Pump, in particular transmission oil pump

Abstract

The present invention relates to a pump (10), in particular a transmission oil pump. The pump (10) comprises: an electric motor (20) having a stator (30) and a motor rotor (40); and a central axis (50). The pump (10) also comprises a pump device (60) having a gear pump (70) which has an internally toothed outer gear (80) and an externally toothed inner gear (90) that run into each other. The pump device (60) is located inside the electric motor (20). The pump device also has an upper side plate (100) and a lower side plate (110). The pump device and the electric motor (20) are located on a base plate (120) and are enclosed by a housing (130). The pump according to the invention is characterised in that the pump device (60) is located radially within the electric motor (20) and the external gear (80) of the pump device (60) is driven by the motor rotor (40).

Description

[0001] Description

[0002] Pump, especially transmission oil pump

[0003] The present invention relates to a pump, in particular a gear oil pump comprising an electric motor with a stator and a motor rotor, a central axis, a pumping device with a gear pump with an internally toothed external gear and an externally toothed internal gear which run into one another, wherein the pumping device comprises an upper side plate and a lower side plate, further comprising a base plate and a pump housing.

[0004] Such pumps are known from the prior art. In known electric oil pumps, the individual components—namely, the electric motor, the pumping device, and the electronics—are arranged along the same axis, i.e., axially one behind the other. The arrangement is typically as follows: electric motor, pumping device, and electronics. The drive shaft of the electric motor is coupled to the pumping device. Both the electric motor and the pumping device have housings.

[0005] Due to the axial arrangement of the various components, misalignment of the electric motor's drive shaft and the motor rotor, as well as the pump rotor mounted on the shaft, can often occur. Furthermore, such pumps require a large amount of installation space due to their axial arrangement. The axial arrangement of the individual components also poses the risk of misalignment of the pump rotor, which in turn leads to eccentricity in the pressurized areas of the pumping system and to larger lateral forces on the bearings, which must be compensated for by the bearings. Accordingly, large bearings are required in the pumping system.

[0006] Against this background, the present invention is based on the object of advantageously developing a generic electric pump, providing a compact pump, and eliminating the disadvantages of known electric pumps. To achieve this object, the invention proposes a pump according to the preamble of claim 1, in which the pumping device is arranged radially within the electric motor and the external gear of the pumping device is driven by the motor rotor. Advantageous embodiments and further developments are the subject of the dependent claims.

[0007] By arranging the pumping device radially inside the electric motor, the installation space for the pump is significantly reduced and misalignment caused by the electric motor driving the pumping device is prevented.

[0008] In one embodiment of the invention, the external gear of the pumping device is pressed into the motor rotor. This allows the motor rotor to directly drive the external gear, allowing both components to rotate around the same axis and thus centrally around one and the same axis. In contrast to known pumps, the pumping device is driven by the external gear, which serves as the driving gear of the pumping device. There is no drive shaft connecting the motor to the pumping device.

[0009] According to a further preferred embodiment of the invention, the internal gear of the pumping device is rotatably mounted on a bearing sleeve (bushing) in the pumping device, eccentrically to the central axis. The internal gear is the driven gear in the pumping device and does not have to absorb large forces, nor does the bearing sleeve (bushing), which significantly reduces the risk of misalignment between the motor rotor, external gear, and internal gear.

[0010] In one embodiment, the bearing sleeve (bushing) is arranged on a fastening element that extends eccentrically to the central axis through the upper side plate of the pumping device, the internal gear, the lower side plate, and into the base plate of the pump. The upper side plate, the internal gear, and the lower side plate are thus arranged in a defined position relative to one another. In another embodiment, the lower side plate is designed as a pressure plate.

[0011] In a further embodiment, the motor rotor is rotatably mounted on the lower side plate via a bearing sleeve (bushing).

[0012] In an advantageous development of the invention, the motor rotor is rotatably mounted on the lower side plate via a bearing sleeve (bushing) and on the upper side plate via a bearing sleeve (bushing). The driving rotational forces of the motor rotor and the external gear connected to it thus act exclusively on the side plates and are reduced. The risk of misalignment of the pressurized areas in the pumping device, which can lead to eccentricity, is reduced, and thus the size of the bearings required is reduced.

[0013] According to the invention, the stator is arranged on the base plate. This results in a compact and simple pump design.

[0014] According to one embodiment of the invention, the base plate and the lower side plate are formed in one piece, which further simplifies the structure and reduces the number of components of the pump.

[0015] According to another embodiment, the housing is detachably connected to the base plate. The individual components of the pump can thus be installed first with the base plate, and the housing can be attached as a final step.

[0016] The invention is described in more detail below with reference to the drawings. They show:

[0017] Figure 1: a first embodiment of the pump according to the invention in section,

[0018] Figure 2: a second embodiment of the pump according to the invention in section, and and

[0019] Figure 2a: a view of the pump along line AA in Figure 2.

[0020] Corresponding parts are provided with the same reference numerals in all figures.

[0021] Figure 1 shows a first embodiment of the pump 10 according to the invention. Such a pump, in particular a transmission oil pump, as described below, can be used in many technical fields, such as, for example, in automotive hydraulic systems, automatic transmissions, in commercial vehicles, in oil production systems, in nautical applications, for battery cooling systems and for lubrication systems.

[0022] The pump 10 comprises an electric motor 20 with a stator 30 and a motor rotor 40 with a central axis 50. A pumping device 60 with a gear pump 70 is arranged radially within the electric motor 20. The gear pump 70 has an internally toothed external gear 80 and an externally toothed internal gear 90 running within the gear. In the pumping device 60, an upper side plate 100 is arranged axially above the two gears 80, 90, as indicated with reference to Figure 1, and a lower side plate 110 is arranged axially below the two gears 80, 90.

[0023] The pump device 60, the electric motor 20 and an electronic system (not shown) are arranged on a base plate 120 and enclosed by a housing 130 which is only schematically indicated.

[0024] The electric motor 20 is constructed in a known manner. In the present embodiment, the stator 30 sits on the base plate 120, specifically on an extension 140 of the base plate 120, which determines the positioning of the stator 30 in the pump 10. The motor rotor 40 is provided radially inside the stator 30 in a known manner. The internally toothed external gear 80 of the pump device 60 is pressed into the motor rotor 40 in such a way that a rotationally fixed connection is established between the motor rotor 40 and the external gear 80, whereby the rotation of the motor rotor 40 is transmitted to the external gear 80, and the motor rotor 40 consequently drives the external gear 80 by driving it.

[0025] The externally toothed internal gear 90, which runs radially inward with the external gear 80, is rotatably mounted on a bearing sleeve 150. The pump device 60 is fixed to the base plate 120 by means of a fastening element 160, which is arranged eccentrically to the central axis 50. The fastening element 160 extends through the upper side plate 100, through the internal gear 90, which adjoins it axially in the direction of the base plate 120, and through the lower side plate 110 into the base plate 120, thus fixing the pump device 60 in the base plate 120. The fastening element 160 is fixed in the base plate 120, e.g. screwed, and thus serves to define the positioning of the upper side plate 100, the internal gear 90, the lower side plate 110, and the base plate 120. The bearing sleeve 150 is arranged on the fastening element 160.However, it is also possible to arrange the internal gear 90 directly on the fastening element 160 so that it can rotate and to dispense with the bearing sleeve 150.

[0026] The rotationally fixed connection between motor rotor 40 and external gear 80 is mounted on a bearing sleeve 170, which is arranged on the outer circumference of the lower side plate 110. Figure 1 shows another bearing sleeve 180, which is arranged on the outer circumference of the upper side plate 100. For the radial mounting of the motor rotor 40 with the external gear 80, both bearing sleeves 170 and 180 are not absolutely necessary. It is also possible to provide only one of the bearing sleeves 170 or 180.

[0027] The housing 130, which is only indicated schematically, is detachably fastened to the base plate 120; here, reference can be made to known detachable connections, such as screw connections. Figure 2 shows a second embodiment of the pump 10 according to the invention in section, wherein identical elements are designated by the same reference numerals as in Figure 1. Furthermore, Figure 2a shows the view along line A in Figure 2. The pump 10 in Figure 2 differs from the pump 10 of Figure 1 in that only one side plate, namely the upper side plate 100, is provided. The stator 30 of the electric motor 20 is arranged on the extension 140 of the base plate 120. The internally toothed outer wheel 80 of the pump device 60 is pressed into the motor rotor 40 in the same way as in Figure 1, i.e., is connected to it in a rotationally fixed manner, and is driven by it.

[0028] The pumping device 60, consisting of the upper side plate 100 and the axially adjoining internal gear 90, which runs in the external gear 80, is fixed eccentrically to the central axis 50 on the base plate 120 via a fastening element 160, which extends through the upper side plate 100 and the internal gear 90 into the base plate 120. A bearing sleeve 190 is arranged on the fastening element 160. The bearing sleeve 190 functions as a rotation bearing for the internal gear 90. The lower side plate 110 of Figure 1 is formed here by the extension 140 of the base plate 120.

[0029] In the embodiment shown in Figure 2, the rotationally fixed connection of the motor rotor 40 to the external gear 80 is mounted on a bearing sleeve 200. In this embodiment, the bearing sleeve 200 is arranged on the stepped extension 140 of the base plate 120. Consequently, in this embodiment, the motor rotor 40 and the external gear 80 connected to it are mounted on the base plate 120.

[0030] The electric motor 20 and the pump device 60 as well as the electronics (not shown) are enclosed by the housing 130, which is detachably fastened to the base plate 120.

[0031] The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments can also be combined with one another in other ways without departing from the subject matter of the invention.

[0032] List of reference symbols

[0033] 10 Pump

[0034] 20 electric motor

[0035] 30 Stator

[0036] 40 Motor rotor

[0037] 50 central axis

[0038] 60 pumping device

[0039] 70 Gear pump

[0040] 80 external gear

[0041] 90 internal gear

[0042] 100 upper side plate

[0043] 110 lower side plate

[0044] 120 base plate

[0045] 130 housings

[0046] 140 extension

[0047] 150 bearing sleeve

[0048] 160 Fastener

[0049] 170 bearing sleeve

[0050] 180 bearing sleeve

Claims

Patent claims 1. Pump (10), in particular a gear oil pump, comprising an electric motor (20) with a stator (30) and a motor rotor (40), a central axis (50), a pumping device (60) with a gear pump (70) with an internally toothed external gear (80) and an externally toothed internal gear (90) which run into one another, wherein the pumping device (60) is arranged inside the electric motor (20), wherein the pumping device (60) comprises an upper side plate (100) and a lower side plate (110), further comprising a base plate (120) and a housing (130), characterized in that the pumping device (60) is arranged radially inside the electric motor (20) and the external gear (80) of the pumping device (60) is driven by the motor rotor (40).

2. Pump (10) according to claim 1, characterized in that the external gear (80) of the pumping device (60) is pressed into the motor rotor (40) radially inside the electric motor (20).

3. Pump (10) according to one of claims 1 or 2, characterized in that the internal gear (90) of the pumping device (60) is rotatably mounted on a bearing sleeve (bushing) (150) in the pumping device (60).

4. Pump (10) according to one of claims 1 to 3, characterized in that the bearing sleeve (bushing) (150) is arranged on a fastening element (160) which extends eccentrically to the central axis (50) through the upper side plate (100) of the pumping device (60), the internal gear (90), the lower side plate (110) into the base plate (120) of the pump (10).

5. Pump (10) according to one of claims 1 to 4, characterized in that the lower side plate (110) is designed as a pressure plate.

6. Pump (10) according to one of claims 1 to 5, characterized in that the motor rotor (40) is rotatably mounted on the lower side plate (110) via a bearing sleeve (socket) (170).

7. Pump (10) according to one of claims 1 to 6, characterized in that the motor rotor (40) is rotatably mounted on the lower side plate (110) via a bearing sleeve (socket) (170) and on the upper side plate (100) via a bearing sleeve (socket) (180).

8. Pump (10) according to one of claims 1 to 7, characterized in that the stator (30) is arranged on the base plate (120).

9. Pump (10) according to one of claims 1 to 8, characterized in that the base plate (120) forms the lower side plate (110).

10. Pump (10) according to one of claims 1 to 9, characterized in that the housing (130) is detachably connected to the base plate (120).

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