DE102018208975A1 - Industrial truck with a vehicle frame and with a travel drive - Google Patents

Abstract

The invention relates to an industrial truck with a vehicle frame (3) and a traction drive, wherein the traction drive comprises two drive units (1, 2), wherein the two drive units (1, 2) comprise two brake devices (8, 12), each drive unit ( 1, 2) each having a brake device (8, 12) is permanently assigned and wherein the traction drive further comprises a brake actuation unit (4) for the common actuation of the two brake devices (8, 12). The truck according to the invention is characterized in that at least one of the two drive units (1, 2) and the brake actuation unit (4) or at least the two drive units (1, 2) are connected via a mechanically direct coupling with the vehicle frame (3).

Description

The invention relates to an industrial truck with a vehicle frame and with a traction drive according to the preamble of claim 1.

In the prior art forklifts are known which are driven by two arranged on the front axle electric drive units. The drive units are individually and independently attached to the vehicle frame and serve both the acceleration of the truck during engine operation and the braking of the truck in generator mode. In the latter case, energy is recuperated, so that an operating life of the truck can be extended without recharging. To realize a parking and emergency braking function as well as to support the drive units at high requested braking torques mechanical brakes are usually still provided, which are integrated into the drive units. The mechanical brakes of the two drive units are actuated in each case via a separate actuator assembly. A further development of this concept envisages, while maintaining a paired use Einzelradantriebs, the two drive units firmly connected to each other, so that thereby vehicle forces can be absorbed. Also in this known drive concept two actuation arrangements for the two brakes are usually necessary.

In this context, the describes DE 102 25 038 B4 a drive axle with integrated brake for electric motor driven vehicles, especially for industrial trucks. The drive axle comprises a single-wheel drive for each of the two drive wheels, wherein each independent wheel drive comprises a motor, a transmission and a brake device. For actuating both brake devices, a common actuating unit is provided, wherein the actuating unit is designed as a ball ramp actuator. All components of the drive axle according to DE 102 25 038 B4 are comparatively compact integrated in a common assembly.

From the DE 10 2013 203 401 A1 a drive axle is known which only with respect to the brake of the drive axle of DE 102 25 038 B4 different. The brake of DE 10 2013 203 401 A1 consists of two rotating elements and two non-rotatably held elements, the non-rotatably held elements containing an electrically controllable magnet and are arranged between the two rotating elements. The two rotating elements are each rotatably connected to a drive shaft of one of two drive motors. Upon actuation of the brake for braking, the two rotatably held elements are moved so that they come into contact with the rotating elements and a Reibbremswirkung arises. All elements and components of the drive axle of the DE 10 2013 203 401 A1 are arranged in a common housing and connected to a unit.

However, the known drive units are disadvantageous in that they occupy either comparatively much space, provided that they consist of two individual drive units, each with a single brake and each a single brake operation, or that in case of service, replacing only a single, defective drive unit not possible if it is an integrated drive axle with a common brake actuation unit.

It is an object of the present invention to propose an improved industrial truck.

This object is achieved by the truck with a vehicle frame and with a traction drive according to claim 1. Advantageous embodiments and further developments of the invention will become apparent from the dependent claims.

The invention relates to an industrial truck with a vehicle frame and with a traction drive, wherein the traction drive comprises two drive units, wherein the two drive units comprise two braking devices, each drive unit each having a brake device is fixedly assigned and wherein the traction drive further comprises a brake actuation unit for common actuation of the two braking devices includes. The truck according to the invention is characterized in that the two drive units and the brake actuation unit or at least the two drive units are connected via a mechanically direct coupling with the vehicle frame.

The invention thus describes an industrial truck whose traction drive is designed in accordance with one of the following two alternatives: either only the two drive units are connected to the vehicle frame via a mechanically direct coupling or the two drive units and additionally the brake actuation unit are mechanically coupled directly to the vehicle frame connected.

Both alternatives offer the advantage that a common housing for the travel drive for receiving the three elements can be omitted. This saves space and weight. In addition, in the case of service comparatively easy a defective element be expanded and replaced. Also, the desired gauge of the truck with the greatest possible flexibility can be selected by the installation positions of the two drive units. When using a known traction drive, in which both drive units are integrated in a common housing, the gauge would, however, be fixed. At most on the press-in depth of the wheel rims, the gauge could be influenced here to a small extent.

Furthermore, there is the advantage that it is not necessary to provide a separate brake actuation unit for each drive unit. Instead, according to the invention, only a single brake actuation unit is provided for the common actuation of the two brake devices. This saves costs and installation space.

The truck according to the invention thus combines the advantage of the flexible individual arrangement of the two drive units and the brake actuation unit with the advantage of being able to actuate both brake devices of the two drive units via a common brake actuation unit.

Since according to the invention only at least two of the three elements of the traction drive are mechanically connected directly to the vehicle frame, it may happen that the third, not mechanically directly connected to the vehicle frame element, must be mechanically directly connected to one of the other two elements. In this case, preferably a drive unit and the brake actuation unit are connected via a mechanically direct coupling, which is relatively easy to accomplish because of the usual arrangement of the brake actuation unit axially between two drive units.

The term "connected via a mechanically direct coupling" is understood in the context of the invention, an immediate coupling of the corresponding elements of the drive with each other or with the vehicle frame, ie, several elements or all elements of the drive are - if they are connected via a mechanically direct coupling are - not grouped into modules, which are then arranged together on other elements of the vehicle frame. In particular, a housing enclosing all elements is not provided. A housing enclosing the elements would connect the elements only via a mechanically indirect coupling with the vehicle frame of the truck, since the elements would be connected via a mechanically direct coupling with the housing and the housing in turn would be connected via a mechanically direct coupling with the vehicle frame. The coupling between the elements and the vehicle frame would thus only be indirect.

It is preferably provided that the braking devices are integrated in a housing of the respective drive unit. This allows a comparatively compact design of the drive units, without having to provide additional external braking devices, which in turn would require its own housing.

Each drive unit advantageously comprises, in addition to the braking device, a reduction gear and a drive unit. In addition, a drive wheel can be arranged on the drives of the drive units. Thus, the drive units provide in a very compact way all the resources required for the actual drive of the truck.

Furthermore, it is preferably provided that the brake actuation unit is arranged axially in the middle between the two drive units, wherein the brake devices of the drive units each face the brake actuation unit. This makes it easier to operate both brake devices together by the one brake actuation unit.

Since the two drive units and the brake operating unit according to the invention are at least partially not connected to each other via a mechanically direct coupling, but advantageously even all and exclusively connected to the vehicle frame of the truck via a mechanically direct coupling, there is the problem that spacings of the two drive units and the Brake actuation unit are characterized by each other by manufacturing tolerances of the vehicle frame. This may possibly lead to a spacing of the brake actuation unit from being too large or too small for one or both of the two drive units, in that the brake actuation unit could still actuate the brake device of the corresponding drive unit. Therefore, it is preferably provided to adjust the position of the drive units on the vehicle frame via e.g. disc-shaped inserts to be able to change, the inserts can be arranged as needed between the corresponding drive unit and the vehicle frame in order to change a spacing of the corresponding drive unit to the brake operating unit in small steps.

Moreover, it is preferred that the two braking devices are designed as service brakes.

Also preferably, a parking brake is additionally provided.

According to a preferred embodiment of the invention, it is provided that the two drive units, the two brake devices and the brake actuation unit are each connected exclusively to the vehicle frame and not with each other via a mechanically direct coupling. This results in a particularly simple interchangeability of the drive units or the brake actuation unit in case of service, since each element can be removed individually and without affecting the other elements of the vehicle frame. The gauge can also be set very flexible.

According to a further preferred embodiment of the invention, it is provided that the travel drive further comprises sealing collars, which seal the two drive units against the brake actuation unit. Since the two drive units and the brake actuation unit are each connected via a mechanically direct coupling with the vehicle frame, but not with each other, depending on the manufacturing or installation tolerances of the elements in the truck or the vehicle frame different sized gaps or spacings between the occur individual elements of the drive, which in turn allows the ingress of dirt. However, such contamination can hinder the functioning of the brake operating unit or even completely block. By providing the sealing collars between the drive units and the brake actuation unit, the ingress of contaminants is prevented here or at least considerably more difficult.

It is preferably provided that the sealing collars are flexible, in particular made of rubber. This has proven to be particularly suitable against the ingress of contaminants. In addition, so different sized gaps or spacings of the elements of the travel drives can be sealed with a uniform embodiment of the sealing sleeve.

According to another preferred embodiment of the invention, it is provided that the mechanically direct coupling is designed as a detachable screw connection or as a detachable clamping connection. Both types of coupling mentioned on the one hand offer a sufficient degree of reliability, robustness and stability and on the other hand advantageously the ability to expand and replace defective elements comparatively easy.

In general, all types of mechanically direct coupling are preferred, which ensure both a reliable arrangement of the elements on the vehicle frame and are solvable, so allow easy attachment, removal or replacement of the elements.

According to a further preferred embodiment of the invention, it is provided that the brake actuation unit comprises a ball ramp actuator. A brake actuation unit having a ball ramp actuator is typically operated by having one or more pistons exert mechanical force on the ball ramp actuator. In this case, the rotatable discs of the ball ramp actuator are rotated, whereby both discs are moved apart due to a slope of the ball raceways. This increases the width of the Kugelrampenaktuators, which in turn creates a mechanical force that acts on the braking devices of the drive units and can operate them.

It is preferably provided that pressure pieces are provided between the ball ramp actuator and the two brake devices, which reliably transmit the mechanical pressure generated by the ball ramp actuator, which acts on the brake devices, even in the case of possibly existing axial position deviations or axial inclination deviations of the drive units. The pressing pieces compensate for any existing axial position deviation or inclination deviation by transmitting the mechanical pressure generated by the ball ramp actuator in a substantially point-shaped manner and centrally to the braking devices. Preferably, a pressing piece is provided for each braking device. The pressing pieces are preferably formed substantially disc-shaped, but they have on their respective braking device side facing a substantially hemispherical elevation over which the pressure generated by the ball ramp actuator pressure can be transmitted substantially point-like.

According to an alternatively preferred embodiment of the invention, it is provided that the brake actuation unit comprises hydraulically or pneumatically operable pistons or mechanically actuated pressure discs. In this case, the braking devices of the drive units are actuated by hydraulic or pneumatic pistons or by mechanically actuated pressure discs. This provides an efficient and proven alternative to using a ball ramp actuator. In particular, hydraulic brake systems are widely used in various vehicle brake systems, proven many times and technically mature. The mechanically actuated thrust washers are functionally identical to the hydraulically or pneumatically operable pistons, but are operated purely mechanically, e.g. via mechanical springs.

According to another alternative preferred embodiment of the invention, it is provided that the brake actuation unit comprises mechanical levers. This represents a further and likewise feasible possibility for actuating the braking devices. The braking devices of the drive units are actuated by the mechanical levers. The mechanical levers are advantageously operated via a Bowden cable.

According to another alternative preferred embodiment of the invention, it is provided that the brake actuation unit comprises at least one electromagnet. By energizing the at least one electromagnet and the resulting magnetic field, for example, a magnetic actuator or more magnetic actuators can be actuated, which then in turn or in turn actuates or actuate the braking devices of the drive units.

According to a further preferred embodiment of the invention, it is provided that the brake actuation unit is designed to keep the two brake devices actuated in the idle state. That is, the brake operating unit must operate the brake devices to cancel a braking action of the brake devices. Only in the actuated state of the brake operating unit, the brake devices generate no braking effect. In the non-actuated state of the brake actuation unit, however, the brake actuation unit actuates the brake devices, so that they produce a braking effect. This has proved to be advantageous in terms of the reliability of such a truck, as thus the brake devices are automatically actuated in a failure of the brake operating unit and bring the truck quickly to a standstill. The risk of property damage and personal injury due to malfunctioning brake functionality can thus be significantly reduced. This embodiment is particularly suitable for brake actuation units which operate the brake devices electromagnetically.

According to a further preferred embodiment of the invention, it is provided that the two braking devices are designed as disc brakes. Multi-disc brakes allow a comparatively precise metering of the braking effect and are comparatively low-wear and therefore low maintenance. In addition, they can be actuated very easily by applying a mechanical pressure from the axial direction.

It is preferably provided that inner disks of the multi-disc brake are arranged at one end of a shaft driven by the drive unit of the drive unit and that outer disks are arranged on the housing of the drive unit. The shaft driven by the drive unit of the drive unit is particularly preferably a motor shaft. Thus, a drive torque and a drive speed of the drive unit can be braked quickly and effectively.

According to a further preferred embodiment of the invention, it is provided that the two drive units are designed as electromotive drive units. The drive units are accordingly electric motors. Electromotive drive units are compact, have a comparatively high torque and are locally emission-free. As a result, they are particularly suitable for the traction drive of industrial trucks, since they themselves must be as compact as possible in order to be able to operate in comparatively narrow and often non-ventilated or poorly ventilated warehouses.

The invention will be explained by way of example with reference to embodiments shown in the figures.

• 1 beispielhaft einen Fahrantrieb für ein nicht dargestelltes Flurförderzeug,
• 2 einen stellenweisen Querschnitt durch den Fahrantrieb,
• 3 die Bremsbetätigungseinheit sowie die anliegenden Bereiche der Antriebseinheiten,
• 4 ebenfalls die Bremsbetätigungseinheit sowie die anliegenden Bereiche der Antriebseinheiten und
• 5 beispielhaft den Übergang der Bremsbetätigungseinheit zu einer Antriebseinheit.

It shows:

• 1 an example of a traction drive for a truck, not shown,
• 2 a local cross-section through the drive,
• 3 the brake actuation unit and the adjoining areas of the drive units,
• 4 also the brake control unit and the adjacent areas of the drive units and
• 5 exemplifies the transition of the brake actuation unit to a drive unit.

Identical objects, functional units and comparable components are denoted by the same reference numerals across the figures. These objects, functional units and comparable components are identical in terms of their technical features, unless the description explicitly or otherwise implies otherwise.

1 shows an example of a traction drive for a truck, not shown, consisting of two independently in a vehicle frame 3 (only partially shown in 1 ) installed drive units 1 and 2 , The drive unit 1 and the drive unit 2 are doing a mechanically direct coupling with the vehicle frame 3 connected. Axially centered between the drive units 1 and 2 is a brake control unit 4 arranged. The brake control unit 4 is also via a mechanically direct coupling with the vehicle frame 3 connected, but not with the drive units 1 and 2 , Also the drive units 1 and 2 are not connected to each other via a mechanically direct coupling. The drive unit 1 is according to the example with the vehicle frame 3 at the junction 25 firmly connected via a mechanically direct coupling. The drive unit 2 is with the vehicle frame 3 at the junction 26 firmly connected via a mechanically direct coupling. In the couplings of the drive units 1 and 2 to the vehicle frame 3 For example, each is by means of three screws 30 manufactured screw connections, which ensure a sufficiently high stability of the connection. In addition, the screw connections are detachable again, so that the drive units 1 and 2 eg in case of service simple and fast from the vehicle frame 3 can be solved. The vehicle frame 3 is comparatively stiff and ensures accurate positioning of the drive units 1 and 2 so that the required distance between the brake control unit 4 and the drive units 1 and 2 is reproducible with sufficient accuracy to the distance tolerance with the actuating travel of the brake operating unit 4 compensate.

2 shows a cross-sectional view through the drive units 1 and 2 as well as the brake actuation unit 4 of the 1 , The brake control unit 4 is with her case 29 at the junction 27 with the vehicle frame 3 firmly connected via a mechanically direct coupling. Again, the mechanically direct coupling via a screw connection by means of screws 30 produced. One as an electric motor 7 trained drive unit 7 the drive unit 1 drives a reduction gear 5 the drive unit 1 on. Likewise drives as an electric motor 11 trained drive unit 11 the drive unit 2 a reduction gear 9 the drive unit 2 on. At an output 6 of the reduction gear 5 as well as on a downforce 10 of the reduction gear 9 In each case, an unillustrated drive wheel can be mounted, which by the drive unit 1 respectively. 2 can be driven or braked.

3 and 4 show the brake control unit 4 as well as the adjacent areas of the drive units 1 and 2 of the 1 and 2 again in more detail and from different views. 3 shows a longitudinal section, 4 a cross section. As can be seen, is located on the reduction gear 5 opposite side of the electric motor 7 one end of a motor shaft 13 , which the inner fins 16 the drive unit 1 associated multi-disc brake 8th receives. Accordingly, located on the reduction gear 9 opposite side of the electric motor 11 one end of a motor shaft 14 , which the inner fins 16 the drive unit 2 associated multi-disc brake 12 receives. The motor shaft 13 and the inner plates 16 are non-rotatable but axially displaceable connected to each other. The outer disks 15 the multi-disc brake 8th are non-rotatable but axially displaceable with a housing 23 the drive unit 1 connected. The inner disks 16 and the outer plates 15 the multi-disc brake 8th are mutually arranged to the required friction surface between the inner plates 16 and the outer plates 15 provide. A lid 17 is fixed to the case 23 the drive unit 1 , eg by screws 30 connected (see 5 ). The lid 17 and the case 23 are neither mutually rotatable nor mutually axially displaceable. The lid 17 takes a pressure washer 18 on. The pressure disc 18 Functionally corresponds to a piston, which is hydraulically or pneumatically actuated, for example. In contrast to a hydraulic or pneumatic operability, the thrust washer 18 however, a purely mechanical operability. In the unactuated state of the multi-disc brake 8th is the distance between the motor housing 23 and the pressure disc 18 in the area of the disk pack 8th greater than the total thickness of the inner plates 16 and outer plates 15 the multi-disc brake 8th , The inner disks 16 and the outer plates 15 can move without axial force. This creates no braking torque between the motor shaft 13 and the housing 23 , The pressure disc 18 is by springs 28 (please refer 5 ) axially against the lid 17 pressed. The multi-disc brake 8th is in one of the housing 23 , the lid 17 and the pressure disc 18 enclosed space formed partly with oil for lubrication of the multi-disc brake 8th can be filled. The structure of the drive unit 2 is a mirror image of the structure of the drive unit 1 , The drive unit 2 includes a lid 17 ' , the case 24 , a pressure washer 18 ' , Inner fins 16 ' and outer plates 15 ' ,

Between the drive unit 1 and the drive unit 2 is the brake control unit 4 , The housing 29 the brake operating unit 4 takes the parking brake actuator 22 and the service brake actuator 21 on. A ball ramp actuator 20 gets from the case 29 guided radially and is movable in the axial direction. The brake control unit 4 has no direct mechanical coupling with the drive units 1 and 2 , The drive units 1 and 2 as well as the brake actuation unit 4 are just above the vehicle frame 3 indirectly connected. The positions of the drive units 1 and 2 and the brake control unit 4 can thus have relatively large deviations from each other. If necessary, the axial position of the drive units 1 and 2 with inserts between the drive units 1 and 2 and the vehicle frame 3 be set. Of the ball ramp 20 can the operating force on pressing pieces 31 even with possible axial position deviations and axis pitch deviations of the axes 32 of the motor 7 . 33 of the motor 11 and 34 the brake operating unit 4 to each other so on the pressure discs 18 . 18 ' the drive units 1 and 2 transmit that a sufficiently even distribution of pressure on the disc brakes 8th and 12 is guaranteed, since the corresponding force approximately punctiform and centered on the pressure discs 18 . 18 ' is transmitted.

The ball ramp actuator 20 is actuated by the pressure washer 18 . 18 ' of the parking brake actuator or the service brake actuator are pressed in the direction of the center of the axle. This increases the width of the Kugelrampenaktuators 20 , The pressure disc 18 move on the multi-disc brakes 8th and 12 until an axial force acts on it. As a result of this axial force, a braking torque between the motor shaft 13 and the housing 23 as well as the motor shaft 14 and the housing 24 be built, which by the engines 7 and the reduction gear 5 or the engine 11 and the reduction gear 9 is transmitted to the drive wheels.

5 shows an example of the transition of the brake operating unit 4 to the drive unit 1 , To the brake control unit 4 To protect against dirt are sealing collars 19 between the brake control unit 4 and the engines 7 and 11 be provided. The sealing collars 19 are made of rubber and thus elastic, so that they have a position and angle deviations of the drive units 1 and 2 and the brake control unit 4 allow and compensate

LIST OF REFERENCE NUMBERS

1

drive unit

2

drive unit

3

vehicle frame

4

Brake actuation unit

5

Reduction gear

6

output

7

Drive unit, electric motor

8th

Brake device, multi-disc brake

9

Reduction gear

10

output

11

Drive unit, electric motor

12

Brake device, multi-disc brake

13

motor shaft

14

motor shaft

15, 15 '

outer disk

16, 16 '

inner disk

17, 17 '

cover

18, 18 '

pressure washers

19

sealing sleeve

20

ball ramp

21

service brake actuator

22

Parkbremsenaktuator

23

casing

24

casing

25

junction

26

junction

27

junction

28

feathers

29

casing

30

screw

31

Plungers

32

axis

33

axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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 10225038 B4 [0003, 0004]
• DE 102013203401 A1 [0004]

Claims (11)

Truck with a vehicle frame (3) and with a traction drive, wherein the traction drive comprises two drive units (1, 2), wherein the two drive units (1, 2) comprise two braking devices (8, 12), each drive unit (1, 2) a brake device (8, 12) is permanently assigned, and wherein the travel drive further comprises a brake actuation unit (4) for the common actuation of the two brake devices (8, 12), characterized in that the two drive units (1, 2) and the brake actuation unit ( 4) or at least the two drive units (1, 2) are connected via a mechanically direct coupling with the vehicle frame (3). Truck after Claim 1 , characterized in that the two drive units (1, 2), the two brake devices (8, 12) and the brake actuation unit (4) are each connected exclusively to the vehicle frame (3) and not to each other via a mechanically direct coupling. Truck after at least one of Claims 1 and 2 , characterized in that the traction drive further comprises sealing collars (19) which seal the two drive units (1, 2) against the brake actuation unit (4). Truck after at least one of Claims 1 to 3 , characterized in that the mechanically direct coupling is designed as a detachable screw connection or as a detachable clamping connection. Truck after at least one of Claims 1 to 4 , characterized in that the brake actuating unit (4) comprises a ball ramp actuator (20). Truck after at least one of Claims 1 to 4 , characterized in that the brake actuating unit (4) comprises hydraulically or pneumatically acting piston. Truck after at least one of Claims 1 to 4 , characterized in that the brake actuating unit (4) comprises mechanical levers. Truck after at least one of Claims 1 to 4 , characterized in that the brake actuating unit (4) comprises at least one electromagnet. Truck after at least one of Claims 1 to 8th , characterized in that the brake actuating unit (4) is adapted to keep the two braking devices (8, 12) operated in the idle state. Truck after at least one of Claims 1 to 9 , characterized in that the two braking devices (8, 12) as lamellae brakes (8, 12) are formed. Truck after at least one of Claims 1 to 10 , characterized in that the two drive units (1, 2) as electromotive drive units (1, 2) are formed.

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