在曲柄滑块机构中，均质曲柄OA重<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/84a5752d51f348bb977d2f922952d028.png?x-oss-process=image/sharpen,200"/>，受力偶作用以角速度<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/0025d677b72e44d7aa987f96be9a49a7.png?x-oss-process=image/sharpen,200"/>转动；并带动总质量<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/6f05b95d3314478e816cc8f6248f443e.png?x-oss-process=image/sharpen,200"/>的滑槽、连杆和活塞B做水平往复运动。已知机构在铅直平面内，在活塞上作用力<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/54439856f92d4c3a87b9760a09d9a5d2.png?x-oss-process=image/sharpen,200"/>。假设滑块质量和摩擦不计，此时作用在曲柄O上的最大水平分力是（）。<br/> <img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/9e93b0ca30544c898a511bd8454eec85.png?x-oss-process=image/sharpen,200"/>