Product Description

1 Product Specification

Electric Specification		Bodywork Specification
Motor Type	Middle Drive, CZPT brand	Frame	Aluminum Alloy 6061# / Foldable
Motor Power	48V 350W	Tyres	20″*4.0 KENDA
Working Style	PAS & Throttle, PAS by speed	Rim	Alloy Single Wall 60MM
Controller	bafang	Brake	F/R :Tektro Disc brake 180mm
Display	bafang LCD	Brake Lever	Tektro, Cut-off while braking
Light	F: LED	Front Fork	Steel
Battery	48V 10.4Ah	Derailleur	Shimano 7-speed tourney
Charger	50-60AH, AC90-240	Other	Seat post: Promax
Performance		Business Item
Max Speed	25KM/H	Available Colors	Customized, Y.S color code
Range	35-45KM	Body Size
Max Loading	100KG	Packing Size	1550*280*780
Climbing	20%	N.W / G.W	28kgs/38kgs
Charge Time	5-6H / Cricle Life > 600times	Container Load

2 Company information
    HangZhou Merry Gold Machinary Co.,ltd, is a manufacturer and trader specialized in machinery and electronics products such as ebike electric bicycle. We mainly offer motors, electric bicycles,electric vehicles and its spare parts, bicycle and its spare parts etc. We have exported our electric bikes and its rated products to over 60 countries in the world, especially in US, Canada, Mexico, France, Spain, Italy, Germany, Australia, New Zealand, Russia, North Europe etc All of our products can comply with international quality standards and are greatly meeting in a variety of markets around the world. For example, we have EN15194 European certificate, CE certificate and EEC certificate. These certificates ensure us can enter into any country. We can also provide OEMand ODM service if you need. We are located in HangZhou city, ZheJiang province, which is about 150km from ZheJiang city. If you are interested in any of our products or discuss a customized order, please feel free to contact us and kindly get back your comments to us. We are sure any of your feedback will get our prompt attention & reply. We are looking forward to establishing successful business relationships with clients all over the world.

3 packaging and shipping
We fold the electric bikes and wrap them with foamed plastic films and pack them in cartons
The electric bikes ordered by our clients can be shipped by sea, air and train.

4 Our service

1. OEM Manufacturing Welcome: product, package, etc…
2. Sample Order
3. All inquiries will be replied in 24 hours
4. After the sending,we will track the shipment for you each 2 days until it arrives. When you  got the electric mountain bikes, please test them and give us a feedback. if you have any question,  please contact us. we will offer the solve way for you.

5 Certificates

6 FAQ
 

Q1. What is your terms of packing?
A: Generally,electric mountain bikes is packed with foam protection and foam block inside, cartons outside. If you have any legally registered
patent, we can pack the electric mountain bikes in your branded boxed after getting your authorization letters.

Q2. What is your terms of payment?
A: T/T 30% as deposit, and 70% before delivery. We’ll show you the photos of the electric mountain bikes and packages before you pay the balance.

Q3. What is your terms of delivery?
A: EXW, FOB, CFR, CIF, DDU.

Q4. How about your delivery time?
A: Generally, it will take 30-60 days after the receipt of deposit payment. If there are materials stocked for this style, then it
takes around 15-30 days.

Q5. Can you produce according to the samples?
A: Yes, the production can be arranged depending on your samples or technical drawings. We can build the molds and fixtures.

Q6. What is your sample policy?
A: The samples can be supplied if there are ready parts in stock, and the client will cover the sample and courier cost.

Q7. Do you test all of your electric bike bicycle before delivery?
A: Yes, the goods are all 100% test and inspected before delivery.

Q8. How do you make our business long-term and good relationships?
A: 1. We keep quality and competitive price to ensure our clients’ benefit;
2. We respect every customer as our friend and we sincerely do business no matter where they come from.

 

 

How to Choose the Right Worm Shaft

You might be curious to know how to choose the right Worm Shaft. In this article, you will learn about worm modules with the same pitch diameter, Double-thread worm gears, and Self-locking worm drive. Once you have chosen the proper Worm Shaft, you will find it easier to use the equipment in your home. There are many advantages to selecting the right Worm Shaft. Read on to learn more.

Concave shape

The concave shape of a worm’s shaft is an important characteristic for the design of a worm gearing. Worm gearings can be found in a wide range of shapes, and the basic profile parameters are available in professional and firm literature. These parameters are used in geometry calculations, and a selection of the right worm gearing for a particular application can be based on these requirements.
The thread profile of a worm is defined by the tangent to the axis of its main cylinder. The teeth are shaped in a straight line with a slightly concave shape along the sides. It resembles a helical gear, and the profile of the worm itself is straight. This type of gearing is often used when the number of teeth is greater than a certain limit.
The geometry of a worm gear depends on the type and manufacturer. In the earliest days, worms were made similar to simple screw threads, and could be chased on a lathe. During this time, the worm was often made with straight-sided tools to produce threads in the acme plane. Later, grinding techniques improved the thread finish and reduced distortions resulting from hardening.
When a worm gearing has multiple teeth, the pitch angle is a key parameter. A greater pitch angle increases efficiency. If you want to increase the pitch angle without increasing the number of teeth, you can replace a worm pair with a different number of thread starts. The helix angle must increase while the center distance remains constant. A higher pitch angle, however, is almost never used for power transmissions.
The minimum number of gear teeth depends on the angle of pressure at zero gearing correction. The diameter of the worm is d1, and is based on a known module value, mx or mn. Generally, larger values of m are assigned to larger modules. And a smaller number of teeth is called a low pitch angle. In case of a low pitch angle, spiral gearing is used. The pitch angle of the worm gear is smaller than 10 degrees.

Multiple-thread worms

Multi-thread worms can be divided into sets of one, two, or 4 threads. The ratio is determined by the number of threads on each set and the number of teeth on the apparatus. The most common worm thread counts are 1,2,4, and 6. To find out how many threads you have, count the start and end of each thread and divide by two. Using this method, you will get the correct thread count every time.
The tangent plane of a worm’s pitch profile changes as the worm moves lengthwise along the thread. The lead angle is greatest at the throat, and decreases on both sides. The curvature radius r” varies proportionally with the worm’s radius, or pitch angle at the considered point. Hence, the worm leads angle, r, is increased with decreased inclination and decreases with increasing inclination.
Multi-thread worms are characterized by a constant leverage between the gear surface and the worm threads. The ratio of worm-tooth surfaces to the worm’s length varies, which enables the wormgear to be adjusted in the same direction. To optimize the gear contact between the worm and gear, the tangent relationship between the 2 surfaces is optimal.
The efficiency of worm gear drives is largely dependent on the helix angle of the worm. Multiple thread worms can improve the efficiency of the worm gear drive by as much as 25 to 50% compared to single-thread worms. Worm gears are made of bronze, which reduces friction and heat on the worm’s teeth. A specialized machine can cut the worm gears for maximum efficiency.

Double-thread worm gears

In many different applications, worm gears are used to drive a worm wheel. These gears are unique in that the worm cannot be reversed by the power applied to the worm wheel. Because of their self-locking properties, they can be used to prevent reversing motion, although this is not a dependable function. Applications for worm gears include hoisting equipment, elevators, chain blocks, fishing reels, and automotive power steering. Because of their compact size, these gears are often used in applications with limited space.
Worm sets typically exhibit more wear than other types of gears, and this means that they require more limited contact patterns in new parts. Worm wheel teeth are concave, making it difficult to measure tooth thickness with pins, balls, and gear tooth calipers. To measure tooth thickness, however, you can measure backlash, a measurement of the spacing between teeth in a gear. Backlash can vary from 1 worm gear to another, so it is important to check the backlash at several points. If the backlash is different in 2 places, this indicates that the teeth may have different spacing.
Single-thread worm gears provide high speed reduction but lower efficiency. A multi-thread worm gear can provide high efficiency and high speed, but this comes with a trade-off in terms of horsepower. However, there are many other applications for worm gears. In addition to heavy-duty applications, they are often used in light-duty gearboxes for a variety of functions. When used in conjunction with double-thread worms, they allow for a substantial speed reduction in 1 step.
Stainless-steel worm gears can be used in damp environments. The worm gear is not susceptible to rust and is ideal for wet and damp environments. The worm wheel’s smooth surfaces make cleaning them easy. However, they do require lubricants. The most common lubricant for worm gears is mineral oil. This lubricant is designed to protect the worm drive.

Self-locking worm drive

A self-locking worm drive prevents the platform from moving backward when the motor stops. A dynamic self-locking worm drive is also possible but does not include a holding brake. This type of self-locking worm drive is not susceptible to vibrations, but may rattle if released. In addition, it may require an additional brake to keep the platform from moving. A positive brake may be necessary for safety.
A self-locking worm drive does not allow for the interchangeability of the driven and driving gears. This is unlike spur gear trains that allow both to interchange positions. In a self-locking worm drive, the driving gear is always engaged and the driven gear remains stationary. The drive mechanism locks automatically when the worm is operated in the wrong manner. Several sources of information on self-locking worm gears include the Machinery’s Handbook.
A self-locking worm drive is not difficult to build and has a great mechanical advantage. In fact, the output of a self-locking worm drive cannot be backdriven by the input shaft. DIYers can build a self-locking worm drive by modifying threaded rods and off-the-shelf gears. However, it is easier to make a ratchet and pawl mechanism, and is significantly less expensive. However, it is important to understand that you can only drive 1 worm at a time.
Another advantage of a self-locking worm drive is the fact that it is not possible to interchange the input and output shafts. This is a major benefit of using such a mechanism, as you can achieve high gear reduction without increasing the size of the gear box. If you’re thinking about buying a self-locking worm gear for a specific application, consider the following tips to make the right choice.
An enveloping worm gear set is best for applications requiring high accuracy and efficiency, and minimum backlash. Its teeth are shaped differently, and the worm’s threads are modified to increase surface contact. They are more expensive to manufacture than their single-start counterparts, but this type is best for applications where accuracy is crucial. The worm drive is also a great option for heavy trucks because of their large size and high-torque capacity.