CN219565215U

CN219565215U - Ball circulation assembly for power steering gear and power steering gear

Info

Publication number: CN219565215U
Application number: CN202223493722.4U
Authority: CN
Inventors: 杜海滨; 冯明飞; 张学俭
Original assignee: Bosch Automotive Steering Jinan Co Ltd
Current assignee: Bosch Automotive Steering Jinan Co Ltd
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2023-08-22
Anticipated expiration: 2032-12-27

Abstract

The utility model discloses a ball circulation assembly for a power steering machine, comprising: the piston has a first end and a second end, the first end is provided with a first sealing part for sealing contact with the inner wall of the housing of the power steering engine and a second sealing part for sealing contact with the worm, and the piston has an inner spiral raceway; the worm penetrates through the piston, and is provided with an outer spiral rollaway nest, the outer spiral rollaway nest and the inner spiral rollaway nest form a channel, and a plurality of balls capable of rolling are accommodated in the channel; the top contact surface of the second end part is provided with a groove, the groove accommodates a circulating pipe for the ball to enter and move back and forth, a fixing piece is arranged between the circulating pipe and the groove, the fixing piece is provided with an open accommodating cavity for accommodating the circulating pipe, and the end part of the fixing piece is provided with a top surface in sliding contact with the inner wall of the shell of the power steering gear. Namely, the circulating pipe area is not subjected to additional pressure, deformation and failure are not easy to occur, and smooth rolling of the balls and smooth movement of the piston are ensured.

Description

Ball circulation assembly for power steering gear and power steering gear

Technical Field

The present utility model relates to power steering systems, and more particularly to a ball circulation assembly for a power steering machine and a power steering machine.

Background

Common steering gears are rack and pinion type, worm crank pin type, and recirculating ball type. The circulating ball steering gear has higher transmission efficiency due to more depending on rolling friction, is lighter and more comfortable to operate, has smaller abrasion of mechanical parts and longer service life, and plays an important role in the circulating ball steering gear of medium and large-sized commercial vehicles.

The circulating ball is arranged in the spiral groove of the worm, namely a small ball in a closed pipeline between the worm and the piston, so that the effect of converting sliding friction between the piston and the worm into rolling friction with smaller resistance is achieved, the circulating ball cannot adopt any pressing mode due to high-low pressure difference, the phenomenon of locking is easily caused by the dislocation of a half pipe when the ball rolls in actual use, and great danger is brought; if the worker uses screws to screw half pipes to fasten properly in the same pressure chamber, i.e. without pressure difference, when high pressure acts on the pressing block, the pressure must be transferred to the circulating pipe, the circulating pipe is subjected to high pressure for a long time, or extremely large force is instantaneously encountered, and failure and deformation are possibly generated. Failure of the circulation tube can cause unsmooth rolling or even jamming of the balls therein, causing steering failure of the vehicle with serious consequences.

Accordingly, there is a need for an improvement to overcome the technical problems of the prior art.

Disclosure of Invention

The utility model aims to solve the problem of installation of a circulating pipe. In order to solve the above technical problem, the present utility model provides a ball circulation assembly for a power steering machine, comprising: a piston having a first end and a second end, the first end being provided with a first seal for sealing contact with an inner wall of a housing of a power steering engine and a second seal for sealing contact with the worm, and the piston having an inner spiral raceway; a worm penetrating the piston, the worm having an outer spiral raceway which spells up a channel with the inner spiral raceway, a number of balls being accommodated therein capable of rolling; the top contact surface of the second end part is provided with a groove, the groove accommodates a circulating pipe for the balls to enter and move back and forth, a fixing piece is arranged between the circulating pipe and the groove, the fixing piece is provided with an open accommodating cavity for accommodating the circulating pipe, and the end part of the fixing piece is provided with a top surface in sliding contact with the inner wall of the shell of the power steering gear.

In a possible embodiment, the circulation tube connects the channels formed by the outer spiral race and the inner spiral race.

In a possible embodiment, the circulation tube is formed by buckling two half tubes.

In a possible embodiment, the fixing element is an interference fit with the recess of the piston.

In a possible embodiment, the fixing member comprises symmetrically arranged side beams, the side beams and the end portions are surrounded to form the open accommodating cavity, the side beams are provided with protruding portions, and the fixing member is in interference fit with the grooves of the piston through the protruding portions.

In a possible embodiment, the top contact surface of the second end is a circular arc contact surface.

In a possible embodiment, the fixing element is manufactured from engineering plastic.

In a possible embodiment, the first and second sealing portions are configured as one or more grooves for receiving a seal, and/or the piston is made via forging and machining, including grinding, milling or broaching.

In a possible embodiment, the maximum radial dimension of the cross section of the second end of the piston is smaller than the maximum radial dimension of the cross section of the first end.

In another aspect, the present utility model provides a power steering apparatus comprising: a steering input shaft; a housing having a hydraulic chamber with a machined inner surface; a ball circulation assembly for a power steering engine, wherein the piston is mounted within the housing and the piston is in sliding contact with an inner surface of the housing, and the piston is coupled to the steering input shaft for reciprocal movement relative to the housing along an axial direction of the housing; and a steering output shaft engaged with the engagement portion of the piston for outputting power to the outside.

In a possible embodiment, the housing comprises: a first section having an inner surface in sliding contact with a first end of the piston; and a second section connected to the first section and having an inner surface in sliding contact with the second end of the piston.

According to the technical scheme of the utility model, the effective sealing area provided by the first sealing part and the second sealing part on the first end part, namely the circulating pipe area is not subjected to additional pressure, is not easy to deform and lose efficacy, and the fixing part can well fix the circulating pipe in the groove of the piston at the smaller second end part, so that smooth rolling of the ball and smooth movement of the piston are ensured, and safety and effectiveness of automobile steering are ensured.

Drawings

The utility model will be more fully understood by reference to the following detailed description of specific embodiments taken in conjunction with the accompanying drawings. Wherein:

FIG. 1 shows a schematic cross-sectional construction of an embodiment of a power steering engine of the present utility model;

FIG. 2 shows a partial schematic view of an embodiment of a ball circulation assembly for a power steering engine in accordance with the present utility model;

FIG. 3 shows an enlarged partial cross-sectional schematic view taken along line A-A of an embodiment of a ball circulation assembly for a power steering engine in accordance with the present utility model;

FIG. 4 shows a schematic view of an embodiment of a mount for a ball circulation assembly of a power steering engine in accordance with the present utility model;

Detailed Description

To assist those skilled in the art in precisely understanding the subject matter claimed herein, a detailed description of the utility model is provided below in connection with the accompanying drawings. In the drawings, like reference numerals designate like or corresponding technical features.

Referring to fig. 1 to 4, a ball circulation assembly for a power steering machine (100) according to an embodiment of the present utility model includes: a piston 1 and a worm 2. The piston 1 has a first end 11 and a second end 12, the first end 11 being provided with a first seal 111 for sealing contact with the inner wall of the housing 3 of the power steering machine 100 and a second seal 112 for sealing contact with the worm 2, and the piston 1 has an inner spiral raceway 10. The worm 2 extends through the piston 1, the worm 2 having an outer spiral raceway 20, the outer spiral raceway 20 and the inner spiral raceway 10 forming a channel in which a number of balls 13 are accommodated which are capable of rolling therein. The top contact surface 121 of the second end 12 is provided with a groove 122, the groove 122 accommodates the circulation pipe 14 into which the ball 13 enters and moves back and forth, a fixing member 15 is provided between the circulation pipe 14 and the groove 122, the fixing member 15 has an open accommodation cavity 152 accommodating the circulation pipe 14, and an end 153 of the fixing member 15 has a top surface 154 in sliding contact with an inner wall of the housing 3 of the power steering machine 100.

The effective sealing area provided by the first sealing part and the second sealing part on the first end part, namely the circulating pipe area is not subjected to additional pressure any more, deformation and failure are not easy, the circulating pipe can be well fixed in the groove of the piston at the smaller second end part by the setting of the fixing part, the rolling smoothness of the ball and the movement smoothness of the piston are ensured, and the safety and the effectiveness of the automobile steering are ensured. And the open receiving chamber 152 is provided to receive the circulation tube 14 during the assembly process, to maintain the circulation tube 14 not to be detached, i.e., to maintain the entire steering gear at an angle where the worm is disposed in the direction of gravity during the assembly process.

In some embodiments, the maximum radial dimension of the cross-section of the second end 22 is less than the maximum radial dimension of the cross-section of the first end 11. Since the maximum radial dimension of the cross section of the second end of the piston is smaller than the maximum radial dimension of the cross section of the first end and the corresponding second section is configured such that the maximum radial dimension of the cross section of at least a portion thereof is smaller than the maximum radial dimension of the cross section of the first section as the housing fits in the following, this arrangement can reduce the working material of the piston and ensure that the circulation tube area is no longer subjected to additional pressure.

The circulation pipe 14 connects the channels formed by the outer spiral raceways 20 and the inner spiral raceways 10 to form a return channel, and ensures that the balls 13 return to an initial position in the return channel, thereby recirculating. When the ball appears as a problem, the circulating pipe can be directly disassembled, and the ball is taken out for replacement, so that the whole replacement steering mechanism is not needed, and the maintenance cost is saved. The circulating pipe 14 can be formed by buckling two half pipes, and the design of the half pipes is more beneficial to disassembly, maintenance and repair.

The fixing piece 15 is in interference fit with the piston 1, so that the circulating pipe 14 can be better fixed in the groove 122 of the piston 1, and the circulating pipe is kept connected with a channel formed by the outer spiral rollaway nest 20 and the inner spiral rollaway nest 10, so that smooth rolling of the balls is ensured.

In some embodiments, the fixing member 15 includes a side member 155 symmetrically disposed, the side member 155 and the end 153 enclose the open receiving cavity 152, the side member 155 is provided with a protrusion 151, and the fixing member 15 is interference fit with the recess 122 of the piston 1 through the protrusion 151. Based on the consideration of convenient disassembly and assembly, the fixing piece 15 can only be provided with protruding parts on the side beams 155 on two sides to ensure interference clamping in the grooves 122 of the piston 1, and the side beams have certain installation elasticity, so that the assembly is easier. Gaps can be reserved at other positions, so that the disassembly and maintenance are simpler.

The top contact surface 121 of the second end 12 is a circular arc contact surface. Based on the processing consideration, the inside of the shell is generally provided with an arc-shaped inner surface, and the top contact surface is provided with an arc-shaped contact surface, so that the piston and the shell can be better in sliding fit.

The fixing member 15 is made of engineering plastic. The engineering plastic has excellent comprehensive performance, high rigidity, less creep, high mechanical strength, good heat resistance and good electrical insulation, can be used for a long time in harsh chemical and physical environments, and can be used as engineering structural materials instead of metals.

The first and second sealing portions 111, 112 are configured as one or more grooves for receiving a sealing member, whereby a sealing member such as an O-ring can be fitted into the grooves for sealing contact with the inner wall of the housing 3 and the worm 2. Of course, the specific structural form, arrangement position, arrangement number and the like of the grooves are allowed to be flexibly set and adjusted according to the actual application requirement. The effective sealing area provided by the first and second seals on the first end, i.e., the circulation tube area, is no longer subject to additional pressure and is less prone to deformation failure.

A power steering machine 100 according to an embodiment of the present utility model includes: a steering input shaft 4; a housing 3 having a hydraulic chamber with a machined inner surface; a ball circulation assembly for a power steering machine 100, in which a piston 1 is installed in a housing 3 with a second end 12 in sliding contact with an inner surface of the housing 3, and the piston 1 is connected to a steering input shaft 4 for outputting kinetic energy (e.g., hydraulic energy, pneumatic energy, etc.) provided by a power device (e.g., an internal combustion engine, an electric motor, etc.) such as an oil pump or an air compressor, etc., to the outside via a steering output shaft 5 to form steering power with increased energy so as to overcome the problem of insufficient application of force by a user such as a vehicle driver.

An engagement portion 16 may be provided on the second end portion 12 so as to engage with the steering output shaft 5 of the power steering machine 100 through the engagement portion 16, thereby achieving power transmission from the reciprocating motion of the piston 1 with respect to the housing 3 to the rotational motion of the steering output shaft 5. Generally, the engagement portion 16 may be provided with a plurality of teeth according to specific needs, while the steering output shaft 5 is provided with corresponding teeth, and the power transmission operation is accomplished by engagement between these teeth.

The housing 3 comprises a first section 31 and a second section 32.

A first section 31, the inner surface of which is in sliding contact with the first end 11 of the piston 1; and a second section 32 connected to the first section 31 and having an inner surface in sliding contact with the second end 12 of the piston 1. That is, in the case where both the diameter of the worm rod connected to the piston and the inner diameter of the first section of the casing are kept the same as those of the existing products (the inner diameter is not different), the forces (such as hydraulic force, pneumatic pressure) and the like applied to the piston can be maintained unchanged, so that by reducing the radial dimension of the cross section of the second section, the manufacturing materials of the casing can be saved quite effectively, and the weight of the casing and the power steering gear can be reduced, the manufacturing cost of the products can be reduced, and the competitiveness of the products can be improved.

According to the technical scheme, the manufacturing material consumption of parts such as the shell and the piston can be effectively saved, the whole weight of the power steering engine can be reduced, and meanwhile, the power steering engine has positive effects of realizing light weight of the whole engine, reducing energy consumption, reducing manufacturing cost of products and the like.

The above detailed description is illustrative of the present utility model and is not intended to be limiting. In summary, various changes and modifications may be made by one of ordinary skill in the relevant art without departing from the scope of the utility model, and therefore, all equivalent technical solutions are intended to fall within the scope of the utility model, which is defined by the claims.

Claims

1. A ball circulation assembly for a power steering machine (100), comprising:

a piston (1), the piston (1) having a first end (11) and a second end (12), the first end (11) being provided with a first seal (111) for sealing contact with an inner wall of a housing (3) of the power steering machine (100) and a second seal (112) for sealing contact with the worm (2), and the piston (1) having an inner spiral raceway (10);

the worm (2) penetrates through the piston (1), the worm (2) is provided with an outer spiral rollaway nest (20), the outer spiral rollaway nest (20) and the inner spiral rollaway nest (10) form a channel, and a plurality of balls (13) capable of rolling in the channel are accommodated in the channel;

it is characterized in that the method comprises the steps of,

the top contact surface (121) of the second end part (12) is provided with a groove (122), the groove (122) is provided with a circulating pipe (14) for the ball (13) to enter and move back and forth, a fixing piece (15) is arranged between the circulating pipe (14) and the groove (122), the fixing piece (15) is provided with an open accommodating cavity (152) for accommodating the circulating pipe (14), and the end part (153) of the fixing piece (15) is provided with a top surface (154) in sliding contact with the inner wall of the shell (3) of the power steering gear (100).

2. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the circulation tube (14) connects the channel formed by the outer spiral raceway (20) and the inner spiral raceway (10).

3. The ball circulation assembly for a power steering machine (100) according to claim 1, wherein the circulation tube (14) is composed of two half tubes that are snap-fitted.

4. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the fixing member (15) is an interference fit with the recess (122) of the piston (1).

5. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the fixing element (15) comprises symmetrically arranged side beams (155), the side beams (155) and the end portions (153) enclose an open receiving cavity (152), the side beams (155) are provided with protrusions (151), and the fixing element (15) is in interference fit with the grooves (122) of the piston (1) through the protrusions (151).

6. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the top contact surface (121) of the second end (12) of the piston (1) is a circular arc contact surface.

7. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the fixing member (15) is manufactured from engineering plastic.

8. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the first seal (111) and the second seal (112) are configured as one or more grooves for mounting seals and/or that the piston (1) is manufactured via forging and machining, including grinding, milling or broaching.

9. Ball circulation assembly for a power steering machine (100) according to claim 1, characterized in that the maximum radial dimension of the cross section of the second end (12) of the piston (1) is smaller than the maximum radial dimension of the cross section of the first end (11).

10. A power steering machine (100), characterized in that the power steering machine (100) comprises:

a steering input shaft (4);

a housing (3) having a hydraulic chamber with a machined inner surface;

a ball circulation assembly for a power steering machine (100) according to any one of claims 1-9, wherein the piston (1) is mounted in the housing (3) and the piston (1) is in sliding contact with said inner surface of the housing (3), and the piston (1) is connected to the steering input shaft (4) for reciprocal movement relative to the housing (3) in the axial direction of the housing (3); and a steering output shaft (5) which is engaged with the engagement portion (16) of the piston (1) to output power to the outside.

11. A power steering machine (100) according to claim 10, wherein the housing (3) comprises:

a first section (31) whose inner surface is in sliding contact with the first end (11) of the piston (1); and

a second section (32) connected to the first section (31) and having an inner surface in sliding contact with the second end (12) of the piston (1).