TWM555816U - Electric power assistant steering system - Google Patents

Description

Electric power steering system

This creation is related to the electric power steering system, especially an electric power steering system.

With the development of automotive technology and the rise of environmental awareness, cars have gradually replaced traditional hydraulic power steering systems with electric power steering systems because of:

1. Traditional hydraulic power steering system When the engine is running, the hydraulic pump is always in working state and consumes part of the power of the engine, so that the total engine oil consumption is increased. In contrast, the electric power steering system uses a battery as an energy source, operates independently of the engine without increasing the power consumption of the engine, and is also more efficient than the hydraulic power steering system, saving fuel consumption.

2. The electric power steering system can be integrated on the same device to increase the convenience of assembly and maintenance. The hydraulic power steering system arranges the components of different functions in different places and generates the steering assist function through the pipeline configuration.

3. The electric power steering system does not have the hydraulic oil replacement problem of the hydraulic power steering system, and is more friendly to the environment.

4. The electric power steering system can adjust the auxiliary force to improve the stability and comfort of the car operation for different driving situations through the software control. The hydraulic power steering system maintains a fixed auxiliary force and cannot change the auxiliary force with the driving condition.

For electric power steering systems, it can be divided into column-assisted electric power steering system (Column EPS), pinion-assisted electric power steering system (Pinion-EPS) and rack-assisted electric power steering system (Rack EPS). . For the rack-assisted electric power steering system (Rack-EPS), the operation mode is that after the user turns the steering wheel, the steering column drive gear meshes with the rack portion of the bogie to drive the bogie to move. The angle sensor mounted on the steering column transmits a signal to the electronic control unit, and the electronic control unit controls the motor drive belt in the belt drive, and the belt drive nut rotates, and then the nut drives the steering The screw portion of the frame moves to produce the effect of providing the steering assist force to the user.

However, regardless of the type of electric power steering system, the bogie inside the steering mechanism is connected to the tie rods, and the tie rods are connected to the wheels. After the bogie pulls the tie rod by the driving force, the wheel can be pulled to produce the steering effect; at the same time, the wheel pulls the tie rod and applies force to the bogie of the steering system, so that the bogie needs to bear the force from the tie rod. The force of the tie rod can be divided into an axial force (acting along the axial direction of the bogie) and a radial force (acting along the radial direction of the bogie) if the longitudinal direction of the bogie is axial. When the axial force acts on the bogie, the bogie is supported by the gear meshing the rack portion and the nut screwing the screw portion, resulting in a small influence of the bogie. On the other hand, when the radial force acts on the bogie, since the gear is pivotally connected to the steering mechanism housing and the rack portion abuts against the steering mechanism housing, the rack portion of the bogie can be supported, and the screw portion is due to the steering mechanism housing The body has a gap and cannot transmit radial force to the steering mechanism housing, causing the bogie to deform and shorten the service life of the steering system.

The main purpose of this creation is to provide an electric power steering system that increases the service life of the steering system.

According to the present invention, an electric power steering system includes a steering mechanism having a housing and a bogie having a first opening and a second opening; the bogie Provided in the housing and respectively passing through the first opening and the second opening, the bogie having a rack portion and a screw portion and defining an extension shaft. a gear pivotally connecting the housing and engaging the rack portion; a nut in which the screw portion is screwed. A motor is secured to the housing, the motor having an output shaft. A drive wheel secures the output shaft. A passive wheel sleeves the nut. And a flexible element sleeved on the driving wheel and the driven wheel. The electric power steering system is characterized in that the bogie has a positioning groove at the screw portion, and the positioning groove is formed along the extending shaft; a ring member is fixed to the housing and is passed through the screw portion, The ring member is located between the nut and the second opening, the ring member has a guiding groove; and a plurality of rolling members are disposed in the positioning groove and the guiding groove.

Thereby, when the radial force acts on the bogie, since the radial force received by the screw portion can be transmitted to the ring member through the rolling member located in the positioning groove and supported by the housing, the bogie deformation is reduced. , thereby improving the service life of the steering system.

In addition, there are a plurality of retaining rings which are respectively fixed at the two ends of the ring member to fix the ring member or the casing to prevent the rolling member from coming off the ring member.

The number of the positioning grooves is six, which are respectively a first positioning groove to a sixth positioning groove; the number of the guiding grooves is six, which are respectively a first guiding groove to a sixth guiding groove; each of the rolling And respectively disposed in the first positioning groove and the first guiding groove, the second positioning groove and the second guiding groove, the third positioning groove and the third guiding groove, the fourth positioning groove and The fourth guiding groove, the fifth positioning groove and the fifth guiding groove, and the sixth positioning groove and the sixth guiding groove. By increasing the number of positioning grooves and guiding grooves, the effect of the ring member supporting the screw portion is enhanced.

It is also possible to distribute the guide grooves equidistantly over the ring member, thereby ensuring a radial force in response to each direction.

In addition, the first guiding groove and the second guiding groove may form a first group, the third guiding groove and the fourth guiding groove form a second group and the fifth guiding groove and the The sixth guiding groove forms a third group; the distance between the first guiding groove and the second guiding groove, the distance between the third guiding groove and the fourth guiding groove, the fifth guiding groove and the sixth The distances of the guiding grooves are equal to each other; the distance between the first guiding groove and the second guiding groove is smaller than the distance between the first guiding groove and the sixth guiding groove, so as to design the rolling element reflow structure.

If the first set, the second set and the third set are distributed equidistantly to the ring, thereby ensuring that the radial forces are addressed in each direction.

In order to explain in detail the technical features of the present invention, the following preferred embodiments are described below with reference to the following:

As shown in FIG. 1-3, an electric power steering system 10 according to a preferred embodiment of the present invention mainly includes a steering mechanism 11, a gear 12, a nut 13, a motor 14, and a ring member. 15 and a plurality of rolling members 16.

The steering mechanism 11 has a housing 111 and a bogie 112 having a first opening 111a and a second opening 111b. The bogie 112 is disposed in the housing 111 and passes through the first opening 111a and the second opening 111b, respectively. The bogie 112 has a rack portion 112a and a screw portion 112b and defines an extension shaft 112c. A plurality of tie rods 21 that connect the wheels are coupled to the bogie 112 and are driven by the bogie 112.

The gear 12 pivotally connects the housing 111 and engages the rack portion 112a. The gear 12 is rotated by a steering column (not shown), and the rack portion 112a is driven to move the bogie 112.

The nut 13 is screwed into the screw portion 112b in the housing 111. When the nut 13 is rotated, the screw portion 112b can be driven to move.

The motor 14 is fixed to the housing 111, and the motor 14 has an output shaft 141. A driving wheel 142 is fixed to the output shaft 141. A passive wheel 144 is sleeved to the nut 13. And a flexible member 143, such as a belt or chain, is sleeved over the drive wheel 142 and the driven wheel 144. When the motor 14 is controlled to rotate the output shaft 141, the power is transmitted through the driving wheel 142 to drive the flexible member 143, and then transmitted to the nut 13 through the driven wheel 144, so that the screw portion 112b can be moved.

Referring to Figures 2, 4 and 5, the electric power steering system of the present invention is characterized in that the bogie 112 has a positioning groove 113 in the screw portion 112b, and the positioning groove 113 is formed along the extending shaft 112c.

A ring member 15 is fixed to the housing 111 and is passed through the screw portion 112b. The ring member 15 is located between the nut 13 and the second opening 111b. The ring member 15 has a guiding groove 151.

A plurality of rolling elements 16 are disposed in the positioning groove 113 and the guiding groove 151.

Thereby, when a radial force acts on the bogie 112, the radial force (the component of the force perpendicular to the extension shaft 112c) received by the screw portion 112b can be transmitted to the rolling member 16 positioned in the positioning groove 113 to The ring member 15 is then supported by the housing 111, thereby reducing the deformation of the bogie 112 and thereby increasing the service life of the steering system.

It is worth mentioning that there are a plurality of retaining rings 22 which are respectively fixed at the two ends of the ring member 15 to fix the ring member 15 or the casing 111 to prevent the rolling member 16 from coming off the ring member 15.

Further, the number of the positioning grooves 113 is six, which are sequentially a first positioning groove to a sixth positioning groove 113a-113f. The number of the guiding grooves 151 is six, which are a first guiding groove to a sixth guiding groove 151a-151f. Each of the rolling elements 16 is respectively disposed on the first positioning groove 113a and the first guiding groove 151a, the second positioning groove 113b and the second guiding groove 151b, the third positioning groove 113c and the third guiding a guiding groove 151c, the fourth positioning groove 113d and the fourth guiding groove 151d, the fifth positioning groove 113e and the fifth guiding groove 151e, and the sixth positioning groove 113f and the sixth guiding groove 151f. By increasing the number of the positioning grooves 113 and the guiding grooves 151, the effect of the ring member 15 supporting the screw portion 112b is enhanced.

It should be noted that if the guide grooves 151 are distributed equidistantly to the ring member 15, it is possible to ensure the radial force in response to each direction.

In addition, in the embodiment, the first guiding groove 151a and the second guiding groove 151b are further formed into a first group G1, a third guiding groove 151c and the fourth guiding groove. 151d forms a second group G2 and the fifth guiding groove 151e and the sixth guiding groove 151f form a third group G3. The distance between the first guiding groove 151a and the second guiding groove 151b, the distance between the third guiding groove 151c and the fourth guiding groove 151d, and the distance between the fifth guiding groove 151e and the sixth guiding groove 151f Equal to each other. The distance between the first guiding groove 151a and the second guiding groove 151b is smaller than the distance between the first guiding groove 151a and the sixth guiding groove 151f. In this way, since the distance between each of the guiding grooves 151 in the group is closer to each of the guiding grooves 151 outside the group, it is convenient to design the rolling member reflow structure, and let the first group G1 and the second group The group G2 and the third group G3 each form a rolling element reflow structure. And the first group G1, the second group G2 and the third group G3 are equidistantly distributed on the ring member, thereby ensuring the radial force in response to each direction.

10‧‧‧electric power steering system
11‧‧‧pinion steering mechanism
111‧‧‧Shell
111a‧‧‧first opening
111b‧‧‧second opening
112‧‧‧steering rack
112a‧‧‧toothed portion
112b‧‧‧screwed portion
112c‧‧‧Extension axis
113‧‧‧Positioning ditch
113a-113f‧‧‧First positioning groove – sixth positioning groove
12‧‧‧ Gears (pinion)
13‧‧‧ Nuts
14‧‧‧Motor
141‧‧‧ Output shaft
142‧‧‧Drive wheel
143‧‧‧Flexible components
144‧‧‧passive wheel
15‧‧‧rings
151‧‧‧ Guide groove
151a-151f‧‧‧first guiding groove-sixth guiding groove
16‧‧‧Roller
21‧‧‧Tie rod
22‧‧‧stop ring
G1-G3‧‧‧Group 1 - Group 3

Figure 1 is a perspective view of a first preferred embodiment of the present invention showing an electric power steering system. Fig. 2 is a schematic cross-sectional view showing the first preferred embodiment of the present invention, showing the inside of the electric power steering system. Figure 3 is a partial perspective view of the first preferred embodiment of the present invention showing the motor, output shaft, drive wheel and nut. Figure 4 is a partial perspective view of the first preferred embodiment of the present invention showing the bogie and the ring member. Figure 5 is a side view of Figure 4 with the stop ring removed and the bogie, ring and rolling elements shown.

11‧‧‧Steering mechanism

111‧‧‧Shell

111a‧‧‧first opening

111b‧‧‧second opening

112‧‧‧ bogie

112a‧‧‧Rack Department

112b‧‧‧ Screw Department

12‧‧‧ Gears

13‧‧‧ Nuts

14‧‧‧Motor

142‧‧‧Drive wheel

143‧‧‧Flexible components

15‧‧‧rings

21‧‧‧Tie rod

22‧‧‧stop ring

Claims (6)

An electric power steering system includes a steering mechanism having a housing and a bogie having a first opening and a second opening; the bogie is disposed in the housing and respectively worn Out of the first opening and the second opening, the bogie has a rack portion and a screw portion and defines an extension shaft; a gear pivotally connects the housing and engages the rack portion; a nut is The housing is screwed into the screw portion; a motor is fixed to the housing, the motor has an output shaft; a driving wheel is fixed to the output shaft; a passive wheel is sleeved to the nut; and a flexible component is The electric power steering system is characterized in that: the bogie has a positioning groove on the screw portion, and the positioning groove is formed along the extending shaft; a ring member is fixed to the a housing passing through the screw portion, the ring member being located between the nut and the second opening, the ring member having a guiding groove; and a plurality of rolling members disposed on the positioning groove and the guiding groove Inside. The electric power steering system according to the first aspect of the patent application, wherein: the plurality of retaining rings are further fixed to the ring member or the housing at both ends of the ring member. According to the electric power steering system of claim 1, wherein: the number of the positioning grooves is six, which are respectively a first positioning groove to a sixth positioning groove; the number of the guiding grooves is six, respectively a guiding groove to a sixth guiding groove; each of the rolling elements is respectively disposed on the first positioning groove and the first guiding groove, the second positioning groove and the second guiding groove, and the third positioning a groove and the third guiding groove, the fourth positioning groove and the fourth guiding groove, the fifth positioning groove and the fifth guiding groove, and the sixth positioning groove and the sixth guiding groove. An electric power steering system according to claim 3, wherein each of the guide grooves is equidistantly distributed on the ring member. The electric power steering system according to claim 3, wherein the first guiding groove and the second guiding groove form a first group, the third guiding groove and the fourth guiding groove form a second The group and the fifth guiding groove and the sixth guiding groove form a third group; the distance between the first guiding groove and the second guiding groove, the distance between the third guiding groove and the fourth guiding groove The distance between the fifth guiding groove and the sixth guiding groove is equal to each other; the distance between the first guiding groove and the second guiding groove is smaller than the distance between the first guiding groove and the sixth guiding groove. An electric power steering system according to claim 5, wherein the first group, the second group and the third group are equidistantly distributed on the ring member.