导向套 杯士 衬套 Bushing
2026年6月16日
导向套=杯士（Bushing音译），二者是同一种零件，只是叫法不同
行业区分：模具行业叫导套，油缸/机械/电机行业常叫杯士、衬套。
一、核心通用作用（所有场景通用）
1. 精准直线导向
约束轴、活塞杆、导柱只能沿直线往复/旋转运动，控制间隙，防止跑偏、偏斜、卡死，保证设备运动精度。
2. 支撑承重、吸收侧向力
承受轴的径向偏心载荷，避免轴直接摩擦壳体，分散冲击力，防止单边磨损。
3. 减磨耐磨、自润滑
杯士常用青铜、石墨铜、SF-1复合轴承、POM/PTFE塑料，摩擦系数极低；含油槽/多孔储油结构，形成油膜，减少发热、拉伤，延长轴与机体寿命。
4. 隔离金属硬碰硬
软质耐磨衬套作为中间介质，杜绝钢轴直接磨钢壳体，保护昂贵主体零件。
5. 减震降噪
缓冲运动冲击，减小运行震动、异响，低速无爬行卡顿。
二、分场景详细功能
1. 液压油缸杯士（活塞杆导向套，最常见）
• 装在油缸缸头内部，支撑活塞杆，保证活塞杆直线伸缩；
• 分担侧向负载，防止活塞杆歪磨油封；
• 若杯士磨损间隙变大，油封会单边受力快速漏油；
• 配合防尘圈、油封，辅助防尘、保油润滑，缓冲液压冲击。
2. 模具导套（模具导向套）
• 和导柱配对使用，控制动模、定模合模精度；
• 保证模具每次闭合位置一致，防止产品飞边、尺寸偏差；
• 高硬度耐磨材质，承受高频开合冲击，延长模具寿命。
3. 电机/小型滑动轴承杯士（粉末冶金铜铁杯士）
• 电机转轴旋转支撑，多孔材质吸附润滑油，长期免维护；
• 替代滚珠轴承，结构小巧、低成本，适合小型静音马达。
三、补充区分：导向套/杯士 vs 导向环
• 杯士（导向套）：整圈套筒，完整包裹轴，承载大、支撑强，油缸缸头、模具导柱用；
• 导向环：分段薄环，只局部支撑活塞，承载小，装在活塞外圈。
四、简单总结
杯士（导向套）本质是滑动耐磨衬套，四大核心：定轨迹、撑载荷、减磨损、护机体，是各类直线/旋转运动机构必备耐磨支撑件。
Self-lubricating Bushings Introduction (≈300 words English)
Self-lubricating bushings, also known as self-lubricating cup sleeves, are a type of bearing component designed to work without frequent manual oil or grease refilling. They solve the drawbacks of traditional metal bearings that rely on regular lubrication, such as oil leakage, high maintenance costs and pollution.
This product mainly consists of a metal base and solid lubricant embedded inside. The metal substrate provides high mechanical strength, load resistance and dimensional stability, supporting heavy radial and axial loads during operation. Graphite, PTFE or molybdenum disulfide are commonly used solid lubricants distributed evenly on the bushing’s inner sliding surface. When the equipment runs and generates friction heat, the solid lubricant slowly separates out to form a continuous thin oil film between the bushing and the rotating shaft. This film greatly reduces friction coefficient, lowers wear and avoids metal direct contact.
Self-lubricating bushings adapt to complicated working conditions. They perform well in high temperature, low speed, heavy load, dust-prone and sealed environments where liquid lubricants cannot stay stable. They are widely applied in auto parts, hydraulic machinery, textile equipment, injection molds, construction machinery and household appliances.
Compared with rolling bearings, self-lubricating bushings have a simpler structure, smaller installation space and stronger shock absorption capacity. They cut long-term maintenance labor and extend the service life of moving assemblies. Without liquid lubrication, they also meet environmental protection requirements and are ideal for food, medical and precision instrument industries with strict cleanliness standards. In short, they are efficient, low-cost and eco-friendly sliding parts for modern mechanical transmission systems.
