Idle gear structure for natural gas engine

Abstract

The idle gear structure for the natural gas engine comprises a large idle gear, a cylindrical pin, a small idle gear, a lining and a gear shaft, the large idle gear and the small idle gear are connected in an interference fit mode through the diameter D1, and the small idle gear and the lining are connected in an interference fit mode through the diameter D2. The cylindrical pin is embedded in a pin hole between the large idle gear and the small idle gear, and the large idle gear, the cylindrical pin, the small idle gear and the lining are connected into a whole and do work and transfer motion around sliding friction of the gears. Pull-out force meeting requirements can be kept between the idle gear and the small idle gear, connection between the idle gear and the small idle gear is increased, the idle gear and the small idle gear are kept relatively static and free of sliding in the high-speed rotation process, and therefore sliding between the idle gear and the small idle gear, abnormal heating between the gear bushing and the gear shaft caused by following rotation of the small idle gear and shaft burning locking faults are prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of natural gas engines, and in particular relates to an idler gear structure for natural gas engines. Background Art

[0002] Among various mechanical products, the exploration of engine gear transmission technology is the most common thing. In the existing technology, the problem of engine idler gear burning and shaft locking is difficult to solve, especially for natural gas engines. The engine has high thermal load, high speed, and high-speed operation of the idler gear, which is more prone to burning shaft locking failure; an idler gear structure for natural gas engines has relatively small changes to the original engine. On the basis of meeting the power performance of the original engine, its economy and exhaust emissions can be greatly improved.

[0003] The direct cause of such burning shaft locking failure between the idler gear and the idler gear shaft should be the abnormal heating between the gear bushing and the gear shaft. The cause of abnormal heating is the continuous relative high-speed rotation friction between the gear hole and the outer surface of the shaft under poor lubrication. After the friction begins, the lubrication system is abnormal, or the oil circuit is not smooth, or the oil pump does not supply oil in time, the friction surface is in a dry state and heats up rapidly. This heat immediately causes the entity expansion of the relevant components, which directly leads to the disappearance of the normal matching clearance, blocking the oil channel, and the subsequent lubricating oil cannot enter the friction surface. The temperature of the friction surface rises rapidly, and the matching surface of the shaft and bushing reaches a molten state, achieving bonding. That is: high-speed rotation of gears → failure of lubrication system → heating of friction pair → expansion of gears and shafts → disappearance of matching clearance → closure of the circulation channel of the shaft surface → normal high-speed rotation of the crankshaft gear driving the large idler gear → rapid heating of the friction pair → bonding of the bushing and the shaft.

[0004] The above process is a vicious cycle between lubrication performance and heat generation. In this process, the idler gear is always rotating at high speed without being restricted by the load from other gears in the gear system and PTO until the machine stops due to failure. Utility Model Content

[0005] The utility model provides an idler gear structure for a natural gas engine, which solves the problems raised in the above-mentioned background technology.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an idle gear structure for a natural gas engine, including a large idle gear, a cylindrical pin, a small idle gear, a bushing and a gear shaft, the large idle gear and the small idle gear are connected by an interference fit of a diameter dimension D1, the small idle gear and the bushing are connected by an interference fit of a diameter dimension D2, and the cylindrical pin is embedded in the pin hole between the large idle gear and the small idle gear.

[0007] Preferably, an interference fit is adopted between the cylindrical pin and the pin hole.

[0008] The beneficial effects of adopting the above technical solution are:

[0009] The utility model can maintain the required pull-out force between the idle gear and the small idle gear, increase the connection between them, and keep the two relatively still without sliding during high-speed rotation, thereby preventing sliding between the two and preventing the small idle gear from following the rotation to cause abnormal heating between the gear bushing and the gear shaft, resulting in a burning shaft locking fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is an assembly drawing provided by the utility model;

[0011] Figure 2 It is a cross-sectional view of the structure of the utility model.

[0012] Figure 3 This is the force analysis view of the structure of the utility model;

[0013] in:

[0014] 1. Large idler gear; 2. Cylindrical pin; 3. Small idler gear; 4. Bushing; 5. Gear shaft. DETAILED DESCRIPTION

[0015] The specific implementation methods of the utility model are further explained in detail below with reference to the accompanying drawings through the description of embodiments, with the aim of helping technicians in the field to have a more complete, accurate and in-depth understanding of the concept and technical solution of the utility model and facilitating its implementation.

[0016] like Figures 1 to 3 As shown, the utility model is an idler gear structure for a natural gas engine, which can maintain a required pull-out force between the idler gear and the small idler gear, increase the connection between them, and keep the two relatively still without sliding during high-speed rotation, thereby preventing sliding between the two, and preventing the small idler gear from rotating with the gear bushing and causing abnormal heating between the gear shaft, resulting in a burning shaft locking fault.

[0017] Specifically, Figures 1 to 3 As shown, it includes a large idle gear 1, a cylindrical pin 2, a small idle gear 3, a bushing 4 and a gear shaft 5. The large idle gear 1 is connected to the small idle gear 3 by an interference fit of a diameter dimension D1, and the small idle gear 3 is connected to the bushing 4 by an interference fit of a diameter dimension D2. The cylindrical pin 2 is embedded in the pin hole between the large idle gear 1 and the small idle gear 3.

[0018] An interference fit is adopted between the cylindrical pin 2 and the pin hole.

[0019] Embodiment 1:

[0020] The cylindrical pin 2 is embedded in the pin hole between the large idler gear 1 and the small idler gear 3 with a rivet-like effect. An interference fit is adopted between the cylindrical pin 2 and the pin hole, and the diameter dimension D=6mm (fit tolerance p9 / m6); the pin hole depth dimension L=8mm, and the end face distance between the cylindrical pin 2 and the large idler gear 1 is L1=0.5mm.

[0021] Theoretically, the large idler gear 1, the cylindrical pin 2, the small idler gear 3, and the bushing 4 are connected as a whole, and perform work by sliding friction around the gear shaft 5 to transmit motion.

[0022] Embodiment 2:

[0023] Figure 3 Note: The radial load caused by the pressure angle of the tooth is much smaller than the driving force. It is ignored in the force diagram to simplify the calculation, and the gear driving force is used as the calculation verification basis.

[0024] According to the principle of equality of action and reaction, Figure 2 For gears F23=F32, F12=F21

[0025] The force on the idler gear bushing is mainly the radial pressure F generated by the gear drive, which is opposite to the gear drive force and its magnitude is the sum of the two sets of drive forces.

[0026] F=F32+F12=M1 / r1+M1 / r1=724 / 0.126+724 / 0.126=11492.1N

[0027] Check calculation:

[0028] When the load F = 11492.1N, the speed n = 1909r / min (gear speed n1 = 1431.75),

[0029]

[0030] Conclusion: Under the high speed condition of 1909r / min, the idler gear bushing pressure and circumferential speed did not exceed the required values ​​and met the requirements.

[0031] The above is an exemplary description of the utility model in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the utility model; or the above-mentioned concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. An idler gear structure for a natural gas engine, characterized in that: The invention comprises a large idler gear (1), a cylindrical pin (2), a small idler gear (3), a bushing (4) and a gear shaft (5); the large idler gear (1) and the small idler gear (3) are connected by an interference fit of a diameter dimension D1; the small idler gear (3) and the bushing (4) are connected by an interference fit of a diameter dimension D2; and the cylindrical pin (2) is embedded in a pin hole between the large idler gear (1) and the small idler gear (3).

2. The idler gear structure for a natural gas engine according to claim 1, characterized in that: An interference fit is adopted between the cylindrical pin (2) and the pin hole.

Images