JPS60166775A - Noncircular gear - Google Patents

Abstract

PURPOSE:To reduce the leak amount of fluid and improve the accuracy in flow-rate metering by making the top-part thickness of the gear tooth in the major-axis part of a plurality of noncircular gear bodies larger than that of other gear, and forming a concaved part which is engaged with the gear tooth in the major-axis part, into the minor-axis part. CONSTITUTION:The top part-thickness (a) of the gear tooth 14 at the major- axis part of a noncircular gear body 11 is made larger than the top-part thickness (b) of other gear tooth 15, and the addendum 14a of the gear 14 is formed into circular from having the center 0 of revolution of the noncircular gear body 11 as center of curvature. A concaved part 16 which can be meshed with the gear 14 in the major-axis part 12 is formed into the minor-axis part 13 of the noncircular gear body 11. The gear 14 of the major-axis part 12 shifts along the inner peripheral surface 17a of a casing 17, and a certain gap 18 is formed between the addendum 14a and the inner peripheral suface 17a, and the gap width (c) equal to the top-part thickness (a) can be obtained. Therefore, the flow resistance of the fluid which tends to leak through the gap 18 is increased by the gap width (c), and the leak amount can be reduced.

Description

[Detailed Description of the Invention] This invention provides a
This invention relates to non-circular gears that are provided and rotate while meshing with each other.

A non-circular pawl is installed as a rotor in the gauging of a pump, fluid prime mover, or fluid flow meter, and the rotor is rotated to provide a pumping action.The fluid flow rate is measured by rotating the rotor using fluid pressure. There are some things that you should do.

FIG. 1 shows a conventional fluid flow meter, which has a 1G1 casing, and has an inlet 2 on one side of the casing 1 and an outlet 3 on the other side. A pair of non-circular gears 5, 5 that rotate about a rotating shaft 4.4 are housed in the goosink 1 in a manner that they mesh with each other. Therefore, the fluid pressure l flowing in from the inlet 2 causes the non-circular gear 5°5
rotates, and the fluid flow rate is measured by integrating the number of rotations.

However, as shown in FIG. 2, the non-circular pawls 5, 5 are created with teeth having the same tooth thickness (in the case of non-dislocation) over the entire circumference. Furthermore, the teeth 7 on the long diameter portion 6 of this non-circular gear 5.5 move along the inner circumferential surface 1a of the casing 1. Therefore, the tip of the tooth 7 and the inner peripheral surface 1a of the casing 1
There is a slight gap 8 between the two, and there is a disadvantage that fluid leaks from this gap 8.

Fluid a1 leakage occurs not only in the gap 8, but also between the side surface of the casing 1 and the non-circular tooth JaL5, and between the non-circular teeth JaL5, but the leakage ml in the gap 8 is slightly smaller. Lead. Therefore, if the gap 8 is filled with debris n, leakage i
Although it is possible to improve the accuracy of the flowmeter by reducing the flowmeter, there are some limitations due to the machining accuracy and the change in the gap 8 due to the two pillars of the bearing.

This invention has been made in light of the above circumstances, and its purpose is to increase the thickness of the top part of the teeth in the fφ part of each non-circular m wheel to be larger than the other thickness, so that the inside of the 'r-thing is A non-circular pawl that can reduce the amount of fluid leakage without narrowing the gap between the circumferential direction and the tooth tip, and can be applied to υIL failure meters to improve the flow-measuring accuracy. This is what we are trying to provide.

Hereinafter, the present invention will be explained based on an embodiment shown in drawing ζ.

FIG. 3 shows the first embodiment, in which 11 is a non-circular gear body with an oval shape, 12 is a major diameter portion thereof, and 13 is a minor diameter portion thereof. The tooth 14 in this long diameter portion 12j has a top tooth thickness a larger than that of the other teeth 15, and in this embodiment, the tooth profile is formed by filling one tooth groove. There is. The tips 14a of the teeth 14 are formed into arcuate surfaces with the rotation center 0 of the non-circular gear body 1) as the center of curvature. Further, the short diameter portion 13 is provided with four portions 16 that can mesh with the rat4 of the long diameter portion 12.

The non-circular pawl configured in this manner is housed in the casing 17 of the pump, fluid flow load, etc., and is engaged with the casing 17 with a phase difference of 90°. Therefore, the tooth I4 in the long diameter portion 124 of each non-circular heavy body 11.11
transfers to the inner circumferential surface 17aj8 of the casing 17, and the tips 14. of the teeth 14. and the inner peripheral surface 1 of the casing 17
7, a certain gap 18 is formed between the top l113 thickness a and the gap width C which is the same as the top tooth thickness a of the tongue whose top l113 thickness a is M. This Jinma leprosy C causes tooth tip 14. The flow resistance of the body trying to flow (leak (5t) L) through the gap 18 between the inner circumferential surface 17a and the inner peripheral surface 17a is large, and the amount of leakage decreases.

Gear cutting for this non-circular gear body can be done by the commonly used generating gear cutting method using Oldham's joint, but the cutter used (bob or pinion cutter)
In this case, the long diameter portion 12 and the short diameter portion 13 may have curved teeth, and only the zigzag teeth 14 and the recessed portion 16 may have a special tooth shape. Furthermore, non-circular gears made of plastic or sintered metal can be easily manufactured by simply changing the molding die.

The non-circular teeth Mζ are shifted so that the long diameter part 12 is shifted to (+) and the short diameter part 13 is shifted to (-) so that the sum of the shift forces becomes zero at all meshing points. 4: It will be more effective if you apply decorative examples.

In addition, FIG. 4 is applied to a cubic pawl, and the same constituent parts are given the same numbers and the explanation is omitted.

FIG. 5 shows a second embodiment, in which the tooth height of the tooth 14 in the long diameter portion 12 is made higher than the other teeth 15, and the tooth tip 14a is aligned with the rotation center 0 of the non-circular gear body 11. It is formed into a circular arc surface with the center of curvature, which can reduce the amount of leakage and increase the discharge capacity per rotation of the rotor. Also,
FIG. 6 shows the second embodiment applied to a cubic gear.

〔Effect of the invention〕

As explained above, according to the present invention, leakage from the gap between the tip of the non-circular I# tooth and the inner peripheral surface of the casing can be significantly reduced, and the volumetric efficiency can also be increased. , if you apply it to a flow meter, it will become a meter! <11 If applied to pumps, the effect of improving efficiency will be diminished.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a non-circular gear type flowmeter, Fig. 2 is a front view showing a conventional non-circular gear, Fig. 3 is a front view showing a first embodiment of the present invention, and Fig. 4 is the same. FIG. 5 is a front view showing the second embodiment of the present invention, and the sixth factor is a front view showing the same modification. 11... Non-circular gear body, 12... Long diameter portion, 13.
...Short diameter portion, 14...Teeth, 14.・・・Tip of tooth, I6・
... recess, 17... casing. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) In non-circular gears that are installed in the casing of a pump or flow meter and rotate while meshing with each other, the i (top tooth thickness of the teeth passing through the diameter part) of each non-circular gear body is A non-circular pawl characterized by being larger than other teeth and having four parts on the short diameter part that mesh with the teeth on the long diameter part. (2) Claim 1 ζ Here, the tooth height of the tooth in the major diameter portion is made higher than other teeth, and the tooth tip is a circular arc whose center of rotation is the center of rotation of the non-circular gear body. A non-circular gear characterized by being formed on a surface.