JPH01109021A - Finishing method for precise engagement gear - Google Patents

Abstract

PURPOSE:To obtain a gear having no rotary interference by containing drive and driven gears machined into predetermined shapes under engaged state, then placing lubricant mixed with polishing powder in the gap between both gears and rotating both gears. CONSTITUTION:Inner and outer rotors A, B are set while being engaged with some eccentricity. Then pressure is applied onto an upper cover 8 and a fixing shaft 7 is driven with liquid lubricant mixed with polish powder being fed into the gap through a dripping port 15 so as to rotate the inner rotor A and a stopper 11. Consequently, the outer rotor B, a jig 10, a supporting tool 9 and an outer rotor stopper 12 are also rotated so as to polish the tooth faces of the rotors A, B while preventing burning. As a result. uneven tooth faces of gear having micro gap can be polished easily and efficiently, resulting in elimination of rotary interference.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an efficient method for manufacturing meshing gears used as rotors of gear pumps, gear motors, etc., or as rotational power transmission elements, especially gears with small meshing gaps. ,
Concerning methods for finishing with high precision.

[Conventional technology]

For example, the internal gear used as a pump rake in a high-pressure pump is designed to prevent pressure leakage at the interdental seal between the driving gear and the driven gear (inner rotor and outer mouth).
It is desirable to make the meshing gap between the two parts as close to zero as possible. In terms of noise countermeasures during use, the smaller the meshing gap, the better.

However, gears with small meshing clearances are accompanied by the problem of rotational interference. That is, this type of precision gear is manufactured by cutting steel or sintering using powder metallurgy, etc.
In this case, variations in the combination gap cannot be avoided due to machining errors caused by tool wear, rigidity of the processing machine, and the like. Therefore, especially gears designed to mesh with minute gaps of 0°06 fin or less have problems such as rotational interference and seizure, and smooth rotation cannot be guaranteed.

Incidentally, the problem of rotational interference can be eliminated if the gears after being machined into a predetermined shape are corrected one by one by final polishing using a precision measuring instrument, but this is not suitable for mass production and is not practical.

Therefore, the present invention aims to provide a finishing method that can efficiently produce precision meshing gears with stable quality and free from rotational interference.

[Means for solving problems]

The method of this invention meshes a driving gear and a driven gear, which have been machined into a predetermined shape, in the same state as when in use.

Furthermore, a lubricant mixed with abrasive powder is placed in the gap between the teeth of both gears, and while the driving gear and driven gear are rotated under this condition, the target meshing state of both gears is achieved. It consists of polishing the tooth surface until the value (design value) is reached.

In addition, the lubricant containing abrasive powder can be supplied between the teeth by pouring it,
It may be applied to the tooth surface.

[Function] The lubricant placed in the gaps between the teeth prevents seizure due to friction of the meshing surfaces with no gaps, allowing the unstraightened gears to rotate. On the other hand, the polishing powder in the lubricant enters between the meshing surfaces and gradually polishes the surfaces with high friction. Further, as the polishing of the irregular tooth surfaces progresses and the meshing clearance becomes appropriate, the meshing resistance decreases to a predetermined value. Therefore, if polishing is continued until a predetermined meshing resistance value is detected, rotational interference during practical use will be eliminated.

C Example] The attached figure shows an example of a final polishing device for internal gears.

In Figure 1, 1 is a motor, 2 is a reducer, 3 is a torque converter,
4 is a polishing head.

As shown in FIG. 2, the polishing head 4 includes a casing 6 mounted on a table s, a mounting shaft 7 of an inner rotor (external gear) A connected to the tip of the output shaft of a torque converter, an upper lid 8 of the casing, The stator holder, which is fixed on a rotatable support S within the casing, is rotatably supported by a jig 10, an inner rotor holder 11 which is pressed by the upper lid 8, and rotates integrally with the inner rotor A, and an upper 118. Outer rotor holder 12 that rotates integrally with outer rotor (internal gear) B
It is composed of: 13 is each rotor presser 11.12
14 is a bearing, 15 is a seal ring provided at the lower end of
16 is a lubricant recovery port provided on the bottom wall of the casing 6, and 17 (FIG. 1) is a clamp for pressurizing the upper cover 8.

Note that the stator receiving jig 10 can also be replaced with a rotor setting groove corresponding to the outer diameter of the outer rotor. Further, the upper cover 8 and the inner rotor holder 11 can be pulled out upward, and furthermore, by removing both, the two rotors A and B can be removed from the mounting shaft 7 and the jig 10.

In the polishing apparatus constructed as described above, the inner rotor A and the outer rotor B, which are objects to be polished, are set in the same state as when in use, that is, in a state in which they are eccentric by a predetermined amount as shown in FIG. After this, pressure is applied to the upper part 118, and while pouring liquid lubricant containing polishing powder from the dripping port 15 into the gap between the teeth, the mounting shaft 7 is driven to rotate the inner rotor A and its presser foot 11, and further, Finish polishing of the tooth surface of the rotor ASB is performed while the outer rotor B, the jig 10, its support 9, and the outer rotor holder 12 are also driven to rotate to prevent seizure.

Furthermore, when the polishing progresses and the torque of the torque converter 3 drops to a predetermined value, the relay is activated and the motor 1 is stopped.

Therefore, the meshing clearance of the rotor ASB is always managed to be constant, and high quality is guaranteed. Furthermore, since the rotors A and B are polished simultaneously while rotating, the time required for finishing can be shortened.

For example, in the illustrated device, the maximum operating pressure is 170 kg/c.
Internal gears with the following specifications used in pumps for construction machinery,
That is, the inner rotor A has 6 teeth and a height (thickness) of 10.
■■, Outer rotor B has 7 teeth, the outermost diameter is 90mm, the height is 10mm -, and the gap between the tips of the teeth is 0.04w or less. When finishing polishing a gear, the polishing time per set is 5 It was less than a minute.

〔effect〕

As explained above, according to the present invention, while the driving gear and the driven gear are meshed and rotated, the tooth surfaces are polished using the abrasive powder in the lubricant by utilizing the relative sliding of the meshing surfaces. Therefore, it is possible to easily and efficiently polish irregular tooth surfaces of precision gears with minute combination gaps to eliminate rotational interference and seizure of the gears.

In addition, by detecting whether or not the meshing state has reached the target value based on the torque of the drive shaft, the meshing resistance can be controlled to a constant level, thereby reducing variations in quality.

The present invention is particularly suitable for finishing polishing of precision internal gears used in high-pressure pumps, low-viscosity fuel supply pumps, hydraulic motors that utilize high pressure, etc., and is useful for further increasing the pressure and discharge efficiency of such equipment. It can contribute to improvements in power conversion efficiency and power conversion efficiency, but it can also be used to finish general meshing gears used as transmission elements to prevent seizure and reduce noise during use.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of an apparatus for implementing the method of the present invention, FIG. 2 is a sectional view of the polishing head, and FIG. 3 is a plan view of the polishing head with the top cover removed. 1...Motor, 2...Reducer, 3...
... Torque converter, 4 ... Polishing head, 6
...Casing, 7...Mounting shaft, 8.
...Top lid, 10...Stator holder jig, 1
1... Inner rotor holder, 12...
Outer rotor holder, 13... Seal ring,
A: Inner rotor, B: Outer rotor. Patent applicant: Sumitomo Electric Industries, Ltd.

Claims (2)

[Claims] (1) A driving gear and a driven gear that have been machined into a predetermined shape are meshed together in the same state as when in use and placed in a casing, and furthermore, a lubricant containing abrasive powder is placed in the gap between the teeth of both gears. A method for finishing precision meshing gears, which comprises polishing tooth surfaces while rotating the drive gear and driven gear under this condition until the meshing state of both gears reaches a target value (design value). (2) The method for finishing precision meshing gears according to claim 1, characterized in that reaching the target value of the meshing state is detected based on meshing resistance.