CN219809369U

CN219809369U - Gear rack transmission structure

Info

Publication number: CN219809369U
Application number: CN202222188696.8U
Authority: CN
Inventors: 孟庆周; 何欣; 孟繁星; 周子钰
Original assignee: Shenzhen Tales Technology Co ltd
Current assignee: Shenzhen Tales Technology Co ltd
Priority date: 2022-07-20
Filing date: 2022-08-19
Publication date: 2023-10-10
Anticipated expiration: 2032-08-19
Also published as: CN117469361A; CN117469354A; CN117432760A; CN117432772A; CN117432774A; CN219827633U

Abstract

The embodiment of the disclosure discloses a gear rack transmission structure. The gear and rack transmission structure comprises a rack and a gear; the gear teeth have first engaging portions protruding outwardly and the gear tooth grooves have second engaging portions recessed inwardly; on the cross section of the gear, the edges of the first meshing part and the second meshing part are arc-shaped; the rack teeth are provided with third meshing parts protruding outwards, and the rack tooth grooves are provided with fourth meshing parts recessed inwards; on the cross section of the rack, the edges of the third meshing part and the fourth meshing part are arc-shaped; at least one of the first engaging portion, the second engaging portion, the third engaging portion, and the fourth engaging portion is a rolling engaging portion including a plurality of rolling members arranged outside an edge thereof, the rolling members being capable of rolling in an engaging direction, the plurality of rolling members constituting engaging positions of the rolling engaging portion; during the transmission, the first engagement portion is engaged with the fourth engagement portion, or the second engagement portion is engaged with the third engagement portion.

Description

Gear rack transmission structure

Technical Field

The disclosure relates to the technical field of mechanical structures, and in particular relates to a gear rack transmission structure.

Background

With the increasing demands of industry for high precision and small size, the performance requirements of the gear and rack transmission structure are also increasing.

The inventor finds that the gear rack in the prior art has sliding friction in the meshing process, high transmission resistance, high mechanical efficiency to be improved, involute meshing, linear wear resistance all the time, and long service life to be improved.

Disclosure of Invention

In view of this, the embodiments of the present disclosure provide a rack and pinion transmission structure, which at least partially improves the mechanical efficiency of the rack and pinion transmission structure and improves the service life of the rack and pinion transmission structure.

The embodiment of the disclosure provides a gear rack transmission structure, which adopts the following technical scheme:

the gear-rack transmission structure comprises a rack and at least one gear matched with the rack;

the gear comprises gear teeth and gear tooth grooves which are repeatedly arranged along the circumferential direction, wherein the gear teeth are provided with first meshing parts protruding outwards, and the gear tooth grooves are provided with second meshing parts recessed inwards; on the cross section of the gear, the edges of the first meshing part and the second meshing part are arc-shaped;

the rack comprises rack teeth and rack tooth grooves which are repeatedly arranged along the extending direction, wherein the rack teeth are provided with third meshing parts protruding outwards, and the rack tooth grooves are provided with fourth meshing parts recessed inwards; on the cross section of the rack, the edges of the third meshing part and the fourth meshing part are arc-shaped;

At least one of the first engagement portion, the second engagement portion, the third engagement portion, and the fourth engagement portion is a rolling engagement portion including a plurality of rolling pieces arranged outside an edge thereof, the rolling pieces being rollably engaged in an engagement direction, the plurality of rolling pieces constituting an engagement position of the rolling engagement portion;

in the transmission process of the gear-rack transmission structure, the first meshing part is meshed with the fourth meshing part, or the second meshing part is meshed with the third meshing part.

Optionally, the first engagement portion and the second engagement portion each function as a rolling engagement portion; and/or, the third engagement portion and the fourth engagement portion each function as a rolling engagement portion.

Optionally, a first guide member is provided on an outer side of the rolling engagement portion, the first guide member having a first rolling space in which the rolling members roll in the engagement direction, and the plurality of rolling members are placed in the first rolling space.

Optionally, in the extending direction of the rolling engagement portion, the size of the first rolling space is slightly larger than the size of the rolling member, and the first guide restricts movement of the rolling member in the extending direction of the rolling engagement portion.

Optionally, only the first engagement portion and/or the third engagement portion serves as a rolling engagement portion.

Optionally, the rolling engagement part includes a fixed shaft located at the center, and an axial direction of the fixed shaft is parallel to an extending direction of the rolling engagement part; the fixed shaft is provided with a second guide in the circumferential direction, the second guide has a second rolling space in which the rolling members roll in the meshing direction, and the plurality of rolling members are placed in the second rolling space.

Optionally, the size of the second rolling space is slightly larger than the size of the rolling member in the axial direction of the fixed shaft, and the second guide limits the movement of the rolling member in the axial direction of the fixed shaft.

Optionally, a third guide member is provided outside the rolling engagement portion, the third guide member having a third rolling space in which the rolling members roll in the engagement direction, and the plurality of rolling members are placed in the third rolling space.

Optionally, in the extending direction of the rolling engagement portion, a size of the third rolling space is slightly larger than a size of the rolling member, and the third guide restricts movement of the rolling member in the extending direction of the rolling engagement portion.

Optionally, the rolling element is a ball or a needle roller.

Optionally, the radius of the edge of the second engagement portion is slightly larger than the radius of the edge of the third engagement portion; and/or, the radius of the edge of the fourth engagement portion is slightly larger than the radius of the edge of the first engagement portion.

Optionally, the gear includes only the gear teeth and the gear tooth slots, and in a cross section of the gear, a center of arc of an edge of the first engagement portion and a center of arc of an edge of the second engagement portion are the same as a distance between centers of the gear; and on the cross section of the rack, the arc center of the edge of the third meshing part and the arc center of the edge of the fourth meshing part are at the same height.

Optionally, the gear further comprises a gear tooth connection between the gear teeth and the gear tooth slots, the rack further comprises a rack tooth connection between the rack teeth and the rack tooth slots; a first distance is arranged between the arc center of the edge of the first meshing part and the center of the gear, a second distance is arranged between the arc center of the edge of the second meshing part and the center of the gear, and the second distance is smaller than the first distance; on the cross section of the rack, the arc center of the edge of the third meshing part has a first height, and the arc center of the edge of the fourth meshing part has a second height, and the second height is smaller than the first height.

Optionally, in a cross section of the gear, the gear tooth connection portion includes a first connection line protruding outwards and a second connection line recessed inwards, the first connection line being connected with the gear tooth, the second connection line being connected with the gear tooth slot; on the cross section of the rack, the rack tooth connecting part comprises a third connecting wire which is connected end to end and protrudes outwards and a fourth connecting wire which is recessed inwards, wherein the third connecting wire is connected with the rack tooth, and the fourth connecting wire is connected with the rack tooth slot; the first connecting line, the second connecting line, the third connecting line and the fourth connecting line are all arc lines.

Optionally, the first connecting line is an arc line co-rounded with the edge of the first engaging portion, and the second connecting line is an arc line co-rounded with the edge of the second engaging portion; the third connecting line is an arc line which is co-rounded with the edge of the third meshing part, and the fourth connecting line is an arc line which is co-rounded with the edge of the fourth meshing part.

Optionally, the edge of the first engagement portion, the edge of the second engagement portion, the edge of the third engagement portion, and the edge of the fourth engagement portion are all circular arcs with a radian pi.

Optionally, the extending direction of the gear teeth is parallel to the axis of the gear, and the extending direction of the rack teeth is parallel to the normal line of the cross section of the rack; or a first included angle is formed between the extending direction of at least one part of the gear teeth and the axis of the gear, a second included angle is formed between the extending direction of at least one part of the rack teeth and the normal line of the cross section of the rack, and the first included angle and the second included angle are both larger than 0 degrees and smaller than 90 degrees.

Optionally, the extension path of the gear teeth is a curve, a broken line or a straight line; the extending path of the rack teeth is a curve, a broken line or a straight line.

Optionally, the gear comprises at least two gear teeth.

Optionally, the rack and pinion transmission structure includes at least two gears, and at the same time, a part of the gears are fully meshed with the racks, and a gap exists between the other part of the gears and the racks.

Optionally, the rack and pinion transmission structure includes at least one gear set, each gear set is composed of two identical gears, and at the same time, gear teeth of one gear mesh with rack tooth grooves of the rack, and gear tooth grooves of the other gear mesh with rack teeth of the rack.

Optionally, the rack and pinion transmission structure includes at least one gear set, each gear set is composed of two identical gears, and at the same time, gear teeth of two gears mesh with rack tooth grooves of the racks, or gear tooth grooves of two gears mesh with rack teeth of the racks.

The embodiment of the disclosure provides a rack and pinion transmission structure, on the one hand, gear teeth are provided with first meshing parts protruding outwards, gear tooth grooves are provided with second meshing parts recessed inwards, on the cross section of a gear, the edges of the first meshing parts and the edges of the second meshing parts are arc-shaped, on the extending direction of the gear, the edges of the first meshing parts form first meshing surfaces, the edges of the second meshing parts form second meshing surfaces, similarly, on the extending direction of rack teeth, the edges of the third meshing parts form third meshing surfaces, the edges of the fourth meshing parts form fourth meshing surfaces, and during the use of the rack and pinion transmission structure, the first meshing surfaces and the fourth meshing surfaces or the second meshing surfaces and the third meshing surfaces are meshed, and the first meshing surfaces and the second meshing surfaces and the third meshing surfaces are meshed together, instead of involute meshing in the prior art, the contact area is increased, the wear resistance is improved, the service life is further effectively prolonged, the tooth shapes of the gear teeth and the rack teeth are firmer and the strength and the wear resistance are improved; on the other hand, because at least one of the first engaging portion, the second engaging portion, the third engaging portion and the fourth engaging portion serves as a rolling engaging portion, the rolling engaging portion includes a plurality of rolling members arranged outside edges thereof, the rolling members can roll in an engaging direction, the plurality of rolling members constitute an engaging position of the rolling engaging portion, and in the use process of the rack-and-pinion transmission structure, the rolling members roll in the engaging direction to roll, so that rolling friction is generated between the gear and the rack, transmission resistance is small, and mechanical efficiency can be greatly improved.

The foregoing description is only an overview of the disclosed technology, and may be implemented in accordance with the disclosure of the present disclosure, so that the above-mentioned and other objects, features and advantages of the present disclosure can be more clearly understood, and the following detailed description of the preferred embodiments is given with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.

FIG. 1 is a cross-sectional view of a first gear provided by an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of a second gear provided by an embodiment of the present disclosure;

FIG. 3 is a cross-sectional view of a third gear provided by an embodiment of the present disclosure;

FIG. 4 is a cross-sectional view of a fourth gear provided by an embodiment of the present disclosure;

FIG. 5 is a cross-sectional view of a rack provided by an embodiment of the present disclosure;

FIG. 6 is a first block diagram of an edge of a first engagement portion of a first gear according to an embodiment of the present disclosure;

FIG. 7 is a cross-sectional view along FF' of FIG. 6 provided by an embodiment of the present disclosure;

FIG. 8 is a second block diagram of an edge of a first engagement portion of a first gear according to an embodiment of the present disclosure;

FIG. 9 is a cross-sectional view along FF' of FIG. 8 provided by an embodiment of the present disclosure;

FIG. 10 is a schematic diagram I of a cross-section of a gear provided by an embodiment of the present disclosure;

FIG. 11 is a schematic diagram of a cross section of a rack provided by an embodiment of the present disclosure;

FIG. 12 is a schematic diagram II of a cross section of a gear provided by an embodiment of the present disclosure;

FIG. 13 is a schematic view of the meshing positions of a gear and a rack provided by an embodiment of the present disclosure;

FIG. 14 is a second schematic view of the meshing positions of a rack and pinion provided in an embodiment of the present disclosure;

fig. 15 is a third schematic view of the meshing positions of the gear and the rack provided in the embodiment of the present disclosure.

Detailed Description

The present disclosure is described in further detail below with reference to the drawings and the embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant content and not limiting of the present disclosure. It should be further noted that, for convenience of description, only a portion relevant to the present disclosure is shown in the drawings.

In addition, embodiments of the present disclosure and features of the embodiments may be combined with each other without conflict. The technical aspects of the present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Unless otherwise indicated, the exemplary implementations/embodiments shown are to be understood as providing exemplary features of various details of some ways in which the technical concepts of the present disclosure may be practiced. Thus, unless otherwise indicated, features of the various implementations/embodiments may be additionally combined, separated, interchanged, and/or rearranged without departing from the technical concepts of the present disclosure.

The use of cross-hatching and/or shading in the drawings is typically used to clarify the boundaries between adjacent components. As such, the presence or absence of cross-hatching or shading does not convey or represent any preference or requirement for a particular material, material property, dimension, proportion, commonality between illustrated components, and/or any other characteristic, attribute, property, etc. of a component, unless indicated. In addition, in the drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. While the exemplary embodiments may be variously implemented, the specific process sequences may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in reverse order from that described. Moreover, like reference numerals designate like parts.

When an element is referred to as being "on" or "over", "connected to" or "coupled to" another element, it can be directly on, connected or coupled to the other element or intervening elements may be present. However, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element, there are no intervening elements present. For this reason, the term "connected" may refer to physical connections, electrical connections, and the like, with or without intermediate components.

For descriptive purposes, the present disclosure may use spatially relative terms such as "under … …," under … …, "" under … …, "" lower, "" above … …, "" upper, "" above … …, "" higher "and" side (e.g., as in "sidewall"), etc., to describe one component's relationship to another (other) component as illustrated in the figures. In addition to the orientations depicted in the drawings, the spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "below" … … can encompass both an orientation of "above" and "below". Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, when the terms "comprises" and/or "comprising," and variations thereof, are used in the present specification, the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof is described, but the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof is not precluded. It is also noted that, as used herein, the terms "substantially," "about," and other similar terms are used as approximation terms and not as degree terms, and as such, are used to explain the inherent deviations of measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art.

The disclosed embodiments provide a rack and pinion transmission structure, particularly, as shown in fig. 1 to 5, including a rack 10, and at least one pinion 20 matched with the rack 10.

As shown in fig. 1 to 4, the gear 20 includes gear teeth 21 and gear tooth grooves 22 repeatedly arranged in the circumferential direction, the gear teeth 21 having first engaging portions 211 protruding outward, the gear tooth grooves 22 having second engaging portions 221 recessed inward; the edges of the first engagement portion 211 and the second engagement portion 221 are each arc-shaped in the cross section of the gear 20.

As shown in fig. 5, the rack 10 includes rack teeth 11 and rack tooth grooves 12 repeatedly arranged in the extending direction, the rack teeth 11 having third engaging portions 111 protruding outward, the rack tooth grooves 12 having fourth engaging portions 121 recessed inward; the edges of the third and fourth engagement portions 111 and 121 are each arc-shaped in the cross section of the rack 10.

At least one of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 serves as a rolling engagement portion, which includes a plurality of rolling members 30 arranged outside the edges thereof, as shown in fig. 1 to 5, the rolling members 30 being capable of rolling in an engagement direction (the engagement direction being determined by the gear 20 and the rack 10, respectively), the plurality of rolling members 30 constituting engagement positions of the rolling engagement portion.

During the transmission of the rack and pinion transmission structure, the first engagement portion 211 is engaged with the fourth engagement portion 121, or the second engagement portion 221 is engaged with the third engagement portion 111.

The above "at least one of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 as the rolling engagement portion" includes various cases: first, one of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 serves as a rolling engagement portion, and second, two of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 serve as a rolling engagement portion, and a plurality of combinations are possible; third, three of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 as rolling engagement portions may be combined in various ways; fourth, the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 all function as rolling engagement portions.

The rolling elements 30 may be distributed outside the entire rolling engagement portion, i.e., all engagement positions of the rolling engagement portion are the rolling elements 30; alternatively, the rolling elements 30 are distributed at a partial position outside the rolling engagement portion, that is, a partial engagement position of the rolling engagement portion is the rolling elements 30.

The rack and pinion transmission structure with the structure has at least the following technical effects:

On the one hand, the gear teeth 21 are provided with first meshing parts 211 protruding outwards, the gear tooth grooves 22 are provided with second meshing parts 221 recessed inwards, on the cross section of the gear, the edges of the first meshing parts 211 and the edges of the second meshing parts 221 are arc-shaped, on the extending direction of the gear, the edges of the first meshing parts 211 form first meshing surfaces, the edges of the second meshing parts 221 form second meshing surfaces, on the extending direction of the rack teeth 11, the edges of the third meshing parts 111 form third meshing surfaces, and the edges of the fourth meshing parts 121 form fourth meshing surfaces, and on the service process of the gear-rack transmission structure, the first meshing surfaces and the fourth meshing surfaces or the second meshing surfaces and the third meshing surfaces are meshed, and are not involute meshing in the prior art, the surfaces are worn in the transmission process, so that the contact area is increased, the wear resistance is improved, the service life is effectively prolonged, the tooth shapes of the gear teeth 21 and the rack teeth 11 are firmer, the strength and the wear resistance are improved, and the tooth shapes of the same modulus are stronger;

on the other hand, since at least one of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111, and the fourth engagement portion 121 serves as a rolling engagement portion including a plurality of rolling members 30 arranged outside the edges thereof, the rolling members 30 can roll in the engagement direction, the plurality of rolling members 30 constitute the engagement positions of the rolling engagement portions, and during use of the rack-and-pinion transmission structure, the rolling members 30 roll in the engagement direction, thereby making rolling friction between the gear 20 and the rack 10, reducing transmission resistance, and greatly improving mechanical efficiency.

Additionally, it should be added that the gear 20 and the rack 10 applied in the embodiments of the present disclosure have the following technical advantages: the stress is uniform; the contact area is large, and the wear resistance is improved; by tightly meshing the meshing surfaces, the running precision is improved, the stressed area is doubled or even higher than that of the prior art, and the bearing capacity is improved; and the measurement accuracy error is convenient.

The following embodiments of the present disclosure exemplify specific configurations of a rack and pinion transmission structure.

Alternatively, as shown in fig. 1, in the embodiment of the present disclosure, the first engagement portion 211 and the second engagement portion 221 each function as a rolling engagement portion; and/or, the third engagement portion 111 and the fourth engagement portion 121 each function as a rolling engagement portion. In this case, during use of the rack and pinion transmission structure, rolling friction is generated between the first engagement portion 211 and the fourth engagement portion 121, and between the second engagement portion 221 and the third engagement portion 111.

Further, as shown in fig. 6, 7, 8 and 9, in the embodiment of the present disclosure, the outer side of the rolling engagement portion is provided with the first guide 40, and the first guide 40 has the first rolling space in which the rolling members 30 roll in the engagement direction (the direction indicated by the arrow in fig. 6 and 8), and the plurality of rolling members 30 are placed. In the example shown in fig. 6 and 7, the rolling elements 30 are balls, and in the example shown in fig. 8 and 9, the rolling elements 30 are needle rollers. In fig. 6 to 9, the rolling engagement portion of the gear 20 is described as an example, and the rolling engagement portion of the rack 10 may be provided according to the above.

For example, a first guide 40 is provided on the outer side of the rolling engagement portion, and one, two or more rows of rolling members 30 may be placed in the first guide 40 in the extending direction of the rolling engagement portion; alternatively, two or more first guides 40 are provided on the outer side of the rolling engagement portion, and one row of rolling members 30 is placed in each of the first guides 40 in the extending direction of the rolling engagement portion.

Further, in the embodiment of the present disclosure, as shown in fig. 7 and 9, in the extending direction of the rolling engagement portion (the direction indicated by the arrow in fig. 7 and 9), the size of the first rolling space is slightly larger than the size of the rolling members 30, that is, each first guiding member 40 only places one row of rolling members 30, and the first guiding member 40 restricts the movement of the rolling members 30 in the extending direction of the rolling engagement portion, so as to further reduce the transmission resistance and improve the mechanical efficiency.

The above-described structure of the first guide 40 is only an example, and one skilled in the art may set it according to actual needs.

Alternatively, in the embodiment of the present disclosure, only the first engagement portion 211 and/or the third engagement portion 111 is used as the rolling engagement portion, and fig. 2 and 3 illustrate a case where only the first engagement portion 211 is used as the rolling engagement portion in the gear 20, and other cases can be obtained by those skilled in the art based on fig. 2 and 3, which are not described herein.

Alternatively, as shown in fig. 2, in the embodiment of the present disclosure, the rolling engagement portion includes a fixed shaft 50 at the center, and an axial direction of the fixed shaft 50 is parallel to an extending direction of the rolling engagement portion; the fixed shaft 50 is provided with a second guide 60 in the circumferential direction, the second guide 60 having a second rolling space in which the rolling members 30 roll in the engaging direction, and the plurality of rolling members 30 are placed. In fig. 2, in order to clearly show the positional relationship between the fixed shaft 50 and the rolling member 30, the structure of the second guide 60 is simplified or partially hidden, and those skilled in the art may refer to the specific structure, number, placement manner of the rolling member 30, etc. of the first guide 40, and the specific structure, number, placement manner of the rolling member 30, etc. of the second guide 60 are set, which will not be described herein.

Similarly, a second guide 60 is provided outside the fixed shaft 50, and one, two or more rows of rolling members 30 may be placed in the second guide 60 in the axial direction of the fixed shaft 50 (or the extending direction of the rolling engagement portion); alternatively, two or more second guides 60 are provided outside the fixed shaft 50, and a row of rolling members 30 is placed in each second guide 60 in the axial direction of the fixed shaft 50.

Further, in the embodiment of the present disclosure, the size of the second rolling space is slightly larger than the size of the rolling elements 30 in the axial direction of the fixed shaft 50, that is, each second guiding element 60 only places one row of rolling elements 30, and the second guiding elements 60 limit the movement of the rolling elements 30 in the axial direction of the fixed shaft 50, so as to further reduce the transmission resistance and improve the mechanical efficiency.

Alternatively, in the embodiment of the present disclosure, the outer side of the rolling engagement portion is provided with the third guide having the third rolling space in which the rolling members 30 roll in the engagement direction, and the plurality of rolling members 30 are placed in the third rolling space. The specific structure, number, placement of the rolling members 30, etc. of the third guide member can be set by those skilled in the art with reference to the specific structure, number, placement of the rolling members 30, etc. of the first guide member 40, and will not be described herein.

Further, in the embodiment of the disclosure, in the extending direction of the rolling engagement portion, the size of the third rolling space is slightly larger than the size of the rolling elements 30, that is, each third guiding element only places one row of rolling elements 30, and the third guiding elements limit the movement of the rolling elements 30 in the extending direction of the rolling engagement portion, so as to further reduce the transmission resistance and improve the mechanical efficiency.

Of course, the person skilled in the art may also use only the second engagement portion 221 and/or the fourth engagement portion 121 as the rolling engagement portion, and in the example shown in fig. 4, only the case where the second engagement portion 221 of the gear 20 is used as the rolling engagement portion is shown, and other cases will be available to the person skilled in the art based on fig. 4, and no further description is given here.

Alternatively, the rolling elements 30 in the embodiments of the present disclosure may be balls or needles, and those skilled in the art may select other rolling elements according to actual needs.

Alternatively, in the embodiment of the present disclosure, the radius of the edge of the second engagement portion 221 may be greater than or equal to the radius of the edge of the third engagement portion 111, and the radius of the edge of the fourth engagement portion 121 may be greater than or equal to the radius of the edge of the first engagement portion 211. Further, in the embodiment of the present disclosure, the radius of the edge of the second engagement portion 221 is selected to be slightly larger than the radius of the edge of the third engagement portion 111, and/or the radius of the edge of the fourth engagement portion 121 is selected to be slightly larger than the radius of the edge of the first engagement portion 211. The effect of the above "slightly larger" is that: when the rack and pinion transmission structure is used, the first engagement portion 211 of the gear 20 can smoothly engage with and disengage from the fourth engagement portion 121 of the rack 10, so as to avoid jamming, and the second engagement portion 221 of the gear 20 can smoothly engage with and disengage from the third engagement portion 111 of the rack 10, so as to avoid jamming. The dimension range of "slightly greater" can be selected by those skilled in the art according to actual needs, on the principle that engagement of the engagement portions can be achieved and jamming can be avoided at the same time. For example, the radius of the edge of the second engagement portion 221 is larger than the radius of the edge of the third engagement portion 111 by 0.05 μm, 0.1 μm, 0.2 μm, 0.5 μm, or the like, and the radius of the edge of the fourth engagement portion 121 is larger than the radius of the edge of the first engagement portion 211 by 0.05 μm, 0.1 μm, 0.2 μm, 0.5 μm, or the like.

Alternatively, as shown in fig. 10, only the edges of the meshing portions are indicated by simple lines in fig. 10 and the following figures, the structures such as rolling members are not shown, and the gear 20 includes only the gear teeth 21 and the gear tooth grooves 22, and in the cross section of the gear 20, the distances between the arc center of the edge a of the first meshing portion 211 (indicated by the upper right black point in fig. 10) and the arc center of the edge B of the second meshing portion 221 (indicated by the lower right black point in fig. 10) are d, which are the same as the centers of the gears 20 (indicated by the middle black point in fig. 10), that is, in the orientation shown in fig. 10, the arc center of the edge a of the first meshing portion 211 and the arc center of the edge B of the second meshing portion 221 are on the same circumference centered around the center of the gear 20. Similarly, as shown in fig. 11, in the cross section of the rack 10, the arc center of the edge C of the third meshing portion 111 (shown as a right-hand black dot in fig. 11) and the arc center of the edge D of the fourth meshing portion 121 (shown as a left-hand black dot in fig. 11) are at the same height (specifically, in the Z-direction in fig. 11). In this case, in the transmission process of the rack and pinion transmission structure, the operation is stable and the vibration is small.

Alternatively, as shown in fig. 12, only the edge of the meshing portion is indicated by a simple line in fig. 12, the structure of a rolling member or the like is not shown, the gear 20 further includes a gear tooth connection portion 70 between the gear tooth 21 and the gear tooth slot 22, and in the cross section of the gear 20, a first distance is provided between the arc center of the edge a of the first meshing portion 211 (shown as a left-hand black dot in fig. 12) and the center of the gear 20, and a second distance is provided between the arc center of the edge B of the second meshing portion 221 (shown as a right-hand black dot in fig. 12) and the center of the gear 20 (not shown in fig. 12), the second distance being smaller than the first distance. That is, in the orientation of the cross section of the gear 20 (refer to the orientation shown in fig. 12), the arc center of the edge a of the first engagement portion 211 and the arc center of the edge B of the second engagement portion 221 are on different circumferences centered on the center of the gear 20. Similarly, the rack 10 further includes a rack tooth connecting portion between the rack tooth 11 and the rack tooth slot 12, and in a cross section of the rack 10, an arc center of an edge of the third engaging portion 111 has a first height, and an arc center of an edge of the fourth engaging portion 121 has a second height, which is smaller than the first height. In this case, there are effects of speed change and vibration during the transmission of the rack and pinion transmission structure.

Further, as shown in fig. 12, in the cross section of the gear 20, the gear tooth connecting portion 70 includes a first connecting line 71 protruding outward and a second connecting line 72 recessed inward, which are connected end to end, the first connecting line 71 being connected to the gear tooth 21, the second connecting line 72 being connected to the gear tooth slot 22, the first connecting line 71 and the second connecting line 72 each being an arc. Similarly, in the cross section of the rack 10, the rack tooth connecting portion includes a third connecting line protruding outward and connecting end to end and a fourth connecting line recessed inward, the third connecting line being connected to the rack tooth 11, the fourth connecting line being connected to the rack tooth slot 12; the third connecting line and the fourth connecting line are arc lines. When the gear tooth connecting portion 70 and the rack tooth connecting portion have the above structure, the meshing area between the gear 20 and the rack 10 in the rack-and-pinion transmission structure can be further increased.

Further, in the embodiment of the present disclosure, as shown in fig. 12, the first connection line 71 is an arc line co-rounded with the edge of the first engagement portion 211, and the second connection line 72 is an arc line co-rounded with the edge of the second engagement portion 221. Similarly, the third connecting line is an arc line co-rounded with the edge of the third engaging portion 111, and the fourth connecting line is an arc line co-rounded with the edge of the fourth engaging portion 121. In this case, during the transmission of the rack and pinion transmission structure, the first connection line 71 is also engaged with the fourth connection line, or the second connection line 72 is also engaged with the third engagement line, thereby further increasing the engagement area between the gear 20 and the rack 10.

Alternatively, in the embodiment of the present disclosure, as shown in fig. 10 and 11, the edges of the first engagement portion 211, the second engagement portion 221, the third engagement portion 111 and the fourth engagement portion 121 are each circular arcs of an arc of pi, i.e., half of the entire circumference, so that the engagement area between the gear 20 and the rack 10 is further increased.

Alternatively, the gear 20 in the embodiment of the present disclosure may be a straight gear, a helical gear, and the rack 10 may be a straight rack, a helical rack, or the like. When the gear 20 is a straight gear and the rack 10 is a straight rack, the extending direction of the gear teeth 21 is parallel to the axis of the gear 20, and the extending direction of the rack teeth 11 is parallel to the normal line of the cross section of the rack 10; when the gear 20 is a helical gear and the rack 10 is a helical rack, a first included angle is formed between the extending direction of at least a portion of the gear teeth 21 and the axis of the gear 20, a second included angle is formed between the extending direction of at least a portion of the rack teeth 11 and the normal line of the cross section of the rack 10, and the first included angle and the second included angle are both greater than 0 ° and less than 90 °, and may further be selected to be 10 ° to 45 °.

Further, in the embodiment of the present disclosure, the extending path of the gear teeth 21 is a curve (e.g., an arc), a fold line (e.g., a herringbone), or a straight line, and the extending path of the rack teeth 11 is a curve (e.g., an arc), a fold line (e.g., a herringbone), or a straight line. It must be understood by those skilled in the art that the extension path of the gear teeth 21 is the same as the extension path of the rack teeth 11.

Optionally, the gear 20 in embodiments of the present disclosure includes at least two gear teeth 21, e.g., 2, 3, 4, 5, 8, 10, 15, 20, etc., with a wider range of selectable numbers of gear teeth 21. While the gears in the prior art are involute gears, if the number of gear teeth is small, undercut problems will occur, in the embodiment of the present disclosure, the gears 20 are engaged with the engagement surfaces, and no undercut problem will occur no matter how many gear teeth 21 are provided.

Optionally, the rack and pinion gear arrangement of the disclosed embodiments may also include a drive element (component that drives rotation of the gear) and/or structural member that is integrally formed with the main structural portion of the gear 20. The above main body structure portion may include a structure located inside the gear teeth 21 and the gear tooth grooves 22, a portion of the gear teeth 21 or the gear tooth grooves 22 other than the rolling member 30 (or rolling member and guide member, or rolling member, fixed shaft, guide member, etc.).

The above transmission elements may be any structure such as gears, gear rings, racks, driving shafts, etc., the shape of which may be regular or irregular, the structural members may be any component capable of functioning structurally, the positional relationship (up-down, left-right, inside-outside, coaxial or not, etc.), the size relationship (equal, unequal) etc. between each transmission element and each structural member and the gears may be various, and the shape of which is not limited herein, and may be selected by those skilled in the art according to actual needs.

The main body structure of the gear 20 in the disclosed embodiments may be machined by milling, and thus, the transmission elements and/or structural members may be integrally formed with the main body structure. Of course, when other parts are needed to be matched with the gear 20, the parts and the gear 20 can be made into an integral part, the number of assembly stages is reduced, the number of parts is greatly reduced, the number of assembly stages is greatly reduced, the multi-stage assembly precision error is greatly reduced, various comprehensive instabilities are greatly reduced, the number of fasteners or positioning parts is greatly reduced, and the integral part has stronger rigidity, and has stronger integral structure precision and retentivity.

The prior art old-fashioned gears are limited by several conventional processing methods, such as making other parts on the gears into separate parts, and then assembling the separate parts. When each stage of assembly is assembled, precision errors (concentricity, cylindricity, position degree, verticality, levelness, parallelism and the like) are generated, the errors can be accumulated along with the increase of part cooperation, or single parts are possibly qualified, and the whole multi-layer multi-stage assembly is disqualified to cause precision super tolerance, so that various comprehensive instabilities are generated; the multi-stage assembly needs to use a fastener or a positioning piece, or the working time is increased along with the time, the precision retention degree of the multi-stage assembly overall structure is reduced, and the rigidity is reduced.

Alternatively, as shown in fig. 13, only the edges of the respective meshing portions are shown in fig. 13 by simple lines, and the rack-and-pinion transmission structure includes at least two gears 20, and at the same time, one portion of the gears 20 is fully meshed with the rack 10 (the gear teeth 21 are fully meshed with the rack teeth 12, or the gear teeth 22 are fully meshed with the rack teeth 11), and another portion of the gears 20 is in clearance with the rack 10 (the gear teeth 21 are in clearance with the rack teeth 12, or the gear teeth 22 are in clearance with the rack teeth 11). This may be achieved in particular by adjusting the distance between the gears 20 and/or the relative positions of the gears 20 and the rack 10 at the time of initial placement.

The above "same time" does not refer to a specific time, but refers to a time when the above meshing relationship exists between the different gears 20 and the rack 10 during the transmission. In the entire transmission, there are a plurality of times described above, taking two times adjacent to each other, for example, one gear 20, and if the gear 20 is completely engaged with the rack 10 at the present time, there is a gap between the gear 20 and the rack 10 at the next time, and if there is a gap between the gear 20 and the rack 10 at the present time, the gear 20 is completely engaged with the rack 10 at the next time.

In the transmission process of the gear-rack transmission structure with the structure, the meshing effect of different gears 20 and racks 10 can realize dynamic compensation, namely complete meshing and clearance, so that resonance reduction shared by a plurality of gears 20 can be further improved, the stress is more uniform, the average stress surface and acting force are more stable, the acting force of the double stress surface is even, the effect of bearing capacity is improved, and the reverse clearance can be effectively reduced.

Specifically, as shown in fig. 13, the rack-and-pinion transmission structure includes two gears 20, and at the same time, the left gear 20 is fully engaged with the rack 10 (see the position indicated by the left broken line circle in fig. 13), and a slight gap exists between the right gear 20 and the rack 10 (see the position indicated by the right broken line circle in fig. 13). In addition, the above-described dynamic compensation effect can be achieved regardless of whether the meshing positions of the two gears 20 and the rack 10 are similar (both concave-to-convex, or convex-to-concave) or opposite (one is concave-to-convex, and the other is convex-to-concave) at the same time.

Alternatively, as shown in fig. 14, the rack and pinion transmission structure includes at least one gear set each composed of two identical gears 20, in which gear teeth 21 of one gear 20 mesh with rack teeth grooves 12 of the rack 10 (convex-concave, as shown by the right-hand dashed circle in fig. 14) and gear teeth grooves 22 of the other gear 20 mesh with rack teeth 11 of the rack 10 (concave-convex, as shown by the left-hand dashed circle in fig. 14) at the same time. Based on the above, in the transmission process of the rack-and-pinion transmission structure, the meshing positions of the two gears 20 and the rack 10 are just opposite, which is helpful for realizing that errors are equally divided and improving the operation precision.

The above "same time" does not refer to a specific time, but refers to a time when the above meshing relationship exists between the different gears 20 and the rack 10 during the transmission.

Alternatively, as shown in fig. 15, the rack and pinion transmission structure includes at least one gear set, each of which is composed of two identical gears 20, in which gear sets, gear teeth 21 of two gears 20 mesh with rack teeth grooves 12 of the rack 10 (both are convex-concave as shown by a broken line circle in fig. 15), or gear teeth grooves 22 of two gears 20 mesh with rack teeth 11 of the rack 10 (both are concave-convex).

It should be noted that the above "same time" does not refer to a specific time, but refers to a time during transmission, the above meshing relationship between the different gears 20 and the rack 10 occurs.

In the description of the present specification, reference to the terms "one embodiment/manner," "some embodiments/manner," "example," "a particular example," "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/manner or example is included in at least one embodiment/manner or example of the application. In this specification, the schematic representations of the above terms are not necessarily for the same embodiment/manner or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/modes or examples described in this specification and the features of the various embodiments/modes or examples can be combined and combined by persons skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

It will be appreciated by those skilled in the art that the above-described embodiments are merely for clarity of illustration of the disclosure, and are not intended to limit the scope of the disclosure. Other variations or modifications will be apparent to persons skilled in the art from the foregoing disclosure, and such variations or modifications are intended to be within the scope of the present disclosure.

Claims

1. A rack and pinion transmission structure, characterized by comprising a rack and at least one pinion matched with the rack;

2. The rack and pinion transmission structure according to claim 1, wherein the first engagement portion and the second engagement portion each function as a rolling engagement portion; and/or, the third engagement portion and the fourth engagement portion each function as a rolling engagement portion.

3. The rack and pinion transmission structure according to claim 2, wherein a first guide member having a first rolling space in which the rolling members roll in the meshing direction is provided on an outer side of the rolling meshing portion, the plurality of rolling members being placed in the first rolling space.

4. The rack and pinion transmission structure according to claim 1, wherein only the first engagement portion and/or the third engagement portion serves as a rolling engagement portion.

5. The rack and pinion transmission structure according to claim 4, wherein the rolling engagement portion includes a centrally located fixed shaft, an axial direction of which is parallel to an extending direction of the rolling engagement portion; the fixed shaft is provided with a second guide in the circumferential direction, the second guide has a second rolling space in which the rolling members roll in the meshing direction, and the plurality of rolling members are placed in the second rolling space.

6. The rack and pinion transmission structure according to claim 4, wherein a third guide member having a third rolling space in which the rolling members roll in the meshing direction is provided on an outer side of the rolling meshing portion, the plurality of rolling members being placed in the third rolling space.

7. The rack and pinion transmission structure according to any one of claims 1 to 6, wherein the rolling members are balls or needles.

8. The rack and pinion transmission structure according to any one of claims 1 to 6, wherein the gear includes only the gear teeth and the gear tooth grooves, and in a cross section of the gear, a center of arc of an edge of the first engagement portion and a center of arc of an edge of the second engagement portion are the same as a distance between centers of the gears; and on the cross section of the rack, the arc center of the edge of the third meshing part and the arc center of the edge of the fourth meshing part are at the same height.

9. The rack and pinion gear arrangement of any one of claims 1-6 wherein the gear further comprises a gear tooth connection between the gear teeth and the gear tooth slots, the rack further comprising a rack tooth connection between the rack teeth and the rack tooth slots; a first distance is arranged between the arc center of the edge of the first meshing part and the center of the gear, a second distance is arranged between the arc center of the edge of the second meshing part and the center of the gear, and the second distance is smaller than the first distance; on the cross section of the rack, the arc center of the edge of the third meshing part has a first height, and the arc center of the edge of the fourth meshing part has a second height, and the second height is smaller than the first height.

10. The rack and pinion transmission structure of claim 9 wherein, in cross section of the gear, the gear tooth connection includes an outwardly convex first connection line connected end-to-end and an inwardly concave second connection line connected with the gear tooth socket; on the cross section of the rack, the rack tooth connecting part comprises a third connecting wire which is connected end to end and protrudes outwards and a fourth connecting wire which is recessed inwards, wherein the third connecting wire is connected with the rack tooth, and the fourth connecting wire is connected with the rack tooth slot; the first connecting line, the second connecting line, the third connecting line and the fourth connecting line are all arc lines.

11. The rack and pinion transmission structure according to claim 10, wherein the first connecting line is an arc line that is co-rounded with an edge of the first engagement portion, and the second connecting line is an arc line that is co-rounded with an edge of the second engagement portion; the third connecting line is an arc line which is co-rounded with the edge of the third meshing part, and the fourth connecting line is an arc line which is co-rounded with the edge of the fourth meshing part.

12. The rack and pinion transmission structure according to any one of claims 1 to 6, wherein edges of the first engagement portion, the second engagement portion, the third engagement portion, and the fourth engagement portion are arc lines having an arc degree of pi.

13. The rack and pinion transmission structure according to any one of claims 1 to 6, characterized in that an extending direction of the gear teeth is parallel to an axis of the gear, and an extending direction of the rack teeth is parallel to a normal line of a cross section of the rack; or a first included angle is formed between the extending direction of at least one part of the gear teeth and the axis of the gear, a second included angle is formed between the extending direction of at least one part of the rack teeth and the normal line of the cross section of the rack, and the first included angle and the second included angle are both larger than 0 degrees and smaller than 90 degrees.

14. The rack and pinion transmission structure of claim 13 wherein the path of extension of the gear teeth is a curve, a broken line, or a straight line; the extending path of the rack teeth is a curve, a broken line or a straight line.

15. A rack and pinion gear arrangement according to any one of claims 1 to 6 wherein the gear comprises at least two gear teeth.

16. A rack and pinion transmission structure according to any one of claims 1 to 6, comprising at least two of said gears, wherein at the same time, a part of said gears is fully engaged with said racks and a gap exists between another part of said gears and said racks.

17. A rack and pinion transmission arrangement according to any one of claims 1 to 6 comprising at least one gear set, each of said gear sets being formed of two identical said gears, one of said gear sets having gear teeth in engagement with rack teeth of said rack and the other gear tooth in engagement with rack teeth of said rack at the same time.

18. A rack and pinion transmission structure according to any one of claims 1 to 6 comprising at least one gear set, each of said gear sets being comprised of two identical said gears, wherein at the same time, the gear teeth of two of said gears mesh with the rack teeth of said rack or the gear teeth of two of said gears mesh with the rack teeth of said rack.