Electric power steering device

Abstract

The utility model discloses an electric power steering device which comprises a ball screw connected to a wheel through a transmission mechanism; the ball nut is meshed with the ball screw, and a turbine is arranged outside the ball nut; and the first worm and the second worm are respectively meshed with the worm wheel, and the first worm and the second worm are respectively driven by a first motor and a second motor. The device is simple and compact in structure and good in accuracy and responsiveness.

Description

Technical Field

[0001] The utility model relates to the technical field related to motor vehicle steering, and more specifically, to an electric power steering device. Background Art

[0002] Ball screws are used to convert rotary motion into linear motion. They have the advantages of high efficiency and high precision and are suitable for motor vehicle steering. However, existing ball screw steering devices all have belts, such as the utility model patent with application number 2006100754536. The belt transmission has low precision and poor responsiveness, and is deformed and worn after long-term use. Therefore, it is necessary to design a technical solution that can overcome the above defects to a certain extent. Utility Model Content

[0003] One object of the utility model is to provide an electric power steering device with a simple and compact structure and good accuracy and responsiveness.

[0004] In order to achieve these purposes and other advantages of the utility model, according to one aspect of the utility model, the utility model provides an electric power steering device, including: a ball screw, which is connected to a wheel through a transmission mechanism; a ball nut, which is meshed with the ball screw, and a turbine is arranged outside the ball nut; a first worm and a second worm, the first worm and the second worm are respectively meshed with the turbine, and the first worm and the second worm are respectively driven by a first motor and a second motor.

[0005] Furthermore, the ball screw is connected to the wheel via a steering rod to drive the wheel to steer.

[0006] Furthermore, the ball nut is connected to the turbine via a rubber member.

[0007] Furthermore, the rubber piece is annular and is sleeved on the outside of the ball nut and the inside of the turbine.

[0008] Furthermore, a first annular groove is provided on the outer side of the ball nut, a second annular groove is provided on the inner side of the turbine, and the inner and outer sides of the rubber member have protrusions so that the cross-section is cross-shaped, and the inner and outer protrusions of the rubber member are respectively accommodated in the first annular groove and the second annular groove.

[0009] Furthermore, the top of the protrusion is stepped, and the bottoms of the first annular groove and the second annular groove are correspondingly stepped.

[0010] Furthermore, the first worm and the second worm rotate in the same or opposite directions.

[0011] The utility model at least has the following beneficial effects:

[0012] The utility model includes a ball screw, a ball nut, a turbine, a first worm and a second worm. The turbine is sleeved outside the ball nut. The first worm and the second worm are respectively meshed with the turbine. The first worm and the second worm are respectively driven by a first motor and a second motor. The utility model does not use a belt drive, thus overcoming the defects of low precision, poor responsiveness and easy deformation and wear of the belt drive. The utility model is more compact, has a simple transmission structure and is more practical. The two worms and the two motors can quickly provide a larger torque when needed, and when one of them is abnormal, the steering is not affected.

[0013] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0015] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0016] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0017] like Figure 1 As shown, an embodiment of the present application provides a ball screw steering device, comprising: a ball screw 1, which is connected to a wheel 7 through a transmission mechanism; a ball nut 2, which is meshed with the ball screw 1, and a turbine 4 is arranged outside the ball nut 2; a first worm 5 and a second worm 6, the first worm 5 and the second worm 6 are respectively meshed with the turbine 4, and the first worm 5 and the second worm 6 are respectively driven by a first motor and a second motor;

[0018] In the above embodiment, the ball nut 2 is sleeved on the ball screw 1 and meshes with each other, and is combined with balls, reversers, etc. to form a nut mechanism of the ball screw 1; the ball nut 2 is externally connected to a turbine 4, which is meshed with the first worm 5 and the second worm 6 respectively, and the first worm 5 and the second worm 6 are driven by the first motor and the second motor respectively; the first worm 5 and / or the second worm 6 rotate, driving the turbine 4 to rotate, thereby driving the ball nut 2 to rotate, thereby driving the ball screw 1 to perform linear motion, and the ball screw 1 is connected to the wheel 7 through a transmission mechanism, thereby realizing the deflection of the wheel 7; it can be seen that this embodiment does not use belt drive, which overcomes the defects of easy deformation and wear of the belt and the low transmission accuracy and poor responsiveness due to the existence of elasticity, and the turbine worm can be arranged vertically, the structure is more compact and simple, and it is convenient to use in motor vehicles, the two worms and the two motors can work simultaneously when needed, quickly provide greater torque, and when one of them is abnormal, it does not affect the steering, and the redundancy is good.

[0019] In another embodiment, the ball screw 1 is connected to the wheel 7 through a steering rod 101, and is used to drive the wheel 7 to steer; the steering rod 101 is connected to the wheel 7 and to the ball screw 1, and the ball screw 1 moves linearly under the drive of the ball nut 2, thereby driving the wheel 7 to deflect and achieve steering.

[0020] In another embodiment, the ball nut 2 is connected to the turbine 4 through a rubber member 3; the rubber member 3 is annular and is sleeved on the outside of the ball nut 2 and the inside of the turbine 4; the outer side of the ball nut 2 is provided with a first annular groove (see Figure 1 The inner side of the turbine 4 is provided with a second annular groove (see Figure 1 In the area where the turbine in the middle contacts the rubber part), the rubber part 3 has protrusions on both sides inside and outside, so that the cross-section is cross-shaped, and the protrusions on both sides of the rubber part 3 are respectively accommodated in the first annular groove and the second annular groove; specifically, the rubber part 3 has a certain elasticity, is annular, and has a cross-shaped cross-section, and the protrusions on both sides inside and outside are respectively connected to the first annular groove and the second annular groove by interference fit, or are connected through a connecting piece; the rubber part 3 can buffer the vibration between the worm and the turbine 4, the ball screw 1 and the ball nut 2, and reduce the noise generated by the vibration, and the cross-shaped rubber part 3 can buffer the vibration in the axial and radial directions to a certain extent, further reduce the noise, and can reduce the processing accuracy requirements for the ball screw and the ball nut 2, reducing the processing cost.

[0021] In another embodiment, the top of the protrusion is stepped, and the bottoms of the first annular groove and the second annular groove are correspondingly stepped; see Figure 1The protrusion includes at least two steps. When the protrusion is respectively interference-fitted with the first annular groove and the second annular groove, the stepped setting can better achieve connection, make the connection tighter, and increase the contact area between the rubber part 3 and the ball nut 2 and the turbine 4, thereby improving the buffering effect.

[0022] In another embodiment, the rotation directions of the first worm 5 and the second worm 6 are the same or opposite; the two worms and the two motors can work simultaneously when needed, so as to quickly provide a larger steering torque; one can also be started first, and when a larger torque is needed, the other can be started to increase the required steering torque, and the rotation directions of the second worm and the second motor can also be opposite to modify the steering torque; and when one of them is abnormal, the other works normally, so as not to affect the steering and improve redundancy.

[0023] The number of devices and processing scale described here are used to simplify the description of the utility model. The application, modification and variation of the electric power steering device of the utility model are obvious to those skilled in the art.

[0024] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. An electric power steering device, characterized in that: include: a ball screw connected to the wheel via a transmission mechanism; A ball nut meshed with the ball screw, with a turbine being disposed outside the ball nut; A first worm and a second worm, wherein the first worm and the second worm are respectively engaged with the turbine, and the first worm and the second worm are respectively driven by a first motor and a second motor.

2. The electric power steering device according to claim 1, characterized in that: The ball screw is connected to the wheel through a steering rod and is used to drive the wheel to steer.

3. The electric power steering device according to claim 1, characterized in that: The ball nut is connected to the turbine through a rubber member.

4. The electric power steering device according to claim 3, characterized in that: The rubber piece is annular and is sleeved on the outside of the ball nut and the inside of the turbine.

5. The electric power steering device according to claim 4, characterized in that: The outer side surface of the ball nut is provided with a first annular groove, the inner side surface of the turbine is provided with a second annular groove, the inner and outer sides of the rubber member have protrusions so that the cross-section is cross-shaped, and the inner and outer protrusions of the rubber member are respectively accommodated in the first annular groove and the second annular groove.

6. The electric power steering device according to claim 5, characterized in that: The top of the protrusion is stepped, and the bottoms of the first annular groove and the second annular groove are correspondingly stepped.

7. The electric power steering device according to claim 1, characterized in that: The first worm gear and the second worm gear rotate in the same direction or in opposite directions.

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