DE102022210114A1 - Steering arrangement with multi-stage planetary gear for an industrial truck and industrial truck with the steering arrangement - Google Patents

Abstract

A steering arrangement 2 for an industrial truck 1 is proposed, with a wheel carrier 9 for the rotatable mounting of at least one vehicle wheel, wherein the wheel carrier 9 can be pivoted about a vertical pivot axis 100, with an electric steering drive 7 for generating a steering torque, with a multi-stage planetary gear 8 for translating the steering torque to the wheel carrier 9, wherein the steering drive 7 is connected coaxially to the pivot axis 100 to an input planetary stage P1 of the planetary gear 8 and the wheel carrier 9 is connected coaxially to the pivot axis 100 to an output planetary stage P3 of the planetary gear 8, and with a support section 21 that can be fastened to a vehicle frame of the industrial truck for supporting the steering drive 7 and the planetary gear 8, wherein either the support section 21 or the wheel carrier 9 forms an output planetary carrier 18c of the output planetary stage P3 of the planetary gear 8.

Description

The invention relates to a steering arrangement for an industrial truck with the features of the preamble of claim 1. The invention further relates to an industrial truck with the steering arrangement.

Industrial trucks with a three-wheel chassis are often steered with the help of electrically driven swivel axle steering, with at least one rear wheel being rotatably mounted on the vehicle frame via a steering arm in order to enable steering movements of 360 degrees and more. Such swivel axle steering systems usually have an electric steering motor and a steering gear, via which a steering torque generated by the steering motor is transmitted to the steering frame. For example, a multi-stage planetary gear can be used as the steering gear.

The publication DE 10 2006 029 283 A1 discloses a steering gear, in particular for industrial trucks, consisting of a housing with a gear drive and a coupling with at least one steerable impeller. In order to achieve a precise steering movement with the possibility of control at any time, it is provided that the gear drive consists of at least one gear stage, which can be driven by a motor and the output takes place on the impeller via a gear component. The use of a 3-stage planetary gear makes it possible to transmit large torques, so that such steering gears can preferably be used to transport larger loads.

The invention is based on the object of creating a steering arrangement of the type mentioned, which is characterized by a compact and robust structure.

This object is achieved by a steering arrangement with the features of claim 1 and an industrial truck with the features of claim 15. Further refinements and advantages according to the invention can be found in the corresponding subclaims as well as the following description and the attached figures.

The subject of the invention is a steering arrangement which is designed and/or suitable for an industrial truck. The steering arrangement has the particular function of transmitting a steering movement to at least one vehicle wheel of the industrial truck and/or steering the industrial truck while driving.

The steering arrangement has a wheel carrier which is designed and/or suitable for rotatably supporting the at least one vehicle wheel and can be pivoted about a vertical pivot axis. In particular, the at least one vehicle wheel is designed as a steerable vehicle wheel, preferably a rear wheel, which can be pivoted about the pivot axis to implement the steering movement by the wheel carrier. Preferably, the wheel carrier can be pivoted about the pivot axis with a steering angle of more than 180 degrees, preferably more than 360 degrees. In particular, “vertical” in relation to the pivot axis is to be understood as meaning that the pivot axis is aligned vertically, preferably substantially perpendicular, to a hallway level when the steering arrangement is installed. The vehicle wheel preferably defines a wheel rotation axis around which the vehicle wheel rotates when driving. Particularly preferably, the wheel rotation axis is aligned horizontally, preferably in the same direction, with respect to the hallway level. In principle, at least one vehicle wheel is driveless. Alternatively, the at least one vehicle wheel can also be driven by an electric wheel drive. For example, the wheel drive is arranged coaxially to the wheel rotation axis and/or is designed as a wheel hub drive integrated into the vehicle wheel.

The steering arrangement has an electric steering drive for generating a steering torque or the steering movement. In particular, the electric steering drive has an electric motor which takes electrical energy from an energy storage device and converts it into mechanical power in order to apply the steering torque to the wheel carrier or to pivot the wheel carrier about the pivot axis. In particular, the electric motor has a stator and a rotor rotating about a rotor axis of rotation, the pivot axis being defined by the rotor axis of rotation and/or the pivot axis and the rotor axis of rotation being arranged on the same axis as one another. To put it simply, the steering drive is arranged coaxially to the pivot axis. Preferably, the stator is arranged in a rotationally fixed and/or stationary manner with respect to a vehicle frame of the vehicle.

The steering arrangement has a multi-stage planetary gear, which is designed and/or suitable for transmitting the steering torque to the wheel carrier. The steering drive is connected to an input planetary stage of the planetary gear arranged coaxially to the pivot axis, and the wheel carrier is connected to an output planetary stage of the planetary gear arranged coaxially to the pivot axis. In other words, the steering drive is connected to the wheel carrier via the multi-stage planetary gear. In the Specifically, the planetary gear has a gear ratio of i > 1. In other words, the planetary gear is used to slow down, whereby the speed is reduced and the transmitted steering torque is increased.

The steering arrangement has a support section which can be attached to a vehicle frame of the industrial truck and which is designed and/or suitable for supporting the steering drive and the planetary gear. In particular, the electric drive is arranged or supported in relation to the pivot axis on an axial end face of the support section and the planetary gear on the other axial end face of the support section, in particular facing away from the electric drive. Preferably, the steering drive, in particular the stator, and/or the planetary gear are supported on the support section in a rotationally fixed manner, at least in the rotational direction. In particular, the support section is designed as a housing section of a housing for receiving the planetary gear and/or the steering drive.

Within the scope of the invention it is proposed that the wheel carrier forms an output planetary carrier of the output planetary stage of the planetary gear. Alternatively, it is provided that the support section forms an output planetary carrier of the output planetary stage of the planetary gear. In particular, the output planetary carrier serves for the rotatable mounting of output planetary gears of the output planetary stage. In particular, the output planetary carrier is formed by several separate planetary bolts, which are connected in a rotationally fixed manner to the wheel carrier or the support section. In particular, the wheel carrier or the support section has a plurality of receiving openings distributed around the pivot axis, with one of the planetary bolts being mounted in each receiving opening. For example, the planetary bolts can be mounted in the receiving opening in a form-fitting and/or force-fitting manner, in particular via a press fit, in a rotationally fixed manner. Alternatively, the output planet carrier is formed by a plurality of planet bolt sections, which are formed in one piece on the wheel carrier or the support section. In particular, “in one piece” is to be understood as meaning that the planetary bolt sections and the wheel carrier or the support section are made from a common material section, e.g. from a single casting. In particular, at least or exactly one output planet gear is rotatably mounted on each of the planet bolts or planet bolt sections.

The advantage of the invention is, in particular, that the design of the wheel carrier or the support section as an output planetary carrier enables a particularly compact and cost-effective design of the planetary gear and thus of the steering drive. By integrating the output planetary carrier on the wheel carrier or the support section, a separate planetary carrier for the output planetary stage can be dispensed with, which can save additional weight. Another advantage is that the rotationally symmetrical structure of the steering arrangement not only requires little space and is lightweight, but also achieves optimal force distribution.

In a specific embodiment of the invention it is provided that the support section is designed as a bearing plate of the steering drive. In particular, the end shield is designed to secure the electric motor of the steering drive against contact in the axial direction with respect to the pivot axis and at the same time to rotatably support a drive shaft connected to the rotor in a rotationally fixed manner about the pivot axis. For this purpose, the support section has a motor bearing receptacle in which a motor bearing for supporting the drive shaft is accommodated, the drive shaft being guided through the motor bearing receptacle and the motor bearing into the planetary gear. The end shield preferably has a drive housing section for at least partially accommodating the steering drive and/or a gear housing section for at least partially accommodating the planetary gear. In particular, the drive housing section and the transmission housing section directly adjoin the support section. The support section, the drive housing section and the transmission housing section are preferably made from a common material section. By designing the support section as a bearing shield, a steering arrangement is proposed which is characterized by a compact structure and a small number of components.

In a further development it is provided that the steering arrangement has a fastening flange which can be fastened to the vehicle frame and to which the support section is connected in a rotationally fixed manner. In particular, the support section and the fastening flange are screwed to the vehicle frame via a common screw connection. For this purpose, the fastening flange and the support section have common fastener receptacles for receiving one fastener each, which are arranged lying on a common pitch circle around the main axis. The fastening means can, for example, be screw bolts arranged on the vehicle frame or screws that can be screwed into the vehicle frame. Particularly preferably, the support section is connected to the fastening flange via the transmission housing section. Preferably, the gear housing section and the fastener form The connection flange includes a gear housing for the planetary gear.

According to this development, the wheel carrier is pivotably supported on the fastening flange via a pivot bearing arranged concentrically to the planetary gear. In particular, the pivot bearing comprises a first and a second pivot bearing, which are preferably arranged in an O-arrangement. Preferably, the two pivot bearings are each designed as a tapered roller bearing. Alternatively, the pivot bearing comprises a double-row pivot bearing. In particular, the double-row pivot bearing is designed as a preset double-row tapered or spherical roller bearing. In particular, an inner ring of the at least one pivot bearing is connected in a rotationally fixed manner to the wheel carrier and an outer ring of the at least one pivot bearing is connected in a rotationally fixed manner to the fastening flange. Preferably, the at least one pivot bearing is axially supported via axial contact surfaces on the fastening flange and/or the wheel carrier. Optionally, the steering arrangement can additionally have a sealing device which is arranged radially between the wheel carrier and the fastening flange in order to protect or seal the pivot bearing against the ingress of foreign particles, in particular against environmental influences from outside. For example, the sealing device is designed as a rotational direction, which enables dynamic sealing in the event of relative rotation between the wheel carrier and the mounting flange. The concentric arrangement of the pivot bearing to the planetary gear thus proposes a particularly compact and space-saving arrangement, which is also characterized by simple sealing.

In a further specification, it is provided that the wheel carrier has a cylinder section arranged coaxially to the pivot axis, the pivot bearing being supported on an outer circumference of the cylinder section. In particular, the cylinder section extends in the axial direction with respect to the pivot axis to the support section, the planetary gear being arranged radially inside the cylinder section and the pivot bearing being arranged radially outside the cylinder section. In other words, the cylinder section limits the planetary gear in the radial direction compared to the pivot bearing. The cylinder section can therefore be used to provide a particularly compact support for the pivot bearing, which is characterized in particular by a low axial height.

In a further specific implementation it is provided that the pivot bearing is secured in the axial direction with respect to the pivot axis via a securing means which is fixed to the outer circumference of the support section. In particular, the securing means is designed as a locknut which engages in a thread of the support section. Preferably, the preload of the pivot bearing, in particular of the two pivot bearings, can be adjusted using the locknut. Alternatively, the securing means can be designed as a securing ring which engages in an annular groove of the support section. Here, the pivot bearing, the double-row pivot bearing, is adjusted via a narrow tolerance chain, also known as the “set-right” setting. Optionally, a locking plate is arranged between the locknut and the pivot bearing, which prevents the locknut from twisting. A pivot bearing is therefore proposed, which is characterized by a compact arrangement. In addition, a pretension of the pivot bearing can be adjusted via the securing means.

In a further embodiment, it is provided that the planetary gear has a ring gear arranged coaxially to the pivot axis, the planetary gears of the planetary stages, in particular the input and output planetary gears, each meshing with an associated ring gear section of the ring gear. In other words, the planetary gear has exactly one or a single ring gear for the several planetary stages. Alternatively, however, it can also be provided that the cylinder section itself forms the ring gear. In particular, the ring gear sections are formed by different toothing sections, which can differ from one another in terms of the number of teeth and/or tip circle diameter. In principle, the planetary gear can be designed as a two-stage planetary gear, with the input and output planetary gears each meshing with an associated ring gear section. Alternatively, the planetary gear has more than two, preferably more than three, in particular more than four planetary stages, each of which meshes with an associated ring gear section. The ring gear is preferably arranged radially within the cylinder section. A planetary gear is therefore proposed, which is characterized by a particularly compact structure and a reduced number of components.

In a further specification, it is provided that the ring gear is connected to the support section in a rotationally fixed manner when the wheel carrier forms the output planetary carrier. In particular, the output planet carrier thus forms an output of the planetary gear, with the ring gear remaining stationary or fixed to the housing. In principle, the ring gear can be form-fitting and/or force-fitting and/or be cohesively connected to the support section at least in a rotationally fixed manner. For this purpose, the ring gear preferably has a circumferential fastening collar, which is connected to the support section via at least or exactly one fastening means. For example, the fastening means can be designed as a screw. A particularly simple and cost-effective assembly of the ring gear is therefore proposed.

In an alternative specification, it is provided that the ring gear is connected to the wheel carrier in a rotationally fixed manner when the support section forms the output planetary carrier. In particular, the ring gear thus forms an output of the planetary gear, with the planet carrier of the output planetary stage remaining stationary or fixed to the housing. In particular, the ring gear is accommodated in the cylinder section of the wheel carrier and is connected to the cylinder section in a form-fitting and/or non-positive and/or material-locking manner at least in the direction of rotation around the pivot axis. In particular, the ring gear is pressed into the cylinder section via cutting teeth. Alternatively, however, as already described above, the cylinder section itself can form the ring gear, the ring gear sections being formed as toothed sections formed on the cylinder section. A particularly compact arrangement of the ring gear is therefore proposed.

In a specific implementation it is provided that the planetary gear is designed as a three-stage planetary gear. For this purpose, an intermediate planetary stage is arranged between the input and output planetary stages. The planetary gear has an input sun gear section, which is non-rotatably connected to the drive shaft of the steering drive and meshes with input planetary gears of the input planetary stage. Furthermore, the planetary gear has an intermediate sun gear section, which is connected in a rotationally fixed manner to an input planetary carrier of the input planetary stage and meshes with intermediate planetary gears of the intermediate planetary stage. The planetary gear has an output sun gear section which is non-rotatably connected to the intermediate planetary carrier and is in meshing engagement with the output planetary gears. In particular, the input planetary gears mesh with an input ring gear section of the ring gear, the intermediate planetary gears with an intermediate ring gear section and the output planetary gears mesh with an output ring gear section. In principle, the input sun gear section and/or intermediate sun gear section and/or the output sun gear section can be designed as a separate sun gear, which is non-rotatably connected to the drive shaft or the associated planet carrier. For example, the input and/or intermediate and/or the output sun gear section can be connected to the drive shaft or the respective planet carrier via a positive connection, for example a spline, and/or a frictional connection, for example a press fit. Alternatively, the input sun gear section and the drive shaft or the intermediate and/or the output sun gear section and the respective planet carrier can be made in one piece, in particular from a common material section. A planetary gear is therefore proposed which is characterized by a simple, inexpensive and compact structure.

In a first specification, it is provided that the input planetary stage is arranged on the side of the steering drive and the output planetary stage is arranged on the side of the wheel carrier when the wheel carrier forms the planetary carrier. In other words, the steering drive is arranged on an input side and the wheel carrier on an output side of the planetary gear. The sun gear sections are arranged one behind the other in the axial direction. To put it simply, the input sun gear section is arranged on the input side or on the side of the steering drive and the output sun gear section is arranged on the output side or on the side of the wheel carrier, with the intermediate sun gear section being arranged in the axial direction between the input and the output sun gear sections. A planetary gear is therefore proposed, which is characterized by a particularly simple and therefore cost-effective structure.

In an alternative specification, it is provided that the input planetary stage is arranged on the side of the wheel carrier and the output planetary stage is arranged on the side of the steering drive when the support section forms the planetary carrier. In other words, the steering drive is arranged on an output side or output side and the wheel carrier on an input side or drive side of the planetary gear. The intermediate and output sun gear sections are each designed as a hollow shaft, with the drive shaft being guided in the axial direction through the intermediate and output sun gear sections. A planetary gear is therefore proposed which is characterized by a particularly low axial height.

In a further embodiment it is provided that the steering arrangement has a sensor unit which is designed and/or suitable for detecting a steering angle of the wheel carrier. In particular, the sensor unit is designed to detect an absolute steering angle. For this purpose, the sensor unit has a coaxial pivot axis arranged sensor rod, which is connected to the wheel carrier in a rotationally fixed manner at a first axial end and is operatively connected to a steering angle sensor at a second axial end. The sensor rod is guided coaxially to the pivot axis by the steering drive and the planetary gear. In particular, the steering arrangement has a control unit, wherein the control unit is designed to control and/or regulate the drive unit based on the detected steering angle. In particular, the steering angle sensor is connected to the control unit for signaling purposes in order to transmit the detected steering angle to the control unit. Preferably, the sensor rod is non-rotatably connected to a sensor element at the second end, the sensor element being rotatable about the pivot axis relative to the steering angle sensor and being detectable and/or detected by the steering angle sensor. Preferably, the sensor element is arranged outside the drive housing of the steering drive and/or within a sensor housing. For example, the steering angle sensor can be designed as a potentiometer or a Hall sensor. A particularly compact and rotationally symmetrical integration of the sensor unit into the steering arrangement is therefore proposed.

In a further specification, it is provided that the drive shaft and the sun gear sections of the planetary gear each have a through opening arranged coaxially to the pivot axis, through which the sensor rod is passed. In particular, the drive shaft and the sun gear sections each form a guide sleeve for the sensor rod. The through openings are arranged coaxially and/or aligned with one another with respect to the pivot axis. A sensor rod is therefore proposed which can be integrated into the steering arrangement in a simple and compact manner.

In a further concrete implementation it is provided that the sensor rod is permanently and clearly oriented towards the wheel carrier in the direction of rotation around the pivot axis. For this purpose, the sensor rod has a form-fitting contour at the first axial end, which can be brought into engagement in just a single orientation with a sensor rod receptacle on the wheel carrier that is designed to be complementary to the form-fitting contour. In particular, the sensor rod receptacle forms a form-fitting, unique counterpart to the form-fitting contour in the direction of rotation around the pivot axis, so that the form-fitting contour and the sensor rod receptacle cannot be brought into engagement with one another in an orientation other than the desired one. In particular, in the simplest case, the form-fitting contour is designed as a flattening, which engages in the sensor rod receptacle directly or via a separate insert part. If the sensor rod engages directly in the sensor rod receptacle, the sensor rod receptacle can have a complementary counter contour. Alternatively, the counter contour is formed on the insert, the insert in turn having a positive outer contour, which interacts positively, preferably clearly or in only one orientation, with an inner contour of the sensor rod receptacle. The sensor rod holder preferably has a shape that can be produced using a slot milling cutter or an end milling cutter. For example, the sensor rod holder can have an L-shape for this purpose. This means that the sensor rod holder can be manufactured easily and cost-effectively. Particularly preferably, the sensor rod has a form-fitting contour which has an angle of 90° to the bisector of the L-shaped sensor rod receptacle. This ensures that the insert part, inserted in any way, clearly positions the sensor rod rotationally to the pivot axis.

Another subject of the invention relates to an industrial truck with the steering arrangement as already described above or according to one of claims 1 to 14. Preferably, the industrial truck has at least or exactly two wheel axles and at least or exactly three vehicle wheels. In particular, the industrial truck has a steering arrangement with at least one, preferably exactly two, steerable, in particular driveless, vehicle wheels. In particular, the vehicle has a front axle with two front wheels and a rear axle with one or two rear wheels, the rear wheel or wheels forming the steerable vehicle wheel.

• 1 eine schematische Darstellung eines Flurförderfahrzeugs mit einer Lenkanordnung;
• 2 eine Schnittdarstellung der Lenkanordnung für das Fahrzeug gemäß 1;
• 3 in gleicher Darstellung wie 2 eine alternative Ausführung der Lenkanordnung.

Further features, advantages and effects of the invention emerge from the following description of preferred embodiments of the invention. In the following:

• 1 a schematic representation of an industrial truck with a steering arrangement;
• 2 a sectional view of the steering arrangement for the vehicle according to 1 ;
• 3 in the same representation as 2 an alternative design of the steering arrangement.

1 shows a highly schematic representation of an industrial truck 1 with a steering arrangement 2, which is set up to steer the industrial truck 1. The industrial truck 1 is a three-lane industrial truck, for example a forklift, and has a driven front axle 3 with a first and a second front wheel 4a, 4b and a rear axle 5 with a first and a second rear wheel 6a, 6b. The two rear wheels 6a, 6b each form a steerable one Vehicle wheel of the industrial truck 1. For this purpose, the two rear wheels 6a, 6b are about a pivot axis 100 via the steering arrangement 2, as in 2 shown, pivotable. In this case, the steering angle can be any, including 360° or larger.

The steering arrangement 2 includes an electric steering drive 7, a multi-stage planetary gear 8 and a wheel carrier 9, which serves to accommodate the two rear wheels 6a, 6b. The steering drive 7 is designed to generate a steering torque, which is translated to the wheel carrier 9 via the planetary gear 8 in order to pivot the wheel carrier 8 and thus the two rear wheels 6a, 6b about the pivot axis 100.

The industrial truck 1 also has a drive machine 10, which is connected to the two front wheels 4a, 4b via a transfer case 11 and serves to drive the first and second front wheels 4a, 4b.

The industrial truck 1 has an electrical energy storage 12, which is used to provide and store electrical energy for the drive machine 10 and the steering drive 7. The electrical energy storage 12 is, for example, a battery or an accumulator.

2 shows the steering arrangement 2 in a sectional view as an embodiment of the invention. The steering drive 7 has a stator 13 and a rotor 14, wherein the rotor 14 rotates relative to the stator 13 about the pivot axis 100. The steering drive 7 also has a drive shaft 15 which is connected to the rotor 14 in a rotationally fixed manner and is driven by the rotor 14 about the pivot axis 100 during operation.

In an installed state, the steering drive 7 is arranged vertically, with the pivot axis 100 being arranged essentially perpendicular to a hallway level 101. The floor level 101 is defined by a surface on which the two rear wheels 6a, 6b, not shown here, stand up or roll during operation. The two rear wheels 6a, 6b, not shown, are mounted on the wheel carrier 9 so that they can rotate about a horizontal wheel rotation axis 102. The wheel rotation axis 102 is aligned parallel and/or in the same direction as the hallway level 101. In particular, the pivot axis 100 and the wheel rotation axis 102 are aligned at an angle, preferably at right angles, to one another.

The planetary gear 8 is designed as a three-stage planetary gear and has an input planetary stage P1, an intermediate planetary stage P2 and an output planetary stage P3, which are arranged axially one after the other and coaxially to the pivot axis 100. The input planetary stage P1 is arranged on the side of the steering drive 7 or a drive side of the planetary gear 8 and the output planetary stage P3 is arranged on the side of the wheel carrier 9 or an output side of the planetary gear 8.

The input planetary stage P1 has at its end an input sun gear section 16a which is non-rotatably connected to the drive shaft 15 and which meshes with input planetary gears 17a of the input planetary stage P1. The input planetary gears 17a are rotatably mounted on an input planetary carrier 18a of the input planetary stage P1.

The intermediate planetary stage P2 has an intermediate sun gear section 16b which is non-rotatably connected to the input planetary carrier 18a and which meshes with intermediate planetary gears 17b of the intermediate planetary stage P2. The intermediate planetary gears 17b are rotatably mounted on an intermediate planetary carrier 18b of the intermediate planetary stage P2.

The output planetary stage P3 has an output sun gear section 16c which is non-rotatably connected to the intermediate planetary carrier 18b and which meshes with output planetary gears 17c of the output planetary stage P3. The output planetary gears 17c are rotatably mounted on an output planetary carrier 18c of the output planetary stage P3.

In the exemplary embodiment shown, the drive shaft 15 is designed in one piece with the input sun gear section 16a, with the drive shaft 15 having running teeth at the end for this purpose. The intermediate and output sun gear sections 16b, 16c are each designed as a separate sun gear, which is positively and/or non-positively connected to the respective planet carrier 18b, 18c.

The output planet carrier 18c is formed on the wheel carrier 9, wherein for this purpose a plurality of planet bolts 19 are connected to the wheel carrier 9 in a rotationally fixed manner. For this purpose, the wheel carrier has a plurality of receiving openings 20 located around the pivot axis 100 on a common pitch circle, wherein one of the planet bolts 19 is mounted in a rotationally fixed manner, in particular pressed into each receiving opening 20.

The steering arrangement 2 has a support section 21, which serves to support the steering drive 7, in particular the stator 13, and to support the planetary gear 8. The support section 21 is designed as a bearing plate, which limits the steering drive 7 in the axial direction relative to the planetary gear 8. The Support section 21 has a motor bearing receptacle 22 in which a motor bearing 23 for supporting the drive shaft 15 is accommodated.

Directly adjoining the support section 21 is a drive housing section 24 for partially accommodating the steering drive 7 and a gear housing section 25 for partially accommodating the planetary gear 8. For example, the support section 21, the drive housing section 24 and the transmission housing section 25 are made from a common material section or are designed as a sheet metal component.

The steering arrangement 2 has a fastening flange 26, which is used to fasten the steering arrangement 2 to a vehicle frame, not shown, of the vehicle 1. The transmission housing section 25 and the fastening flange 26 are fastened or can be fastened together to the vehicle frame via a plurality of fastening openings 27 to form a transmission housing. For this purpose, a fastening means, not shown, can be mounted on the vehicle frame via the fastening opening 27. For example, the fastening means are designed as screws which are screwed into the vehicle frame from below via the fastening openings 27.

Furthermore, the steering arrangement 2 has a pivot bearing 28, which serves to rotatably mount the wheel carrier 9. The pivot bearing 28 has a first and a second pivot bearing 29a, 29b, which are each received in a pivot bearing seat 30a, 30b of the fastening flange 26. The two pivot bearings 29a, 29b are designed as tapered roller bearings in an O arrangement. The planetary stages P1, P2, P3 and the pivot bearing 28 are arranged coaxially and/or concentrically with respect to the pivot axis 100.

The wheel carrier 19 also has a cylinder section 31, which extends radially within the gear housing section 25 coaxially to the pivot axis 100 in the direction of the support section 21, the two pivot bearings 29a, 29b being supported in the radial direction on an outer circumference of the cylinder section 31. The planetary gear 8 or the planetary stages P1, P2, P3 are arranged or accommodated radially within the cylinder section 31. Due to the rotationally symmetrical structure of the steering arrangement 2, in addition to the small space requirement, an optimal distribution of force is achieved while at the same time keeping the weight low.

The pivot bearings 29a, 29b are supported in the axial direction with respect to the pivot axis 100 on the fastening flange 26 and the wheel carrier 9 and secured via a securing means 32. The securing means 32 is designed as a locknut, which is screwed on via a thread located on the support section 31 and is supported in the axial direction on the inner ring of the first pivot bearing 29a. This allows the preload of the pivot bearings 29a, 29b to be adjusted. In addition, the securing means 32 is secured against rotation by a securing plate 33 arranged between the securing means 32 and the first pivot bearing 29a.

The steering arrangement 2 has a sealing device 34, which is arranged radially between the fastening flange 34 and the wheel carrier 9 and seals the pivot bearing 28 and the planetary gear 8 against foreign particle entry from the outside, such as moisture, dirt, etc. The sealing device 34 is designed, for example, as a rotary seal, which ensures a dynamic seal between the wheel carrier 9 and the fastening flange 26 during a pivoting movement of the wheel carrier 9. A steering arrangement 2 is therefore proposed, which is characterized by exactly one or a single rotary seal for sealing the planetary gear 8.

The planetary gear 8 has a ring gear 35 arranged coaxially to the pivot axis 100, which is arranged radially within the cylinder section 31 and is connected to the support section 21 in a rotationally fixed manner. For this purpose, the ring gear 35 has a circumferential fastening collar 36, which is directed radially outwards and is fastened to the support section 21 in a rotationally fixed manner via one or more fastening means 37. The fastening means 37 are designed, for example, as screws, which are each screwed into a threaded hole in the fastening collar 36.

The ring gear 35 has an input, intermediate and output ring gear section 38a, 38b, 38c, the input planetary gears 17a meshing with the input ring gear section 38a, the intermediate planetary gears 17b with the intermediate ring gear section 38b and the output planetary gears 17c with the output ring gear section 38c. The ring gear sections 38a, 38b, 38c have, for example, a different number of teeth or a different tip circle diameter. A three-stage planetary gear 8 is therefore proposed, which is characterized by a single ring gear 35 for all planetary stages P1, P2, P3.

If a steering torque is generated by the steering drive 7, this is transmitted to the wheel carrier 9 via the drive shaft 15 and the three planetary stages P1, P2, P3, whereby it rotates relative to the fastening flange 26 about the pivot axis 100 is twisted. Here, the output planet carrier 18c, which is non-rotatably connected to the wheel carrier 9, is driven, with the ring gear 35 remaining stationary or fixed to the housing on the support section 21.

The steering arrangement 2 also has a sensor unit 39, which is designed to detect a steering angle of the wheel carrier 9. For this purpose, the sensor unit 39 has a sensor rod 40, which is guided coaxially with respect to the pivot axis 100 through the steering drive 7 and the planetary gear 8. For this purpose, the drive shaft 15 and the sun gear sections 16a, 16b, 16c each have a through opening 41 through which the sensor rod 40 is guided from a steering angle sensor 42 to the wheel carrier 9.

The sensor rod 40 has a form-fitting contour 43 at a first axial end, which is received in a form-fitting manner in a sensor rod receptacle 44 formed in the wheel carrier 9 in the direction of rotation around the pivot axis 100. The form-fitting contour 43 and the sensor rod receptacle 44 are coordinated with one another in such a way that the sensor rod 40 is permanently and clearly oriented towards the wheel carrier 9 against rotation about the pivot axis 100. In other words, the sensor rod 40 can be brought into engagement with the sensor rod receptacle 44 in just a single orientation.

In the interests of cost-effective production, the form-fitting contour 43 is designed, for example, as a flattened area which engages in an insert part 45 inserted in the sensor rod holder 44. The insert part 45 has, on the one hand, a form-fitting, unambiguous counter-contour to the form-fitting contour 43 and a form-fitting, unambiguous outer contour as a counterpart to an inner contour of the sensor rod holder 44. For example, the sensor rod holder 44 is designed in such a way that it can be produced simply and inexpensively with a slot milling cutter or an end mill and preferably has an L-shape in the travel path of the milling cutter. A form-fitting contour 43 which has an angle of 90° to the bisector of the L-shape is particularly advantageous. This ensures that the insert part 45, in any manner inserted, clearly positions the sensor rod 40 in a rotational manner relative to the pivot axis 100.

At a second axial end, the sensor rod 40 is connected in a rotationally fixed manner to a signaling sensor element 46, which can be detected by the steering angle sensor 42. For this purpose, the second axial end of the sensor rod 40 is also clearly positively connected to the sensor element 46, which thus carries out the rotation of the wheel carrier 9 about the pivot axis 100. Above the sensor element 46, the signal-receiving steering angle sensor 42 is arranged, which remains stationary or fixed to the housing when the sensor rod 40 is rotated. For example, the steering angle sensor 42 can be designed as a Hall sensor, with the sensor element 46 serving to influence a magnetic field that can be detected by the Hall sensor.

The steering arrangement 2 has a further support section 47, which serves to support the steering drive 7. The further support section 47 is designed as a further end shield, which limits the steering drive 7 in the axial direction relative to the sensor element 46. The further support section 47 has a further engine mount receptacle 48, in which a further engine mount 49 for supporting the drive shaft 15 is accommodated.

On the axial end face facing away from the steering drive 7, a sensor housing section 50 is arranged, on which the steering angle sensor 42 is mounted on the outside. The further support section 47 and the steering angle sensor 42 together form a sensor housing for the sensor element 46 in order to protect it against environmental influences.

3 shows an alternative embodiment of the steering arrangement 2 in the same representation as 2 , whereby only the main differences will be discussed below. The steering arrangement 2 of the 3 essentially differs in that the input planetary stage P1 is arranged on the side of the wheel carrier 9 and the output planetary stage P3 on the side of the steering drive 7.

Here, the output planet carrier 18c is formed on the support section 21, for which purpose several planet bolt sections 51 lying on a common pitch circle around the pivot axis 100 are formed on the support section 21 for the rotatable mounting of the output planet gears 18a. For example, the support section 21, the drive housing section 24, the gear housing section 25 and the planetary bolt sections 51 are made from a common material section or are designed as a sheet metal component.

The ring gear 35 is arranged radially within the cylinder section 31 and is connected to it in a rotationally fixed manner, the input planetary gears 17a meshing with the associated ring gear sections 38a, 38b, 38c. For this purpose, the ring gear 35 has a circumferential cutting toothing 52 on the outside, via which the ring gear 35 is pressed into the cylinder section 31.

In this embodiment, the intermediate and output sun gear sections 16b, 16c are each designed as a hollow shaft, with the drive shaft 15 being guided in the axial direction through the intermediate and output sun gear sections 16b, 16c. The drive shaft 15 thus penetrates with the input sun gear section 16a arranged at the end as far as the wheel carrier 9 and drives the input planet gears 17a there.

If a steering torque is generated by the steering drive 7, this is transmitted to the wheel carrier 9 via the drive shaft 15 and the three planetary stages P1, P2, P3, whereby it is rotated about the pivot axis 100 relative to the fastening flange 26. Here, the ring gear 35, which is non-rotatably connected to the wheel carrier 9, is driven, with the output planetary carrier 18c remaining stationary or fixed to the housing on the support section 21.

As with the in 2 In the variant shown, the sensor rod 40 penetrates the drive shaft 40 via the through opening 41 to the wheel carrier 9.

Reference symbols

1

Industrial truck

2

Steering arrangement

3

Front axle

4a,b

Front wheels

5

rear axle

6a,b

rear wheels

7

Steering drive

8th

Planetary gear

9

Wheel carrier

10

prime mover

11

Transfer case

12

Energy storage

13

stator

14

rotor

15

drive shaft

16a

Input sun gear section

16b

Intermediate sun gear section

16c

Output sun gear section

17a

Input planetary gears

17b

Intermediate planetary gears

17c

Output planetary gears

18a

Entrance planetary carrier

18b

Intermediate planetary carriers

18c

Output planetary carrier

19

planetary bolt

20

Recording opening

21

Support section

22

Engine mount mount

23

Engine mount

24

Drive housing section

25

Transmission housing section

26

mounting flange

27

mounting holes

28

Swivel bearing

29a,b

Pivot bearing

30a,b

Pivot bearing seat

31

Cylinder section

32

security means

33

locking plate

34

Sealing device

35

ring gear

36

Fastening collar

37

Fasteners

38a

Entrance holwheel section

38b

Intermediate wheel section

38c

Home holrade section

39

Sensor unit

40

Sensor rod

41

Passage opening

42

Steering angle sensor

43

Form-fitting contour

44

Sensor rod holder

45

Insert

46

Sensor element

47

another support section

48

additional engine mount mount

49

another engine mount

50

Sensor housing section

51

Planetary bolt sections

52

cutting teeth

100

Pivot axis

101

Hallway level

102

Wheel rotation axis

P1

Entrance planetary stage

P2

Intermediate planetary stage

P3

Output planetary stage

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006029283 A1 [0003]

Claims (15)

Steering arrangement (2) for an industrial truck (1), with a wheel carrier (9) for the rotatable mounting of at least one vehicle wheel (6a, 6b), the wheel carrier (9) being pivotable about a vertical pivot axis (100), with an electric steering drive ( 7) for generating a steering torque, with a multi-stage planetary gear (8) for transmitting the steering torque to the wheel carrier (9), the steering drive (7) being coaxial with the pivot axis (100) with an input planetary stage (P1) of the planetary gear (8) and the Wheel carrier (9) is connected coaxially to the pivot axis (100) with an output planetary stage (P3) of the planetary gear (8) in terms of transmission technology, with a support section (21) which can be fastened to a vehicle frame of the industrial truck (1) for supporting the steering drive (7) and the planetary gear (8), characterized in that either the support section (21) or the wheel carrier (9) forms an output planetary carrier (18c) of the output planetary stage (P3) of the planetary gear (8). Steering arrangement (2) according to Claim 1 , characterized in that the support section (21) is designed as a bearing plate of the steering drive (7). Steering arrangement (2). Claim 1 or 2 , characterized by a fastening flange (26) that can be fastened to the vehicle frame, the support section (21) being connected to the fastening flange (26) in a rotationally fixed manner and the wheel carrier (9) being pivotable via a pivot bearing (28) arranged concentrically to the planetary gear (8). the mounting flange (26) is supported. Steering arrangement (2). Claim 3 , characterized in that the wheel carrier (9) has a cylinder section (31) arranged coaxially to the pivot axis (100), the pivot bearing (28) being supported on an outer circumference of the cylinder section (31). Steering arrangement (2) according to Claim 4 , characterized in that the pivot bearing (28) is secured in the axial direction with respect to the pivot axis (100) via a securing means (32), wherein the securing means (32) is fixed to the outer circumference of the support section (21). Steering arrangement (2) according to one of the preceding claims, characterized in that the planetary gear (8) has a ring gear (35) arranged coaxially to the pivot axis (100), wherein the planet gears (17a, 17b, 17c) of all planetary stages (P1, P2, P3) are each in meshing engagement with a ring gear section (38a, 38b, 38c) of the ring gear (35). Steering arrangement (2) according to Claim 6 , characterized in that the ring gear (35) is connected in a rotationally fixed manner to the support section (21) when the wheel carrier (9) forms the output planet carrier (18c). Steering arrangement (2). Claim 6 , characterized in that the ring gear (35) is connected to the wheel carrier (9) in a rotationally fixed manner when the support section (21) forms the output planetary carrier (18c). Steering arrangement (2) according to one of the preceding claims, characterized in that the planetary gear (8) is designed as a three-stage planetary gear (8), an intermediate planetary stage (P2) being arranged between the input and output planetary stages (P1, P3), wherein the planetary gear (8) has an input sun gear section (16a), which is non-rotatably connected to a drive shaft (15) of the steering drive (7) and meshes with input planetary gears (17a) of the input planetary stage (P1), an intermediate sun gear section (16b), which is non-rotatably connected to an input planetary carrier (17a) of the input planetary stage (P1) and meshes with intermediate planetary gears (17b) of the intermediate planetary stage (P2), and an output sun gear section (16c) which is non-rotatably connected to an intermediate planetary carrier (18b) of the intermediate planetary stage (P2). is connected and is in meshing engagement with intermediate planetary gears (17b) of the output planetary stage (P3). Steering arrangement (2). Claim 9 , characterized in that the input planetary stage (P1) is arranged on the side of the steering drive (7) and the output planetary stage (P3) on the side of the wheel carrier (9) when the wheel carrier (9) forms the planetary carrier (18a), the Sun gear sections (16a, 16b, 16c) are arranged one behind the other in the axial direction. Steering arrangement (2). Claim 9 , characterized in that the input planetary stage (P1) is arranged on the side of the wheel carrier (9) and the output planetary stage (P3) on the side of the steering drive (7) when the support section (21) forms the planet carrier (18b), the Intermediate sun gear section (16b) and the output sun gear section (16c) are each designed as a hollow shaft (35) and the drive shaft (15) in the axial direction through the intermediate sun gear section (16b) and the output son nenrad section (16c) is guided to the side of the wheel carrier (9). Steering arrangement (2) according to one of the preceding claims, characterized by a sensor unit (39) for detecting a steering angle, the sensor unit (39) having a sensor rod (40) arranged coaxially to the pivot axis (100), which is rotationally fixed at a first axial end is connected to the wheel carrier (9) and is operatively connected at a second axial end to a steering angle sensor (42), the sensor rod (40) being guided coaxially to the pivot axis (100) through the steering drive (7) and the planetary gear (8). Steering arrangement (2). Claim 12 , characterized in that the drive shaft (15) and the sun gear sections (16a, 16b, 16c) of the planetary gear (8) each have a through opening (41) arranged coaxially to the pivot axis (100) for the passage of the sensor rod (40). Steering arrangement (2). Claim 12 or 13 , characterized in that the sensor rod (40) is permanently and clearly oriented towards the wheel carrier (9) in the direction of rotation around the pivot axis (100), the sensor rod (40) having a positive locking contour (43) at the first axial end, which in only can be brought into engagement in a single orientation with a sensor rod receptacle (44) on the wheel carrier (9) which is designed to be complementary to the form-fitting contour (43). Industrial truck (1) with the steering arrangement (2) according to one of the preceding claims.

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