Plastic Worm Research Articles

Experimental and numerical study of a plastic worm meshed with a steel helical gear

In this paper, the transmission mechanism of a plastic worm meshed with a steel helical gear is applied to achieve power transmission and motion transfer. Tooth profile equations of the gear pair are derived and general meshing conditions are proposed in terms of gear geometry. A mathematical model of the tooth profiles of the gear pair is established. Contact stress analysis and general evolution law of the tooth profiles are discussed using the finite element method. Material characteristics, mesh generation, contact definition, and constraint conditions are given. For comparison, analysis results of a steel worm meshed with a steel helical gear is also provided. Through the hobbing process, injection molding, and machining center, samples of steel helical gears, plastic worm, and steel worm are completed, respectively. A characteristic test of the transmission mechanism of the plastic worm meshed with a steel helical gear is carried out based on the microtransmission experimental platform. The contrasting results show that the plastic worm has better transmission performance.

Largemouth bass use prior experience, but not information from experienced conspecifics, to avoid capture by anglers

AbstractAngler satisfaction is based on the presence of catchable fish, and therefore, understanding the mechanisms driving catchability is important for fisheries biologists and managers. Lure avoidance learning (including via social learning) may be a driver of catchability, but these mechanisms have not been explored in depth. To address this, largemouth bass, Micropterus salmoides (Lacépède), were stocked into four ponds, and two were angled using a green plastic worm. Naïve bass were then introduced into all ponds, and angling commenced using a sequence of three lures (green plastic worm, white plastic worm and in‐line spinnerbait). Naive bass stocked alongside experienced conspecifics were not less catchable, indicating socially learned lure avoidance did not take place. Catch rates declined across sessions until the switch to the spinnerbait, when rates temporarily spiked. This suggests that the similarity of a novel lure to previously experienced lures may determine if a fish avoids angling capture.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide.

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

Vermicomposting of Waste Corn Pulp Blended with Cow Dung Manure using Eisenia Fetida

Waste corn pulp was investigated as a potential feedstock during vermicomposting using Eisenia fetida. Corn pulp is the major staple food in Southern Africa and constitutes about 25% of the total organic waste. Wastecooked corn pulp was blended with cow dung in the ratio 6:1 respectively to optimize the vermicomposting process. The feedstock was allowed to vermicompost for 30 days. The vermicomposting took place in a 3- tray plastic worm bin. Moisture content, temperature, pH, and electrical conductivity were monitoreddaily. The NPK content was determined at day 30. During vermicomposting, moisture content increased from 27.68% to 52.41%, temperature ranged between 19- 25◦C, pH increased from 5.5 to 7.7, and electrical conductivity decreased from 80000µS/cm to 60000µS/cm. The ash content increased from 11.40% to 28.15%; additionally the volatile matter increased from 1.45% to 10.02%. An odorless, dark brown vermicompost was obtained. The vermicompost NPK content was 4.19%, 1.15%, and 6.18% respectively. Keywords—corn pulp, Eisenia fetida, vermicomposting, waste management

Efficiency prediction of worm gear with plastic worm wheel

This study proposes a method to predict the efficiency of a worm gear with a plastic worm wheel. The theoretical efficiency is obtained from friction coefficient experiments and mathematical calculations. A tribometer is used to measure the friction coefficient of nylon6 on steel at various normal pressures. Gear geometry is employed to calculate the position of the contact point and the curvature at the contact point, and Hertz’ Law is employed to calculate the contact area. In order to verify the efficiency prediction method, the efficiency of a worm gear which is used in an EPS system is theoretically calculated by the method, and then, the result is compared with the measured efficiency of the worm gear. With consideration of all factors, the theoretical efficiency was very accurate, showing the same efficiency trend with the increase of output torque and little difference among the values. Their maximum values were obtained at the same output torque. This efficiency prediction method can be applied to various types of gears with plastic materials.

The Development of Decelerating Motor of Electronic Power Steering

This study is making a product for the development of one process worm wheel of making a shape for gear for worm wheel without hobbing manufacturing process. Because of removing a hobbing process, plastic worm wheel for increased productivity and equivalent quality is produced in the result. As the result, this product is selling to Hyundai Mobis, Mando, TRW, KOYO/NSK/Showa(Japan), Delphai(America). The core technology and different strategy are as follows. The technology protection for of worm whee is currently patent process Molding process of helical gear(No. 10-2008-0105908). Further patent procedure for molding system for positioning decision of inserting boss is currently prepared. As gear procedure in hobbing machine without gear machining procedure, most of all, core development technology which is making a gear tooth is main topic. So that, in case of currently developed worm wheel, because core and mold base are not developed in the first procedure, gear is machining in hobbing M/C as the second procedure. In the later, patent for mold base structure will be prepared in this study results.

Consequences of fishing lure retention on the behaviour and physiology of free-swimming smallmouth bass during the reproductive period

When break-offs occur during recreational angling, lures may be retained by the fish. To date, there have been few studies on the consequences of lure retention on sportfish. This study evaluated how the retention of three different types of lures (i.e., crankbait, jig and plastic worm—all with barbed hooks) influenced the behaviour, physiology and reproductive success of nesting, male smallmouth bass ( Micropterus dolomieu) relative to controls released after lure removal. Bass were angled from their nests and subjected to a simulated lure retention scenario in which one of three lure types was placed in the upper middle jaw. Males were subsequently released and their behaviour (time to return to nest, parental care behaviour) was monitored. Immediately after release, fish with retained lures exhibited altered behaviour relative to control fish, attempting to expel the lure. However, these differences in behaviour were no longer apparent after 24 h even for those fish that retained the lures. Rates of nest abandonment did not differ between treatment and control fish in the short term. Fish were rarely able to liberate themselves from the retained lure in the several days post-treatment. Physiological sampling conducted on jig treatment fish and angled controls revealed elevated blood glucose concentrations in fish that had retained lures for 24 h, while lactate concentrations and hematocrit did not differ between treatment and control fish. These results demonstrate that lure retention in the short-term influences both the behaviour and physiology of smallmouth bass. Given that lures were generally retained throughout the study period, there may be merit in anglers using barbless hooks that may be more readily shed by fish that break the line, reducing the welfare impacts associated with lure break-offs on wild fish. Additional studies are needed to understand the longer term consequences of lure retention in free-swimming fish.

1206 プラスチックヘリカルおよびウォームホイールの発熱と動力伝達効率(すべり及び動力伝達性能,一般講演)

This paper describes the heat generation and power transmission efficiency of plastic helical wheel meshed with steel worm. The test machine for plastic worm gears was newly developed, in which the center distance and shaft angle are variable and the transmission efficiency can be measured. Experiments were carried out using plastic helical or worm wheel and steel worms under various running conditions. The temperatures of plastic helical and worm wheels and the torques of the input and output shaft were measured. The effects of torques and rotational speeds on the gear teeth temperatures and the transmission efficiencies between meshing gear teeth were determined.

小モジュールプラスチックウォームギヤの効率と騒音(O.S.07-1 歯車の効率,O.S.09-1 プラスチック歯車(1))

小モジュールプラスチックウォームギヤの効率と騒音(O.S.07-1 歯車の効率,O.S.09-1 プラスチック歯車(1))

新しい耐熱性ポリアミドからなるウォームホイールの耐久性(O.S.07-1 歯車の効率,O.S.09-1 プラスチック歯車(1))

New polyamide resin Nylon 9T (PA9T) has excellent properties such as heat resistance, low water absorption, chemical resistance and wear resistance, which are required for gear applications. Injection molded plastic worm wheels are used in applications ranging from motion translation in copiers and printers to transmitting torque in automobile parts. In this study, the durability of injection molded plastic worm wheels was tested without lubrication under various torque and temperature conditions. The test was carried out on several engineering plastics including polyacetal (POM), Nylon 46 (PA46), PA9T, and PA9T wear resistant grades that are internal lubricated with polyolefin or PTFE or silicones.

811 小モジュールプラスチックウォームギヤの効率と騒音

811 小モジュールプラスチックウォームギヤの効率と騒音

615 ウォーム歯車の効率に及ぼす歯形と転位の影響 : プラスチックウォーム歯車の場合

615 ウォーム歯車の効率に及ぼす歯形と転位の影響 : プラスチックウォーム歯車の場合

1112 小モジュールプラスチックウォームギヤの効率

1112 小モジュールプラスチックウォームギヤの効率

A Study for the Development of Plastic Worm Gears. Plastic Worm Gears filled with Fiber and Solid Lubricant.

Worm gears, which undergo a great deal of sliding, produce a large amount of heat and suffer from a high degree of wear, being low in resistance to heat and wear. However, plastic worm gears are currently demanded for use in food processing machinery which should be free of oil that can get into products. In the hope of developing practical worm gears from composite plastic material filled with fiber and solid lubricants, worm gears made of such plastics are produced, and tests are carried out to determine the degree of wear, coefficient of friction, surface roughness and changes in temperature.

A study for development of plastic worm gears. 2nd report, Plastic worm gear filled with mica filler.

In use, worm gears, the teeth of which are slid a relatively long distance, generate a large quantity of heat. It is impossible for plastics, which are inferior in heat resistance, to be applied for such worm gears for use in the transmission of high power without lubricants. The first report suggests that composite plastics filled with carbon fibers, solid lubricants, etc. are suitable as materials for worm gears. However, the worm gears made of the composite plastics are expensive. In this study, inexpensive plastics of nylon filled with mica fillers have been developed, and their application to worm gears has been examined. Increasing amounts of the mica filler cause the heat resistance temperature to become higher. However, they reduce the bonding degree of the nylon to the mica attained in the polymerization. Accordingly, when the composite plastics of nylon are used for the sliding parts, the wear resistance may be insufficient. The wear resistance, coefficient of friction, surface roughness, surface temperature, and worm gears of the nylon composite plastics with various amounts of mica filler have been examined to determine the optimum amount of the mica filler.

A study for development of plastic worm gears. (1st report. Plastic worm gears filled with fiber and solid lubricant).

A study for development of plastic worm gears. (1st report. Plastic worm gears filled with fiber and solid lubricant).

Qualitative analysis of plastic worm and worm gear failures

Plastic worm and worm gear failures observed during a series of experiments with different worm-gear material combinations and various lubricants in a 30:1 ratio speed reducer are reported. A qualitative analysis is presented of the different modes of failure which include (1) wear, (2) surface fatigue, (3) plastic flow, (4) scoring and (5) fracture. In general, failures observed in plastic gears were similar to those of metal gears, but because of the differences in material properties distinct failure characteristics were found for plastic worms and gears.

Wear damage to plastic worms and gears

Scanning electron microscope (SEM) investigation of the sliding contact surfaces of plastic worm and worm gear teeth has revealed that pitting and ridging are major wear types.

Rotating foundation caissons drill their way to rock

Plastic worm and worm gear failures observed during a series of experiments with different worm-gear material combinations and various lubricants in a 30:1 ratio speed reducer are reported. A qualitative analysis is presented of the different modes of failure which include (1) wear, (2) surface fatigue, (3) plastic flow, (4) scoring and (5) fracture. In general, failures observed in plastic gears were similar to those of metal gears, but because of the differences in material properties distinct failure characteristics were found for plastic worms and gears.