Drive Unit for an Industrial Transport Vehicle

Abstract

A drive unit, in particular for an industrial transport vehicle, is at least comprised of a gearbox with at least one gear stage, a drive motor and a running wheel. To minimize the costs when there are substantially greater loads on the running wheel, there are provisions in accordance with the invention for the running wheel to be directly connected to a bevel gear on the output side, which is supported by a first bearing element for accommodating the load and by a second bearing element that serves to provide stabilization and that is supported in the gearbox . The first bearing element bears all of the loads here, whereas the second bearing element with substantially smaller dimensions merely has to cushion tilting forces that arise.

Claims

1. A drive unit for an industrial transport vehicle, at least comprising a gearbox with at least one gear stage, a drive motor and a running wheel, wherein the running wheel is directly connected to a bevel gear on the output side, which passes the load to be supported via a first bearing element for accommodating the load into the gearbox through an outer bearing race and which is supported by a second bearing element for stabilization with respect to the gearbox.

2. The drive unit according to claim 1, wherein the gearbox has a rear housing wall that is diametrically turned away from the running wheel and that is designed to be completely closed and formed in a single piece, or that the gearbox has a rear housing wall diametrically turned away from the running wheel, wherein the gearbox is closed by the rear housing wall and a cap.

3. The drive unit according to claim 1, wherein, the bevel gear has a support element formed in one piece in the direction of a rear housing wall or that the bevel gear has an open recess in the direction of a rear housing wall.

4. The drive unit according to claim 1, wherein the gearbox has a support element formed in the direction of the running wheel or that the gearbox has a pot-shaped recess in the interior into which the bevel gear projects with a support element.

5. The drive unit according to claim 1, wherein, support elements and recesses are arranged coaxially with respect to one another and mesh with one another.

6. The drive unit according to claim 1, wherein the first bearing element has a coaxially internal arrangement with respect to the running wheel and is within the width of the running wheel.

7. The drive unit according to claim 1, wherein the first bearing element has an inner bearing shell and an outer bearing shell or that the first bearing element has an outer bearing shell, whereas an inner bearing shell is formed by a bearing surface of the bevel gear.

8. The drive unit according to claim 1, wherein an inner or outer bearing shell of the first bearing element is axially movable and can be fixed in place with a retaining ring or that the first bearing element can be fixed in place with a retaining ring.

9. The drive unit according to claim 1, wherein the first bearing element has a seal accessible from the running-wheel side.

10. The drive unit according to claim 1, wherein the second bearing element is mounted on a support element of the bevel gear and is mounted in a recess of the gearbox or that the second bearing element is mounted on a support element of the gearbox and is mounted in a recess of the bevel gear.

11. The drive unit according to claim 1, wherein the bevel gear is a ring gear.

12. The drive unit according to claim 1, wherein a first gear stage is comprised of a spur gear driven by a drive motor via a driving pinion, said spur gear transferring the torque via a drive shaft to a second gear stage, wherein the second gear stage is comprised of a second bevel gear and a spiral gearing of the drive shaft.

13. The drive unit according to claim 1, wherein, the running wheel is directly connected to the bevel gear on the output side, which meshes via gearing with a drive shaft and passes the load to be supported via the first bearing element for accommodating the load into the gearbox through an outer bearing race and which is supported by a second bearing element for stabilization with respect to the gearbox.

14. The drive unit according to one of claim 1, wherein, a drive shaft is supported by the bearing elements on the head side and/or that the drive unit is connected to the industrial transport vehicle via a turntable bearing.

15. The drive unit according to claim 1, wherein, the gearbox is connected to an inner ring of a turntable bearing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will be explained once again below with the aid of the figures. The drawings show the following:

[0022] FIG. 1 shows a first embodiment in a cutaway side view of a drive unit,

[0023] FIG. 2 shows a second embodiment of a drive unit in a cutaway side view and

[0024] FIG. 3 shows a third embodiment of a drive unit in a cutaway side view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] FIG. 1 shows a drive unit 1 in a cutaway view that has a first gear stage 2 and a second gear stage 3. The two gear stages 2, 3 are mounted in a gearbox 4, which can be connected via a turntable bearing 5 to an industrial transport vehicle that is not shown. In the example that is shown, the housing cover of the gearbox 4 is already designed as an inner ring 6 of the turntable bearing and is accommodated by the outer ring 7 of the turntable bearing. The inner ring 6 of the turntable bearing simultaneously serves here to accommodate an electric motor, not shown, which forms the first gear stage 2 with the aid of a pinion 8 and a spur gear 9. The transfer of the torque via a spiral gearing 11 to a bevel gear 12 takes place through a shaft 10. Both the pinion 8 and the spur gear 9 mesh with one another, and the spiral gearing 11 likewise meshes with the bevel gear 12. The bevel gear 12 further serves to fasten a running wheel carrier 13 to a running wheel 14. Because of the turntable bearing 5, the gearbox 4 with the gear stages 2, 3 can be swiveled over an angle range of 360 degrees, so not just the propulsion, but also the steering of an industrial transport vehicle can be carried out with the aid of the drive unit 1 and the running wheel 14.

[0026] The running wheel 14 with the running wheel carrier 13 and the bevel gear 12 are supported with a first bearing element 15 to accommodate a payload of the industrial transport vehicle of several tons. This bearing element 15 serves to accommodate all of the loads that can arise from the transport vehicle's own weight and the transport of goods by the industrial transport vehicles. The bearing element 15 is fixed in place here in the gearbox 4 with a retaining ring 16 and is additionally sealed towards the outside by a sealing element 17; the sealing element 17 seals the entire gearbox 4. The sealing element 17 is further protected against damage and contamination with a protective ring 18 that can be pressed in. The running wheel carrier 13 and the bevel gear 12 are connected with several screw bolts 19, just as the housing cover 6 is screwed together with the gearbox 4 via further screw bolts 20.

[0027] The special feature of this drive unit 1 is that the bevel gear 12 is essentially comprised of a solid material and has a support element 22 aligned in the direction of a rear housing wall 21. A second bearing element 23 is fastened to a support element 22 and fixed in place with two retaining rings 24, 25. The second bearing element 23 is mounted on a support element 22 and mounted in a recess 26 of the gearbox 4. The support element 22 projects into the recess 26 here. In the example that is shown, the rear housing wall 21 is not completely closed, but instead has a through-hole that is closed up by the cap 27 that can be pressed in.

[0028] The second bearing element 23 has substantially smaller dimensions than the first bearing element 15 and merely serves to accommodate tilting forces that arise so that a vertical position of the running wheel 14 is maintained.

[0029] The special advantage of this embodiment is that a single first bearing element 15 can be used and only has to have sufficient dimensions to accommodate the corresponding loads. The second bearing element 23, in contrast, is not intended to be used to accommodate loads, but instead merely to accommodate tilting forces that may arise, and can have correspondingly smaller dimensions, so substantial costs can be saved.

[0030] FIG. 2 shows, in a cutaway side view, a second drive unit 50 that likewise has two gear stages 51, 52. The two gear stages 51, 52 are installed in a gearbox 53 that has a completely closed rear housing wall 54 in this design variant. The gearbox 53 is closed up with a gearbox cover in the upper area that is in turn designed in the form of an inner ring 55 of the turntable bearing and consequently constitutes, together with the outer ring 56 of the turntable bearing, a turntable bearing. The first gear stage 51 has the same structure as the first example and is comprised of a driving pinion 57 that is mounted on the shaft of an electric motor, not shown, and that meshes with a spur gear 59. The spur gear 58 is mounted on a shaft 59 that is equipped on the opposite end with a spiral gearing 60, which in turn meshes with a bevel gear 61. The bevel gear 61 serves to fasten a running wheel carrier 62, which is fastened with the aid of screw bolts 63. The running wheel carrier 62 serves to mount a running wheel 64. The bevel gear 61 is designed with a pot shape with respect to the first example and has a recess 65 into which a support element 66 of the rear housing wall 54 of the gearbox 53 projects.

[0031] The bevel gear 61 is supported with respect to the gearbox 53 via a first bearing element 67; the bearing element 67 is in turn fixed in place with a retaining ring 68 and sealed with a sealing element 69. The sealing element 69 seals off the entire gearbox 53 in connection with this; access exists to the gearbox 53 to disassemble or assemble the gear stages after removal of the running wheel carrier 62 with the running wheel 64. The gearbox 53 is provided in this special case with a one-piece rear wall and has a support element 70 that projects into the recess 65 of the bevel gear 61. A second bearing element 71 that is supported on the bevel gear 61 is mounted on the support element 70, which is in a one-piece design with the rear housing wall. Tilting forces are in turn cushioned via the second bearing element 71, so the running wheel 64 remains in a horizontal position. The first bearing element 67 accommodates all of the loads, whereas the second bearing element 71 is merely provided to safeguard tilting forces.

[0032] FIG. 3 shows, in a cutaway side view, a drive unit 100 with a first gear stage 101 and a second gear stage 102. The two gear stages 101, 102 are mounted in a gearbox 103, which is connected via a turntable bearing 104 to an industrial transport vehicle that is not shown. The turntable outer bearing 105 is connected to the industrial transport vehicle here, whereas the inner ring 106 of the turntable bearing is simultaneously designed in the form of an upper housing cover of the gearbox 103. The inner ring 106 of the turntable bearing, also the housing cover, is connected to the other housing parts via screw bolts 107. The gearbox 103 serves to accommodate a running wheel 108 here, which is connected via a running wheel carrier 109 to a bevel gear 110 with screw bolts 114. The bevel gear 110 is part of the second gear stage 102 and meshes with a spiral gearing of the drive shaft 111. The drive shaft 111 has a spur gear 112 at one end, which can be driven by a pinion 113 of an electric motor that is not shown. The bevel gear 110 is supported with respect to the gearbox 103 via a first bearing element 115 in this design variant. Tilting forces that arise are cushioned via a second bearing element 116 and passed to the gearbox 103. In this design, the bevel gear 110 has a pot shape and this consequently makes a coaxial arrangement of a support element 117 possible, which is formed in one piece on the rear housing wall 122 in the form of a gearbox 103. The support element is arranged in coaxial fashion with respect to the first and second bearing elements 115, 116 and the running wheel 108. The second bearing element 116 is mounted with its inner race on the support element 117 and supports the bevel gear 110 with the outer race. The position of the second bearing element 116 has been chosen in such a way in this case that it is within the width of the running wheel 108. The bevel gear 110 is supported with respect to the gearbox 103 by the first bearing element 115; the first bearing element 115 is comprised of an outer bearing shell 118 without the use of an inner bearing shell and, instead of that, a bearing surface is formed on the outside of the bevel gear 110. The outer bearing shell is fixed in place in the gearbox 103 with a retaining ring 119. Both the retaining ring 119 and the first bearing element 115 are sealed up with a sealing ring 120. After removing the running wheel 108, the possibility exists because of these construction measures to carry out the further disassembly of the two gear stages from one side of the gearbox 103. The sealing ring 120 is further protected by a protective ring 121.

LIST OF REFERENCE NUMERALS

[0033] 1 Drive unit

[0034] 2 Gear stage

[0035] 3 Gear stage

[0036] 4 Gearbox

[0037] 5 Turntable bearing

[0038] 6 Inner ring of the turntable bearing

[0039] 7 Outer ring of the turntable bearing

[0040] 8 Pinion

[0041] 9 Spur gear

[0042] 10 Shaft

[0043] 11 Spiral gearing

[0044] 12 Bevel gear

[0045] 13 Running wheel carrier

[0046] 14 Running wheel

[0047] 15 Bearing element

[0048] 16 Retaining ring

[0049] 17 Sealing element

[0050] 18 Protective ring

[0051] 19 Screw bolt

[0052] 20 Screw bolt

[0053] 21 Rear housing wall

[0054] 22 Support element

[0055] 23 Bearing element

[0056] 24 Retaining ring

[0057] 25 Retaining ring

[0058] 26 Recess

[0059] 27 Cap

[0060] 50 Drive unit

[0061] 51 Gear stage

[0062] 52 Gear stage

[0063] 53 Gearbox

[0064] 54 Rear housing wall

[0065] 55 Inner ring of the turntable bearing

[0066] 56 Outer ring of the turntable bearing

[0067] 57 Driving pinion

[0068] 58 Spur gear

[0069] 59 Shaft

[0070] 60 Spiral gearing

[0071] 61 Bevel gear

[0072] 62 Running wheel carrier

[0073] 63 Screw bolt

[0074] 64 Running wheel

[0075] 65 Recess

[0076] 66 Support element

[0077] 67 Bearing element

[0078] 68 Retaining ring

[0079] 69 Sealing element

[0080] 70 Support element

[0081] 71 Bearing element

[0082] 100 Drive unit

[0083] 101 Gear stage

[0084] 102 Gear stage

[0085] 103 Gearbox

[0086] 104 Turntable bearing

[0087] 105 Turntable outer bearing

[0088] 106 Inner ring of the turntable bearing

[0089] 107 Screw bolt

[0090] 108 Running wheel

[0091] 109 Running wheel carrier

[0092] 110 Bevel gear

[0093] 111 Drive shaft

[0094] 112 Spur gear

[0095] 113 Pinion

[0096] 114 Screw bolt

[0097] 115 Bearing element

[0098] 116 Bearing element

[0099] 117 Support element

[0100] 118 Bearing shell

[0101] 119 Retaining ring

[0102] 120 Sealing ring

[0103] 121 Protective ring

[0104] 122 Rear housing wall