WO2018083254A1

WO2018083254A1 - Arrangement for supporting a planet gear

Info

Publication number: WO2018083254A1
Application number: PCT/EP2017/078212
Authority: WO
Inventors: Christian Baumann; Daniel Wolf; Ümit Kutluay
Original assignee: Zf Friedrichshafen Ag
Priority date: 2016-11-07
Filing date: 2017-11-03
Publication date: 2018-05-11
Also published as: DE102016221756A1

Abstract

The invention relates to an arrangement for supporting a planet gear (1) by means of a planet pin (3) in a planet carrier (2) of a planetary gearset, wherein the planet gear (1) is arranged on the planet pin (3) and the planet pin (3) is held in the planet carrier (2) at ends of the planet pin by means of a first plain bearing (4) and a second plain bearing (5). According to the invention, the planet gear (1) is arranged on the planet pin (3) by means of a third plain bearing (6).

Description

Arrangement for mounting a planetary gear

The invention relates to an arrangement for mounting a planetary gear by means of a planetary pin in a planetary carrier of a planetary gear according to the preamble of claim 1.

By WO 2013/106878 A1, a planetary gear with a planet carrier and planet gears was known, which are each mounted by means of a planetary pin in the planet carrier. The planetary gear is rotatably mounted on the planet pins, z. B. by means of a press fit. In a further embodiment, planet gear and planet pins are integrally formed. The planetary pin is mounted on both sides of the planet gear by means of plain bearings, preferably of multi-layer plain bearings in the planet carrier. In this respect, each planet gear is mounted on two slide bearings relative to the planet carrier.

Hydrodynamic plain bearings have proven themselves for continuously rotating high-speed shafts. Problems can occur when the plain bearings are operated at low speeds or at low sliding speeds. This applies z. As for plain bearings in wind turbines, especially for the first stage of a transmission: here, due to low sliding speeds often subject to wear mixed friction.

An object of the invention is to improve the storage of planet gears in the planet carrier on, in particular critical conditions such. B. to avoid mixed friction or mitigate their harmful effect.

The invention comprises the features of claim 1. Advantageous embodiments will be apparent from the dependent claims.

According to the invention, the planet gear is mounted on the planet pin via a further slide bearing, ie the bearing of the planet gear in the planet carrier comprises a total of three slide bearings arranged on the planet pin. The planetary pin can thus be independent of the speed of the planetary gear in the two in Planet carrier arranged slide bearings rotate while the planetary gear can rotate independently of the speed of the planetary pin. Thus, a speed compensation between Planentenrad and planet pins or a compensation of the sliding speeds in the two outer plain bearings on the one hand and the middle plain bearing on the other hand is achieved. This results in the advantage that caused by mixing friction wear is reduced or avoided.

Of course, the inventive bearing arrangement applies not only to a planetary gear and a planetary pin, but also for the entirety of arranged in the planetary gear planetary gears, d. H. usually at least three. It is also within the scope of the invention that the bearing assembly according to the invention can be used outside of a planetary gear, for example in stationary gearboxes, for example, for supporting an intermediate gear on a bolt, which is mounted in a transmission housing. In addition, an application outside of gears in general engineering is possible, for example, for mounting a rotating member on an axis, which in turn is mounted on both sides in stationary slide bearings. The storage according to the invention is particularly suitable for sliding bearings with relatively low sliding speeds.

According to a preferred embodiment, the planetary pin is hollow, d. H. he has a substantially cylindrically shaped cavity, which firstly reduces the weight and also the heat dissipation is improved. In addition, the cavity offers the possibility of components such. B. for oil supply and to allow the supply of oil to the plain bearings.

According to a further preferred embodiment, the sliding bearings, a lubricant, preferably oil supplied via the planet carrier. The oil supply can take place either in the region of the outer plain bearings, which are located in the planet carrier, or by an oil collecting space in the planet carrier in the cavity of the planetary pin. According to a further preferred embodiment, the lubricant, in particular the oil from an oil sump into which the planetary gears are immersed with the planet pins, can be supplied. The rotating in a transmission housing planet carrier is open at the side, so that the hollow planet pins, when they dip into the oil sump, are filled with oil, which is sufficient for at least one revolution of the planet carrier for lubrication of the plain bearings. This is called passive oil supply.

According to a further preferred embodiment, the planet pin is formed as a bush made of a carrier material with a sliding layer. The support material for the bushing is preferably made of steel, while the arranged on the circumference of the steel bushing sliding layer of white metal or bronze or other suitable sliding bearing material consists. The socket can be simplified in several parts formed from cylinders of different material.

According to a further preferred embodiment, radial bores for the oil supply of the plain bearings are arranged in the bushing respectively the planet pins. The entering into the cavity of the planetary bolt oil can thus through the radial bores out into the bearings, d. H. get between the sliding surfaces.

According to a further preferred embodiment, grooves or helical grooves are provided on the circumference of the planetary bolt or the bush in the longitudinal or circumferential direction, which provide for the distribution of the oil on the sliding layer of the planetary pin.

According to a further preferred embodiment, an oil pump is arranged within the planetary bolt or the bush, which assumes an active oil supply of the sliding bearing. The arrangement of the oil pump in the cavity of the planetary bolt is a space-saving solution and an improved oil supply.

According to a further preferred embodiment, the oil pump is electrically and / or mechanically driven. Preferably, the oil pump has a coaxial with Planet pin arranged drive shaft, which protrudes outwardly from the planet pins and can be driven by a gear drive. In addition, a drive of the housing of the oil pump from the outside via a gear drive is also possible, so that the pump shaft and the housing can be driven simultaneously in opposite directions. Thus, an increased pump speed, combined with a larger flow rate is achieved.

According to a further preferred embodiment of the oil pump is associated with at least one memory for receiving oil. This may preferably be a memory on the suction side of the oil pump or a memory on the pressure side of the oil pump. Thus, a continuous oil supply of the plain bearings is achieved. The memory and / or the oil pump may be arranged in exemplary embodiments in the planetary pin or on the planet carrier.

According to a further preferred embodiment, the memory may be formed as a bubble, membrane or piston accumulator. Thus, commercial, d. H. inexpensive components used for the oil supply and are arranged to save space within the planetary bolt.

By introducing a load in the planetary gear, the planetary gear can tilt with respect to the axis of rotation, since form due to the helical teeth on ring gear and sun opposing forces. The tilting leads to areas with higher load (load zone) and lower load training. In order to be able to compensate for the lubricant pressure that forms in the load zone, a compensation device is provided, for example in the form of compensation bores between the load zones. These compensation holes are provided in addition to the through holes for oil supply. The compensation can be carried out between load zones on the same side (axially offset, small offset in the circumferential direction) and simultaneously or alternatively between opposite load zones. For the exchange between opposing bores flexible hose connections through the hollow planetary pin or spiral grooves on the inner cylinder jacket surface are conceivable, which by a second Zylinderman- be closed tel, wherein the second cylinder shell, for example, can be pressed or glued.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below, which may result from the description and / or the drawing further features and / or advantages. Show it

1 shows a sliding bearing according to the invention of a planetary gear by means of a planetary pin in a planet carrier,

2 shows a planetary gear with sliding bearing according to the invention and passive oil supply of the plain bearings,

3 shows the planetary gearbox with active oil supply via axial and radial bores in the planetary pin with oil supply via the planet carrier,

4 is a schematic representation of an active oil supply by means of mechanically driven oil pump and storage,

5 shows the planetary gear with active oil supply by means of pump and oil supply via the planet carrier,

Fig. 6 shows another embodiment of an active oil supply with memory on the pressure side of the oil pump and

7 shows a further embodiment of a passive oil supply with oil pump sucking from the oil sump.

Fig. 1 shows a simplified representation of a sliding bearing according to the invention of a planetary gear 1 in a planet carrier 2 by means of a planetary pin 3, which is designed as a hollow pin or socket 3. The planetary pin 3 is received in the planetary carrier 2 via a first sliding bearing 4 and a second sliding bearing 5, and the planetary gear 1 is rotatably mounted on the planetary pin 3 via a third sliding bearing 6. Due to its floating mounting, the planetary pin 3 is also referred to as "floating pin" 3. All plain bearings 4, 5, 6 are designed as hydrodynamic plain bearings and are supplied with a lubricating oil, which is not shown here. 2 shows a partially illustrated planetary gear 7, which comprises a housing 8, a planet carrier 9 rotatably mounted in the housing 8, and a planet gear 11 mounted in the planet carrier 9 via a planet pin 10. The planet gear 11, of which several are arranged on the circumference, engages on the one hand in a sun gear 12 and on the other hand in a ring gear 13 a. The planet carrier 9 corresponds to the planet carrier 2 in Fig. 1, the planetary pin 10, the planet shaft 3 and the planetary gear 11, the planetary gear 1 in Fig. 1. The planetary pin 10 is formed as a hollow body and has a socket 10 a of a carrier material, for. As steel and a sliding coating 10b, which forms a continuous cylindrical sliding surface. The planetary pin 10 with the sliding coating 10b forms with the planet carrier 9, a first sliding bearing 14 and a second sliding bearing 15 and the planetary gear 11, a third slide bearing 16. In the sleeve 10a and the sliding coating 10b are a plurality of continuous radial bores 17 for the oil supply of the sliding bearing 14th , 15, 16 arranged.

The oil supply to the plain bearings 14, 15, 16 via a swamp, not shown, which is located in the lower part of the transmission housing 8, not shown, and in which the planet carrier 9 with the planetary gears 11 and the planet pins 10 is immersed. The planet carrier 9 has on its left side in the drawing on an oil collection chamber 9a and an oil inlet opening 9b, through which oil enters during immersion in the oil sump and enters the interior of the planetary bolt 10, as illustrated by the angled arrow P. This is called passive oil supply.

Fig. 3 shows the planetary gear 7 as shown in Fig. 2, but with an alternative oil supply, a so-called active oil supply. For the same or analog parts, the same reference numerals as in Fig. 2 are used. The oil supply in this embodiment takes place via pressure oil, which passes from the housing 8 in the planet carrier 9, from this in the planetary pin 10 and from this to the plain bearings 14, 15, 16. Between the planet carrier 9 and the housing 8, a first rotary feedthrough 18 and between planet carrier 9 and planet pins 10, a further rotary feedthrough 19 is arranged, which is connected to the first rotary feedthrough 18 via a channel 20. In the socket 10a of Planetary bolt 10 are longitudinal bores 17a and outgoing therefrom transverse bores 17b arranged, via which the lubricating oil to the sliding bearings 14, 15, 16, respectively, the sliding surfaces is supplied. In the described type of active oil supply is a forced circulation lubrication.

The oil supplies described in FIGS. 2 and 3, d. H. The passive oil supply according to FIG. 2 and the active oil supply according to FIG. 3 can also be combined with each other, wherein for example the two outer plain bearings 14, 15 are lubricated via an active oil supply and the middle plain bearing 16 via the passive oil supply.

Fig. 4, which corresponds to Fig. 1, shows a further embodiment of the oil supply of the sliding bearings 4, 5, 6; the same reference numbers are used for the same or analog parts. In the cavity of the planetary pin 3, an oil pump 21 is arranged, which has a first outwardly projecting drive shaft 21a and a second to the opposite side of the planetary pin 3 outstanding drive shaft 21b. The first drive shaft 21 a corresponds to a pump or displacer shaft, while the second drive shaft 21 b is connected to the housing of the oil pump 21. Both drive shaft 21a, 21b are driven in opposite directions, so that there is an increased differential speed with respect to a stationary pump housing. The oil pump 21 is connected on the pressure side via a distributor channel 21c with the plain bearings 4, 5, 6. The two pump shafts 21a, 21b are driven via a first gear stage 22a and a second gear stage 22b. The pump 21 is associated with a memory 23 on the suction side, via which the oil pump 21 can supply oil. Alternatively, the oil pump can suck oil from the oil sump. In addition - which is not shown - another memory can be arranged on the pressure side of the pump, z. B. a bladder, so that the oil supply can be independent of the operating state.

FIG. 5 shows a further exemplary embodiment for an oil supply of the slide bearings 14, 15, 16 of the planetary gear 7, again using the same reference numbers as in FIGS. 2, 3 and 4. The oil supply of the plain bearings 14, 15, 16 follows here by means disposed in the cavity of the planetary bolt 10 pump 24 which is mechanically driven: the pump shaft 24a protrudes from the planetary pin 10 frontally and is driven via a gear stage 25, wherein one of the gears mounted on the pump shaft 24a and the other gear housing side is. On the suction side, the oil pump 24 is connected to the housing 8 via the oil rotary bushings 18, 19 and the channel 20. On the pressure side lines 26 lead the lubricating oil in the plain bearings 14, 15, 16.

Fig. 6 shows a further embodiment of an oil supply, which substantially corresponds to the embodiment of FIG. 5, again using the same reference numerals for the same or analogous parts. The oil pump 24 is the pressure side, an oil reservoir 27, which may be formed as a membrane or piston accumulator assigned. On the suction side, the oil pump 24 - as in the embodiment of FIG. 5 - via the oil rotary feeders 18, 19 connected to the housing 8.

Fig. 7 shows a further embodiment for an oil supply of the sliding bearing 14, 15, 16. In the cavity of the planetary pin 10 is a mechanically driven by a gear stage 25 oil pump 28 is arranged, which sucks the lubricating oil from the oil sump (not shown). The suction opening in the pump 28 is characterized by an angled arrow 28a. The oil pump 28 is the pressure side of a memory 27 - as in the embodiment of FIG. 6 - assigned. As stated above, the planetary pin 10 immersed due to the rotation of the planetary carrier 9 in each revolution in the oil sump. During the immersion phase, oil enters the cavity of the planetary pin 10, so that the pump 28 can suck in oil via the suction opening 28a and convey it into the reservoir 27. The oil pump 28 is driven by the gear stage 25. The housing-side gear of the gear stage 25 may preferably be formed as a toothed segment and arranged in the region of the oil sump, so that the pump 28 is driven only during the dipping phase. Preferably, a check valve (without reference numeral) is arranged in the pressure-side oil line of the pump 28, so that the plain bearings 14, 15, 16 are continuously supplied with lubricating oil. reference numeral

planet

planet carrier

planet shaft

first sliding bearing

second sliding bearing

third plain bearing

planetary gear

casing

planet carrier

a oil picking room

b oil inlet opening

0 planet pins

0a socket

0b slip coating

1 planetary gear

2 sun wheel

3 ring gear

4 first sliding bearing

5 second sliding bearing

6 third slide bearing

7 radial bore

7a longitudinal bore

7b transverse bore

8 rotary feedthrough

9 more rotary feedthroughs

0 channel

1 oil pump

1a first drive shaft

1 b second drive shaft

1c distribution channel

2a first gear stage b second gear stage

Storage

oil pump

a pump shaft

gear stage

oil line

oil storage

oil pump

a suction opening

flow arrow

Claims

claims

1. Arrangement for mounting a planetary gear (1, 11) by means of a planetary pin (3, 10) in a planetary carrier (2, 9) of a planetary gear (7), wherein the planetary gear (1, 11) on the planet pins (3, 10) arranged and the planet pins (3, 10) end over a first sliding bearing (4, 14) and a second sliding bearing (5, 15) is received in the planet carrier (2, 9), characterized in that the planet gear (1, 11) via a third sliding bearing (6, 16) on the planet pins (3, 10) is arranged.

2. Arrangement according to claim 1, characterized in that the planet pins (3, 10) is hollow.

3. Arrangement according to claim 1 or 2, characterized in that the sliding bearings (14, 15, 16) a lubricant via the planet carrier (9) can be fed.

4. Arrangement according to claim 1 or 2, characterized in that the sliding bearings (14, 15, 16) a lubricant via an oil sump, in which the planet pins (10) is fed, can be fed.

5. Arrangement according to claim 2, 3 or 4, characterized in that the planet pin (10) as a socket (10 a) of a carrier material with a sliding layer (10 b) is formed.

6. Arrangement according to claim 5, characterized in that in the bushing (10a) radial bores (17) are arranged for the oil supply.

7. Arrangement according to one of claims 1 to 6, characterized in that the planet pins (3, 10) has lubrication grooves on its circumference.

8. Arrangement according to one of claims 2 to 7, characterized in that within the planet bolt (3, 10) respectively of the bushing (10 a) an oil pump (21, 24, 28) is arranged.

9. Arrangement according to claim 8, characterized in that the oil pump (21, 24, 28) is mechanically and / or electrically driven.

10. Arrangement according to claim 9, characterized in that the oil pump (21, 24, 28) at least one memory (23, 27) is assigned.

11. The arrangement according to claim 10, characterized in that the at least one memory (23, 27) is designed as a bubble, diaphragm or piston accumulator.

12. Arrangement according to one of the preceding claims, characterized in that the planet pin (10) has at least one compensating device for compensating a lubricating pressure in the presence of load zones.