A pulley could be caused to rotate by creating longitudinal vibrations in a cord that passes over the pulley. For little amplitudes and high frequencies, the motion of the cord is definitely too small to note and the pulley appears to be spinning without cause, creating a striking effect. Pulley rotations were noticed for a number of pulleys and cords; nearly any such system will work. The quickness and direction of the rotation depends upon the various physical parameters of the system: vibration frequency and amplitude, cord pressure, and the radius and instant of inertia of the pulley.
Welded pulley:
While welded pulley is welded and machined parts items into a whole, the machining and material cost is high.
Spinning pulley:
Spinning pulley followed stamping and spinning technology, through the production process, it is formed by extruding the whole part materials. These pulleys possess high production efficiency. Not merely can it save recycleables and price, but also can be used longer because of its better wear-resisting and rust-proof. At this point this pulley is certainly well enjoyed in the high-end market in the auto market, home appliances industry, machinery 
market ETC. We are haapy that you ask for our mature and professional spinning technology.
V-belt Spinning Pulley, Steel Pulley, Split Pulley for Lawn Mower
Product Details
Model Number:P100-42 10016
Brand Name:Renchi
Origin:China (mainland)
Key Specifications/Unique Features:
V-belt spinning pulley steel pulley split pulley for yard mower
Material: warm rolled steel plate
Thickness: 4.0mm
Out diameter: 122mm
Weight: 0.390kg
V-Belt type: SPB
Surface area treatment: zinc plated yellow
Primary Competitive Advantages:
Prompt Delivery
Quality Approvals
Service
Small Orders Accepted
Origin
Experienced Staff
Form A
Green Product
Price
Ever-power C339SP Get clamp with spinning pulley
The Ever-powerC339JS Get Clamp with Spinning Pulley is flexible and fast, and because of its pincer jaw design can be affixed to a wider variance of round or square pipes, beams and pubs than traditional clamps. It includes a push-switch lock for extra basic safety and 3.9″ pulley for raising drapes or other articles in TV, video and photographic studios and theaters. The Get Clamp will endure to 331 lb.
PRODUCT HIGHLIGHTS
– Zinc-Plated Steel Construction
– 3.9″ Pulley
– Load Capacity: 331 lb / 150 kg
Ever-power Get Clamp with 100mm Spinning Pulley
About Ever-powerGrab Clamp
The C339SP is fitted with a 100mm diameter pulley to provide a quick and robust hanging point for TV and theatre sceneries. The grab clamp has been designed to be installed on a wide range of beams, pipes and bars, whether round, sq ., or rectangular in section. It needs no adapter – just open up and clamp it.