阅读说明：本技术 电的线性驱动器 (Electric linear drive ) 是由 J.基拉 于 2019-08-09 设计创作，主要内容包括：提出一种电的线性驱动器(1),所述电的线性驱动器具有驱动器壳体(3),在所述驱动器壳体中构造有两个转向区域(6),其中,转向小齿轮单元(22)围绕转动轴线(14)能扭转地支承在至少一个转向区域(6)中。所述转向小齿轮单元(22)含有两个转向小齿轮(16、17),其中,两个转向小齿轮(16、17)的外周的齿部(18)整体式地构造在一件式的小齿轮轴(42)中。齿带(8、9)围绕每个转向小齿轮(16、17)缠绕,所述齿带作用于从动滑块(32)处。(An electric linear drive (1) is proposed, comprising a drive housing (3), in which two steering regions (6) are formed, wherein a steering pinion unit (22) is mounted in at least one steering region (6) so as to be rotatable about a rotational axis (14). The steering pinion unit (22) comprises two steering pinions (16, 17), wherein the outer circumferential toothing (18) of the two steering pinions (16, 17) is integrally formed in a one-piece pinion shaft (42). Toothed belts (8, 9) are wound around each steering pinion (16, 17), said toothed belts acting on the follower slides (32).)

1. Electric linear drive having a drive housing (3) with a longitudinal direction (2a) and a transverse direction (15a) which is orthogonal to the longitudinal direction, and having a driven slide (32) which can be driven by an electric drive (35) relative to the drive housing (3) in a linear driven movement (36) along the longitudinal direction (2a), wherein the drive housing (3) has two deflection regions (6, 7) which are spaced apart from one another along the longitudinal direction (2a) and in which two deflection rollers (12, 13) are arranged in a coaxial orientation next to one another along the transverse direction (15a) and can be rotated about a rotation axis (14) which extends along the transverse direction (15a), wherein two toothed belts (8, 13) which act on the driven slide (32) and are arranged next to one another along the transverse direction (15a), 9) Respectively wound around one of the deflecting rollers (12, 13) arranged in the two deflecting regions (6, 7), and wherein at least one of the deflecting rollers (12, 13) arranged in one of the two deflecting regions (6, 7) is designed as a deflecting pinion (16, 17), the steering pinion has an outer peripheral toothing (18) with which the associated toothed belt (8, 9) is in engagement, characterized in that at least the two steering pinions (16, 17) arranged in one of the two steering regions (6, 7) are combined to form a steering pinion unit (22) which can be rotated uniformly about the axis of rotation (14) and which has a one-piece pinion shaft (42), the outer circumferential toothing (18) of the two steering pinions (16, 17) is formed in one piece in the pinion shaft.

2. The electric linear drive as claimed in claim 1, characterized in that the steering rollers (12, 13) of both steering regions (6, 7) are designed as steering pinions (16, 17), wherein the steering pinions (16, 17) of each of the two steering regions (6, 7) are combined to form a steering pinion unit (22) which can be rotated uniformly about the axis of rotation (14) and which has a one-piece pinion shaft (42) in which the peripheral toothing (18) of the two steering pinions (16, 17) is designed in one piece.

3. The electric linear drive as claimed in claim 1 or 2, characterized in that the electric drive (35) is in rotary drive connection with a steering pinion unit (22) arranged in one of the two steering regions (6, 7) so that two toothed belts (8, 9) can be driven in a uniform revolving movement (38), from which a driven movement (36) of the driven slide (32) is generated, wherein the electric drive (35) is expediently attached externally to the drive housing (3).

4. The electric linear drive according to one of claims 1 to 3, characterized in that a length section (54) of the pinion shaft (42) of the steering pinion unit (22) axially between the two outer circumferential teeth (18) is radially constricted and has a smaller diameter than a length section (43) of the two outer circumferential teeth sections (18) of the pinion shaft (42).

5. Electrical linear driver according to one of the claims 1 to 4, each steering pinion (16, 17) of the steering pinion unit (22) has, axially on both sides of the peripheral toothing (18), an annular support wall (44, 45) for the lateral support of a toothed belt (8, 9) wound around the peripheral toothing (18) and arranged coaxially with respect to the peripheral toothing (18), wherein for each steering pinion (16, 17) there is an annular inner support wall (44) at an axially inner side of the peripheral toothing (18) facing the respective other steering pinion (16, 17) of the steering pinion unit (22) and an annular outer support wall (45) at an opposite axially outer side of the peripheral toothing (18).

6. The electric linear drive according to claim 5, characterized in that the peripheral toothing (18) of each steering pinion (16, 17) is circumferentially radially extended beyond by two annular support walls (44, 45) associated with the peripheral toothing.

7. The electric linear drive as claimed in claim 5 or 6, characterized in that the annular inner support walls (44) of the steering pinion unit (22) are each formed by two semicircular annular sections (55, 56) which are separated in relation to the pinion shaft (42) and which are placed radially outward from diametrically opposite sides to one another to the pinion shaft (43) and are fixed to the pinion shaft (42) in the form of an annular structure (57).

8. The electric linear drive as claimed in claim 7, characterized in that the semicircular annular sections (55, 56) of the support wall (44) forming the interior of one steering pinion (16, 17) are configured or arranged separately and axially spaced apart from the semicircular annular sections (55, 56) of the support wall (44) forming the interior of the other steering pinion (17, 16).

9. The electric linear drive as claimed in claim 8, characterized in that each semicircular annular section (55, 56) has a semicircular supporting section (58) which directly delimits a peripheral section of the associated inner supporting wall (44, 45) and a semicircular retaining section (62) which is arranged radially inwardly at the semicircular supporting section (58), wherein each semicircular annular section (55, 56) with its retaining section (62) is inserted into an annular groove (63) of the pinion shaft (42) which is open radially to the outside and is fixed in the annular groove (63).

10. The electric linear drive according to claim 9, characterized in that the annular groove (63) has an undercut cross section, wherein the annular groove has a fitting section (64) which is open radially on the outside and a fastening section (65) which is axially coupled in the pinion shaft (42) to the fitting section (64) and is radially on the outside bounded by the pinion shaft (42), wherein a retaining section (62) of each annular section (55, 56) which is countersunk from the radially outside into the fitting section (64) projects axially beyond the associated supporting section (58) of the annular section (55, 56) and axially into the fastening section (65) of the annular groove (63), in which it is radially supported at the pinion shaft (42).

11. The electric linear drive as claimed in claim 10, characterized in that the retaining section (62) of each annular segment (55, 56) is supported with its radial outer face (68) at a supporting face (66a) of the pinion shaft (42) which is directed radially inward and delimits the fastening section (65) of the annular groove (63), wherein, expediently, a radial inner face of each annular segment (55, 56) is spaced apart from a groove bottom face (67) of the annular groove (63) which is diametrically opposite the inner face.

12. The electric linear drive as claimed in claim 10 or 11, characterized in that the two ring segments (55, 56), which together form an inner support wall (44), are axially fixed in position by a spring-elastic stop ring (72) which is open at one point of its circumference and which engages into an annular stop groove (73) of the pinion shaft (42) on the side facing axially away from the teeth (18) associated with the outer circumference of the ring segments (55, 56) and supports the ring segments (55, 56) on the side facing away from the outer circumferential teeth (18).

13. The electric linear drive as claimed in claim 7, characterized in that the ring sections (55, 56) belonging to one steering pinion (16, 17) and the ring sections (55, 56) belonging to the other steering pinion (17, 16) are each constructed as a one-piece component of a one-piece support shell (75, 76) having a semicircular cross section, wherein the steering pinion unit (22) has two such support shells (75, 76) which are placed radially outwardly from the sides diametrically opposite one another to the pinion shaft (42) in a region axially between the two mutually spaced-apart peripheral teeth (18) forming a sleeve structure (82) and which are fixed to the pinion shaft (42).

14. The electric linear drive as claimed in claim 13, characterized in that the annular sections (55, 56) of the respective support shells (75, 76) are formed by semicircular radial projections (77) which are formed in one piece in the region of mutually opposite end sides of a shell-shaped connecting section (78) of the support shells (75, 76).

15. The electric linear drive as claimed in claim 13 or 14, characterized in that the two support shells (75, 76) are held together in the formed condition of the sleeve structure (42) by means of a fastening threaded fastener (83) which directly connects the support shells and extends peripherally alongside the pinion shaft (42) and at the same time is clamped radially to the pinion shaft (42).

16. The electric linear drive according to one of claims 5 to 15, characterized in that the annular outer support wall (45) of each steering pinion (16, 17) of the steering pinion unit (22) is formed by a support ring (47) which is plugged onto the pinion shaft (42) from the outside, said support ring being expediently fastened to the pinion shaft (42) by means of a rolling bearing (24) for the rotational bearing of the steering pinion unit (22) with respect to the drive housing (3) and which is plugged onto the pinion shaft (42) on the opposite side of the support ring (47) from the peripheral toothing (18).

Technical Field

The invention relates to an electric linear drive having a drive housing with a longitudinal direction and a transverse direction which is orthogonal to the longitudinal direction, and having a driven carriage which can be driven in a linear driven movement in the longitudinal direction by means of an electric drive relative to the drive housing, wherein the drive housing has two deflection regions which are spaced apart from one another in the longitudinal direction and in which two deflection rollers which are arranged next to one another in a coaxial orientation in the transverse direction and can be rotated about a rotation axis which extends in the transverse direction are arranged in each case, wherein two toothed belts which act on the driven carriage and are arranged next to one another in the transverse direction are each wound about one of the deflection rollers arranged in the two deflection regions, and wherein at least the deflection roller arranged in one of the two deflection regions is designed as a deflection pinion, it has peripheral teeth with which the associated toothed belt is in engagement.

Background

An electric linear drive of this type known from WO02/060641a1 has an elongated drive housing with two end-side deflection regions in which two deflection rollers are arranged in each case so as to be rotatable, coaxially next to one another in the transverse direction of the drive housing. Two toothed belts arranged next to one another in the transverse direction are each wound around one of the deflecting rollers associated with the two deflecting regions and are fastened to a follower slide, which is mounted on the drive housing so as to be linearly displaceable in the longitudinal direction of the drive housing. An electric drive is located in the drive housing, which acts directly on the drive carriage and can drive it in a linear, driven movement. In the case of the driven movement, the toothed belt runs around the deflecting roller and closes a slot formed in the drive housing for preventing the ingress of dirt. The deflecting roller arranged in one of the two deflecting regions is designed as a separate deflecting pinion having an outer circumferential toothing with which the respectively associated toothed belt is in engagement.

EP2110201B1 discloses an electric linear drive in the form of a toothed belt drive, which has a rotatably mounted steering pinion in each of two steering regions of the drive housing that are spaced apart from one another, wherein the toothed belt wound around the two steering pinions acts on the output slide. One of the steering pinions can be driven in rotation by an electric drive, which is attached externally to the drive housing, in order to produce an orbital movement of the toothed belt and thus a linear driven movement of the driven slide.

Electric linear drives equipped with toothed belts are also known from US5517872 and EP0534875a 1.

Disclosure of Invention

The invention is based on the object of providing an electric linear drive equipped with two toothed belts, which is simple to produce and can be operated with low wear.

In order to solve this problem, in combination with the features mentioned at the outset, it is provided according to the invention that at least the two steering pinions arranged in one of the two steering regions are combined to form a steering pinion unit which can be rotated uniformly about the axis of rotation and which has a one-piece pinion shaft in which the peripheral toothing of the two steering pinions is formed in one piece.

The electric linear drive according to the invention has a drive housing with two deflection regions arranged at a distance from one another in the longitudinal direction of the drive housing. In the two deflection regions, there are two deflection rollers arranged coaxially next to one another, which in at least one of the two deflection regions are designed as deflection pinions equipped with peripheral toothing. Two toothed belts arranged next to one another in the transverse direction run around two deflection rollers, each associated with one of the deflection regions, and at least one of the deflection rollers is designed as a deflection pinion. At least the two steering pinions arranged in one of the steering regions are not designed separately, but are combined to form a steering pinion unit that can be rotated in a unified manner. The steering pinion unit has a one-piece pinion shaft in which the teeth of both outer peripheries of the associated steering pinion are integrally, i.e. directly, formed. The toothed section of the outer circumference of the steering pinion, which is contained in the steering pinion unit, can thus always be rotated synchronously only at the same time, which is responsible for the same rotational movement of the two toothed belts and thus for the precise and low-wear operation of the linear drive. Furthermore, the teeth of the outer circumference, which are formed as a one-piece component of the pinion shaft, can be produced with high precision and exactly coaxial orientation during the production of the pinion shaft, which also advantageously contributes to the precision and wear characteristics. The assembly of the linear drive is also simplified by the steering pinion unit, since the time-consuming coaxial alignment measures of the associated steering pinion are dispensed with.

Advantageous developments of the invention result from the dependent claims.

In a possible embodiment, the steering rollers arranged in only one of the steering regions are configured as steering pinions which are combined to form a steering pinion unit. The deflecting rollers of the other deflecting region can be embodied, for example, as non-toothed deflecting rollers or as separate deflecting pinions which can be rotated independently of one another. It is considered particularly advantageous, however, if the deflecting rollers of the two deflecting regions are designed as deflecting pinions, and if the deflecting pinions of each of the two deflecting regions are combined to form a deflecting pinion unit with a one-piece pinion shaft and a toothed section integrally formed in the pinion shaft.

The electric linear drive expediently comprises an electric drive, by means of which a linear output movement of the output slide can be caused. The electric drive is expediently arranged at the drive housing.

In principle, an electric drive can interact directly with the output slide in order to produce the output movement. Preferably, however, the electric linear drive is designed as a toothed belt drive, wherein the electric drive is preferably in rotary drive connection with a steering pinion unit arranged in one of the two steering regions and rotatably drives the steering pinion unit. Due to the meshing engagement, the resulting rotational movement of the steering pinion unit produces a uniform revolving movement of the two toothed belts, wherein the driven slide arranged on the toothed belts is driven by the revolving movement. The driven movement is generated when the toothed belt is driven, whereby an electric drive is used to connect the two toothed belts.

The length section of the pinion shaft of the respective steering pinion unit axially between the two steering pinions is preferably radially constricted so that it has a smaller diameter than two axially adjacent length sections of the pinion shaft, each having a toothed section.

In a particularly advantageous embodiment, each steering pinion of each steering pinion unit has, on both axial sides of the toothing of its outer circumference, in each case an annular support wall arranged coaxially with respect to the axis of rotation for the lateral support of a toothed belt wound around the toothing. This ensures that the toothed belt, during its pivoting movement, is reliably in meshing engagement with the associated steering pinion and does not slide off laterally. Expediently, the peripheral toothing of each steering pinion is radially extended beyond and around by two annular supporting walls associated therewith. In this way, a lateral support of the toothed belt can be achieved over the total material thickness of the toothed belt.

For better differentiation, the two supporting walls associated with one and the same peripheral tooth are also referred to as inner supporting wall and outer supporting wall in the following. The inner support wall is located axially inwardly of the outer peripheral toothing and faces the respective other steering pinion of the same steering pinion unit, while the outer support wall is located axially outwardly of the outer peripheral toothing with respect to the opposite thereof. Each steering pinion unit therefore has two inner support walls, each of which belongs to one of the two steering pinions, and an outer support wall is arranged axially on the outside relative to the inner support wall and axially spaced apart from the latter.

Preferably, the two annular inner support walls of the steering pinion unit are each formed by two semicircular ring segments separated with respect to the pinion shaft, which are placed radially outward from diametrically opposite sides of each other to the pinion shaft, so that they jointly form an annular structure coaxially surrounding the pinion shaft. The annular structure can have small gaps in the transition region between the two annular sections, depending on the circumferential extension of the semicircular annular section. The annular section is fixed to the pinion shaft so that it can participate in the rotational movement of the pinion shaft and at the same time can perform its supporting task with respect to the associated toothed belt. Although the inner supporting wall is arranged in the region axially inside the teeth, it can be fitted comfortably and precisely by the division.

In an expedient embodiment, the semicircular ring segments of the two steering pinions belonging to the same steering pinion unit, which form the inner supporting wall, are formed separately from one another. In this case, the ring section belonging to one steering pinion is arranged axially spaced apart from the likewise separately formed ring section of the other steering pinion. When assembling the steering pinion unit, the ring segments can be fixed independently of one another at the pinion shaft.

Preferably, each semicircular annular section has a semicircular support section which directly defines the peripheral section of the associated inner support wall and furthermore has a semicircular retaining section which is arranged radially inwardly of the semicircular support section. Each annular portion is inserted with a semicircular retaining portion into an annular groove of the pinion shaft that is open on the outside in the radial direction and is fixed in the annular groove that is coaxial with respect to the pinion shaft.

The retaining section of the semicircular annular section can be fixed in an associated annular groove of the pinion shaft, for example, by an adhesive or welded connection. However, it is considered advantageous if the annular groove has an undercut cross section and each annular segment has a stepped outer contour, so that the annular segments are supported in the annular groove in a radial direction with respect to the axis of rotation.

The annular groove preferably has a groove section, referred to as an assembly section, which is open on the radial outside and also has a further groove section, which is axially coupled in the pinion shaft to the assembly section, is referred to as a fixing section and is bounded on the radial outside by a section of the pinion shaft. The fastening section is therefore configured in the pinion shaft to some extent according to the type of an annular groove which is axially open only on one side, wherein the open side of the fastening section merges into a mounting section which is open toward the radial outer circumference of the pinion shaft. The retaining section of the ring section, which is recessed radially from the outside into the mounting section, projects beyond the associated supporting section of the same ring section in such a way that it projects axially into the fastening section of the ring groove and is supported radially in relation to the pinion shaft in said fastening section.

Expediently, the cross section of the annular groove and the cross section of the respective annular section are adapted to one another in such a way that the retaining section of each annular section bears with its radially outer face against a radially inwardly directed bearing face of the pinion shaft, which radially outwardly delimits the fixing section of the annular groove. Preferably, however, each annular portion has an inner diameter which is slightly larger than the inner diameter of the groove base of the annular groove, so that there is at least a small radial distance between the radially inner face of each annular portion and the groove base of the annular groove lying opposite it.

The two annular sections, which together form the inner support wall, are expediently axially fixed in position on the pinion shaft by means of a spring-elastic retaining ring. The spring-elastic retaining ring is open at one point on its circumference, so that the retaining ring can be inserted onto the pinion shaft in the radial direction in the temporarily elastically expanded condition. Preferably, a locking groove is formed coaxially in the pinion shaft, to be precise on the side of the ring segment facing axially away from the outer circumferential toothing, into which the locking ring can be inserted or is inserted. Thereby, the ring segment is supported by the ring segment at its side axially facing away from the teeth of the outer circumference. On the opposite axial side, the ring segments are expediently supported on the associated peripheral toothing.

In an equally advantageous manner and method of realizing the annular inner support wall by means of a semicircular annular section, it is provided that the annular sections of the two steering pinions are integrated in pairs into a one-piece support housing having a semicircular cross section. The steering pinion unit has two such support shells, on the axial end regions of which one of the ring segments is arranged in each case, and which, in the region of the pinion shaft axially between two mutually spaced-apart peripheral teeth, are placed radially outward from the sides diametrically opposite one another in the region of the pinion shaft forming a sleeve structure and are fixed on the pinion shaft.

Depending on the length of the peripheral extension of the support shells, small gaps can be present in the transition regions between the support shells.

Preferably, the annular section of the respective support shell is formed by a semicircular radial projection which is formed in one piece in the region of the mutually opposite end sides of the shell-shaped connecting section of the support shell.

For fastening at the pinion shaft, the two support shells are preferably held together by means of fastening threaded fasteners which connect them directly and extend peripherally alongside the pinion shaft, so that a sleeve structure is obtained and the two support shells are radially clamped to the pinion shaft. In this connection, it is advantageous if the circumferential extensions of the support shells are each slightly less than 180 °, so that a small gap is formed in the transition region between the support shells, which ensures that the support shells clamp sufficiently firmly against the outer circumference of the pinion shaft when the fastening screw fastener is tightened.

The annular outer support wall of the steering pinion unit is expediently designed as a separate component with respect to the pinion shaft, as is the inner support wall. The outer support wall of each ring is formed in this respect by an uninterrupted support ring which is coaxial with respect to the pinion shaft. The support ring can be comfortably inserted onto the pinion shaft from the outside of the shaft when assembling the linear drive. Therefore, the division is omitted here.

Each support ring is expediently axially fixed on the pinion shaft by means of a rolling bearing for the rotational mounting of the steering pinion unit with respect to the driver housing. The rolling bearings are plugged onto the pinion shaft on the opposite side of the support ring from the teeth of the outer circumference. Thereby, the support ring is axially arranged and fixed between the outer circumferential toothing and the rolling bearing.

Drawings

The invention will be explained in more detail below with reference to the attached drawings. Wherein:

fig. 1 shows a perspective illustration of a preferred embodiment of an electrical linear drive according to the invention, wherein the electrical drive of the linear drive is indicated only by a dot-dash line,

figure 2 shows the linear drive from figure 1 in a longitudinal section according to section line II-II from figure 1,

figure 3 shows the linear drive from figure 1 in a cross section according to section line III-III in the steering region equipped with a steering pinion unit,

fig. 4 shows a perspective single illustration of an assembly of a preferred embodiment of a steering pinion unit and two rolling bearings arranged on the steering pinion unit,

figure 5 shows a side view of the assembly from figure 4 in a viewing direction according to arrow V from figure 4,

fig. 6 shows a longitudinal section through the assembly from fig. 5 according to section line VI-VI from fig. 5, wherein the dashed framed part is also shown enlarged again in isolation,

figure 7 shows a cross-section according to section line VII-VII from figure 6,

figure 8 shows a cross-section according to section line VIII-VIII from figure 6,

figure 9 shows a single illustration in perspective alternative to the embodiment of figures 4 to 6 of a combination comprising a preferred further embodiment of a steering pinion unit,

figure 10 shows the assembly from figure 9 in a side view in the viewing direction according to arrow X from figure 9,

figure 11 shows a further side view of the assembly from figure 9 in the direction of the arrow XI from figure 9,

fig. 12 shows a longitudinal section through the assembly from fig. 10, with a section line XII-XII from fig. 10, wherein the dashed-dotted framed part is also shown enlarged again in isolation,

FIG. 13 shows a cross-section according to section line XIII-XIII from FIG. 12, an

Fig. 14 shows a cross section according to section line XIV-XIV from fig. 12.

Detailed Description

An electric linear drive, generally designated by reference numeral 1, has a housing, referred to as a drive housing 3, with a longitudinal extension, which extends along an imaginary longitudinal axis 2. In the following, the axial direction of the longitudinal axis 2 is also referred to as longitudinal direction 2 a.

Preferably, the drive housing 3 comprises a strip-shaped (strangförmig) hollow profile part 11 extending in the longitudinal direction 2a, on whose two mutually opposite end sides one of the two end caps 4, 5 is respectively seated, which is also referred to as first end cap 4 and second end cap 5 for better differentiation in the following.

A deflection region 6, 7, in which two first and second toothed belts 8, 9 extending in the longitudinal direction 2a within the drive housing 3 are deflected, is located within the respective end cap 4, 5. The deflecting region 6 in the first end cap 4 is also referred to below as the first deflecting region 6, and the deflecting region 7 formed in the second end cap 5 is also referred to as the second deflecting region 7.

In each of the two deflection regions 6, 7, two deflection rollers 12, 13 are located, which can be rotated relative to the drive housing 3 about a rotation axis 14, wherein the rotation axis 14 coincides with an axial direction of an imaginary transverse axis 15 of the drive housing 3, which is orthogonal to the longitudinal axis 2. The two deflecting rollers 12, 13 arranged in the same deflecting zone 6, 7 are oriented coaxially to each other and spaced apart from each other in the transverse direction 15 a.

Expediently, in each deflection region 6, 7 there is a rotary bearing 19 via which the deflection rollers 12, 13 in the same deflection region 6, 7 are mounted at the drive housing 3 so as to be rotatable about the axis of rotation 14 relative to the drive housing.

The steering rollers 12, 13 of the two steering zones 6, 7 are designed as steering pinions (Umlenkritzel), wherein the steering pinions associated with the same steering zone 6, 7 are also referred to as a first steering pinion 16 and a second steering pinion 17 for better differentiation.

Each steering pinion 16, 17 has at its radially outer periphery an outer peripheral toothed portion 18 which is coaxial with the axis of rotation 14. The toothing 18 is expediently designed as a straight toothing whose teeth and tooth interspaces have a longitudinal extension parallel to the longitudinal axis 14.

The steering pinions 16, 17 associated with the same steering region 6, 7 are combined to form a steering pinion unit 22 that can be rotated uniformly about the axis of rotation 14. Each steering pinion unit 22 has a longitudinal axis 23 coinciding with the associated axis of rotation 14, which simultaneously defines the longitudinal axis of each steering pinion 16, 17.

Within the steering pinion unit 22, the two steering pinions 16, 17 are arranged spaced apart from one another in the axial direction of the longitudinal axis 23.

The bearing device 19 comprises, for example, two rolling bearings 24, which each run between one of two axial end regions 25 of the steering pinion unit 22 and the drive housing 3. No further bearing means for the rotary bearing of the steering pinion unit 22 are present.

Each toothed belt 8, 9 extends in a plane orthogonal to the axis of rotation 14, which is referred to as a first revolution plane 8a in the case of the first toothed belt 8 and as a second revolution plane 9a in the case of the second toothed belt 9. The two planes of revolution 8a, 9a are arranged parallel to one another and at a distance from one another. The first steering pinions 16 of the two steering pinion units 22 lie in the first swivel plane 8a, while the second steering pinions 17 of the two steering pinion units 22 lie in the second swivel plane 9 a. The first toothed belt 8 is wound around the two first steering pinions 16, and the second toothed belt 9 is wound around the two second steering pinions 17. The two toothed belts 8, 9 are thereby arranged side by side with a spacing in the transverse direction 15 a.

Each toothed belt 8, 9 has at its inner side a toothed section 26 which is in meshing engagement with the toothed sections 18 of the outer circumference of the two steering pinions 16, 17 wound by the toothed belts.

Each toothed belt 8, 9 has two belt run- back sections 27, 28, which extend between the two deflection regions 6, 7 and in particular within the drive housing 3. In each case a follower slide 32 of the linear drive 1 is fastened to the first belt path section 27 of the two belt path sections 27, 28, said follower slide being mounted linearly displaceably in the longitudinal direction 2a directly or indirectly at the drive housing 3. The displacement bearing provided for this purpose is shown at 33 and comprises, for example, one or more guide rails 34 fixed to the drive housing 3, on which the output slide 32 is mounted so as to be linearly displaceable. Preferably, the at least one guide track 34 is arranged inside the hollow profile part 11 and is fixed at the hollow profile part 11.

The electric linear drive 1 expediently comprises an electric drive 35, indicated by dashed lines in fig. 1, by means of which the output slide 32 can be driven in one or the other axial direction in a linear output movement 36 following the longitudinal direction 2 a. At the output slide 32, at least one fastening interface 37 is located, at which a component to be moved by the output slide 32, for example a machine component, can be fastened.

According to the preferred embodiment shown, the drive force generated by the electric drive 35 is transmitted to the output slide 32 with the two toothed belts 8, 9 connected in between. The drive device 35 is arranged at the drive housing 3 and has a rotatably drivable drive shaft 39 indicated by a dashed line in fig. 3, which is in rotary drive connection with the steering pinion unit 22 arranged in the first steering region 6. The electric drive unit 35 comprises, in particular, an electric motor, for example a stepping motor or a servomotor. The electric drive unit is attached in particular externally to the first end cap 4, expediently to one of the two end faces of the end cap 4 oriented orthogonally to the longitudinal axis 2. Illustratively, there are the following advantageous possibilities: the drive unit 35 is fitted at each of the two aforementioned end faces of each of the two end caps 4, 5.

When the steering pinion unit 22 driven by the electric drive 35 rotates about its longitudinal axis 14, this causes a uniform revolving movement 38, indicated by the double arrow, of the two toothed belts 8, 9 in the two revolving planes 8a, 9a in one or the other direction, wherein the first belt revolving section 27 acting on the output slide 32 is always displaced in the same axial direction, so that the output slide 32 is entrained by the execution of its output movement 36.

Next, a preferred embodiment of the steering pinion gear unit 22 will be described. It is advantageous if such a steering pinion unit 22 is arranged in each steering region 6, 7 and if the two steering pinion units 22 are of identical design to one another, this applies to the exemplary embodiment shown. In this regard, additional description can be limited to one of the steering pinion units 22.

In a not shown embodiment of the electric linear drive 1, only one of the two steering regions 6, 7 is equipped with a steering pinion unit 22. In the other steering region, two separate rotatable steering pinions or alternatively two rotatable gearless steering rollers, which are likewise independent of one another, are instead present.

Fig. 4 to 8 show a preferred first exemplary embodiment of the steering pinion unit 22, while fig. 9 to 12 show an equally preferred second exemplary embodiment of the steering pinion unit 22. In the case of a paired use of the steering pinion units 22, it is expedient if the two steering pinion units 22 are of identical design.

The description relates to two exemplary embodiments of the steering pinion unit 22, as long as they are not explained differently in individual cases.

The steering pinion unit 22 is characterized in that it has a one-piece pinion shaft 42, in which the peripheral toothed sections 18 of the two steering pinions 16, 17 are integrally formed. The two peripheral teeth 18 are thus formed directly into the one-piece pinion shaft 42, wherein the peripheral teeth are produced in particular by a cutting method. Prototype-forming manufacturing by material-dependent pressure casting or injection molding is likewise possible.

The outer circumferential toothing 18 is expediently situated radially outside at a length section of the pinion shaft 42, which is referred to below as the toothing-length section 43, which projects radially outward with respect to the length section of the pinion shaft 42 that is axially coupled on both sides. Each tooth-length section 43 represents to some extent an annular collar (ringburn) which is provided with teeth 18 at the radial outer periphery.

Each steering pinion 16, 17 has an annular inner support wall 44 on the axial inner side of the outer peripheral toothing 18 facing the respective other steering pinion 17, 16 of the same steering pinion unit 22. On the opposite axial outer side of each peripheral tooth 18 there is an outer support wall 45, which is likewise annular. Said support walls 44, 45 are coaxially arranged with respect to said longitudinal axis 23.

The teeth 18 of each outer circumference are thereby axially flanked on both sides by annular supporting walls, more precisely by the inner supporting wall 44 and by the outer supporting wall 45. The support walls 44, 45 of each steering pinion 16, 17 delimit an annular guide space 46 in which the length section of the toothed belt 8, 9 that is currently wound around the steering pinion 16, 17 runs, wherein the toothed belt 8, 9 is laterally supported by the two support walls 44, 45 so that it cannot slide laterally from the peripheral toothing 18 downward.

The clear distance between the two support walls 44, 45 is preferably slightly greater than the width of the toothed belts 8, 9, so that they are guided in their revolving movement 38 without any significant friction.

In an embodiment not shown, the support walls 44, 45 have radially outward extensions like the peripheral teeth 18. Advantageously, however, according to the embodiment shown, the peripheral toothing 18 of each steering pinion 16, 17 is radially extended beyond, annularly around the longitudinal axis 23, by two annular support walls 44, 45 associated therewith.

It is particularly advantageous if the two support walls 44, 45 are inclined at the inner faces facing one another in such a way that the guide space 46 widens radially outward. In this way, a secure penetration of the toothed belt into the guide space 46 is ensured in the case of the revolving movement 38.

In both embodiments, the annular outer support wall 45 is expediently formed by a support ring 47 which is uninterrupted in its peripheral direction and which is a separate structural component with respect to the pinion shaft 42 and which, when it is assembled, is inserted axially outward onto the pinion shaft 42 in the axial direction of the longitudinal axis 23.

Expediently, each support ring 47 is seated on one of two outer end sections 48 of the pinion shaft 42 axially opposite one another, which are each coupled to one of the tooth-length sections 43 and have a smaller diameter in relation thereto.

Each support ring 47 is pushed axially onto the outer end section 48, in particular to such an extent that it bears against the end face of the tooth length section 43 of the pinion shaft 42, which has the larger outer diameter, facing the support ring.

The support ring 47 can be pushed up, for example, optionally pressed on or with a clearance fit.

Expediently, the rolling bearings 24 mounted at the axial end regions 25 serve to fix each support ring 47 axially immovably with respect to the pinion shaft 42. The same rolling bearing with its inner ring 52 is pushed onto the outer end section 48 on the side of the support ring 47 axially opposite the tooth-length section 43, so that it presses the support ring 47 against the axial end face of the tooth-length section 43.

Preferably, the annular body of the support ring 47 has an L-shaped cross section. One of the L legs forms the outer support wall 45. The other L-leg forms a sleeve-shaped fastening section 53 which coaxially surrounds the outer end section 48.

The inner supporting wall 44 is formed by a separate structural component from the pinion shaft 42, which is not subsequently placed on the pinion shaft 42 until after the manufacture of the outer peripheral toothing 18, which facilitates the simple production of the outer peripheral toothing 18.

The length section of the pinion shaft 42, which is axially between the two outer circumferential teeth and is referred to below as the intermediate section 54, is radially constricted and has a smaller diameter than the two tooth/length sections 43 connected thereto.

Each inner support wall 44 is divided in its circumferential direction and is composed of two semicircular annular sections 55, 56 which are separated with respect to the pinion shaft 42. The two ring segments 55, 56 are placed radially outward from the diametrically opposite sides of the pinion shaft 42 to the pinion shaft 42 and are fixed to the pinion shaft 42, forming a ring structure 57.

Thus, although the intermediate section 54 carrying the inner support wall 44 has a smaller diameter than the tooth length section 43, the inner support wall 44 can be configured separately from the pinion shaft 42.

In the embodiment of fig. 4 to 8, each inner support wall 44 is formed by two semicircular annular sections 55, 56, which are constructed separately and independently of the annular sections 55, 56 forming the respective other inner support wall 44. The ring segments 55, 56 present can thus be fitted independently of one another at the pinion shaft 42.

Each semicircular annular section 55, 56 has a semicircular supporting section 58, which directly defines a peripheral section of the associated inner support wall 44 extending in the peripheral direction of the longitudinal axis 23, and a semicircular retaining section 62, which is arranged radially inwardly in one piece at the semicircular supporting section 58. In the pinion shaft 42, a radially outwardly open annular groove 63 is formed in the intermediate portion 54 directly connected to each tooth-length portion 43, said annular groove being arranged coaxially with respect to the longitudinal axis 23. The two associated annular segments 55, 56 are inserted with their retaining sections 62 into each of the two annular grooves 63. The ring segments 55, 56 are fixed independently of one another in the associated ring groove 63 via the retaining sections 62.

Preferably, the annular body of each annular section 55, 56 has a substantially L-shaped cross-sectional profile with a first L-leg forming said support section 58 extending in a plane orthogonal to said longitudinal axis 23 and a second L-leg forming said retaining section 62, said second L-leg being axially oriented in the axial direction of said longitudinal axis 23.

The annular groove 63 has an undercut cross section, which is formed by a fitting section 64 that is open toward the radially outer peripheral surface of the pinion shaft 42 and a fixing section 65 that is axially coupled to the fitting section 64. The fastening section 65 is embodied in the material of the pinion shaft 42 as an axially open annular groove and is open toward the mounting section 64.

The fastening section 65 is bounded radially on the outside by an outer annular surface 66 of the pinion shaft 42 pointing radially inward, while the mounting section 64 is bounded radially on the inside by an annular groove base 67 of the pinion shaft 42 pointing radially outward. The undercut cross section of the annular groove 63 is thus represented in the present exemplary embodiment by an L-shaped cross-sectional contour.

Each annular portion 55, 56 is inserted with its retaining portion 62 from the radially outer side into a mounting portion 64 of the annular groove 63 and is displaced within the annular groove 63 in the direction of the associated peripheral toothing 18 in such a way that the retaining portion 62 projects axially into a fastening portion 65 of the annular groove 63.

Each annular portion 55, 56 is thereby prevented from falling radially out of the annular groove 63 by the retaining portion 62 projecting into the fastening portion 65.

Preferably, the retaining section 62 is designed such that its radial outer face 68 has a diameter which at least substantially corresponds to the diameter of the radially inwardly directed outer annular face 66 of the fastening section 65. In this way, the radially inwardly directed outer annular surface 66 forms an annular support surface 66a, against which the annular segments 55, 56 can be supported with their radial outer surfaces 68 of the holding sections 62 with coaxial centering.

Preferably, the radial thickness of the retaining section 62 is slightly smaller than the radial distance between the support surface 66a and the groove bottom 67, so that an annular gap remains radially between the annular portions 55, 56 and the groove bottom 67.

Preferably, at least a narrow intermediate space 69 is present in each of the two transition regions of the two annular portions 55, 56, which are arranged diametrically opposite to one another with respect to the longitudinal axis 23, in the peripheral region of the pinion shaft 42. This ensures that the two annular sections 55, 56 do not abut one another and are oriented independently of one another with respect to the pinion shaft 42.

The two annular portions 55, 56, which each form the inner support wall 44, are preferably held in the annular groove 63 in an axially immovable manner by a spring-elastic retaining ring 72. An annular stop groove 73, which is likewise formed in the pinion shaft 42 and is open radially on the outside and into which the stop ring 72 engages from the radially outside, is coupled to each annular groove 63 on the side axially opposite the tooth length portion 43.

A spring-elastic stop ring 72, which can be seen well, for example, from fig. 8, has a discontinuity 74 at one point of its circumference, the circumferential length of which is dimensioned such that the stop ring 72 extends only slightly over 180 ° around the longitudinal axis 23. During assembly, the locking ring 72 is pressed onto the pinion shaft 42 from the radially outer side, so that it expands for a short time until it snaps into the locking groove 73.

The stop ring 72 is mounted in such a way that it axially supports the two adjacent ring segments 55, 56 and presses them against the facing end faces of the tooth length sections 43. In this way, the ring segments 55, 56 are held in the ring groove 63 in a loss-proof manner.

In the exemplary embodiment of fig. 9 to 12, the ring segments 55, 56 of one inner support wall 44 are each connected to the ring segments 55, 56 of the axially spaced-apart other inner support wall 44 to form a one-piece structural unit which has the shape of a shell which is semicircular in cross section and is therefore referred to as a support shell 75, 76.

The steering pinion unit 22 has two such bearing shells 75, 76, wherein the two first annular sections 55 of the two inner bearing walls 44 form the first bearing shell 75 and the two second annular sections 56 of the two inner bearing walls 44 form the second bearing shell 76.

Each support shell 75, 76 has at its two mutually opposite end sides a semicircular radial projection 77 which represents one of the ring segments 55, 56 and which projects radially outward from a shell-shaped connecting section 78, which is semicircular in cross section, of the associated support shell 75, 76.

The two support shells 75, 76 are placed with their concave sides in the intermediate section 54 from the diametrically opposite sides to the pinion shaft 42 radially outside, so that they jointly form a sleeve structure 82 which coaxially surrounds the pinion shaft 42.

The axial length of the support shells 75, 76 is dimensioned such that the radial projection 77 delimiting the annular sections 55, 56 is located directly next to one of the peripheral teeth 18 on the axial inner side. Preferably, the supporting shells 75, 76 engage with a clearance fit between the end faces of the two tooth-length sections 43 facing each other.

In principle, the two supporting shells 75, 76 can be fixed to the pinion shaft 42 in any manner. A particularly advantageous type of fastening, which is achieved in the present exemplary embodiment, provides that no fastening elements act directly between the support shells 75, 76 and the pinion shaft 42, but rather that the two support shells 75, 76 are held together by means of fastening threaded fasteners 83 which connect them directly and extend peripherally next to the pinion shaft 42 and at the same time are clamped radially to the outer periphery of the pinion shaft 42.

In each case two transition regions between the two support shells 75, 76, at least one fastening screw 83 is preferably arranged, which is supported with its screw head on the first support shell 75 and is screwed with its threaded shank into the second support shell 76. The longitudinal axis of the fixed threaded fastener 83 is preferably oriented tangentially to the intermediate section 54 of the pinion shaft 42. The screw head of the fastening screw 83 is expediently accommodated in the connecting section 78 in a sunk manner.

Preferably, at least narrow intermediate spaces 84 are respectively present in the transition regions of the two support shells 75, 76, which are arranged diametrically opposite one another with respect to the longitudinal axis 23, in the peripheral region of the pinion shaft 42. It is thereby ensured that the two bearing shells 75, 76 do not bear against one another and can be clamped by the fastening screw 83 against the outer circumference of the pinion shaft 42 in a manner fixed relative to the pinion shaft.

The curvature at the inner side of the support shells 75, 76 facing the radial direction of the pinion shaft 42 is at least partially the same as the curvature of the outer face of the associated length section of the pinion shaft 42. Thereby, the support shells 75, 76 are arranged concentrically on the pinion shaft 42. The curvature equality mentioned preferably occurs at least between the two axial end sections of the support shells 75, 76 and the length section of the intermediate section 54 which is adjacent to the end sections radially inwardly and is in each case coupled to one of the peripheral teeth 18.