CN105937602A - Double-arc gear - Google Patents

Abstract

The present invention discloses a double circular arc gear, comprising a plurality of gear teeth, wherein the basic tooth profile of each gear tooth comprises a convex circular arc and a concave circular arc, wherein the convex circular arc is connected to the concave circular arc by a groove line segment, and the groove line segment is formed by translating the common tangent of the convex circular arc and the concave circular arc toward the inner side of the convex circular arc; during the running-in process of the double circular arc gear of the present invention, the tooth profile formed by the groove line segment does not participate in meshing, and can effectively avoid pitting corrosion generated during the running-in process of the involute tooth profile of the ordinary tangent type double circular arc gear; after the running-in, the involute tooth profile formed by the original groove line segment smoothly transitions with the convex circular arc and the concave circular arc of the gear tooth, and can reduce the load of the convex circular arc and the concave circular arc, and improve the service life of the gear; and because the overlap degree of the involute tooth profile is higher than the overlap degree of the transition circular arc tooth profile of the stepped double circular arc gear, the transmission is smoother.

Description

A double arc gear

technical field

The invention belongs to a mechanical element for transmitting motion and power, specifically a gear, more specifically a double-arc gear.

Background technique

The basic tooth profile of the existing common tangent type double arc gear is composed of convex arc, concave arc and common tangent to the convex arc and concave arc. The gear processed by the hob made of this tooth profile The working tooth shape is divided into two parts: one part is the double arc tooth shape processed by its double arc part, and the other part is the involute tooth shape processed by the common tangent part. This kind of double-arc gear is prone to pitting at the involute tooth profile during running-in, resulting in gear failure. In order to solve the problem of pitting, the national standard file of gears GB12759-91 proposes a stepped double-arc gear, using a transitional arc to replace the common tangent of the convex and concave arcs. However, since the transition arc of the stepped double-arc gear does not participate in the meshing, while the involute tooth profile of the common tangent double-arc gear participates in the meshing, so the coincidence degree of the stepped double-arc gear Compared with the common tangent type double circular arc gear, the coincidence degree is smaller. Therefore, compared with the common tangent double-arc gear, the gear teeth of the stepped double-arc gear have a greater impact on meshing and disengagement, and the stability is worse than that of the common tangent double-arc gear, which affects the use of the gear. life.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a double circular arc gear which is less prone to pitting during running-in and has stable transmission after running-in.

The technical scheme that the present invention adopts for solving its technical problem is:

A double arc gear, comprising a plurality of teeth, the basic tooth profile of each tooth includes a convex arc and a concave arc, the convex arc is connected with the concave arc through a groove line segment, and the concave The groove segment is formed by the translation of the common tangent of the convex arc and the concave arc to the inner side of the convex arc.

As a preferred embodiment of the present invention, the groove line segment is formed by translating the common tangent by half the difference between the radius of curvature of the concave arc and the radius of curvature of the convex arc.

The beneficial effect of the present invention is: the basic tooth profile of each gear tooth of a kind of double circular arc gear of the present invention has used groove line segment to replace the common tangent line of convex arc and concave arc, and described groove line segment is formed by convex The common tangent of the circular arc and the concave circular arc is formed by translation. During the running-in process of the gear, the involute tooth shape formed by the groove line segment does not participate in the meshing, which can effectively avoid the involute of the common common tangent double arc gear. Pitting corrosion occurs during the running-in process of the open-line tooth profile. After the running-in process, the double-arc tooth profile formed by the convex arc and the concave arc and the involute tooth profile formed by the groove line segment transition smoothly. The involute tooth shape can bear part of the load when the gears mesh, which reduces the load of the convex arc and the concave arc, and improves the service life of the gear. The transitional arc tooth shape has a high degree of coincidence, so the transmission is more stable.

Description of drawings

Fig. 1 is the structural representation of the basic tooth profile of gear tooth of the present invention;

Fig. 2 is a structural schematic diagram of the basic tooth profile of the stepped double arc gear;

Fig. 3 is a schematic diagram of the basic tooth profile structure of the common tangent type double circular arc gear;

Fig. 4 is a schematic diagram of the relationship between the oil film pressure and the width of the teeth of the stepped double arc gear;

Fig. 5 is a schematic diagram of the relationship between the oil film pressure and the width of the gear teeth of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. However, it should be noted that the description of the following embodiments is schematic and does not constitute a specific limitation to the present invention.

Referring to Fig. 1, a double-arc gear of the present invention includes a plurality of teeth, and the basic tooth profile of each tooth includes a convex arc 1 and a concave arc 2, and the center line segment in the figure is the pitch circle of the gear , the convex arc 1 is connected to the concave arc 2 through the groove line segment 3, and the groove line segment 3 is translated to the inner side of the convex arc 1 by the common tangent line 4 of the convex arc 1 and the concave arc 2 Formed, where, Δ _r =P _b -P _a , where P _b is the radius of curvature of the concave arc, P _a is the radius of curvature of the convex arc, The distance is the running-in amount of a single gear tooth, after the running-in, there is a smooth transition between the convex arc 1 and the concave arc 2 and the groove line segment 3 . The translation distance of the groove line segment 3 relative to the common tangent line 4 can be adjusted according to the specific running-in conditions of the gear transmission, and is not limited to fixed value.

Referring to Figures 1 to 3, since the tooth shape formed by the groove line segment 3 does not participate in the meshing during the running-in process, pitting corrosion of the tooth shape formed by the groove line segment 3 during the running-in process is avoided, and the problem is solved. The ordinary public tangent double circular arc gear shown in Figure 3 has the problem of pitting corrosion during the running-in process. At the same time, the tooth shape formed by the groove line segment 3 is an involute tooth shape, and the involute tooth shape is compared with that in Fig. The national standard document GB12759-91 of the gear shown in 2 shows that the tooth profile of the transition arc part of each gear tooth of the stepped double arc gear proposed by the national standard file GB12759-91 has a higher coincidence degree, so a double arc gear of the present invention The overall coincidence degree is higher than that of the stepped double arc gear, and the transmission movement is more stable.

Referring to Figure 4, the existing stepped double arc gear forms two separate oil films during the gear transmission process, the abscissa W in the figure is the width of the oil film, and the vertical coordinate P is the pressure of the oil film, where the difference between A1 and A2 The distance between A2 and A3 is the oil film width corresponding to the tooth shape of the transition arc, and the distance between A3 and A4 is the concave circle The tooth shape of the arc corresponds to the oil film width, and the oil pressure on both sides of the two oil films is zero, so there are four leakage points. Referring to Fig. 5, the abscissa W in the figure is the oil film width, and the vertical coordinate P is the oil film pressure. A double-arc gear of the present invention connects the two oil films of the stepped double-arc gear into one oil film, The leakage points of the oil film are A5 and A6. Compared with the oil film of the stepped double-arc gear, the oil film leakage point has changed from four to two. The oil film area of the gear is several times larger, and the friction and wear between the tooth surfaces of the gear are reduced. On the one hand, the transmission efficiency is improved, and on the other hand, it helps to prolong the service life of the gear.

The above descriptions are only the preferred implementation modes of the present invention, as long as the technical solutions to achieve the purpose of the present invention by basically the same means fall within the scope of protection of the present invention.

Claims (2)

1. a Novikov gears with double circular arc tooth profiles, including multiple gear teeth, the basic rack tooth profile of each gear teeth includes dome arc (1) and concave arc (2), it is characterized in that: described dome arc (1) is connected with described concave arc (2) by groove line segment (3), by the common tangent (4) of described dome arc (1) with described concave arc (2), to the direction, inner side of described dome arc (1), translation is formed described groove line segment (3).

2. a kind of Novikov gears with double circular arc tooth profiles as claimed in claim 1, it is characterised in that: the distance of the half that described groove line segment (3) is translated the difference of the radius of curvature of described concave arc (2) and the radius of curvature of described dome arc (1) by described common tangent (4) is formed.