Middle-position arc cylindrical gear and machining method thereof

Abstract

The machining method comprises the following steps that a disc type tooth-shaped milling cutter is adopted to be fixed to a machine tool spindle, and a gear blank is installed on a device capable of dividing teeth and rotating at a certain angle; the disc-type tooth-shaped milling cutter does linear motion and rotary motion at the same time, the linear motion speed of the disc-type tooth-shaped milling cutter is set to v1, the angular speed at the gear milling pitch circle of the gear blank is converted into the linear speed, namely, the pitch circle linear speed of the gear blank is v2, and the v1 and the v2 are the same in direction and equal in speed; and the arc involute tooth-shaped structure with the symmetrical middle position is obtained. The middle-position arc cylindrical gear can replace herringbone teeth, is good in manufacturability and low in manufacturing cost, can be transformed through numerical control milling equipment, is more stable and lower in noise compared with a cylindrical gear, and meanwhile, the number of meshed teeth is larger.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of mid-position circular arc cylindrical gear and its processing method. BACKGROUND

[0002] Herringbone tooth has huge role and influence in power transmission industry, it has bidirectional cancellation axial force in meshing transmission, can reach balanced transmission function, has excellent transmission function and characteristics.But its manufacturing process is very complex, cause its manufacturing cost is very high.In many transmission scenes, although herringbone tooth process cost is higher, but herringbone tooth is irreplaceable gear variety, and herringbone tooth above 6-grade precision cannot be achieved integral structure, because with tool interference cannot be ground processing;And national standard GB / T1840-1989 "circular arc cylindrical gear" stipulates that the tooth profile is spiral helical gear, cannot achieve bidirectional cancellation axial force. SUMMARY

[0003] In order to solve the above technical problems, the present application provides a kind of mid-position circular arc cylindrical gear with simple structure and low manufacturing cost, and provides corresponding processing method.

[0004] The technical scheme for solving the above technical problems of the present application is: a kind of mid-position circular arc cylindrical gear, its tooth is mid-position symmetrical circular arc involute tooth profile structure, its involute forms complete single tooth profile by 20 ° pressure angle rotation motion cooperation tooth blank to cut out single tooth, then tooth blank indexing repeats this process until cutting out all tooth number.

[0005] A kind of processing method of mid-position circular arc cylindrical gear, comprising the following steps:

[0006] Step one: adopt disc type tooth profile milling cutter fixed on machine tool spindle, tooth blank is installed on the device that can be toothed and rotated at a certain angle;

[0007] Step two: disc type tooth profile milling cutter does linear motion and rotation motion simultaneously, set the linear motion speed of disc type tooth profile milling cutter as υ1, the linear speed of the milling tooth pitch circle of tooth blank, i.e. the linear speed of tooth blank pitch circle is υ2, υ1 and υ2 are in the same direction and the speed is equal;

[0008] Step three: obtain mid-position symmetrical circular arc involute tooth profile structure.

[0009] The processing method of the above-mentioned mid-position circular arc cylindrical gear, the linear motion line of the center of disc type tooth profile milling cutter coincides with the tooth width center line of tooth blank.

[0010] The processing method of the above-mentioned mid-position circular arc cylindrical gear, the tooth profile angle of disc type tooth profile milling cutter is consistent with the pressure angle of gear, in line with standard GB / T2821-2003.

[0011] The processing method of the above-mentioned middle circular arc cylindrical gear, when processing a single tooth, the tooth blank rotates σ° angle, and after the disc-shaped tooth profile milling cutter moves κ distance, the next single tooth can be processed, κ is the linear distance of the disc-shaped tooth profile milling cutter processing a tooth, and σ is the angle of rotation of the tooth blank processing a tooth.

[0012] The processing method of the above-mentioned middle circular arc cylindrical gear, when processing a single tooth, the tooth blank rotates σ° angle, and after the disc-shaped tooth profile milling cutter moves κ distance, the next single tooth can be processed, κ is the linear distance of the disc-shaped tooth profile milling cutter processing a tooth, and σ is the angle of rotation of the tooth blank processing a tooth.

[0013] The beneficial effects of the present application are that the middle circular arc cylindrical gear can replace the herringbone tooth, has good processability, low manufacturing cost, can be modified through numerical control milling equipment, has more stable transmission ratio, lower noise, and more meshing teeth than the cylindrical gear. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a structural diagram of the middle circular arc cylindrical gear.

[0015] Figure 2 It is a force diagram of the involute circular arc tooth surface of the middle circular arc cylindrical gear.

[0016] Figure 3 It is Figure 2 A-A sectional view.

[0017] Figure 4 It is a structural diagram of the disc-shaped tooth profile milling cutter.

[0018] Figure 5 It is a movement relationship diagram of the disc-shaped tooth profile milling cutter and the tooth blank during processing.

[0019] Figure 6 It is a diagram of the center linear motion line of the disc-shaped tooth profile milling cutter coinciding with the tooth width center line of the tooth blank.

[0020] Figure 7 It is a diagram of the disc-shaped tooth profile milling cutter. DETAILED DESCRIPTION

[0021] The present application will be further described below in combination with the drawings and examples.

[0022] As Figure 1 shown, a kind of middle circular arc cylindrical gear, its tooth is middle symmetry circular arc involute tooth profile structure 3, and its involute is formed by 20 ° pressure angle complete single tooth shape and is rotated to cooperate tooth blank and is cut out single tooth (tooth opening) with equal linear speed translation movement, then tooth blank is indexed and repeats this process, until cutting out all tooth number.

[0023] As Figure 2 ,Figure 3 As shown, the tooth profile of the center-positioned circular arc cylindrical gear also has an axial force balancing effect. When forces F1 and F2 are transmitted on the left and right sides, component forces Fx1 and Fx2 are generated. These two forces are equal in magnitude and opposite in direction, achieving axial force balance. The machining parameters of the tooth section are designed based on the tooth profile parameters of the center AA section, and the pressure angle is generally 20°.

[0024] A method for machining a mid-position circular arc cylindrical gear includes the following steps:

[0025] Step 1: Use a disc milling cutter 1 (e.g., Figure 4 As shown, the gear blank 2 is fixed on the machine tool spindle and mounted on a device that can perform gear splitting and rotate at a certain angle.

[0026] Step 2: The disc-type toothed end mill 1 performs both linear and rotary motions simultaneously. The linear motion speed of the disc-type toothed end mill 1 is set as υ1, and the linear velocity converted from the angular velocity at the pitch circle of the tooth blank 2, i.e., the pitch circle linear velocity of the tooth blank, is υ2. υ1 and υ2 are in the same direction and have the same speed.

[0027] Step 3: Obtain a centrally symmetrical involute tooth structure.

[0028] like Figure 6 As shown, the linear motion line of the center of the disc milling cutter 1 coincides with the center line of the tooth width of the tooth blank 2, that is... Figure 6 The two A values ​​are equal.

[0029] The tooth profile angle of the disc-type toothed end mill 1 matches the gear pressure angle, which conforms to standard GB / T2821-2003.

[0030] like Figure 5 As shown, when machining a single tooth, the tooth blank 2 rotates by an angle of σ°, and after the disc tooth end mill 1 moves a distance of κ, the single tooth can be machined. κ is the straight-line distance that the disc tooth end mill moves to machine one tooth, and σ is the angle of rotation of the tooth blank to machine one tooth.

[0031] Let the module be m, the number of teeth be z, the pitch circle circumference be S, л be 3.1415, and the time for the tooth blank 2 to rotate one revolution be t. Then: S = mzл, the linear motion speed of the disc toothed milling cutter υ1 = S / t = mzл / t, and the angular velocity at the pitch circle of the tooth blank θ = 2л / t.

[0032] The mid-circular cylindrical gear of this invention does not belong to the national standard series of gears, but its tooth profile fully conforms to the involute generating principle (the tooth profile at the center line of the tooth width is the standard tooth profile).

[0033] The double helical gear can be replaced, the process is good, the manufacturing cost is low, although there is no special gear manufacturing equipment, the numerical control milling equipment can be modified, with the product application market formed, the special gear manufacturing equipment can be made into a new type of special gear manufacturing equipment according to the forming principle. The innovative structure gear can also be ground, only the tooth profile milling cutter is replaced by a disc type tooth profile grinding wheel (such as Figure 7 ), and other operations and milling principles are the same.

Claims

1. A mid-pitch circular arc cylindrical gear, characterized by: The teeth are of a mid-symmetrical circular-arc involute tooth structure, the involute is formed by 20° pressure angle complete single tooth profile rotating to match the tooth blank to cut out a single tooth, then the tooth blank indexes to repeat the process until all the teeth are cut out.

2. A method of machining a hypocycloidal gear, characterized by, The method comprises the following steps: Step one: a disc-shaped tooth profile milling cutter is fixed on the spindle of a machine tool, and the tooth blank is installed on a device capable of indexing and rotating at a certain angle; Step two: the disc-shaped tooth profile milling cutter simultaneously performs linear motion and rotation, the linear motion speed of the disc-shaped tooth profile milling cutter is set as υ1, the linear speed of the milling tooth pitch circle of the tooth blank converted from the angular speed of the milling tooth pitch circle is υ2, and υ1 and υ2 are in the same direction and have equal speed; Step three: a mid-symmetrical circular-arc involute tooth structure is obtained.

3. The method of machining a center circular-arc cylindrical gear according to claim 2, wherein The center linear motion line of the disc-shaped tooth profile milling cutter coincides with the tooth width center line of the tooth blank.

4. The method of machining a center circular-arc cylindrical gear according to claim 2, wherein The tooth profile angle of the disc-shaped tooth profile milling cutter is consistent with the pressure angle of the gear, and meets the standard GB / T2821-2003.

5. The method of machining a center circular-arc cylindrical gear according to claim 2, wherein When a single tooth is machined, the tooth blank rotates by σ°, and the disc-shaped tooth profile milling cutter moves by κ distance, then the next single tooth is machined, κ is the linear distance of the disc-shaped tooth profile milling cutter for machining a tooth, and σ is the angle of rotation of the tooth blank for machining a tooth.

6. The method of machining a center circular-arc cylindrical gear according to claim 2, wherein Let the modulus be m, the number of teeth be z, the pitch circle circumference be S, 3.1415 be л, and the time for the tooth blank to rotate one round be t, then S=mzл, the linear motion speed υ1 of the disc-shaped tooth profile milling cutter is S / t=mzл / t, and the angular speed θ of the tooth blank at the pitch circle is 2л / t.

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