear pair, it is characterized in that said driving shaft has helical spline, said driven axle is parallel to driving shaft, the helical gear that 2-3 slip that is connected as a single entity arranged on the driving shaft, have 2-3 to be fixed on the helical gear that axle is gone up and above-mentioned helical gear meshes respectively on the driven axle, the centre distance A of said helical spline and the helical gear on it and master, driven axle has following relationship:

3. tg β _Tooth=(2 π A)/((1+i _Tooth) L)

Wherein: β _Tooth-certain is to helical gear helix angle;

i _Tooth-this is to helical gear velocity ratio=(Z _Quilt)/(Z _Main)

=(the number of teeth _Quilt)/(the number of teeth _Main)

2,, it is characterized in that the slip helical gear on the said driving shaft is made up of 2,3,4 of three helical gears that are connected as a single entity as the said gear ratio changeable helical gear transmission device of claim 1.

3,, it is characterized in that the slip helical gear on the said driving shaft is made up of 9,10 of two helical gears that are connected as a single entity as the said gear ratio changeable helical gear transmission device of claim 1.