13/04/2026
Characteristics and Models of Various Transmission Belts
V-Belt
V-belt is the most widely used, wear-resistant and low-cost.
Classification
Standard V-Belt (Most Common)
Models: Y, Z, A, B, C, D, E
Y, Z: Micro and low-power household appliances, small motors
A, B: Machine tools, fans, water pumps (most frequently used)
C, D, E: High-power, heavy-duty machinery
Narrow V-Belt (High-efficiency Narrow Type, Much Stronger Than Standard V-Belt)
Higher load capacity, smaller size, suitable for high-speed and high-power transmission.Models:
Standard Width System (Common in Europe): SPZ, SPA, SPB, SPC (power increases in this order)
Effective Width System (American Standard, Commonly Used): 9N(3V), 15N(5V), 25N(8V) (3V < 5V < 8V)Commonly used in industrial equipment, compressors, machine tools.
Other V-Belt Variants
Banded V-Belt: Multiple belts connected together, anti-vibration, anti-jumping, for high-power fans/pumps
Cogged V-Belt: Cogged side structure, better flexibility, suitable for smaller pulleys, good heat dissipation
Flat Belt (Mainly for Conveying, Also for Transmission)
Features
Thin, good flexibility
For high-speed transmission and light-duty conveying
Obvious slipping, low load capacity
Models: Rubber flat belt, nylon canvas flat belt, canvas flat belt
Applications: Conveyors, textile machines, small transmission devices
Round Belt
Features
Circular cross-section, good elasticity
Ultra-light transmission, allows large center distance and small pulleys
Extremely low load capacity, easy to slip
Models: Classified by diameter: Φ2, Φ3, Φ4, Φ5, Φ6...Applications: Small household appliances, toys, printers, light-duty transmission
Poly-V Belt (Multi-Ribbed Belt)
Features
Combination of flat belt and V-belt, with multiple longitudinal ribs on the back
Good flexibility, low noise, no jumping, stable at high speed
Suitable for compact spaces, high power, multi-pulley transmission
Models: PH,PK, PJ, PL, PM (most common)
PK: Automobiles
PJ: Light-duty (automotive accessories)
PL: Medium-duty (machine tools, compressors)
PM: Heavy-duty
Typical Applications: Automotive engine accessories, air conditioning pumps, steering pumps, high-speed spindles
Timing Belt (Toothed Belt) - Only Non-Slip High-Precision Type
Features
Meshing transmission, no slipping, accurate transmission ratio
High speed, high power, precise positioning
High requirements for center distance and installation accuracy
Fast response, stable transmission
High transmission efficiency (97% - 99%)
Types
Trapezoidal Tooth
Pitch increases gradually from left to right
Imperial Trapezoidal Tooth: MXL, XXL, XL, L, H, XH, XXH
Metric Trapezoidal Tooth: T2.5, T5, T10, T20
Modified Trapezoidal Tooth: AT5, AT10, AT20
Curvilinear Tooth
Circular Arc Tooth (HTD/H): H3M, H5M, H8M
Flat Top Circular Arc Tooth (STPD/S): S3M, S5M, S8M (widely used, also known as high-torque timing belt)
Concave Parabolic Tooth (R): R3M, R5M, R8M
Applications: CNC machine tools, servo transmission, robots, automotive timing belts, precision conveying
