Electric power steering input shaft and screw assembly and device thereof

Abstract

The invention provides an electric power steering input shaft and screw assembly (2). The input shaft and screw assembly (2) comprises a first cylindrical pin (21), an input shaft (22), an elastic torsion bar (23), a needle bearing (24), a second cylindrical pin (25), a screw shaft (26), a steel ball drive pipe (27), a press plate of the drive pipe (28) and a steering nut (29). Provided is an input shaft and screw device and electric power steering thereof which have a high strength and a high reliability.

Description

technical field [0001] The invention belongs to the application field of electromechanical systems and motor vehicles, and in particular relates to a heavy-duty circulating ball type dual-mode electric power steering device. Background technique [0002] From the perspective of the automobile industry, as the number of fuel vehicles continues to grow, vehicle emissions are causing more and more serious pollution to the environment. At the same time, oil, as a non-renewable energy source, is also facing the crisis of depletion. Vehicles and hybrid vehicles have become the focus of the government and society because of their advantages of energy saving and environmental protection, and have become the core development theme of today's wheeled vehicle technology. Electric power steering technology (EPS) has been widely used in domestic and foreign household vehicles due to its significant advantages such as high integration, energy saving, and maintenance-free, but it is mostly...

AI Technical Summary

Problems solved by technology

Due to practical factors such as the large load on the steering axle of heavy vehicles (generally more than 4 tons) and the singleness of the layout of the power steering device (usually located in the power cabin), the use of rack and pinion steering devices or steering column steering devices cannot meet the requirements. , it is necessary to adopt a recirculating ball structure with high overall structural strength and strong impact resistance, and the current recirculating ball steering structure only exists in heavy-duty hydraulic power steering devices and has nothing to do with electric power steering systems

[0007] 2. The structural strength requirements of key components and parts are high, and the system matching is difficult

As far as the recirculating ball hydraulic power steering is concerned, its screw, gear fan shaft, housing, steering nut and other components are often damaged due to external impact loads

[0008] 3. Electromechanical matching is difficult

[0009] In addition, the steering nut, steel ball guide plate and other components in the input shaft and screw device are the most stressed parts in the device. For example, the steel ball guide plate is to ensure the smooth circulation of circulating steel balls in the recirculating ball electric steering gear. Once the steel ball guide is deformed or broken, the circulating steel ball of the recirculating ball electric steering gear will be damaged directly, and the power transmission chain will fail. In severe cases, it will cause damage to the housing, steering nut and other components, thus causing failure to the steering gear. Repair damage; the steering nut not only needs to ensure the meshing strength with the gear fan shaft, but also needs to ensure that the circulating steel balls roll smoothly and the force is uniform, etc.

[0010] In the previous application process of the recirculating ball steering gear structure, steel ball breakage, screw breakage, steel ball conduit deformation and dislocation, cover plate falling off or cracking, etc. occurred frequently, all of which caused serious damage to the steering gear itself. Therefore, a A high-strength, high-reliability input shaft and screw device is a key way to improve the overall performance and reliability of recirculating ball electric steering gear

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