Linear actuator, housing, actuation system and method of assembly

Abstract

The invention relates to a linear actuator (1), a housing (8) for such a linear actuator (1), an actuation system (50) and a method (100) for assembling a linear actuator (1). A linear actuator (1) comprises an actuating mechanism (2) and a housing (8). The actuation mechanism (2) comprises a spindle (3) and a nut (5), the actuation mechanism (2) being configured to convert a rotational motion into a translational motion. The housing (8) comprises two housing parts (8a, 8b), wherein the actuating mechanism (2) is at least partially arranged in the housing (8). According to the invention, the two housing parts (8a, 8b) form a plurality of separate cavities (11a-f) configured to accommodate individual components of the linear actuator (1), in particular individual components of the actuating mechanism (2).

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202110784413.3, titled "Linear Actuator, Housing, Actuation System and Assembly Method", with a filing date of July 12, 2021. Technical Field

[0002] The present invention relates to a linear actuator, a housing for such a linear actuator, an actuation system, and a method for assembling such a linear actuator. Background Art

[0003] Linear actuators are used to convert a rotational movement (such as the rotational movement of an electric motor) into a translational movement (such as the extension or retraction of an output member, such as a push rod). In order to enable linear actuators to be flexibly used for and / or adapted to a variety of different tasks, such linear actuators are typically designed in a modular manner. This results in a large number of variants of such linear actuators.

[0004] However, such (modular) linear actuators can become very complex and include multiple interacting components. For example, a basic ball screw mechanism already includes a threaded spindle and a nut, the nut having an inner raceway for a plurality of balls and a mechanism for recycling the balls, the nut being arranged radially around the spindle. Rotatably mounting the spindle typically requires corresponding bearings.

[0005] To protect these components from the environment, linear actuators typically include a housing in which the actuation mechanism is arranged. The shapes of these housings are typically adapted to the respective variants of the linear actuator and / or the tasks for which the linear actuator is used. Summary of the Invention

[0006] The object of the present invention is to improve linear actuators, in particular to simplify linear actuators and / or allow for simplified assembly thereof.

[0007] This object is solved by a linear actuator, a housing for the linear actuator, an actuation system, and a method for assembling the linear actuator according to the independent claims.

[0008] A first aspect of the present invention relates to a linear actuator, including an actuation mechanism and a housing. The actuation mechanism includes a spindle and a nut, and the actuation mechanism is configured to convert a rotational movement into a translational movement. The housing includes two housing parts, wherein the actuation mechanism is at least partially arranged in the housing. According to the present invention, the two housing parts form a plurality of independent cavities, the cavities being configured to accommodate the respective components of the linear actuator, in particular the respective components of the actuation mechanism.

[0009] In the context of the present invention, the cavity, which is specifically formed by two housing parts, is the hollow space inside the housing. Among them, the plurality of cavities are preferably not closed cavities. Instead, the cavities can be connected such that the components accommodated therein can interact with each other. In addition, it is possible for some components to extend through more than one cavity. For example, the main shaft can pass through the cavity where the bearing for rotatably mounting the main shaft is located and enter the cavity where the nut is located. In other words, the cavities can at least partially overlap and / or merge with each other.

[0010] One aspect of the present invention is based on a method of providing a housing for a linear actuator, the housing comprising two housing parts, in particular two half-housings, wherein the two housing parts are preferably separable along the actuation axis of the linear actuator. Here, the actuation axis of the linear actuator is in particular the axis along which the components of the actuation mechanism (e.g., the main shaft or the nut) and / or the output member of the linear actuator (e.g., the piston or the rod) translate. Preferably, the actuation axis also corresponds respectively to the rotation axis of the actuation mechanism (in particular the nut or the main shaft).

[0011] Furthermore, the two housing parts are preferably configured to form a plurality of independent cavities during assembly for accommodating the respective components of the linear actuator, in particular the components of the actuation mechanism of the linear actuator and / or the components of the drive unit of the linear actuator. For example, one of the cavities can accommodate the nut of the actuation mechanism, while another cavity can accommodate at least a part of the main shaft of the actuation mechanism. By means of the plurality of cavities formed by the two housing parts, at least a part of the respective components of the linear actuator can be placed (in particular translationally fixed) without any additional fastening means or fixing means, such as (elastic) rings, screws, pins, washers and / or the like, thereby simplifying the linear actuator. In other words, the cavities can serve as a base for at least a part of the components. This allows for a reduction in the parts of the linear actuator and / or particularly rapid assembly, making the linear actuator suitable for mass production.

[0012] Preferably, the plurality of independent cavities are configured to hold the respective parts of the linear actuator (in particular the actuation mechanism) in place even during operation of the linear actuator, in particular to at least partially enclose it. Among them, at least a part of the cavity can allow the rotational movement of the accommodated component. Preferably, the plurality of independent cavities are configured to place the components of the linear actuator, in particular the actuation mechanism, according to their functional relationship. For example, the bearing can be arranged to rotatably mount the main shaft relative to the housing by being accommodated in a corresponding cavity concentric with the main shaft.

[0013] In order to achieve a specific fixed base for the components, the shape of the accommodation cavity can be at least substantially defined by the shape of the components. In other words, at least a part of the cavity can be shaped according to the shape of the accommodated component.

[0014] In the following, preferred embodiments of the present invention and modifications thereof will be described, which can be combined with each other or with other aspects of the present invention, as long as they are not explicitly excluded.

[0015] In a preferred embodiment, the two housing parts include an inner wall that separates at least a part of a plurality of independent cavities. Preferably, at least a part of the inner wall is configured to fixedly hold components of an actuation mechanism received by the respective cavity in a translational manner. In other words, at least a part of the components can be held by the respective cavity. Preferably, the inner wall is integral with the two housing parts. To allow interaction between the individual components, the inner wall may include openings through which at least a part of the components may extend at least partially. For example, a spindle may extend from a cavity in which a bearing for rotatably mounting the spindle is located through an opening in the inner wall into a cavity in which a nut is located. By providing the inner wall, the components of the linear actuator, in particular the actuation mechanism, can be arranged in one of the housing parts in a particularly precise manner.

[0016] In another preferred embodiment, at least one of the two housing parts includes an axially extending mating component configured to interact with a corresponding mating component of the nut such that the nut is held against rotation. In this case, the axis preferably relates to the actuation axis of the actuation mechanism. In this way, the nut can be reliably held against rotation without any additional means.

[0017] Preferably, the mating components are complementary. For example, one of the housing parts may include an elongate protrusion extending axially within a cavity for receiving the nut, and the nut may include a groove extending axially on its outer surface. During assembly, the protrusion can be inserted into the groove to rotationally lock the nut relative to the housing while allowing the nut to translate axially. In this way, a particularly simple locking device can be achieved. In addition, the complementary mating components can contribute to correctly positioning the nut relative to the housing part during assembly.

[0018] In yet another preferred embodiment, the linear actuator further includes a motor connected to the actuation mechanism, and at least one of the two housing parts includes an external protrusion for supporting the motor connected to the actuation mechanism. In particular, the external protrusion can be configured to support the motor when the motor is fixed to the housing by a connection part of the motor or by screws. In this way, if the motor is horizontally oriented, the load caused by the weight of the motor can be borne by the connection part and the part of the housing to which the motor is fixed.

[0019] In yet another preferred embodiment, the linear actuator further comprises a drive unit for connecting the electric motor to the actuating mechanism. Preferably, the drive unit includes an input pulley engageable with the motor shaft of the electric motor, an output pulley connected to the actuating mechanism, and a belt running on the input pulley and the output pulley. Herein, "engageable with the motor shaft" shall be understood as "configured to be connected to the motor shaft". In other words, by connecting the motor shaft to the input pulley (e.g., by inserting the motor shaft into the axial hole of the input pulley), the motor shaft can be connected to the actuating mechanism, particularly the drive unit. Preferably, the input pulley, particularly the axial hole, is configured to be rotationally connected to the motor shaft by form fit.

[0020] In yet another preferred embodiment, the output pulley is particularly directly connected to the spindle, wherein the input pulley and / or the output pulley includes two axially extending studs. Preferably, a bearing is press-fitted onto each of the two studs to rotatably mount the input pulley and / or the output pulley and the spindle in the housing, respectively. In other words, the input pulley and / or the output pulley is preferably configured to carry bearings on two axially extending studs. This enables a particularly compact structural arrangement without any additional fastening means.

[0021] To save costs and production time, the output pulley including two studs can be manufactured by casting.

[0022] To make the assembly of the linear actuator particularly easy, the drive unit, particularly the input pulley and / or the output pulley, is fixed in the housing, particularly in two housing parts, by a separate cavity that houses a bearing press-fitted (particularly in a form-fitting manner) onto the axially extending studs. In particular, the bearing can be form-fittingly mounted in a separate cavity formed by the two housing parts.

[0023] In yet another preferred embodiment, the input pulley and / or the output pulley includes a plurality of ribs axially extending on the circumferential surface of each of the two studs. This can simplify the press-fitting of the bearing onto the stud and / or provide a particularly firm base for the bearing on the stud.

[0024] In another preferred embodiment, the output pulley is press-fitted onto the spindle. In this way, a particularly quick assembly without additional fastening means becomes possible, and the assembled linear actuator includes a smaller number of parts compared to conventional actuators.

[0025] Preferably, the spindle includes knurling, particularly in the portion near the spindle thread. This allows the output pulley to have a specific fixing seat on the spindle without any additional fastening means.

[0026] In another preferred embodiment, each of the input pulley and the output pulley includes a pulley ring for guiding a belt, and the pulley rings are disposed at opposite ends of the two pulleys. That is, the pulley ring of the input pulley is preferably disposed at the axial end of the input pulley, which is opposite to the axial end of the output pulley, and the pulley ring of the output pulley is disposed on the axial end of the output pulley. In other words, the two pulley rings are disposed at corresponding ends of the input and output pulleys facing away from each other. For example, the output pulley may include a pulley ring disposed at the axial end of the output pulley facing the actuating mechanism, while the input pulley may include a pulley ring disposed at the axial end of the output pulley facing the opposite direction (i.e., away from the actuating mechanism). In this way, the pulley rings for guiding the belt can be distributed on the two pulleys. In return, each pulley may be more compact. In addition, since in this embodiment, each pulley only includes one pulley ring, the assembly of the drive unit can be facilitated by allowing the belt to slide axially onto each pulley (i.e., it is not necessary to lift the belt over the pulley ring).

[0027] In another preferred embodiment, the linear actuator includes an output member (particularly a push rod connected to the actuating mechanism) and a guiding member slidably mounted on the output member for supporting the output member on the housing. The guiding member may be annular, particularly configured in the form of a hollow cylinder. The guiding member is preferably configured to guide the sliding movement of the output member relative to the housing. For this purpose, the guiding member is preferably received in a corresponding cavity formed by two housing portions. By means of the guiding member, the friction can be reduced compared to an assembly in which the push rod is directly supported on the housing. At the same time, the space requirement can be significantly reduced compared to mounting the output member by means of bearings.

[0028] In another embodiment, the guiding member includes a convex outer surface. The convex outer surface is preferably configured to be supported on the housing. Further preferably, the two housing portions form a cavity having a radially inner surface complementary to the convex outer surface of the guiding member. By this method, the output member can be reliably supported even under non-axial loads.

[0029] In another preferred embodiment, each of the two housing portions includes a rear projection, and the two rear projections form a U-shaped clip for attaching the linear actuator. The rear projections are preferably integrated into the corresponding housing portion, i.e., integrally formed with the housing portion. This enables particularly quick and easy but secure integration into, for example, a production line using a minimum of additional fastening means.

[0030] Preferably, the rear projections are symmetrically arranged with respect to the contact surface defined by the two housing portions. This can simplify the production of the housing portions, particularly in the case where the two housing portions are integrally symmetric, for example by casting.

[0031] In another preferred embodiment, each of the two housing parts is cast from a plastic material, in particular nylon. This allows for quick, inexpensive but accurate production of the two housing parts. In addition, a particularly lightweight housing can be achieved. Alternatively, each of the two housing parts is made of a metallic material, in particular aluminum. This also allows for a particularly durable housing.

[0032] In another preferred embodiment, each of the two housing parts includes an axial through-hole configured to receive fastening screws for mounting the electric motor to the housing, wherein each axial through-hole receives a support tube configured to support the respective fastening screw on the housing. The axial through-holes, in particular four axial screw holes, may be arranged around at least one cavity for receiving the input pulley and / or associated bearings, and / or the axial through-holes extend substantially parallel to the actuation axis of the linear actuator. The support tube is preferably made of metal, in particular steel, so as to be able to reliably withstand the squeezing force exerted when fastening the screw. In this way, the electric motor can be firmly fixed even to the two housing parts made of, for example, plastic or aluminum, without damaging the housing.

[0033] According to a second aspect of the invention, a housing for a linear actuator, in particular for a linear actuator according to the first aspect of the invention, comprises two housing parts which, in the assembled state of the housing, define a contact surface on which the two housing parts are in substantially contact, wherein the actuation mechanism of the linear actuator is at least partially arranged in the housing, and wherein the two housing parts are configured to receive the actuation mechanism such that the actuation axis of the actuation mechanism is substantially parallel to the contact surface in the assembled state of the housing. The actuation mechanism preferably comprises a spindle and a nut and is configured to convert a rotational movement into a translational movement. The output member may be connected, in particular attached, to the nut. This housing enables the assembly of the linear actuator to be particularly easy and quick.

[0034] Preferably, the two housing parts of the housing according to the second aspect of the invention are configured to form a plurality of separate cavities in the assembled state of the housing, which cavities are configured to receive the respective components of the linear actuator, in particular the actuation mechanism.

[0035] Preferably, each of the two housing parts includes an assembly surface. When assembling the housing, the two assembly surfaces can come into contact and define the contact surface. Preferably, each assembly surface is substantially flat. In this way, it is possible to assemble the linear actuator and the housing particularly simply and accurately. In addition, such housing parts can be made particularly easily and quickly, for example by casting.

[0036] According to a third aspect of the present invention, the actuation system comprises a linear actuator according to the first aspect of the present invention and an electric motor connected to the linear actuator. Preferably, the electric motor comprises a connection part by means of which the electric motor is fixed to the housing.

[0037] In a preferred embodiment, two housing parts form an opening for receiving a motor connection part including a motor shaft, wherein at least one of the two housing parts comprises a groove which extends at least partially within the opening and receives a ring of the motor connection part. The connection part, in particular the ring, may comprise a web and a shroud, wherein the web is arranged radially around the motor shaft and the shroud extends radially from the web. In this way, the electric motor can be hooked into the housing, providing a particularly secure and simple attachment of the electric motor to the housing, in particular without the need for additional fastening means. In other words, the electric motor can be fixed to the housing simply by assembling the two housing parts, in particular by fixing the two housing parts to each other, for example by means of screws passing through axial through-holes in the housing parts or by welding.

[0038] Optionally or additionally, the opening comprises at least one part of the connection part which rotatably fixes the electric motor relative to the housing. For example, the opening may match the non-spherical shape of the connection part of the electric motor, in particular the ring. In particular, the opening may comprise two preferably symmetrical planes which radially support two complementary parts of the connection part. In this way, a particularly simple rotational locking can be achieved, in particular without the need for additional fastening means.

[0039] In another preferred embodiment, the linear actuator of the actuation system comprises a drive unit which connects the electric motor to the actuation mechanism. The drive unit preferably comprises an input pulley connected to the motor shaft of the electric motor, an output pulley connected to the actuation mechanism (in particular the main shaft), and a belt running on the input pulley and the output pulley.

[0040] In another preferred embodiment, the input pulley is directly mounted on the motor shaft. For example, the input pulley can be mounted on the motor shaft in a press-fit manner. For this purpose, the input pulley preferably comprises a tapered hole. This allows for particularly rapid assembly. Optionally, the input pulley can be locked on the motor shaft. In this way, the electric motor can be connected to the drive unit without any additional components, in particular fastening means, thereby minimizing rotational play.

[0041] In another preferred embodiment, the drive unit comprises a connection interface for connecting the input pulley to the motor shaft, wherein the connection interface can be mounted on the motor shaft. Preferably, the input pulley is located on the tapered surface of the connection interface. In addition, the input pulley can be fixed on the tapered surface by means of a nut. The nut can be screwed onto the thread of the connection interface adjacent to the tapered surface. By providing a connection interface with a tapered surface, the assembly of the linear actuator and the drive unit becomes particularly easy.

[0042] According to a fourth aspect of the present invention, a method for assembling a linear actuator, in particular for assembling a linear actuator according to the first aspect of the present invention, comprises the following steps: (i) providing a housing, in particular a housing according to the second aspect of the present invention, the housing comprising two housing parts; (ii) disposing an actuating mechanism in one of the two housing parts, the actuating mechanism comprising a spindle and a nut, the actuating mechanism being configured to convert a rotational movement into a translational movement; and (iii) assembling the housing such that the two housing parts form a plurality of separate cavities that accommodate the respective components of the linear actuator, in particular the actuating mechanism.

[0043] For example, when the two housing parts are arranged to form a plurality of cavities, each of the two housing parts may include axially aligned through holes. The two housing parts can then be fixed by screws passing through the through holes of the two housing parts and tightened with nuts. Alternatively, one of the housing parts may include threaded holes. In this case, the two housing parts can be fixed by screws passing through the through hole of one housing part into the threaded hole of the other housing part. In another alternative, the two housing parts can be welded together, in particular by ultrasonic welding.

[0044] The features and advantages described with respect to the first aspect of the present invention and its preferred embodiments are also valid for the second, third, and fourth aspects of the present invention and their preferred embodiments, and vice versa, if there is no otherwise explicit indication and at least technically meaningful. Description of the Drawings

[0045] Further features, advantages, and possible applications of the present invention will become apparent from the following description in conjunction with the drawings, in which the same reference numerals are used throughout for the same or corresponding parts of the present invention. It is shown at least schematically, wherein:

[0046] Figure 1 is a sectional view of an example of an actuating system;

[0047] Figure 2 is Figure 1 an exploded view of the actuating system in

[0048] Figure 3 is a sectional view of another example of an actuating system;

[0049] Figure 4 is Figure 3 an exploded view of the actuating system in

[0050] Figure 5 is an example of a method for assembling a linear actuator. Detailed Description

[0051] Figure 1 An example of an actuation system 50 including a linear actuator 1 and a motor 9 is shown in a sectional view. The linear actuator 1 includes an actuation mechanism 2 which includes a spindle 3 and a nut 5, wherein the actuation mechanism 2 is configured to convert the rotational movement of the spindle 3 into a translational movement of the nut 5. The linear actuator 1 further includes an output member 7 connected to the actuation mechanism 2, in particular to the nut 5, a housing 8 and a drive unit 10, which is configured to connect the motor 9 to the actuation mechanism 2, in particular to the spindle 3.

[0052] In the present example, the actuation mechanism 2 is configured as a ball screw mechanism. For this purpose, the spindle 3 includes a helical outer raceway 4 for guiding balls arranged between the nut 5 and the spindle 3. On the inner surface 6, the nut 5 preferably includes a corresponding inner raceway in order to couple the rotational movement of the spindle 3 to the translational movement of the nut 5. The nut further includes a mechanism for recirculating the balls from the distal end of the nut 5 (i.e., the end facing away from the motor 9 or the drive unit 10 respectively) to the proximal end (i.e., the end facing the motor 9 or the drive unit 10 respectively), and vice versa. However, in other variants, the actuation mechanism 2 can be configured as a simple drive screw mechanism, wherein the spindle includes an external thread meshing with the internal thread of the nut.

[0053] In the illustrated embodiment, the output member 7 is designed in a sleeve shape such that it can accommodate the spindle 3 at the proximal end. At the opposite distal end, an actuating member 7a is screwed into the sleeve-shaped output member 7. The output member 7 is connected to the nut 5 by an external thread at the proximal end, which external thread meshes with a corresponding internal thread of the nut 5, and the internal thread of the nut 5 is provided in a groove 5a for accommodating the proximal end of the output member 7.

[0054] The housing 8 includes two housing parts, only one of which is shown and indicated in Figure 1 by reference numeral 8a. In the assembled state, the two housing parts form a plurality of separate cavities 11a–d, which are configured to accommodate the respective components of the linear actuator 1, in particular the actuation mechanism 2 and / or the drive unit 10. For example, the first cavity 11a is configured to accommodate the nut 5, a part of the spindle 3 and a part of the output member 7. The second cavity 11b is configured to accommodate another part of the spindle 3 and a part of the drive unit 10. The third cavity 11c is configured to accommodate another part of the drive unit 10, and the fourth cavity 11d is configured to accommodate yet another part of the drive unit 10. Through the cavities 11a–d, the different components of the linear actuator 1 can be arranged in the housing 8 according to their functional relationships without any additional fastening means, in particular without any additional means for fixing the components to the housing 8. In other words, the different components of the linear actuator 1 can be held in place, in particular fixed by arranging them in the cavities formed by the two housing parts when assembling the housing 8.

[0055] For example, the inner diameter of the first cavity 11a may correspond to the outer diameter of the nut 5 such that the nut can slide within the first cavity 11a when the main shaft 3 rotates. Thus, the output member 7 fixed to the nut 5 can be translated along the actuation axis 12 of the actuation mechanism 2, in particular, projecting out of or retracting into the housing 8.

[0056] The rotational movement is generated by the electric motor 9 and transmitted through the motor shaft 19a to the drive unit 10. The drive unit 10 includes an input pulley 13 disposed in the fourth cavity 11d, an output pulley 14 disposed in the second cavity 11b, and a belt 15 running on the input pulley 13 and the output pulley 14 and extending through the third cavity 11c. The output pulley 14 is press-fitted onto the portion of the main shaft 3 extending into the second cavity 11b so that the rotational movement is transmitted to the main shaft 3.

[0057] The main shaft 3 is rotatably mounted in the housing 8 by two bearings 16. Each of the two bearings 16, in particular the inner ring 16a of each bearing 16, is press-fitted onto one of the two axially extending studs 14a of the output pulley 14. The corresponding outer ring 16b of each bearing 16 is received by a corresponding cavity (not shown in the drawing reference) in the housing 8.

[0058] In the example shown, the input pulley 13 is connected to the motor shaft 19a by a connection interface 17. The connection interface 17 includes a tapered surface 17a onto which the input pulley 13 is press-fitted. To axially fix the input pulley 13, a nut 18 is screwed onto the corresponding thread of the connection interface 17.

[0059] The electric motor 9 includes a connection portion 19 for fixing the electric motor 9 to the housing 8. The connection portion 19 includes the motor shaft 19a and a ring 19b radially arranged around the motor shaft 19a. The ring 19b engages with a groove 20a disposed in an opening 20 formed when two housing parts are assembled. To support the electric motor 9 fixed to the housing 8 in this way, Figure 1 the housing part 8a shown includes an external projection 21 that contacts the electric motor 9 when the ring 19b engages with the groove 20a.

[0060] Of course, other configurations of the linear actuator 1 are possible. For example, it is conceivable to design the first cavity 11a for fixing the nut 5 translationally and connect the output pulley 14 to the nut 5 instead of the main shaft 3. Thus, the output member 7 can be connected to the main shaft 3 or even formed by the main shaft 3, which can then be translated along the actuation axis 12 when the nut 5 rotates.

[0061] Figure 2 is shown in exploded view Figure 1The actuating system 50 therein. The actuating mechanism 2 including the threaded spindle 3 and the nut 5 is connected to the electric motor 9 via the drive unit 10. The drive unit 10 and the actuating mechanism 2 are at least partially arranged inside a housing including two housing parts 8a, 8b. In the assembled state, the two housing parts 8a, 8b can be fixed to each other by means of a plurality of screws 22.

[0062] The two housing parts 8a, 8b preferably define contact surfaces, wherein the two housing parts 8a, 8b are substantially in contact in the assembled state of the housing. As Figure 2 shown, for this purpose each of the housing parts 8a, 8b can include connecting surfaces 22a, 22b, wherein the two connecting surfaces 22a, 22b are in contact and define the contact surface in the assembled state of the housing. In addition, the two housing parts 8a, 8b are configured to accommodate the actuating mechanism 2 such that the actuating axis of the actuating mechanism 2 (see Figure 1 ) is substantially parallel to the contact surface in the assembled state of the housing. This can be achieved by arranging the individual components of the linear actuator 1, in particular the individual components of the actuating mechanism 2 and / or the drive unit 10, in a plurality of separate cavities 11a-d.

[0063] In Figure 2 it is possible to clearly see a plurality of separate cavities 11a-d. Among them, at least a part of the cavities 11a-d is separated by an inner wall 23 integrated with the two housing parts 8a, 8b. By this method, at least some of the components can be substantially fixed within the housing. For example, the bearing 16 for rotatably mounting the spindle 3 and the housing-related output pulley 14 can be translationally fixed in the corresponding cavity (not shown in the drawing reference) accommodating the bearing 16.

[0064] The housing parts 8a, 8b can also be configured to rotatably fix at least some of the components of the linear actuator 1. For example, each of the housing parts 8a, 8b can include an axially extending mating component 24, which is configured to interact with the corresponding mating component 5b of the nut 5. In Figure 2 the illustrated embodiment, the mating component 24 of the housing parts 8a, 8b is designed as a protrusion axially extending within the first cavity 11a, and the corresponding mating component 5b of the nut 5 is designed as an axially extending groove on the outer surface of the nut 5.

[0065] In addition, the housing parts 8a, 8b can also be configured to prevent rotationally fixing the electric motor 9. For this purpose, the opening 20 formed by the two housing parts 8a, 8b for accommodating the connecting part 19 including the motor shaft 19a and the ring 19b preferably includes a shape complementary to the circumferential shape of the ring 19b. Specifically, the opening 20 can include two parts 26 designed as planes, and the ring 19b radially abuts on the parts 26 by means of the corresponding radial surfaces.

[0066] To simplify and accelerate assembly, the conical surface 17a of the connection interface 17 is grooved. This allows it to be easily slipped onto the motor shaft 19a. The connection interface 17 is fixed to the motor shaft 19a by press-fitting the input pulley 13 onto the conical surface 17a.

[0067] To enable the linear actuator 1 to be attached (e.g., to a component of a production line), each of the housing portions 8a, 8b includes a rear protrusion 25. In the assembled state of the housing, the two rear protrusions 25 form a U-shaped clamp. As Figure 2 shown, the U-shaped clamp is thus integrally formed with the housing.

[0068] Figure 3 Another example of an actuator system 50 including the linear actuator 1 and the motor 9 is shown in a sectional view. Similar to the actuator system 50 shown in Figure 1 and Figure 2 , the linear actuator 1 includes an actuating mechanism 2, which includes a spindle 3 having an outer raceway 4 and a nut 5 having a corresponding inner raceway on its inner surface 6. The actuating mechanism 2 is configured to convert the rotational movement of the spindle 3 into a translational movement of the nut 5. The linear actuator 1 also includes an output member 7 connected to the actuating mechanism 2 (specifically to the nut 5, the housing 8, and the actuating unit 10), which is configured to connect the motor 9 to the actuating mechanism 2, specifically to the spindle 3. Here, the housing 8 also includes two housing portions, only one of which is shown and indicated by the reference numeral 8a. During assembly, the two housing portions form a plurality of cavities 11a-f for accommodating components of the linear actuator 1, such as the actuating mechanism 2 or at least a part thereof, or the drive unit 10 or at least a part thereof.

[0069] Figure 3 The shown actuator system 50 differs from the actuator system 50 shown in Figure 1 and Figure 2 in that the motor 9 is not fixed to the linear actuator 1, specifically to the housing 8, by a connection portion that interacts with an opening formed by the two housing portions. Instead, the motor 9 is fixed to the housing 8 by screws (not shown), which extend through an axial through-hole (not shown) that is substantially parallel to the actuating axis 12 in the rear region of the housing (see Figure 4 ).

[0070] Furthermore, instead of using a connection interface, the motor shaft 19a of the motor 9 is inserted in a form-fitting manner into the axial hole 27 in the input pulley 13 of the drive unit 10. Preferably, the input pulley 13 is rotatably mounted in the housing 8 by means of two additional bearings 28, in particular in the corresponding fourth cavity 11d formed by two housing parts. Thus, the input pulley 13 can be supported substantially by the housing 8 instead of being supported separately by the motor shaft 19a or the connection interface. This is advantageous because the linear actuator 1 can now be assembled without integrating the motor 9. Instead, the motor 9 can be connected to the linear actuator 1, in particular to the actuating mechanism 2, at a later stage in order to form the actuating system 50. For this purpose, the motor 9 can be axially displaced, i.e., parallel to the actuating axis 12, such that the motor shaft 19a passes through the opening 20 and is inserted into the axial hole 27 of the input pulley 13.

[0071] Similar to the bearing 16 mounted on the two axially extending studs 14a of the output pulley 14 of the drive unit 10 (see Figure 1 ), the additional bearings 28, in particular the inner rings of the bearings 28, can be mounted on the two axially extending studs 13a of the input pulley 13. Specifically, the bearings 28 can be press-fitted onto the axial studs 13a. The corresponding outer rings of the bearings 28 can be received by corresponding cavities (not shown by reference numerals) in the housing 8.

[0072] In Figure 3 the example shown, the input pulley 13 and the output pulley 14 each only include a pulley ring 29 for guiding the belt 15 running on the input pulley 13 and the upper pulley 14, in particular for axially fixing the belt 15 in the third cavity 11c of the housing 8. For this purpose, pulley rings 29 are provided at opposite ends of the two pulleys 13, 14 such that the belt 15 runs between the two pulley rings 29. In other words, pulley rings 29 are provided at the two ends of the pulleys 13, 14 facing different directions. Specifically, the pulley ring 29 of the output pulley 14 is arranged at the end facing the actuating mechanism 2, i.e., at the front of the linear actuator 1, while the ring 29 of the input pulley 13 is arranged at the end remote from the actuating mechanism 2, i.e., at the rear of the linear actuator 1.

[0073] In addition, when assembled, the two half - shells form at least one fifth cavity 11e for receiving an end - switch 30, which is arranged to respectively limit the translational movement, i.e., the movement range, along the actuation axis 12 of the actuation mechanism 2, in particular of the nut 5 or the output member 7. For this purpose, the nut 5 may include a switch member 30a, which is configured to actuate the end - switch 30. For example, the nut 5 may include a permanent magnet arranged in a groove on the outer surface of the nut 5, wherein the end - switch 30 is preferably configured to sense the magnetic field of the permanent magnet when the nut 5 moves to a position where the permanent magnet is adjacent to the corresponding end - switch 30. The end - switch 30 may be connected to a control unit (not shown), which is configured to control the motor 9 based on a signal generated by the end - switch 30 when sensing the magnetic field of the permanent magnet.

[0074] The actuation system 50 differs from Figure 1 and Figure 2 the actuation system shown in that the linear actuator 1 includes a guiding member 31, which is configured to guide the movement of the output member 7, in particular to translationally mount the output member 7 in the housing 8. For this purpose, the guiding member 31 is slidably mounted on the output member 7 for supporting the output member 7 on the housing 8. In other words, the guiding member 31 is respectively configured or arranged to at least partially support the output member 7, especially at the distal end of the linear actuator 1. Specifically, the output member 7 can be supported on the one hand by the guiding member 31 and on the other hand by its connection to the nut 5. For this purpose, the guiding member 31 is preferably received in a sixth cavity 11f located at the distal end of the housing 8.

[0075] To support the output member 7 against non - axial loads, such as forces acting respectively radially on the output member 7 or on an actuation part 7a connected to the output member 7, the guiding member 31 includes a convex outer surface 31a. Preferably, the sixth cavity 11f includes a corresponding complementary inner surface for supporting the convex surface 31a. In this way, non - axial loads acting on the output member 7 can be reliably borne by the housing 8, i.e., without stressing the nut 5 and / or the spindle 3.

[0076] Optionally, as Figure 3 shown, the housing part may be configured to form more than one sixth cavity 11f during assembly. During the assembly of the linear actuator 1, the guiding member 31 can then be placed in one of the sixth cavities 11f. Alternatively, more than one guiding member 31 can be placed in more than one sixth cavity 11f. In this way, depending on the intended use of the linear actuator 1, the output member 7 can be optimally supported. For example, it becomes possible to reliably support a particularly short or particularly long output member 7.

[0077] Figure 4 is shown in the exploded view Figure 3The actuating system 50 therein. The actuating mechanism 2 including the threaded spindle 3 and the nut 5 is connected to the electric motor 9 by the drive unit 10. The drive unit 10 and the actuating mechanism 2 are at least partially arranged inside a housing including two housing parts 8a, 8b. For this purpose, when the two housing parts 8a, 8b are assembled, a plurality of cavities 11a-f are formed, and the cavities 11a-f are preferably configured to respectively accommodate at least parts of the actuating mechanism 2 and the drive unit 10.

[0078] In the assembled state, the two housing parts 8a, 8b can be fixed to each other by a plurality of screws 22. For example, by providing threaded holes 32a in one of the two housing parts 8a and corresponding transverse through-holes 32b in the other of the two housing parts 8b, such that the screw 22 can pass through the transverse through-hole 32b and engage with the thread in the hole 32a. To keep the screw 22 against the housing part 8b, washers 33 can be provided. For clarity, only one threaded hole 32a, transverse through-hole 32b or washer 33 is respectively provided with a reference numeral.

[0079] Alternatively, the two housing parts 8a, 8b can include transverse through-holes 32b. Then, the nut can be screwed onto the screw 22 through the transverse through-holes 32b in the two housing parts 8a, 8b to fix the housing parts 8a, 8b in the assembled state. In another alternative, housing parts 8a, 8b without any transverse through-holes or holes can be provided. Instead, the housing parts 8a, 8b can be fixed by welding, especially ultrasonic welding, in the assembled state.

[0080] In Figure 4 In the example shown, the electric motor 9 is fastened to the housing of the linear actuator 1 by a fastening screw 34 passing through a corresponding axial through-hole 35 in the rear region of the housing. The axial through-hole 35 is preferably arranged around the fourth cavity 11d formed when the two housing parts 8a, 8b are assembled, and this fourth cavity is used to accommodate the input pulley 13 of the drive unit 10, thereby allowing a wide load distribution.

[0081] To prevent the fastening screw 34 from compressing the housing, a support tube 36 can be inserted into the axial through-hole 35. The support tube 36 can be configured as a metal tube, especially a steel tube. The support tube 36 can withstand the axial load applied by tightening the fastening screw 34 while radially supporting the fastening screw 34 on the housing (especially the inner surface of the axial through-hole 35).

[0082] Although Figure 4 not shown in the figure, the transverse through-hole 32b can also accommodate such a support tube 36.

[0083] In Figure 4In the configuration of the linear actuator 1 shown, after the linear actuator 1 is assembled, the motor 9 can be included in the actuation system 50. Specifically, the motor 9 can be placed on the protrusion 21 of the assembly housing and axially moved to insert the motor shaft 19a into the axial hole 27 of the input pulley 13 until the motor 9 abuts against the rear part of the housing. Then, the motor 9 can be fastened to the housing by the fastening screw 34. To radially align the motor shaft 19a with the axial hole 27, the protrusion 21 can be adjusted according to the shape of the motor 9, especially the circumferential shape, as Figure 4 shown.

[0084] The two housing parts 8a, 8b are further configured to form at least one sixth cavity 11f during assembly for accommodating the guiding member 31 slidably mounted on the output member 7. In the example shown, the housing parts 8a, 8b form two sixth cavities 11f. When assembling the linear actuator 1, depending on the intended use, it can be selected in which cavity 11f to arrange the guiding member 31.

[0085] Figure 5 An example of a method 100 for assembling a linear actuator is shown. In method step S1, a housing including two housing parts is provided. For this purpose, each of the two housing parts can be cast from a plastic material, such as nylon. Alternatively, each of the two housing parts can be made of a metal material, such as aluminum. Preferably, each of the two housing parts includes an inner wall that defines a plurality of independent cavities for accommodating the respective components of the linear actuator when assembling the housing. The inner wall is preferably formed when casting the two housing parts, for example, they are integrally manufactured with the housing parts.

[0086] In a further method step S2, an actuation mechanism including a spindle and a nut is arranged in one of the two housing parts. Preferably, the other components of the linear actuator are also arranged in one housing part. Specifically, the respective components of the linear actuator are placed such that they are accommodated by the plurality of independent cavities when the housing is assembled.

[0087] After arranging the components in one housing part, in a further method step S3, the housing is assembled. Thereby, a plurality of independent cavities are formed that at least partially enclose the respective components of the linear actuator.

[0088] Preferably, the two housing parts are manufactured in method step S1 such that when assembled in method step S3, the two housing parts define a contact surface where the two housing parts contact. In addition, the two housing parts are preferably manufactured such that by arranging the actuation mechanism in the plurality of cavities, preferably also arranging other components of the linear actuator, such as components of the drive unit, the actuation axis of the actuation mechanism is substantially parallel to the contact surface.

[0089] List of reference numerals

[0090] 1 Linear actuator

[0091] 2 Actuating mechanism

[0092] 3 Spindle

[0093] 4 Outer raceway

[0094] 5 Nut

[0095] 5a Groove

[0096] 5b Fitting component

[0097] 6 Inner surface

[0098] 7 Output member

[0099] 7a Actuating member

[0100] 8 Housing

[0101] 8a, 8b Housing parts

[0102] 9 Motor

[0103] 10 Drive unit

[0104] 11a - f Cavities

[0105] 12 Actuating axis

[0106] 13 Input pulley

[0107] 13a Stud

[0108] 14 Output pulley

[0109] 14a Stud

[0110] 15 Belt

[0111] 16 Bearing

[0112] 16a, 16b Inner ring, outer ring

[0113] 17 Connection interface

[0114] 17a Tapered surface

[0115] 18 Nut

[0116] 19 Connection part

[0117] 19a Motor shaft

[0118] 19b Ring

[0119] 20 Opening

[0120] 20a Slot

[0121] 21 Protrusion

[0122] 22 Screw

[0123] 22a, 22b Connection Surface

[0124] 23 Inner Wall

[0125] 24 Fitting Assembly

[0126] 25 Rear Protrusion

[0127] 26 Portion

[0128] 27 Axial Hole

[0129] 28 Additional Bearing

[0130] 29 Pulley Ring

[0131] 30 End Switch

[0132] 30a Switch Element

[0133] 31 Guide Component

[0134] 31a Convex Outer Surface

[0135] 32a Threaded Hole

[0136] 32b Transverse Through-Hole

[0137] 33 Washer

[0138] 34 Fastening Screw

[0139] 35 Axial Through-Hole

[0140] 36 Support Tube

[0141] 100 Method

[0142] S1 - S3 Method Steps

Claims

1. A linear actuator (1), comprising: - An actuating mechanism (2), including a spindle (3) and a nut (5), the actuating mechanism (2) being configured to convert a rotational motion into a translational motion; and - A housing (8), including two housing parts (8a, 8b), wherein the actuating mechanism (2) is at least partially arranged in the housing (8), wherein, the two housing parts (8a, 8b) - form a plurality of independent cavities (11a-d), the cavities being configured to accommodate respective components of the linear actuator (1), and - form an opening (20) for accommodating a connection part (19) of a motor (9), the connection part (19) including a motor shaft (19a), wherein at least one of the two housing parts (8a, 8b) includes a groove (20a) that at least partially extends within the opening (20), and a ring (19b) of the connection part (19) of the motor (9) can be received in the groove (20a).

2. The linear actuator (1) according to claim 1, characterized in that, The two housing parts (8a, 8b) include inner walls (23), the inner walls (23) separating at least a part of the plurality of independent cavities (11a-f), wherein at least a part of the inner walls (23) is configured to translationally fix the components of the linear actuator (1) accommodated by the respective cavities (11a-f).

3. The linear actuator (1) according to any one of claims 1 or 2, characterized in that, At least one of the two housing parts (8a, 8b) includes an axially extending mating component (24) that is configured to interact with a corresponding mating component (5b) of the nut (5) such that the nut (5) is rotationally fixed against rotation.

4. The linear actuator (1) according to any one of the preceding claims, characterized in that, At least one of the two housing parts (8a, 8b) includes an external protrusion (21) for supporting a motor (9) connected to the actuating mechanism (2).

5. The linear actuator (1) according to any one of the preceding claims, characterized in that A drive unit (10) for connecting a motor (9) to the actuating mechanism (2), wherein the drive unit (10) includes an input pulley (13) engageable with a motor shaft (19a) of the motor (9), an output pulley (14) connected to the spindle (3), and a belt (15) running on the input pulley (13) and the output pulley (14), wherein the input pulley (13) and / or the output pulley (14) includes two axially extending studs (14a), and bearings (16) are press-fitted onto each of the two studs (14a) for rotatably mounting the input pulley (13) or the output pulley (14) and the spindle (3) in the housing (8) respectively.

6. The linear actuator (1) according to claim 5, characterized in that, The input pulley (13) and / or the output pulley (14) includes a plurality of ribs axially extending on a circumferential surface of each of the two studs (14a).

7. The linear actuator (1) according to any one of the preceding claims, characterized in that A drive unit (10) for connecting an electric motor (9) to the actuating mechanism (2), the drive unit (10) comprising an input pulley (13) engageable with the motor shaft (19a) of the electric motor (9), an output pulley (14) press-fitted onto the main shaft (3), and a belt (15) running on the input pulley (13) and the output pulley (14).

8. The linear actuator (1) according to any one of the preceding claims, characterized in that A drive unit (10) for connecting an electric motor (9) to the actuating mechanism (2), the drive unit (10) comprising an input pulley (13) engageable with the motor shaft (19a) of the electric motor (9), an output pulley (14) connected to the main shaft (3), and a belt (15) running on the input pulley (13) and the output pulley (14), wherein each of the input pulley (13) and the output pulley (14) includes a pulley ring (29) for guiding the belt (15), and the pulley ring (29) is provided at opposite ends of the two pulleys (13, 14).

9. The linear actuator (1) according to any one of the preceding claims, characterized in that An output member (7) and a guiding member (31), the guiding member (31) being slidably mounted on the output member (7) for supporting the output member (7) on the housing (8).

10. The linear actuator (1) according to claim 9, characterized in that, The guiding member (31) includes a convex outer surface (31a).

11. The linear actuator (1) according to any one of the preceding claims, characterized in that, Each of the two housing portions (8a, 8b) includes a rear projection (25), and the two rear projections (25) form a U-shaped clamp for attaching the linear actuator (1).

12. The linear actuator (1) according to any one of the preceding claims, characterized in that, Each of the two housing portions (8a, 8b) is cast from a plastic material.

13. The linear actuator (1) according to any one of the preceding claims, characterized in that, Each of the two housing portions (8a, 8b) includes an axial through hole (35) configured to receive a fastening screw (34) for mounting the electric motor (9) to the housing (8), and each of the axial through holes (35) receives a support tube (36) configured to support the corresponding fastening screw (34) on the housing (8).

14. A housing (8) for a linear actuator (1) according to any one of the preceding claims, the housing (8) comprising two housing parts (8a, 8b) which, in the assembled state of the housing (8), define a contact surface on which the two housing parts (8a, 8b) are in substantially contact, wherein the two housing parts (8a, 8b) are configured to receive the actuating mechanism (2) such that the actuating axis (12) of the actuating mechanism (2) is substantially parallel to the contact surface in the assembled state of the housing (8), and the two housing parts (8a, 8b) form, in the assembled state, an opening (20) for receiving a connecting part (19) of a motor (9), the connecting part (19) comprising a motor shaft (19a), wherein at least one of the two housing parts (8a, 8b) comprises a groove (20a) which extends at least partially within the opening (20), and in which a ring (19b) of the connecting part (19) of the motor (9) can be received.

15. An actuating system (50) comprising a linear actuator (1) according to any one of claims 1 to 13 and a motor (9), the motor (9) being connected to the linear actuator (1) and having a connecting part (19) with a ring (19b), wherein, The connecting portion (19) is received in an opening (20) formed by the two housing portions (8a, 8b), and in this case, the ring (19b) is received in a groove (20a) in the opening (20).

16. The actuating system (50) according to claim 15, characterized in that The opening (20) includes at least one portion (26) that non-rotatably fixes the connecting portion (19) of the electric motor (9) relative to the housing (8).

17. The actuating system (50) according to claim 15 or 16, characterized in that The linear actuator (1) includes a drive unit (10) connecting the electric motor (9) to the actuating mechanism (2), the drive unit (10) comprising an input pulley (13) directly mounted on the motor shaft (19a) of the electric motor (9), an output pulley (14) connected to the actuating mechanism (2), and a belt (15) running on the input pulley (13) and the output pulley (14).

18. The actuating system (50) according to any one of the preceding claims, characterized in that A drive unit (10) connecting the motor (9) to the actuating mechanism (2), the drive unit (10) including an input pulley (13) connected to the motor shaft (19a) of the motor (9), an output pulley (14) connected to the actuating mechanism (2), and a belt (15) running on the input pulley (13) and the output pulley (14), wherein the input pulley (13) is located on the conical surface (17a) of a connection interface (17) mounted on the motor shaft (19a).

19. A method (100) for assembling a linear actuator (1) according to any one of claims 1 to 13, comprising the following steps: -(S1) Providing a housing (8) including two housing parts (8a, 8b) that are in contact along a contact surface in the assembled state of the housing (8); -(S2) Arranging an actuating mechanism (2) in one of the two housing parts (8a, 8b) such that the actuating axis (12) of the actuating mechanism (2) is substantially parallel to the contact surface in the assembled state of the housing (8), wherein the actuating mechanism (2) includes a spindle (3) and a nut (5), and the actuating mechanism (2) is configured to convert a rotational movement into a translational movement; and -(S3) Assembling the housing (8) such that the two housing parts (8a, 8b) form a plurality of independent cavities (11a-f) that accommodate the respective components of the actuating mechanism (1) and form an opening (20) for accommodating a connection part (19) of the motor (9), the connection part (19) including a motor shaft (19a), wherein at least one of the two housing parts (8a, 8b) includes a groove (20a) that at least partially extends within the opening (20), and a ring (19b) of the connection part (19) of the motor (9) can be accommodated in the groove (20a).

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