Abstract
The invention relates to a transmission (10), preferably a bevel helical transmission, having a transmission housing (1) and having a drive shaft (2.1), on which a fan (9) is mounted, and comprising a ring cooler (4), which surrounds the drive shaft (2.1), oil lines (7.1, 7.2) for transporting transmission oil in an oil circuit from the interior of the transmission housing (1) to the ring cooler (4) and from the ring cooler (4) into the interior of the transmission housing (1), and an air-guiding hood (3.1, 3.2) surrounding the ring cooler (4) for guiding air suctioned by the fan (9) onto the ring cooler (4).
Claims
1. A transmission (10), preferably a bevel helical transmission, with a transmission housing (1) and a drive shaft (2.1) on which a fan (9) is mounted, comprising a ring cooler (4) which surrounds the drive shaft (2.1), oil lines (7.1, 7.2) for transporting transmission oil in an oil circuit from the interior of the transmission housing (1) to the ring cooler (4) and from the ring cooler (4) into the interior of the transmission housing (1), and an air-guiding hood. (3.1, 3.2) which surrounds the ring cooler (4) for the purpose of guiding air that is sucked in by the fan (9) onto the ring cooler (4), characterized in that the ring cooler (4) has a square basic shape and four cooling elements (4.1), these being arranged along the sides of a square, wherein the cooling elements (4.1) are connected by means of four connecting reservoirs (4.2), wherein the connecting reservoirs (4.2) serve as corner connectors at the corners of the square, at which the oil streams from parallel pipes (4.5) of the ring cooler (4) are mixed together.
2. The transmission as claimed in claim 1, comprising a pump (6) which is connected into the oil circuit and can be driven by a transmission shaft (2.2) of the bevel helical transmission (10).
3. The transmission as claimed in claim 1 or 2, wherein the ring cooler (4) comprises an inlet opening (4.3) for transmission oil and an outlet opening (4.4) for transmission oil, via which the ring cooler (4) is connected into the oil circuit, and one or more pipes (4.5), these running between the inlet opening (4.3) and the outlet opening (4.4) and surrounding the drive shaft (2.1), for the purpose of transporting transmission oil under pressure.
4. The transmission as claimed in claim 3, wherein the ring cooler (4) has slot-type openings (4.6) serving as air channels between the pipes (4.5).
5. The transmission as claimed in claim 4, wherein fins are arranged in the slot-type openings (4.6).
6. The transmission as claimed in one of the preceding claims, wherein the ring cooler (4) radially surrounds the drive shaft (2.1) over its entire axial extent, as far as said drive shaft (2.1) extends outside the transmission housing (1).
7. The transmission as claimed in one of the preceding claims, wherein the drive shaft (2.1) is supported in a bearing cup (5) and the ring cooler (4) surrounds the bearing cup (5) in addition to the drive shaft (2.1).
8. The transmission as claimed in one of the preceding claims, wherein the fan (9) is an axial fan or a radial fan.
Description
[0035] FIG. 1 shows an oblique view of a bevel helical transmission 10 with a ring cooler 4. An essentially cuboid transmission housing 1 comprising two end faces, two side faces, a floor and a lid, has at the drive-side end face a bearing cup 5 in which a drive shaft 2.1 is supported. By means of a bevel stage (not shown) which is arranged in the interior of the transmission housing, the rotation of the drive shaft 2.1 is transmitted to a first intermediate shaft 2.2, which is supported in the two opposing side faces of the transmission housing 1. From there, the rotation is transmitted via a second intermediate shaft 2.3 to a drive shaft 2.4, both of these being supported parallel to the first intermediate shaft 2.2 in the side faces of the transmission housing 1. The drive shaft 2.1 has a feather key for connecting to a motor shaft and the drive shaft 2.4 has a feather key for connecting to a machine.
[0036] Situated in the lower region of the transmission housing, i.e. above the floor, is an oil sump 8 where the transmission oil which is contained in the interior of the transmission housing 1 and used for lubrication and cooling collects due to gravitation. A through-hole at which a first oil line 7.1 begins is incorporated in a side face of the transmission housing 1 in the region of the oil sump 8. The first oil line 7.1 leads to a flange pump 6, which is arranged at the end face of the first intermediate shaft 2.2 on the outside of the transmission housing 1. From there, the first oil line 7.1 leads further along the outside of the transmission housing 1 to an inlet opening 4.3 of a ring cooler 4 which radially surrounds the bearing cup 5. From an outlet opening of the ring cooler 4, which is arranged diametrically opposite to the inlet opening 4.3 on the ring cooler 4, a second oil line 7.2 leads along the outside of the transmission housing 1 to a further through-hole, which is incorporated in the lid of the transmission housing 1.
[0037] During operation of the transmission 10, a motor turns the drive shaft 2.1, resulting in a slower rotation of the first intermediate shaft 2.2, thereby driving the flange pump 6 which is coupled to the first intermediate shaft 2.2. As a result of this, the flange pump 6 sucks transmission oil through the first oil line 7.1 from the oil sump 8 and pushes it through the ring cooler 4, where the transmission oil is cooled. From the ring cooler 4, the transmission oil passes through the second oil line 7.2 back into the interior of the transmission housing 1.
[0038] FIG. 2 shows a side view of the bevel helical transmission 10 shown in FIG. 1, a radial fan 9 which is attached to the drive shaft 2.1 being also illustrated. During operation of the transmission 10, a motor turns the drive shaft 2.1, resulting in an equally rapid rotation of the radial fan 9. A rotation of the radial fan 9 results in ambient air being sucked in from that end of the transmission housing 1 which is opposite to the drive-side end face, along the outside of the transmission housing 1 and over the ring cooler 4 to the radial fan 9, where the ambient air that has been sucked in, now heated correspondingly by the absorption of heat from the transmission, is pushed away radially outwards by the radial fan into the surroundings.
[0039] FIG. 3 shows an oblique view of the bevel helical transmission shown in FIG. 2, which is additionally equipped with a fan hood 3.1, 3.2 as per the present invention. The ring cooler 4 surrounding the bearing cup 5 is concealed under the fan hood 3.1, 3.2 in FIG. 3. The fan hood 3.1, 3.2 comprises a tank-shaped part 3.1 having a baseplate at the end face and a circumferential rim, which encloses the drive-side end face and has a gap that is open towards that end of the transmission housing 1 which is opposite to the drive-side end face, said gap being formed between the edge of the air-guiding hood 3.1 and the outside of the transmission housing 1. The fan hood 3.1, 3.2 additionally comprises a neck part 3.2 in the form of a truncated cone which sits centrally on the baseplate of the tank-shaped part 3.1 and radially surrounds the ring cooler 4. In this case, a cutout corresponding to the size of the neck part 3.2 is provided in the baseplate of the tank-shaped part 3.1 at the point of connection with the neck part 3.2, such that ambient air flowing in via the gap of the fan hood 3.1, 3.2 can flow into the interior of the neck part 3.2. The neck part 3.2 is likewise open at its end face which is oriented towards the fan 9, such that ambient air from the interior of the neck part 3.2 can be sucked towards the fan 9. The neck part 3.2 has corresponding through-holes for passing the first oil line 7.1, this leading towards the ring cooler 4, and the second oil line 7.2, this leading away from the ring cooler 4, through the neck part 3.2 of the fan hood.
[0040] FIG. 4 and FIG. 5 respectively show oblique and axial views of a ring cooler 4 whose basic shape is square as per the axial view shown in FIG. 5. Four cooling elements 4.1 arranged along the sides of a square are connected at the corners of the square by means of four connecting reservoirs 4.2 which serve as corner connectors. Two diametrically opposed connecting reservoirs 4.2 have respectively an inlet opening 4.3 and outlet opening 4.4. Each cooling element 4.1 has six parallel pipes 4.5 which are separated from each other by intermediate slot-shaped openings 4.6. Air can flow through the slot-shaped openings and can therefore flow around the oil ducting pipes 4.5 on all sides for effective heat transfer. For the purpose of mounting the ring cooler 4 on the end face of the transmission housing 1, the ring cooler 4 has mounting flanges 4.7. After transmission oil enters the inlet opening 4.3, the oil stream divides into two partial streams, a first partial stream flowing “leftwards” and a second partial stream flowing “rightwards” to the outlet opening 4.4 situated opposite. Each of the two partial streams is divided again across the parallel pipes 4.5 of the respective first cooling element 4,1 in the flow direction. At the connecting reservoirs 4.2 serving as corner connectors, the oil streams from the individual parallel pipes 4.5 are mixed together again and then divided again over the parallel pipes 4.5 of the respective second cooling element 4.1 in the flow direction. At the connecting reservoirs 4.2 on the outlet side, all of the oil streams from the two partial streams are mixed together again and flow out through the outlet opening 4.4. By virtue of the open structural format of the ring cooler, cooling ambient air can flow around each pipe 4.5 of the ring cooler.
[0041] FIG. 6 and FIG. 7 show the flow course of ambient air in the region of the ring cooler 4 on the inventive bevel helical transmission as per FIG. 3 in two different views, specifically a side view and an oblique view. The ventilation hood 3.1, 3.2 is omitted in FIG. 6 and FIG. 7 in order to allow better illustration of the flow arrows, but is nonetheless taken into consideration with regard to the course of the flow arrows. The fan wheel of the radial fan 9 is likewise omitted in FIG. 7 in order to allow better illustration of the flow arrows, but is taken into consideration with regard to the course of the flow arrows. A rotation of the radial fan 9 results in ambient air being sucked in from that end of the transmission housing 1 which is opposite to the drive-side end face, along the outside of the transmission housing 1 into the gap of the fan hood 3.1, 3.2 and from there over the ring cooler 4, and in particular through the slot-type openings between the pipes 4.5 of the ring cooler 4, to the radial fan 9, where the ambient air that has been sucked in, now heated correspondingly by the absorption of heat from the transmission, is pushed away radially outwards by the radial fan 9 into the surroundings.
