JPS59206689A - Continuous contact gear pump - Google Patents

Abstract

PURPOSE:To prevent force from being applied to the contact part of a tooth profile in a gear pump without causing any change of its delivery amount and pressure, by constituting the gear pump so that theoretical torque of a driving gear of always almost fixed level further theoretical torque of a driven gear of almost zero may be generated by the delivery pressure of fluid. CONSTITUTION:If assuming the volume dQ is delivered when a pair of gears O1, O2 having a number of teeth Z1, Z2 are rotated by the angles dtheta1, dtheta2, required energy for rotating the pair of gears is the power consumed for applying a pressure P to liquid of the volume dQ. Here the relation, where T1=CONSt (T1: rotating torque of the gear O1), T2=O (T2: rotating torque of the gear O2), is a hydrodynamic ideal condition of the gear pump, satisfying a condition of no pulsation without causing any change of the delivery amount and pressure. By this reason, the helix angle of a tooth profile multiplies integrally as against a pitch mpi (m = module) in a tooth width, causing the above condition to be attained.

Description

[Detailed description of the invention] The present invention is based on -month's I! l! The rotor is a continuous contact gear.

% pulsation, and the contact tooth surface of the gear is scorched.

Most conventional gear pumps have a pair of gears of the same shape and size, which is very advantageous in manufacturing, but the driven wheel only rotates by 1 l due to the discharge pressure! It has the disadvantage of generating μchilh surface force.

The present invention has been made by focusing on the above points.

The rationale for FJ is explained below. A pair of gears 0. with the number of teeth zl and z2. , 'o2 rotates by dθI + dθ2 and discharges a volume of dQ, then the energy required to rotate one wheel of the pair (J) is d
Since it is consumed to increase the pressure of P to the fluid of Q, the following equation holds true.

PdQ=T, dQl +T2 dQ2...
(1) (However, T1: The rotational torque of the vii car 0.
T2/rotational torque of gear 02) and satisfies the no-pulsation condition, but in particular, T1=cθnst and T2=0 are ideal hydrodynamic conditions for one gear pop. In order to satisfy T1=C0nSt, the entire locus of the contact point, which is a closed curve, must lie exactly along the tooth width of the gear to form a pitch circle? If the diameter is R1 + 2- the tooth width of the tooth, and the torsion angle β, io is an integer (where m: module), then the torsion of the tooth profile is equal to the pitch m in the tooth width.
It needs to be an integral multiple of π.

Next, the conditions for T2=O will be explained using a specific example.

The limit of a continuous contact tooth profile is a tooth profile whose contact line locus is the respective outer line and pinch inner diameter, as shown in Figure 1, and in the figure, A
indicates the trajectory of the contact line. This is easily understood from the fact that ``the normal to the locus of the contact line must pass within the center line segment'' from the relationship on the substantial side of the tooth profile. From Fig. 1, the included angle of the tooth thickness with the pitch circle is aJ, a!
When 2, 1= −□ (1+ε) ・・・・・・(8)2
2Z.

a! 2 π 1= −(1−G ) ・・・・・・(9)2Z2 The radius of the part is ρal + ρa
2. Letting the dedendum parts be ρdl and ρd2, the following equation is obtained.

0kuθ2 (Oa2 ・・・・・・(12) 0kuθ2<Ob2 ・・・・・・(13) 0kuθ+(Oa+ ・・・・・・(14) 0<(h (θbl ・・...(15) Next, Figure 2 shows a developed view of the contact line (which becomes the seal line) in the direction of the tooth trace, and this shows the theoretical rotational torque TI, 72
(16) (17) Here, if we set T2=0 and rearrange the above equation, we get the following equation.

(18) In particular, Ra2/R2=1, that is, all drive wheels are addendum gears.

Assuming that the driven wheel is an all dedendum gear ・・・・・・(19) becomes.

FIG. 3 shows the results obtained for each case when ZI=6 and Z2=3.4, 5, and 6.7, and the 0 mark indicates the tooth thickness limit of the driven wheel.

In Figure 4, Z1=6. Z2=4 Ra2/R2=1.3
The actual diagram of each tooth profile when RO2/R2=1 is shown. In this example, it has five continuous contact points a-a, and in order for T2=0, ε=0, 5758
It is.

Next, we will explain the case where there is always one continuous contact point. Even in this case, the above-mentioned (1) to (3) still apply. To explain the conditions for 0th order, T2 = O. In this case, in FIG. 5, the locus of the contact point is a one-point continuous contact tooth profile whose center is the outer shape ROtl of the driven wheel and the pitch point P, and T2=0 only in the case of R11/R2 (1). From Figure 5, there is nothing else like this. (23)

Next, FIG. 6 shows a developed view of the contact line (which becomes the seal line) in the direction of the tooth trace, and this shows the theoretical rotational torque TI, T2
If we ask for , we get . Therefore, if alO+''o, T2=0.Therefore, Ba2, especially if Ra2/R2=1.

In FIG. 7, Zl=6. The values were obtained when Zt = 3.4, 5, and 6.7, and the 0 mark in the figure indicates the tooth thickness limit of the driven wheel.

FIG. 8 shows Z1=6. Z2=4 Ra2/R2=1.
4 Shows the actual diagram of each tooth profile when RO2/R2=1, and in order for T2=0, ε=0.5518
It is.

-As is clear from the above explanation, according to the present invention, no force is applied to the contact portion of the tooth profile.

No tooth profile wear, scratches, etc. 11! A continuous contact gear pump can be provided.

[Brief explanation of drawings]

Figures 1 to 4 are diagrams for explaining one embodiment of the present invention, and Figures 5 to 8 are diagrams for explaining other embodiments of the present invention. Figures 2 and 5 are basic chevron diagrams, Figures 2 and 6 are developed diagrams of the contact line in the tooth trace direction, and
7 and 7 are diagrams showing both positive limits of the driven wheel, and FIGS. 4 and 8 are diagrams showing actual tooth profiles. Ol... Drive tooth! ! 02...Sub vI Sho car No.l
Figure 2 To1(Ol l,) = f(
θ4 Fig. 3 1.11.2 1.3 1.4oI 1 Fig. 7 1. + 1.2 7.3 /, 4 1.5 +,
6iRo+ Figure 8

Claims (2)

[Claims] (1) In a gear pump whose rotor is a pair of gears with continuous contact tooth profiles, the theoretical I torque of the driving gear due to the fluid discharge pressure is constant or approximately constant at 1 t, and the theoretical torque of the driven gear is It is constructed so that the torque is approximately zero, so there is no fluctuation in the amount of discharge and discharge pressure. The Si! l! Continuous contact gear pump. (2) , +iii Claim No. (1) z, characterized in that there are one to several points of continuous contact.z
f (I! I! continuous contact copper contact float pump described in I! above) l! The continuous contact gear pop according to claim (1), characterized in that there is always one continuous contact point.