结论：稳定性要在整个抬升行程中评价，不只是极限位置

移位机用于把使用者从床、椅、地面转移到另一个位置。工作时，使用者的全部体重通过吊臂作用在机器上，而随着吊臂的抬升和摆动，载荷的位置持续变化，整机的重心也随之移动。

所以稳定性不是一个静态指标。在某个位置稳定，不代表在整个行程中都稳定。 最危险的位置可能出现在行程中间，而不是两端。

这是移位机测试与其他产品的主要区别：要按行程扫描，而不是取几个点。

受力的特点

载荷位置远离支撑基座。 吊臂伸出后，载荷作用点在基座之外，形成倾覆力矩。

载荷是活动的。 被吊起的人会摆动、会活动，产生动态载荷和侧向力。

基座宽度可调的机型，稳定性随宽度变化。 基座收窄时（为了通过门口或靠近床边）稳定性下降，而这恰恰是实际操作中常用的状态。

地面条件影响大。 斜坡、地毯、门槛都改变稳定性。

第三点在实际事故中占比不低。 操作者为了靠近床边把基座收窄，然后抬升，此时稳定裕度最小。测试必须覆盖这个状态。

稳定性试验的设计

试验状态 要点
基座展开、吊臂各高度 沿行程扫描，找最不利点
基座收窄、吊臂各高度 同上，这是更严的状态
吊臂侧向摆动 摆到极限位置时评价
斜面上 按规定坡度，前后左右四个方向
动态 模拟使用者摆动产生的侧向力
制动状态与非制动状态 脚轮制动对稳定性的影响

「沿行程扫描」是关键做法。 具体是在吊臂从行程下端到上端的过程中，按一定间隔评价稳定性，找出裕度最小的位置。只测行程两端，可能漏掉中间的不利位置。

动态试验也不应省略。 被吊起的人不是静止的物体，摆动产生的侧向力对倾翻有实质影响。

载荷试验的要点

额定载荷的确定。 按声称的最大使用者体重，加上吊兜和附件的重量。

静载试验。 按额定载荷的一定倍数施加，保持规定时间，检查有无永久变形、裂纹、功能异常。

动载试验。 模拟实际的抬升和下降循环，次数按预期使用频次设定。

超载保护。 如果产品有超载保护功能，要验证其动作的可靠性和阈值的准确性。

关键连接件。 吊臂与立柱、吊架与吊臂、吊兜挂钩的连接处，是受力集中的位置，要单独关注。

载荷试验后要复测稳定性。 因为结构如果发生了轻微变形，稳定性可能已经改变。这一步常被省略。

常见的风险场景

把实际中的风险场景列出来，测试方案可以据此设计：

收窄基座后抬升。 前面提过，稳定裕度最小的状态。

在斜坡或不平地面上操作。 家庭环境中的门槛、地毯边缘。

使用者突然活动。 躁动、痉挛产生的侧向力。

单人操作。 说明书要求两人操作但实际只有一人时，操作者可能同时扶持使用者，产生额外的侧向力。

吊兜选配不当。 尺寸或型号不匹配导致受力异常。

电动机型停电。 抬升过程中断电，使用者停在半空。要有应急下降方式。

最后一项是设计上的必备项，且应急下降的操作要简单、在说明书中醒目说明，因为需要它的时候通常是紧急状况。

吊兜与配套件

吊兜是承载使用者的直接部件，它的强度和整机一样重要：

材料强度与缝合强度。 与前面讲过的织带类似，失效多在缝合处。

尺寸匹配。 吊兜尺寸与使用者体型不匹配时，受力分布异常，也影响舒适和安全。

与挂钩的配合。 挂环与挂钩的配合要可靠，不应在摆动中脱开。

老化。 反复清洗和使用会降低强度，要给出检查要点和更换周期。

建议整机测试时使用配套的吊兜，而不是通用件。实际使用中的组合才是真实工况。

说明书上的要点

移位机的说明书应当明确：额定载荷；需要几人操作；基座宽度与稳定性的关系；不可在何种地面使用；使用者躁动时的处理；应急下降的操作；吊兜的选配与检查；以及日常检查清单。

「基座宽度与稳定性的关系」这一条建议用图示说明，因为操作者往往不清楚收窄基座会降低稳定性，只知道它便于靠近床边。

电动与手动机型的差异

两类机型在测试上的侧重不同：

电动机型。 增加电气安全、控制功能、断电应急、电池相关项目。抬升由电机完成，要关注限位的可靠性、超载保护、以及意外动作的防止。

手动机型（液压）。 关注液压系统的保持能力（是否缓慢下降）、操作力、以及密封件的耐久。液压缸泄漏导致的缓慢下降是常见失效。

共同项目。 稳定性、载荷、结构强度、吊兜与连接件、脚轮与制动。

手动机型的「缓慢下降」值得特别关注，因为它是渐进的——新机保持良好，密封件老化后开始泄漏，而操作者往往在下降明显时才察觉。建议做保持试验：加载后静置规定时间，测量下降量，并在耐久后复测。

使用环境的考虑

移位机在实际环境中会遇到测试条件之外的情况：

门口与走廊。 通过宽度决定了基座能否展开。

床下空间。 基座腿能否伸到床下，影响能否靠近使用者。

地面材质。 地毯增加推行阻力，也可能影响稳定性。

空间限制。 狭小的卫生间里操作空间不足。

这些因素虽然不是产品本身的性能，但影响产品能不能安全使用。 建议在资料中给出所需空间的尺寸要求，帮助采购方判断是否适用。

我们的做法

做移位机测试时，我们会按行程扫描稳定性，而不是只测极限位置；并且把收窄基座的状态作为独立的评价条件。这两点是移位机与一般产品测试的主要区别。

另外，载荷试验之后我们会复测稳定性，确认结构变化没有影响安全裕度。

如果你有移位机需要安排测试，想先理清试验状态怎么设计，可以把产品资料和参数发过来一起讨论，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见手动轮椅检测与电动轮椅检测，案例见案例。

English version

Conclusion. A patient hoist transfers a user from bed, chair or floor to another position. In use, the user's entire weight acts on the machine through the boom, and as the boom rises and swings the load position changes continuously and the machine's centre of gravity moves with it. Stability is therefore not a static property: stable at one position does not mean stable throughout travel, and the most hazardous position may lie in the middle rather than at either end. This is the principal difference from testing other products: stability must be scanned across the travel rather than sampled at a few points.

Loading characteristics. The load acts well outside the support base once the boom extends, creating an overturning moment. The load is alive, since a suspended person sways and moves, producing dynamic and lateral forces. On models with adjustable base width, stability varies with width, falling as the base narrows to pass a doorway or approach a bed, which is precisely the state commonly used in practice. And ground conditions matter, with slopes, carpet and thresholds all affecting stability. The third accounts for a substantial share of real incidents: the operator narrows the base to get close to the bed and then lifts, at which point the stability margin is smallest. Testing must cover that state.

Designing stability testing. With the base spread and the boom at a range of heights, scan the travel to find the least favourable point. With the base narrowed and the boom likewise, repeat, this being the more demanding state. With the boom swung laterally, assess at the limit of swing. On a slope, assess at the specified gradient in four directions. Dynamically, simulate the lateral force from a swaying occupant. And assess with brakes applied and released, since castor braking affects stability. Scanning the travel is the key practice: assess stability at intervals as the boom moves from its lowest to its highest position and identify where the margin is smallest, since testing only the two extremes can miss an unfavourable intermediate position. Dynamic testing should not be omitted either, since a suspended person is not a static mass and the lateral force from swaying materially affects overturning.

Load testing. Rated load is set from the declared maximum user weight plus the sling and accessories. Static testing applies a multiple of rated load for a specified period and checks for permanent deformation, cracking and functional abnormality. Dynamic testing simulates actual raising and lowering cycles, with counts set from expected use frequency. Overload protection, where fitted, must be verified for reliability of operation and accuracy of threshold. And critical connections, at boom to mast, spreader bar to boom, and sling hook, concentrate load and warrant individual attention. Re-measure stability after load testing, because slight structural deformation may already have altered it; this step is commonly omitted.

Risk scenarios. Setting out the real scenarios lets the test programme be designed around them. Lifting with the base narrowed, as noted, gives the smallest margin. Operating on a slope or uneven floor, including domestic thresholds and carpet edges. Sudden user movement from agitation or spasm producing lateral force. Single-person operation, where the instructions require two but only one is present and the operator may steady the user, adding lateral force. Mismatched slings, where size or model produces abnormal loading. And power failure on powered models, leaving the user suspended mid-lift, which requires an emergency lowering provision. That provision is essential in design, its operation must be simple, and the instructions must make it prominent, because the circumstances calling for it are urgent.

Slings and accessories. The sling carries the user directly and its strength matters as much as the machine's. Material and seam strength behave as with webbing generally, with most failures at seams. Size matching matters, since a sling mismatched to the user's build produces abnormal load distribution and affects comfort and safety. Engagement with hooks must be secure and must not release during swaying. And ageing from repeated laundering and use reduces strength, so check points and replacement intervals must be given. Test the machine with its matching sling rather than a generic one, since the combination actually used is the real condition.

Instructions. State the rated load, how many operators are required, the relationship between base width and stability, floor conditions on which the hoist must not be used, how to handle an agitated user, emergency lowering, sling selection and inspection, and a daily check list. Illustrate the base width point, since operators often know that narrowing helps them reach the bed without realising that it reduces stability.

How we handle it. We scan stability across the travel rather than testing limit positions only, and treat the narrowed-base state as a separate assessment condition. Those two points are the main differences from testing ordinary products. We also re-measure stability after load testing to confirm that structural change has not eroded the safety margin.

Send us the product information and parameters and we will design the test states. Phone or WeChat: +86 132 4819 8029.