CN1070595C - Helical gear - Google Patents

Abstract

The present invention relates to a helical gear which can not damage teeth and can eliminate slurry although the helical gear is put in slurry fluid. The tooth-shaped curve whose axis has a cross section in the right angle direction is used as a second type tooth shape composed of a trochoid tooth shape; a circular arc (Novikov) tooth shape and an involute tooth shape of a first type tooth shape are formed on a part of the trochoid tooth shape; the engagement point of the tooth-shaped curve has the track that the addendum radii R01 and R02, the radii Rb1 and Rb2, a straight line and the circular arc of the radii a1 and a2 are combined; the addendum radii R01 and R02 uses the gear rotation centers O1 and O2 as the centers; the radii Rb1 and Rb2 are smaller than the pitch circle radii R1 and R2; the straight line passes through a node P; two ends of the engagement points are used for the circular arc which uses the node P as the center. The tooth-shaped curve of the present invention is used as a continuous tangential tooth shape composed of the trochoid curve, the involute curve and the circular arc tooth shape. The part of the trochoid curve with the large slide power is used for eliminate the slurry, and a circular arc gear (novikov tooth shape) and the involute tooth shape part are used for transferring power.

Description

Helical gear

The present invention relates to a kind of helical gear tooth curve, in more detail, relate to a kind of helical gear with tooth curve by the continuous tangent form of gear tooth of trochoid curves and involute curve and circular arc (Ke husband of Novi profile of tooth) formation.

Usually, as profile of tooth, thereby the helical gear with this tooth curve is mainly used in the gear pump that liquid is carried usefulness to helical gear tooth curve, is the gear that rotates in oil groove mostly by single curves such as involute curve or cycloidal curves.

But oil groove contains iron rust or greasy dirt thing, and these solids have the situation of wearing and tearing profile of tooth obviously.Particularly, when the gear pump of the FLUID TRANSPORTATION that is used for slurry fluid, the mud profile of tooth of can wearing and tearing in the fluid makes rotation stop sometimes.

Even the purpose of this invention is to provide a kind of when nipping slurry fluid, also can not damage tooth and and can get rid of the helical gear of mud.

The present invention forms the track of tooth curve contact points from gear gyration center O ₁, O ₂Outside radius R as the center _O1And R _O2Than pitch circle radius R ₁And R ₂Want little radius R _B1And R _B2, the straight line by node P and be radius centered a in order to node with the two ends of straight line, and a ₂The circular arc track that combines and constituted, because its tooth curve becomes by with cycloidal curve, involute curve and the arc toothed continuous phase gear cutting machine profile of tooth that constitutes, so remove profile of tooth engagement mud portion by sliding high-power trochoid curves, and arc toothed, involute profile can be carried out power and transmitted, thereby has prevented in the oil groove mud equivalent damage form of gear tooth in mud or the fluid.

Fig. 1 is the part sectional view of the rotor tooth form example of explanation positive displacement flowmeter of the present invention.

Fig. 1 shows axle Nogata part tooth curve and the path of action in section at explanation helical gear example of the present invention, among the figure, and the 1st, the number of teeth is Z ₁Driving wheel (call O in the following text ₁Gear), the 2nd, the number of teeth is Z ₂Follower (call O in the following text ₂Gear), the 3rd, O ₁The top circle R of gear _O1, the 4th, O ₂The top circle R of gear _O2, the 5th, O ₁The pitch circle R of gear ₁, the 6th, O ₂The pitch circle R of gear ₂, P is a node.

In tooth curve shown in Figure 1, the some P from the pitch circle 5,6 ₁, P ₂As boundary line formation addendum profile of tooth and dedendum of the tooth profile of tooth separately.Below to O ₁, O ₂The structure of the tooth curve of gear 1,2 is illustrated.

O ₁The addendum tooth curve of gear 1 is to use A ₁B ₁C ₁D ₁P ₁The continous curve that illustrates, curve A ₁B ₁Be Outside radius R _OThe tooth top circular arc, curve B ₁C ₁Be that the radius of center on pitch circle is a ₁Arc toothed, curve C ₁D ₁Be O ₂The E of gear 2 ₂The radius vector R that paints of point _C11The trochoid curves of (aftermentioned), and D ₁P ₁Be by radius vector R _C31The involute curve of the pressure angle α that (aftermentioned) constitutes.

O ₁The dedendum of the tooth tooth curve of gear 1 is by P ₁E ₁F ₁G ₁H ₁The continous curve that constitutes, curve P ₁E ₁Be and above-mentioned D ₁P ₁The involute curve of continuous pressure angle α, curve E ₁F ₁Be the radius a of center on the node circle ₂Arc toothed, curve F ₁G ₁Be O ₂The B of gear 2 ₂The radius vector R that paints of point _C21The trochoid curves of (aftermentioned), and curve G ₁H ₁Be with root radius (R ₁+ R ₂-R _O2) be the circle of radius.Similarly, can provide O ₂The tooth curve of gear 2.

In above-mentioned tooth curve, O ₁Trochoid curves C in the addendum of gear 1 ₁D ₁Radius vector R _C11With the trochoid curves F in the dedendum of the tooth ₁G ₁Radius vector R _C21, involute curve D ₁E ₁Radius vector R _C31And O ₂Trochoid curves C in the addendum of gear 2 ₂D ₂Radius vector R _C12With trochoid curves F in the dedendum of the tooth ₂G ₂Radius vector R _C22, involute curve D ₂E ₂Radius vector R _C32Represented with following relation.

θ _a2=cos ^-1{(R ₂ ²+R _b2 ²-a ₂ ²)/2R ₂R _b2}+δ ₂θ _b2=cos ^-1{(R _O2 ²+R ₂ ²-a ₂ ²)/2R _O2R ₂}θb ₂＇=α-cos ^-1(R ₂cosα/R _b2)+δ ₂δ ₂=invα-inv{cos ^-1(R ₂cosα/R _b1)}

$R_{c22}={[R_{O1}^2+{(R_1+R_2)}^2-2R_{O1}(R_1+R_2)\cos \mathrm{\θ}]}^{\frac{1}{2}}...O\≤\mathrm{\θ}\≤{\mathrm{\θ}}_{b1}----\left(5\right)$ θ _a1+cos ^-1{(R ₁ ²+R _b1 ²-a ₁ ²)/2R ₁R _b1}+δ ₁θ _b1=cos ^-1{(R _O1 ²+R ₁ ²-a ₁ ²)/2R _O1R ₁}θ _b1＇=α-cos ^-1(R ₁cosα/R _b1)+δ ₁δ ₁=invα-inv{cos ^-1(R ₁cosα/R _b1)}

The O that obtains like this ₁Gear 1 and O ₂The contact points of gear 2 represented with static system of coordinates, path of action become node as P and with dot and dash line represent 10,11,12,13, P, 14,15,16,17,18,19, P, 20,21 lemniscate curve.

Effect corresponding to claim is that the track of tooth curve contact points is with gear rotating center O ₁, O ₂Tooth circle radius R for the center _O1And R _O2, than pitch circle radius R ₁And R ₂Want little radius R _B1And R _B2, the straight line by node P and be that radius centered is a with the node at the two ends of straight line ₁And a ₂The track of circular arc order combination, its tooth curve conduct is by trochoid curves, involute curve and the arc toothed continuous tangent form of gear tooth that constitutes, even so in containing slurry fluid, rotate, the trochoid curves part that sliding ratio is big can be removed mud, and arc toothed (Ke husband of Novi profile of tooth) and involute profile can transmit as power, thereby are applicable to the pump of handling the fluid contain mud and the rotor of positive displacement flowmeter preferably.

Claims (1)

1. a helical gear is characterized in that, the path of action of tooth curve is that handle is from gear rotating center O ₁, O ₂Outside radius R as the center _O1And R _O2Than pitch circle radius R ₁And R ₂Want little radius R _B1And R _B2, be radius centered a by the straight line of node P and their two ends in order to node ₁And a ₂The track that combines of circular arc, its tooth curve is by trochoid curves, the continuous tangent form of gear tooth of involute curve and arc toothed formation;

O ₁The addendum tooth curve of gear 1 is to use A ₁B ₁C ₁D ₁P ₁The continous curve that illustrates, curve A ₁B ₁Be Outside radius R _OThe tooth top circular arc, curve B ₁C ₁Be that the radius of center on pitch circle is a ₁Arc toothed, curve C ₁D ₁Be O ₂The E of gear 2 ₂The radius vector R that paints of point _C11The trochoid curves of (aftermentioned), and D ₁P ₁Be by radius vector R _C31The involute curve of the pressure angle α that (aftermentioned) constitutes;

O ₁The dedendum of the tooth tooth curve of gear 1 is by P ₁E ₁F ₁G ₁H ₁The continous curve that constitutes, curve P ₁E ₁Be and above-mentioned D ₁P ₁The involute curve of continuous pressure angle α, curve E ₁F ₁Be the radius a of center on the node circle ₂Arc toothed, curve F ₁G ₁Be O ₂The B of gear 2 ₂The radius vector R that paints of point _B21The trochoid curves of (aftermentioned), and curve G ₁H ₁Be with root radius (R ₁+ R ₂-R _O2) be the circle of radius;

In above-mentioned tooth curve, O ₁Trochoid curves C in the addendum of gear 1 ₁D ₁Radius vector R _C11With the trochoid curves F in the dedendum of the tooth ₁G ₁Radius vector R _C21, involute curve D ₁E ₁Radius vector R _C31And O ₂Trochoid curves C in the addendum of gear 2 ₂D ₂Radius vector R _C12With trochoid curves F in the dedendum of the tooth ₂G ₂Radius vector R _C22, involute curve D ₂E ₂Radius vector R _C32Represented with following relation:

θ _A2=cos ^-1{ (R ₂ ²+ R _B2 ²-a ₂ ²)/2R ₂R _B2}+δ ₂θ _B2=cos ^-1(R _{O2 2}+ R ₂ ²-a ₂ ²)/2R _O2R ₂θ _B2＇=α-cos ^-1(R ₂Cos α/R _B2)+δ ₂δ ₂=inv α-inv{cos ^-1(R ₂Cos α/R _B1)

$R_{c22}={[R_{O1}^2+{(R_1+R_2)}^2-2R_{O1}(R_1+R_2)\cos \mathrm{\θ}]}^{\frac{1}{2}}...O\≤\mathrm{\θ}\≤{\mathrm{\θ}}_{b1}----\left(5\right)$

θ _a1=cos ^-1(R ₁ ²+R _b1 ²-a ₁ ²)/2R ₁R _b1}+δ ₁ θ _b1=cos ^-1{(R _O1 ²+R ₁ ²-a ₁ ²)/2R _O1R ₁} θ _b1＇=α-cos ^-1(R ₁cosα/R _b1)+δ ₁ δ ₁=invα-inv{cos ^-1(R ₁cosα/R _b1)}