Nylon Gears Research Articles

A study on the development of low-noise gears. 1st Report. Silencing effect and operation characteristics of nylon gears filled with plasticizers.

Recently, for the plastic gears being assembled in sound apparatuses, those having lower noise are desired. For this purpose, it has been attempted to use plastics filled with plasticizers for gears. When plasticizers are filled into plastics, the viscosity increases, while the strength and wear resistance decrease. However, these has been doubt expreassed as to their practicality. Therefore, in this study, gears were made of a material formed by nylon filled with moret than 10% plasticizers. The effect of silencing was confirmed, and the basic characteristics of the gears, such as the wear of teeth and the change of the tooth profile, were experimentally examined.

Research on the operational characteristics of a plastic gear and an aluminum alloy gear pair.

Recently due to increased usage, there are many instances where plastic gears are used in combination with aluminum alloy gears. In these cases, since aluminum alloy gears are considerably softer than steel gears, the tooth surfaces become extremely worn and rough, and it is feared that the phenomenon of multiplied effect promoting the wear of plastic gears by such rough tooth surfaces may occur. Thus, in this study, an operating test was carried out by combining an MC nylon gear and an aluminum alloy gear, and the actual conditions of the wear of teeth, the roughness of tooth surfaces, the temperature of teeth, the change of tooth profile and so on were investigated.

Term of life and wear of plastic intermediate gears.

The plastic gears used for driving paper-drying drums in paper-making machines and others are used at a gear ratio of 1:1 by putting several gears in a row. Accordingly, the intermediate gears undergo loading on both tooth surfaces, but at present, the operational characteristics of the plastic gears being used in this way have not been elucidated at all. Therefore, in this study, the operation test applying alternating loads was carried out using MC nylon gears and such things as the operational term of life, the wear of teeth, and the state of change of tooth profile were examined.

A study of fiber-filled plastic gears. 1st report Operating characteristics of glass fiber-filled plastic gears.

Recently, plastics, filled with various fibers to make fiber-reinforced composites, have been investigated, and their basic properties have been fairly extensively examined. However, the various properties of these plastics when they are applied to gears have scarcely been revealed. In this study, at first, we prepared three kinds of plastic gears with different fiber-filling rations and made running tests to examine abrasion of the teeth, change of the tooth profiles, temperature of the teeth and noise of the gear. Then we, compared these results with the running-test results of the MC nylon gear which had already been reported, to clarify as much as possible the operating characteristics of plastic gears filled with glass fibers.

Investigation about the Prevention of Tooth Profile Change of Nylon Gears : 3rd Report, Wear and Tooth Profile Change in Profile Shifted Nylon Gears

Two prevention methods are proposed in the previous report as the prevention methods of tooth profile change in the course of operation of a nylon gear which transmits the power. And their effect is confirmed by experiments. In this report as a method simpler than those methods, a plus profile shifting of nylon gear is proposed. In the plus profile shifted gear, the tooth thickness of tooth flank increases and the tooth is less liable to deflect. Meanwhile the sliding of tooth is large. In this report the abrasion of tooth of nylon gear is investigated under several profile modification coefficients and this method is examined to see how useful it is as the prevention method of tooth profile change.

An investigation of the load capacity of nylon gears, when the tooth surface finishing of mating steel gears is different (3rd report, Effect of difference in griding method of steel gear teeth on wear of nylon gear)

Intermeshing a steel gear with a plastic gear allows for nonlubricated running. In such a case, differences in the finish of the tooth flanks of the steel gear affect on the wear of plastic gear. For example, finely ground steel gear teeth reduce plastic gear wear by 30 to 40 percent, compared with hobbed teeth. However, it is not preferable to grind steel gear teeth by using the MAAG 0-degree method, because the teeth cause loading by wear powder of nylon gear. Although grinding marks are desirable to lie in a direction of tooth profile, this is difficult to work. Therefore, we grind steel gear teeth by using the MAAG 15-degrees method which produces grinding marks somewhat nearen the desirable ones, perform the wear test with nylon gears, and examine the difference in effect between the 0-degree method and the 15-degrees method.

Investigation about the Strength of Plastic Gears : 5th Report; Abrasion of Nylon Gear due to the Difference in Materials of Mating Gears.

In the no lubricant operation, it is believed that a stainless steel gear, a brass gear and a cast iron gear are better applicable as the mating gears of nylon gears for rust prevention, than a carbon steel gear. But the abrasion of nylon gear when the nylon gear meshes with these gears is not clear, because these gears have been little used. In this report an abrasion experiment of nylon gear, which meshed with these three metallic gears, was performed. And the abrasion of nylon gear in this experiment was compared and examined with the abrasion of nylon gear in the earlier report, which meshed with the carbon steel gear. The abrasion of nylon gear when the nylon gear meshed with three different materials gears has been made clear.

Investigation about the Prevention of Tooth Profile Change of Plastic Gears : 2nd Report; Abrasion and tooth profile change of nylon gears, reinforced with a stiffener

When the tooth of a nylon gear of visco-elastic body was applied with a force the tooth deflected largely and a rotational lag occurred at the mating steel gear. This caused an abnormal abrasion at nylon gear tooth flanks and the tooth profile changed conspicuously. In order to prevent these things, the nylon gear was developed. The gear included a stiffener of steel in the core of tooth and the tooth was made hard to deflect. In this report, the manufacture of this gear was outlined and the characteristic of abrasion and the tooth profile change in the course of operation were made clear.

Investigation about the Prevention of Tooth Profile Change of Plastic Gears : 1st Report; Amount of Profile Modification of the Steel Gear, which Meshed with the Nylon Gear

As a prevention method of tooth profile change of a nylon gear, which meshes with a steel gear, this paper proposes a profile modification of steel gear. And a reasonable amount of modification is obtained by experiments. From the results, it is clear that the expression of the amount of profile modification Δα (minutes) of steel gear is as follows. Δα = ζ (Tc·T/9.8b) + ξ ζ : Change value of pressure angle change (minutes)/(N·m/m)·s, Tc : Contact period of teeth of nylon gear (second), T : Torque acting on nylon gear (N·m), b : Face width (m), ξ : Basic value of pressure angle change (minutes).

Investigation about the Strength of Plastic Gears : 6th Report, Endurance Limit and Damage State of Nylon Gear for Power Transmission

Investigation about the Strength of Plastic Gears : 6th Report, Endurance Limit and Damage State of Nylon Gear for Power Transmission

Investigation about Load Capacity of Nylon Gears, when Tooth Surface Finishing of Mating Steel Gears is different : 2nd Report; Abrasion of Nylon Gear Meshing with Ground Steel Gear

In the eariler report, it was investigated basically how the surface roughness of a steel cylinder influenced the abrasion of a nylon cylinder. In this report, steel gears were ground to several degrees of roughness by O° teeth ground method of MAAG. And it has been investigated through the experiment how these roughnesses of teeth of steel gears influence the abrasion of nylon gears. These results were compared with the abrasion of a nylon gear, which meshed with a hobbed steel gear. In the intermeshing with a power transmission nylon gear, it has been found that a steel gear whose teeth have been ground, is useful.

Investigation about the Prevention of Tooth Profile Change of Plastic Gear : 1st Report, Quantity of Profile Modification of the Steel Gear, Meshing with the Nylon Gear

鋼歯車とかみ合うナイロン歯車の歯形変化の防止法として本報では鋼歯車に歯形修整を施すことを提案すると共にその適正修整量を実験で求めた。その結果、鋼歯車の歯形修整量Δa(分)は次式でよいことがわかった。Δa=ζ(Tc・T/0.98b)+ξ ζ:歯車変化の変化値[(分)/(N・m/m)・s]、Tc:ナイロン歯車の歯のかみ合い周期(秒)、T:ナイロン歯車に作用するトルク(N・m)、b:歯幅(m)、ξ:歯形変化の基本値(分)

Study on the strength of plastic gears 5. Wear of nylon gears due to difference in material from meshing gears.

Study on the strength of plastic gears 5. Wear of nylon gears due to difference in material from meshing gears.

Investigation about the Strength of Plastic Gears : 4th Report ; Abrasion and State of Tooth Profile Change of Driven Nylon Gear

When the nylon gear is meshed with the steel gear, the data is short that the nylon gear would be used the driving gear or the follower. Nylon gear should be used as the follower, because as the follower is the reduction gear, the contact ratio is less at the follower. But as the materials of nylon is expensive than the materials of steel, the nylon gear request the predominancy. In this report, the abrasion, the state of tooth form variation and the life for the nylon gear of follower was examined. And about these things, the nylon gear of driving was compared and examined with the nylon gear of follower. Then the characteristic of the nylon gear of follower was distinct.

Investigation About the Strength of Plastic Gears : 4th Report, Abrasion and State of Tooth Form Variation for Nylon Gear of Follower

鋼歯車とナイロン歯車の組合せではナイロン歯車を駆動、被動いずれの側に用いるのが適正なのか判断する資料が不足している。稼動の少ない被動側にナイロン歯車を用いたほうが有利と思えるがナイロン材は鋼材より高価なので大歯車をナイロン歯車にするには優位性が明確でなければならない。本報では被動ナイロン歯車の磨耗、歯形の変化形態及び寿命などを実験で調べ駆動ナイロン歯車と比較検討を行いその特徴を明らかにした。

Investigation about Load Capacity of Nylon Gears, Depending on Tooth Surface Finishing of Mating Steel Gears : 2nd Report, Abrasion of Nylon Gear Meshing with Ground Steel Gear

前報では鋼円筒の表面粗さがナイロン円筒の摩耗等に及ぼす影響の基本的なことを調べたので続いて本報では鋼歯車をMAAGの0°歯研削法で各種の粗さに仕上げ,その粗さの違いによるナイロン歯車の摩耗実験によって調べた。また本報では,この実験結果とホブ切鋼歯車とかみあうナイロン歯車の摩耗を比較し動力伝達用ナイロン歯車とのかみあいにおける鋼歯車の歯研削の有益性をも検討した。

Noise and Transmission Efficiency under Deformation of Tooth Form of Nylon Gear

Plastic gears are used when steel gears have problems in noise and lubrication. But as there are not actual result data on plastic gears, the plastic gears are little used. when nylon gears were run for power transmission an abrasion a deformation of tooth form and a life were investigated. In this investigation, changes in noise and transmission efficiency have been investigated when the tooth form of nylon gear is deformed in the course of running.

Sound and Transmission Efficiency by Change of Tooth Form of Nylon Gear

Sound and Transmission Efficiency by Change of Tooth Form of Nylon Gear

Factors Affecting Fatigue Strength of Nylon Gears

The effects of some of the factors which influence fatigue strength of molybdenum disulphide (MoS2) filled cast nylon (type 6) gears such as diametral pitch, pressure angle, pitch line velocity, stress level, and lubrication were investigated. It was found that nylon gears, when properly designed and installed, are subject to minimal wear. Premature failures do occur through tooth interference caused by thermal expansion, tooth deflection and creep of the material. The importance of a proper backlash is discussed. Design capacities of nylon gears using formula and tables are presented.

Investigation about the Strength of Plastic Gear : 2nd Report ; Abrasion of the Nylon Gear for Power Transmission, Meshing with the Steel Gear

The first report stated that the nylon gear was available for use in power transmission. But nylon gear has a problem of abrasion. In this paper, confirming this abrasion, is investigated the dependency of abrasion on load and sliding velocity of tooth in nylon gear for power transmission which meshes with steel gear. It has been confirmed that the phenomenon like a creep occurs on a tooth of power transmission nylon gear. And it has been investigated how this phenomenon influences abrasion of nylon gears.