DE102018218374A1 - transmission - Google Patents

Abstract

A gearbox (1) is provided with a spur gear stage (5) and a planetary stage (6) connected downstream of it, which are arranged in a gearbox housing (4), for translating an input speed of an input shaft (2) into slow speed. The input shaft (2) drives a sun gear (9) of the planetary stage (6) via the spur gear stage (5) consisting of a drive gear (7) and an output gear (8). Planet gears (11) arranged on a planet gear carrier (13) by means of bearing pins (27) are in engagement with the sun gear (9) and a ring gear (14). In order to improve the mounting of the driven gear, to save space on the gear housing and to achieve a compact construction of the gear, a drive shaft (10) of the planetary stage (6), which is non-rotatably connected to the sun gear (9), should also be fixed to the driven gear (8) of the spur gear (5), wherein this has axially projecting hub sections (15 and 16) on both sides of its transverse center plane with cylindrical outer jacket surfaces (21 and 22), and wherein the driven gear (8) via the outer jacket surface (21) of the first hub section (15) in the transmission housing (4) and on the outer circumferential surface (22) of the second hub section (16) on the planet gear carrier (13, 40, 46).

Description

The invention relates to a transmission for translating an input speed of an input shaft into slow speed with a spur gear stage and a planetary stage connected downstream thereof, which are arranged in a gear housing, the input shaft driving a sun gear of the planetary stage via the spur gear stage consisting of a drive wheel and an output gear, the means of which Bearing journals arranged on a planet gear carrier mesh with the sun gear and a ring gear.

Such gears are provided in order to translate a high input speed, which originates, for example, from an electric motor, into slow motion by means of the spur gear stage and the planetary stage and thereby increase the torque. The gears can be multi-stage spur gears or planetary gears. If, as in the present case, the spur gear stage is followed by a planetary stage, further planetary stages can follow to increase the transmission ratio of the planetary stage in the direction of the output. Such gears can be provided in particular in wheel drives of vehicles.

A transmission of the type specified in the preamble of claim 1 is from the DE 40 10 742 C1 known. Thereafter, a transmission of a drive unit is accommodated in a transmission housing which is closed on an open side by means of a cover, an electric motor being screwed onto the cover. A motor shaft of the electric motor, which forms an input shaft of the transmission, rotatably receives a drive wheel of a spur gear stage, which is in engagement with an output gear. This output gear is rotatably mounted on a pin extending from the cover and receives a disk carrier of a multi-disk brake, this disk carrier being connected via a cylindrical attachment to a sun gear of a so-called spur planetary gear serving as a planetary stage.

The sun gear meshes with planet gears, which are also in engagement with the internal toothing of a ring gear arranged in a rotationally fixed manner in the gear housing. The planet gears are rotatably mounted on bearing journals of a planet gear carrier which is connected to a wheel shaft by means of a toothing, a wheel flange formed in one piece with the wheel shaft being designed to receive a vehicle wheel. The multi-disc brake is operated via a two-armed lever, whereby a pressure pin moves the multi-disc carrier together with the driven gear, the shoulder and the sun gear relative to the other elements of the planetary stage, so that the brake discs are pressed together. It is intended to use such a transmission for driving an industrial truck, the multi-disc brake being to be arranged between the spur gear stage and the planetary stage.

It is an object of the present invention to provide an improved mounting of the driven wheel which can be arranged within the transmission housing in a space-saving manner in order to achieve a compact construction of the transmission.

This object is achieved on the basis of the preamble of claim 1 in conjunction with its characterizing features. The subsequent dependent claims each represent advantageous developments of the invention.

According to the invention, a transmission is provided for translating an input speed of an input shaft into slow speed and for this purpose has a spur gear stage and a planetary stage connected downstream thereof, which are arranged in a gear housing. In this case, the input shaft drives a sun gear of the planetary stage via the spur gear stage consisting of a drive gear and an output gear, the planet gears of which are arranged on a planet gear carrier by means of bearing journals and mesh with the sun gear and a ring gear.

In such an arrangement, the output is preferably carried out via the planet carrier, in which case the ring gear is connected in a rotationally fixed manner to the gear housing. Alternatively, however, it is also possible to design the planetary stage in such a way that the planetary gear carrier is fixed and driven off via the ring gear.

According to the invention, a drive shaft of the planetary stage that is non-rotatably connected to the sun gear is also rotatably connected to the driven gear of the spur gear stage.

An external toothing of the drive shaft and an internal toothing provided in a hub of the driven wheel interact in a form-fitting manner. Furthermore, the hub is formed on the driven wheel with hub sections projecting axially on both sides of its transverse center plane, each of which has a cylindrical outer circumferential surface.

These serve to ensure that the driven gear is mounted on the planet gear carrier via the outer lateral surface of the first hub section in the transmission housing and via the outer lateral surface of the second hub section. In the case of a corresponding gearwheel in which the hub is connected to the ring gear via a disk, the hub sections protrude beyond the disk on both sides. On the one hand, this results in an arrangement that saves installation space the radial mounting of the driven gear in the gear housing and opposite the planet carrier.

In contrast, the driven gear in the transmission according to the DE 40 10 742 C1 mounted on the pin extending from the cover via a centrally arranged cylindrical roller bearing, wherein there are also no hub sections projecting on both sides. The output gear and the disk carrier screwed to it perform an axial movement when the brake is actuated on the pin, so that the sun gear also moves. Accordingly, no storage is provided between the planet carrier and the driven gear.

According to a further embodiment of the invention, the first hub section is to be mounted in a recess of the gear housing via a first radial bearing. The radial bearing can be designed as a radial roller bearing, preferably as a ball bearing, angular contact ball bearing, inclined shoulder bearing or tapered roller bearing, which is pressed directly into the cylindrical recess by means of its outer ring. This results in a space-saving arrangement that enables the spur gear stage to be easily installed.

It is also provided that the second hub section is mounted on the journal of the planet carrier via a second radial bearing. Thus, the spur gear stage is supported radially and axially on the adjacent journal of the planet gear carrier, which results in a small space requirement. Furthermore, a longer service life of the bearing can be achieved because it is arranged between two gear elements, between which there are comparatively small speed differences. The number of rolling over of the rolling elements is therefore reduced.

The second radial roller bearing can also be designed as a ball bearing, angular contact ball bearing, inclined shoulder bearing or tapered roller bearing. If, as proposed, the planetary stage is operated with a planetary gear ratio, the ring gear is fixed in the gear housing and an output shaft connected to the planet gear carrier in a rotationally fixed manner is at least indirectly supported in the gear housing. A hub ring is preferably connected in one piece to a wheel flange, the hub ring receiving the output shaft being mounted in the transmission housing.

The transmission is preferably designed as a wheel hub transmission for an industrial truck, the input shaft being drivable via an electric motor and the output shaft being connected to a wheel flange. In the context of such an electric wheel drive, the electric motor is operated at a relatively high speed and low output torque. The present transmission ensures a relatively low speed and a high torque on its output shaft. One of the essential requirements is, moreover, that the transmission arranged directly in the area of the corresponding wheel of the industrial truck has an extremely compact design.

It is particularly advantageous if the bearing journals have extensions provided with recesses at their ends facing the driven wheel, a curved side surface being formed in each of the extensions by the recess produced therein and all side surfaces on a common one for receiving an outer ring of the second radial bearing Circle run. These extensions engage with their curved side surfaces which are adapted to the radius of the outer ring in partial circumferential areas of the outer ring.

In addition, there is also the possibility of designing the bearing journals in such a way that they each have a curved groove at their ends facing the driven wheel, all grooves running on a common circle. In this context, a hollow cylindrical retaining ring is provided, which is provided with axial projections, each of which engages in the grooves. The retaining ring, which can be produced in a non-cutting shaping process, thus receives the second radial roller bearing on its outer ring. The projections, which are designed as curved lugs, engage in the respective grooves of the bearing pins.

In a further embodiment of the invention, a bushing provided with a bottom, into which an outer ring of the first radial bearing is pressed, can be inserted into the recess of the transmission housing. The socket provided with the bottom can be produced in one piece without cutting, the bottom preferably having a smaller wall thickness than the socket. The recess provided in the gear housing for receiving the bushing can penetrate the wall thereof.

According to a further embodiment of the invention, a retaining ring, which surrounds an outer ring of the second radial bearing, is to be connected to end faces of the bearing journals. In a further development of this solution, the retaining ring is intended to be provided with holes for fixing it to the bearing journal, wherein grooved pins, dowel pins or dowel pins running in the holes engage in blind holes in the bearing journal.

Finally, the retaining ring can be fixed to the bearing journal by a screw or adhesive connection.

The invention is not limited to the specified combination of the features of the main claim and the claims dependent thereon. There are also possibilities for combining individual features with one another, also insofar as they emerge from the patent claims, the following description of preferred embodiments of the invention or directly from the drawings. The reference of the claims to the drawings by using reference numerals is not intended to limit the scope of the claims.

• 1 ein Getriebeschema eines Getriebes, das der vorliegenden Erfindung zugrunde liegt,
• 2 eine erste Ausführungsform des Getriebes, bei der Radialwälzlager zur Lagerung eines Abtriebsrades unmittelbar in einer Ausnehmung eines Getriebegehäuses und in einem Planetenträger einer Planetenstufe angeordnet sind, im Längsschnitt,
• 3 eine perspektivische Einzeldarstellung des nach der 2 verwendeten Planetenradträger,
• 4 eine zweite Ausführungsform eines Getriebes im Längsschnitt, wobei Lagerzapfen eines Planetenradträgers an ihren Stirnflächen einen Haltering aufnehmen, der ein Radialwälzlager an seiner Außenmantelfläche umschließt,
• 5 als perspektivische Darstellung eine im Maßstab verkleinerte Einzeldarstellung des nach der 4 verwendeten Planetenradträgers,
• 6 als perspektivische Darstellung den nach der 4 vorgesehenen Haltering,
• 7 einen Längsschnitt einer dritten Ausführungsform eines Getriebes, bei welcher eine hohlzylindrische Haltebuchse in gekrümmt verlaufenden Nuten von Lagerzapfen eines Planetenradträgers angeordnet ist,
• 8 als perspektivische Darstellung eine im Maßstab verkleinerte Einzeldarstellung des nach der 7 verwendeten Planetenradträgers und
• 9 als perspektivische Darstellung der nach der 7 verwendeten Haltebuchse.

Advantageous embodiments of the invention, which are explained below, are shown in the drawings. Show it:

• 1 1 shows a transmission diagram of a transmission on which the present invention is based,
• 2nd 1 shows a first embodiment of the transmission in which radial roller bearings for mounting an output gear are arranged directly in a recess in a transmission housing and in a planet carrier of a planetary stage,
• 3rd a perspective individual representation of the after 2nd used planet carrier,
• 4th 2 shows a second embodiment of a transmission in longitudinal section, bearing journals of a planetary gear carrier receiving a retaining ring on its end faces, which surrounds a radial roller bearing on its outer lateral surface,
• 5 as a perspective view a scaled down individual view of the after 4th used planet carrier,
• 6 as a perspective representation of the after 4th provided retaining ring,
• 7 2 shows a longitudinal section of a third embodiment of a transmission, in which a hollow cylindrical holding bush is arranged in curved grooves of bearing journals of a planet gear carrier,
• 8th as a perspective view a scaled down individual view of the after 7 used planet carrier and
• 9 as a perspective view of the after 7 used holding bush.

In the transmission diagram according to the 1 1 designates a gearbox, which has an input shaft 2nd from an electric motor 3rd is driven. In a gearbox 4th are a spur gear 5 and a planetary stage 6 arranged the gear 1 form. As part of the spur gear stage 5 drives the input shaft 2nd via a non-rotatably arranged drive wheel 7 an output gear 8th on, both this and a sun gear 9 rotationally fixed with a drive shaft 10th are connected. With the sun gear 9 comb four planet gears 11 , of which only one is visible in the transmission diagram. These planet gears 11 are rotatable in one with an output shaft 12th connected planet carrier 13 stored and engaged with a stationary in the gear housing 4th arranged ring gear 14 .

As can further be seen from the schematic illustration, the driven wheel is intended 8th Hub sections 15 and 16 have, which extend on both sides of its transverse central plane. Here is the hub section 15 via a first radial roller bearing 17th in a recess 18th of the gearbox 4th stored. The other hub section 16 extends in the direction of the planet carrier 13 and is on this via a second radial roller bearing 19th stored.

In those described below 2nd , 4th and 7 are different embodiments of the bearing of the driven gear 8th shown. So much for the other components of the transmission 1 coincide with each other, corresponding reference numerals are used for them.

After 2nd drives the rotation on the input shaft 2nd arranged drive wheel 7 the driven gear 8th at. This shows the hub sections 15 and 16 on both sides of its disc 20th extend axially. On outer surface 21 and 22 the hub sections 15 and 16 , which are designed step-like, they take the radial roller bearings 17th and 19th on.

Via the first radial roller bearing 17th is the driven gear 8th in the recess 18th of the gearbox 4th stored, the recess 18th partly by a stepped annular collar 24th is enclosed in the outer ring 23 of the radial roller bearing 17th is pressed. The second radial roller bearing 19th is with its inner ring on the outer surface 22 of the second hub section 16 fixed, its outer ring 25th on the planet carrier 13 is fixed.

As especially from the 3rd that the after the 2nd shows used planetary gear carrier, emerges, there is the planetary gear carrier 13 from a disc body 26 and the output shaft emanate from it 12th and on the other hand journal 27 with axial extensions 28 each with a recess 29 have, each of the recesses 29 due to a curved outer surface 30th is limited.

All exterior surfaces 30th run on a concentric to the planet carrier 13 running circle and grip the circumference of the outer ring 25th at. Thus, the driven gear 8th and the planet carrier 13 rotatably mounted to each other. The output shaft 12th is non-rotatable with a wheel flange 31 connected via two tapered roller bearings 32 and 33 in a wheel hub housing 34 is stored ( 2nd ).

The further design example after the 4th differs from that after the 2nd with regard to the formation of the bearing of the driven gear 8th and the planet carrier. Otherwise, the components of the transmission are correct 1 essentially corresponds to the corresponding components described for FIG. First it can be seen that the first radial roller bearing 17th from a socket 35 which is included a floor 36 having. This jack 35 is again in a recess 37 of the gearbox 4th used.

The second radial roller bearing 19th is in accordance with that in the 2nd shown on the outer surface 22 of the hub section 16 arranged while the outer ring 25th of the second radial roller bearing 17th in a retaining ring 38 is pressed. This retaining ring 38 is on journal 39 of a planet carrier 40 fixed what the trunnion for 39 from the front side with blind holes 41 are provided. Grooved pins 42 are through holes 43 of the retaining ring 38 passed through and reach into the blind holes 41 a.

In the 5 is the planet carrier 40 shown separately, with the one in the trunnion 39 blind holes produced 41 are recognizable. The planet carrier also consists of a disk body 44 and an output shaft integrally formed therewith 45 . The 6 shows the retaining ring 38 with the holes formed in it 43 .

The 7 shows a third embodiment of the invention, the general structure of this transmission again with that of the embodiment examples according to the 2nd and 4th agrees, which is why the same reference numerals are used for components of essentially the same design and these are not explained again. A difference compared to the execution after the 4th consists in the formation of between the driven gear 8th and a planet carrier provided storage.

In this case there is a planet carrier 46 with trunnion 47 by one with an output shaft 48 connected disc body 49 go out, provided, in their end faces 50 curved grooves 51 are trained. These grooves 51 run on a common circle and take a retaining ring 52 in which the outer ring 25th is pressed.

From the 8th goes the course of the in the end faces 50 the bearing journal 47 arranged grooves 51 forth. Again 9 can be seen, the retaining ring 52 , which is designed as a tube section, four axial projections 53 have according to the 7 in the grooves 51 intervention.

Reference list

1

transmission

2nd

Input shaft

3rd

Electric motor

4th

Gear housing

5

Spur gear

6

Planetary stage

7

drive wheel

8th

Output gear

9

Sun gear

10th

drive shaft

11

Planet gears

12th

Output shaft

13

Planet carrier

14

Ring gear

15

Hub section

16

Hub section

17th

first radial roller bearing

18th

Recess

19th

second radial roller bearing

20th

Slice of 8th

21

Outer surface of 15

22

Outer surface of 16

23

Outer ring of 17th

24th

ring-shaped waistband

25th

Outer ring of 19th

26

Disk body of 13

27

Bearing journal

28

axial extensions

29

Recess

30th

curved outer surface of 28

31

Wheel flange

32

Tapered roller bearings

33

Tapered roller bearings

34

Wheel hub housing

35

Rifle

36

Bottom of 35

37

Recess in 4th

38

Retaining ring

39

Bearing journal from 40

40

Planet carrier

41

Blind hole in 39

42

Notch pin

43

drilling

44

Disk body of 40

45

Output shaft

46

Planet carrier

47

Bearing journal

48

Output shaft

49

Disk body of 46

50

End faces of 47

51

Groove in 50

52

Retaining ring

53

Ledges

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 4010742 C1 [0003, 0012]

Claims (12)

Gearbox (1) for translating an input speed of an input shaft (2) into slow speed with a spur gear stage (5) and a planetary stage (6) connected downstream thereof, which are arranged in a gearbox housing (4), the input shaft (2) being connected by a Drive wheel (7) and an output gear (8) existing spur gear stage (5) drives a sun gear (9) of the planetary stage (6), the planet gears (13, 40, 46) of which are arranged on a planet carrier (13, 40, 46) by means of trunnions (27, 39, 47) 11) are in engagement with the sun gear (9) and a ring gear (14), characterized in that a drive shaft (10) of the planetary stage (6) which is non-rotatably connected to the sun gear (9) is also rotationally fixed with the driven gear (8) of the spur gear stage (5) is connected, this having axially projecting hub sections (15 and 16) on both sides of its transverse center plane with cylindrical outer jacket surfaces (21 and 22), and that the driven gear (8) via the outer jacket surface (21) of the first hub enabschnittes (15) in the gear housing (4) and on the outer surface (22) of the second hub portion (16) on the planet carrier (13, 40, 46). Gearbox after Claim 1 , characterized in that the first hub section (15) is supported by a first radial bearing (17) in a recess (18) of the gear housing (4). Gearbox after Claim 1 , characterized in that the second hub section (16) is mounted on the bearing journal (27, 39, 47) of the planet carrier (13, 40, 46) via a second radial bearing (19). Gearbox after Claim 1 , characterized in that the planetary stage (6) is operated with a rotary transmission, in which the ring gear (14) is fixed in the transmission housing (4) and an output shaft (12) connected non-rotatably to the planet carrier (13, 40, 46) at least indirectly in the Gear housing (4) is mounted. Gearbox after Claim 1 , characterized in that the gear (1) is designed as a wheel hub gear for an industrial truck, the input shaft (29 being drivable via an electric motor (3) and the output shaft (12) being connected to a wheel flange (31). Gearbox after Claim 3 , characterized in that the bearing pins (27) have at their ends facing the driven wheel (8) with recesses (29) provided with extensions (28), wherein in each of the extensions (28) through the recess made in it a curved Outer surface (30) is formed and to receive an outer ring (25) of the second radial bearing (19) all outer surfaces (30) run on a common circle. Gearbox after Claim 3 , characterized in that the bearing pins (39) each have a curved groove (51) at their ends facing the driven wheel (8) and that all grooves (51) run on a common circle. Gearbox after Claim 7 , characterized in that a hollow cylindrical retaining ring (52) is provided with axial projections (53) which each engage in the grooves (51). Gearbox after Claim 2 , characterized in that in the recess (29) of the gear housing (4) a socket (35) provided with a bottom (36) is inserted, into which an outer ring (23) of the first radial bearing (17) is pressed. Gearbox after Claim 3 , characterized in that a retaining ring (38) is connected to end faces of the bearing pins (39) and surrounds an outer ring (25) of the second radial bearing (19). Gearbox after Claim 10 , characterized in that the retaining ring (38) for fixing it to the bearing journal (39) is provided with bores (43), grooved pins (42), dowel pins or dowel pins running in the blind bores (41) of the bearing journals running in the bores (43) (39) intervene. Gearbox after Claim 10 , characterized in that the retaining ring (38) is fixed to the bearing journal (39) by a screw or adhesive connection.

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