CN104265872A - Gearshift mechanism - Google Patents

Abstract

The invention relates to a gearshift mechanism. The gearshift mechanism comprises a separating sleeve, a constant mesh gear, a forward gear set, a separating ring, elastic sliding keys, a shifting ring, a sliding key shaft and a backward gear; when working under the conditions that the minimum width of gear keyways is more than the width of the elastic sliding keys, the minimum space between every two adjacent gear keyways is more than the width of the elastic keyways, and the minimum width of the gear keyways is more than and equal to the minimum space between the every two adjacent keyways, the shifting ring drives the elastic sliding ways to move toward the head part, and then the head parts of the elastic sliding keys are wedged into the keyways in a forward gear, so as to realize the forward marching function; when the shifting ring drives the elastic sliding keys to move toward the tail part, the tail parts of the elastic sliding keys are wedged into the keyways in the backward gear under the effect of a guide inclined surface, so as to realize the backward moving function. The gearshift mechanism is simple in structure; the elastic sliding keys are used for shifting, and therefore, the axial space for a sliding gear to perform gearshift can be reduced.

Description

A kind of gear shift mechanism

Technical field the present invention relates to a kind of gear shift mechanism of gearbox, is specifically related to a kind of gear shift mechanism of agricultural equipment gearbox.Belong to agricultural machinery technological field.

The existing gear shift mechanism of background technique comprises sliding key shaft and is enclosed within one group of power shift gear on axle, each shifting gear has different velocity ratios, each shifting gear one end face has deep gouge, in deep gouge, spacer ring is installed, sliding key shaft is provided with chute, elasticity feather key is embedded between chute and ring, can freely along axial sliding movement in chute.Elasticity feather key head is inserted in the gear keyway of forward gear.Ring band dynamic elasticity feather key moves forward, spacer ring makes elasticity feather key head press down, enter certain forward gear keyway, elasticity feather key head recovers distortion in gear keyway, and when transmission of power makes it to rotate to this shifting gear, gear keyway one end face and elasticity feather key head one end face of the gear that elasticity feather key head is inserted into are fitted, the elasticity feather key on chute is driven to rotate, and driving sliding key shaft to rotate, remaining shifting gear dallies, and realizes forward gear gearshift function.

The work of agricultural equipment not only requires forward gears operating speed, often also needs and retreats the cooperation of shelves speed, the operation advantage of competence exertion agricultural equipment.The method utilizing feather key form to carry out shifting gears is relatively less, and rarely have the relevant restriction relation of relative position between elasticity feather key, gear keyway, sliding key shaft to illustrate, as the height etc. of the angle of regulation range when minimum width scope of gear keyway, the minimum separable of adjacent two keyways, elasticity feather key coordinate with gear keyway and elasticity feather key head.

Summary of the invention the object of the invention is to, and overcomes prior art Problems existing, provides a kind of gear shift mechanism with relative position restriction between elasticity feather key, gear keyway, sliding key shaft, improves the reliability of gear shift.

For achieving the above object, technological scheme of the present invention is as follows:

A kind of gear shift mechanism of the present invention, comprises spacer, constant mesh gear, advance 1-4 shelves gear, spacer ring, elasticity feather key, ring, sliding key shaft and reverse gear; Sliding key shaft is fixed on gearbox, and constant mesh gear is fixed on sliding key shaft, and forward gears and reverse gear are enclosed within sliding key shaft; The endoporus of forward gears is respectively equipped with gear keyway, and be respectively equipped with spacer ring between each advance shift gear, sliding key shaft is provided with featherway, and elasticity feather key is arranged in featherway, and can slide axially in featherway; The middle part of elasticity feather key is provided with the ring driving the movement of elasticity feather key; It is characterized in that:

(1) scope of elasticity feather key center line deflection angle theta

$\arcsin \left(\frac{b+2}{D_1}\right)-\arcsin \left(\frac{b}{D_1}\right)\≤\mathrm{\θ}\≤\frac{\mathrm{\π}}{N}-\arcsin \left(\frac{b+2}{D_1}\right)-\arcsin \left(\frac{b}{D_1}\right)$

Wherein, b is that elasticity feather key key is wide; D ₁for bore diameter; N is the number of gear keyway.

(2) gear keyway minimum width S is

S＝2R1·sin(α+θ)＝D ₁·(sinαcosθ+sinθcosα)

And S>b;

Wherein, R1 is bore radius;

(3) the minimum range S1 between adjacent two gear keyways is

$S1=2R1\·\sin \mathrm{\β}=D_1\·[\sin \frac{\mathrm{\π}}{N}\cos (\mathrm{\α}+\mathrm{\θ})-\cos \frac{\mathrm{\π}}{N}\sin (\mathrm{\α}+\mathrm{\θ})].$

And S >=S1>b

Wherein, β is the minimum range half chord length angle between adjacent two gear keyways;

(4) shaft spline height h is

$h\≥\frac{m}{\cos \mathrm{\γ}}+(l-w-m\tan \mathrm{\γ})\sin \mathrm{\γ}$

Wherein, m is elasticity feather key cervical part of esophagus thickness, and w is elasticity feather key head width, and l is elasticity feather key head length, γ elasticity feather key free angle.

Described elasticity feather key afterbody has guiding surface; The height of head T of elasticity feather key is less than sliding key shaft keyway height h; Elasticity feather key free neck end height n is less than sliding key shaft keyway height h; Elasticity feather key freely extends height H

$H\≤h+\frac{\sqrt{D_2^2-b^2}-\sqrt{d^2-b^2}}{2}$

Wherein, d is sliding key shaft diameter, D ₂for gear keyway diameter of bore.

Advantage of the present invention and beneficial effect as follows: structure of the present invention is simple, adopts elasticity feather key to shift gears, and reduces axial space when carrying out shift speed change by shifting slide gear; The present invention also specify that the restriction relation of relative position between elasticity feather key, gear keyway, sliding key shaft, improves the reliability of gear shift.

Accompanying drawing explanation

Fig. 1 is a kind of gear shift mechanism structure schematic diagram;

Fig. 2 is elasticity feather key and gear keyway cooperating tangent plane schematic diagram;

Fig. 3 is elasticity feather key and sliding key shaft cooperating tangent plane schematic diagram;

Fig. 4 is elasticity feather key front schematic view.

Icon explanation

1. spacer; 2. constant mesh gear; 3. advance 1 grade of gear; 4. advance 2 grades of gears; 5. advance 3 grades of gears; 6. advance 4 grades of gears; 7. spacer ring; 8. elasticity feather key; 9. ring; 10. sliding key shaft; 11. reverse gears; 12. elasticity feather key heads; 13. elasticity feather key afterbodys; B. elasticity feather key is wide; R1. bore radius; R2. gear keyway internal bore radius; S. gear keyway minimum width; S1. the minimum range between adjacent two gear keyways; α. contact edge and elasticity feather key centerlines; θ. elasticity feather key center line angle of yaw; β. the minimum range half chord length angle between adjacent two gear keyways; H. elasticity feather key freely extends height; H. sliding key shaft keyway height; T. elasticity feather key height of head; W. elasticity feather key head width; L. elasticity feather key head length; N. elasticity feather key free neck end height; γ. elasticity feather key free angle; M. elasticity feather key cervical part of esophagus thickness; D. sliding key shaft diameter.

Embodiment, in order to illustrate the present invention instead of restriction the present invention further, is illustrated below in conjunction with embodiment.

Embodiment 1: a kind of gear shift mechanism

As Figure 1-4, gear shift mechanism of the present invention, comprises spacer 1, constant mesh gear 2, advance 1 grade of gear 3, the 2 grades of gears 4 that advance, the 3 grades of gears 5 that advance, advances 4 grades of gears 6, spacer ring 7, elasticity feather key 8, ring 9, sliding key shaft 10, reverse gears 11; Sliding key shaft 10 is fixed on gearbox, and constant mesh gear 2 is fixed on sliding key shaft 10, and forward gears 3-6 and reverse gear 11 are enclosed within sliding key shaft 10; The endoporus of forward gears 3,4,5,6 is respectively equipped with gear keyway, and be respectively equipped with spacer ring 7 between each advance shift gear, sliding key shaft 10 is provided with featherway, and elasticity feather key 8 is arranged in featherway, and can slide axially in featherway; The middle part of elasticity feather key 8 is provided with the ring 9 driving the movement of elasticity feather key; Elasticity feather key afterbody 13 has guiding surface.

Gear keyway minimum width S should meet

S＝2R1·sin(α+θ)＝D ₁·(sinαcosθ+sinθcosα)

Minimum range S1 between adjacent two gear keyways is

$S1=2R1\·\sin \mathrm{\β}=D_1\·[\sin \frac{\mathrm{\π}}{N}\cos (\mathrm{\α}+\mathrm{\θ})-\cos \frac{\mathrm{\π}}{N}\sin (\mathrm{\α}+\mathrm{\θ})].$

For ensureing that gear key tooth because falling into sliding key shaft keyway, and can not affect transmission, the minimum range S1>b between adjacent two gear keyways should be made.

Can ensure that the condition of good, reliable transmission is: it is wide that gear keyway minimum width is greater than elasticity feather key key, it is wide that minimum range between adjacent two gear keyways is greater than elasticity feather key key, and gear keyway minimum width equals greatly the minimum range between adjacent two gear keyways.Namely

S≥S1>b。

The scope of elasticity feather key 8 center line deflection angle theta is

$\arcsin \left(\frac{b+2}{D_1}\right)-\arcsin \left(\frac{b}{D_1}\right)\≤\mathrm{\θ}\≤\frac{\mathrm{\π}}{N}-\arcsin \left(\frac{b+2}{D_1}\right)-\arcsin \left(\frac{b}{D_1}\right)$

Sliding key shaft 10 keyway height h should meet

$h\≥\frac{m}{\cos \mathrm{\γ}}+(l-w-m\tan \mathrm{\γ})\sin \mathrm{\γ}$

The height of head T of elasticity feather key 8 is less than sliding key shaft 10 keyway height h; The free neck end height n of elasticity feather key 8 is less than sliding key shaft 10 keyway height h; Freely the extending height H and should meet of elasticity feather key 8

$H\≤h+\frac{\sqrt{D_2^2-b^2}-\sqrt{d^2-b^2}}{2}$

When gear shift mechanism of the present invention enters working state, dynamic elasticity feather key 8 is with to move to cephalad direction ring 9, then elasticity feather key head 12 is inserted in the keyway of forward gear, and forward gear drives the constant mesh gear 2 be fixed on sliding key shaft 10 to rotate, and realizes advancement function; When ring 9 is with dynamic elasticity feather key 8 rearwardly direction is moved, elasticity feather key afterbody 13, is inserted in the keyway of reverse gear 11 under the effect of guiding surface, and reverse gear 11 drives the constant mesh gear 2 be fixed on sliding key shaft 10 to rotate, and realizes rewind function.

In addition to the implementation, the present invention can also have other mode of execution.The coordinated scheme that all employing equivalent way are formed, all in the protection domain of application claims.

Claims (5)

1. a gear shift mechanism, comprises spacer, constant mesh gear, advance 1-4 shelves gear, spacer ring, elasticity feather key, ring, sliding key shaft and reverse gear; Sliding key shaft is fixed on gearbox, and constant mesh gear is fixed on sliding key shaft, and forward gears and reverse gear are enclosed within sliding key shaft; The endoporus of forward gears is respectively equipped with gear keyway, and be respectively equipped with spacer ring between each advance shift gear, sliding key shaft is provided with featherway, and elasticity feather key is arranged in featherway, and can slide axially in featherway; The middle part of elasticity feather key is provided with the ring driving the movement of elasticity feather key; It is characterized in that:

(1) scope of elasticity feather key center line deflection angle theta

$\arcsin \left(\frac{b+2}{D_1}\right)-\arcsin \left(\frac{b}{D_1}\right)\≤\mathrm{\θ}\≤\frac{\mathrm{\π}}{N}-\arcsin \left(\frac{b+2}{D_1}\right)-\arcsin \left(\frac{b}{D_1}\right)$

Wherein, b is that elasticity feather key key is wide; D ₁for bore diameter; N is the number of gear keyway;

(2) gear keyway minimum width S is

S＝2R1·sin(α+θ)＝D ₁·(sinαcosθ+sinθcosα)

And S>b;

Wherein, R1 is bore radius; θ is elasticity feather key center line angle of yaw; α is contact edge and elasticity feather key centerlines;

(3) the minimum range S1 between adjacent two gear keyways is

$S1=2R1\·\sin \mathrm{\β}=D_1\·[\sin \frac{\mathrm{\π}}{N}\cos (\mathrm{\α}+\mathrm{\θ})-\cos \frac{\mathrm{\π}}{N}\sin (\mathrm{\α}+\mathrm{\θ})].$

And S >=S1>b;

Wherein, β is the minimum range half chord length angle between adjacent two gear keyways;

(4) shaft spline height h is

$h\≥\frac{m}{\cos \mathrm{\γ}}+(l-w-m\tan \mathrm{\γ})\sin \mathrm{\γ}$

Wherein, h is shaft spline height, and m is elasticity feather key cervical part of esophagus thickness, and w is elasticity feather key head width, and l is elasticity feather key head length, γ elasticity feather key free angle.

2. a kind of gear shift mechanism according to claim 1, is characterized in that described elasticity feather key height of head T is less than shaft spline height h.

3. a kind of gear shift mechanism according to claim 1 and 2, is characterized in that described elasticity feather key free neck end height n is less than shaft spline height h.

4. a kind of gear shift mechanism according to claim 1 or 3, is characterized in that described elasticity feather key freely extends height H and is

$H\≤h+\frac{\sqrt{D_2^2-b^2}-\sqrt{d^2-b^2}}{2}$

Wherein, d is sliding key shaft diameter, D ₂for gear keyway diameter of bore.

5. a kind of gear shift mechanism according to claim 1, is characterized in that described elasticity feather key afterbody has guiding surface.