DE20201118U1 - Flow machine unit has cooling lubricant supplied to bearing set for common shaft positioned between rotor of electric motor and blade wheel housing - Google Patents

Abstract

The flow machine unit has at least one blade wheel (1) directly coupled to the rotor (12) of an electric motor (10) and mounted on a common shaft (2), supported by a bearing set (21) at one end of the rotor, between the latter and a blade wheel housing (3,4) and a second bearing set at the opposite end of the rotor. At least the first bearing set is supplied with a cooling lubricant, provided by water or a mixture of water and an additive.

Description

Miscel Oy Ltd. "Hot Gas Machine"

VIN-33230 Tampere PS 11354 DE ₁ G

Utility model application

Turbomachine unit

The invention relates to a turbomachine unit with a blade wheel (e.g. compressor impeller) which is coupled directly, i.e. without the interposition of a gear, to the rotor of an electrical machine (e.g. electric motor). The invention is based on patent application DE 101 63 950.3, according to which a turbomachine unit is designed as an electrically driven gas compressor. This is suitable for compressing very hot gases (up to approx. 1200 C), among other things by using water-lubricated bearings, so that contamination of the gas by lubricating oil is avoided. Furthermore, at least the bearing assembly located between the blade wheel and the electrical machine is designed as a heat insulator in order to protect the electrical machine from the high gas temperature.

The invention is based on the object of making the unit described in DE 101 63 950.3 even more versatile. This object is achieved in that the impeller and its housing allow the unit to be used either as a gas compressor or as a gas turbine and that the electrical machine can therefore be used either as a motor or as a generator. This makes it possible for a unit designed according to the invention to be used either to compress hot gases or to recover energy from a pressurized (especially hot) gas. To further develop the invention, a cooling air blower can be coupled to the rotor, which supplies cooling air under pressure to the interior of the electrical machine and at the same time ensures the necessary internal pressure.

A gas compressor is described below using a longitudinal section (Fig. IA and IB) as an example; however, this can also be used as a gas turbine. The compressor impeller 1 and the rotor 12 of an electric motor 10 are both attached to a common shaft 2. The electric motor is a high-speed motor

for speeds between 10,000 and 150,000 rpm. Its stator is designated 11 and a cylindrical housing part 13. A bearing assembly 21 or 22 is attached to each end of the housing part 13 for the shaft 2. A "first" bearing assembly 21 is located between the electric motor 10 and the housing parts 3, 4, 5 belonging to the compressor impeller 1. A "second" bearing assembly 22 is located at the other end of the electric motor 10.

The first bearing assembly 21 comprises a bearing cover 23 rigidly connected to the housing part 13. In it there is an inner bearing housing 25 in which several radial plain bearing segments 30 are arranged. These directly support the rotating shaft 2. To lubricate the radial bearing formed in this way, a radial supply line 27 for cooling and lubricating fluid is provided in the bearing cover 23; this is preferably a mixture of water and an additive. The radial supply line 27 opens into an annular channel 28 which is located in the inner bearing housing 25. From here, several radial connecting channels 29 run to the plain bearing elements 30 and between them directly to the shaft 2 in order to lubricate the surfaces sliding on one another and to cool the shaft 2 and the plain bearing elements 30.

So-called bearing shaft seals 17 are provided on both sides of the plain bearing elements 30 on the inner bearing housing 25. These can be designed as contactless labyrinth seals, for example. In addition, the bearing cover 23 has an inner shaft seal 15 on the motor side, with the help of which the motor interior 14 is sealed against the bearing assembly 21. There is an intermediate space 19 between the inner shaft seal 15 and the inner bearing housing 25. Furthermore, an intermediate space 9 is provided between the bearing assembly 21 and the cover 4 of the compressor housing 3, 4, 5. The aforementioned intermediate spaces 9 and 19 are in direct line connection with an outlet channel 37 for the cooling and lubricating fluid. After reaching the plain bearing elements 30, this flows along the shaft 2, i.e. past the labyrinth seals 17 into the intermediate spaces 9 and 19; it then leaves the bearing assembly 21 through the outlet channel 37. It serves not only as a bearing lubricant but also for cooling the entire bearing assembly 21. The bearing assembly 21 thus also serves as a heat insulator, which counteracts the risk of heat transfer from the compressor housing 3, 4, 5 to the electric motor 10. If necessary, a branch line 27' can be provided from the supply line 27 to the intermediate space 9, through which

- for additional cooling of the compressor housing cover 4 - cooling and lubricating fluid flows directly into the intermediate space 9.

In order to prevent coolant and lubricant from penetrating the engine interior 14, compressed air can be fed into the engine interior 14 (at 45). This results in a weak air flow, past the shaft seal 15, from the engine interior 14 into the intermediate space 19. This air flow prevents an opposite flow of liquid from the intermediate space 19 into the engine interior 14.

Sealing elements 4' are provided between the housing cover 4 of the compressor housing and the shaft 2. A heat insulation plate 5 is arranged between the spiral housing part 3 and the housing cover 4.

According to Figure 1B, a second bearing assembly 22 is located at the other end of the electric motor 10. This in turn comprises a bearing cover 24 (with shaft seal 15) as well as a supply line 27 and an outlet channel 37 for the cooling and lubricating fluid. Furthermore, a two-part inner bearing housing 26, 26a is provided, again for receiving segmented radial plain bearing elements 30. In addition, schematically indicated (preferably also segmented) axial bearing elements 31, 31a are provided, which guide the shaft 2 in the axial direction, on the one hand (at 31) by direct contact with the shaft 2, on the other hand (at 31a) by contact with a plate 6 screwed to the shaft 2. The cooling and lubricating fluid flows from the feed channel 27 through an annular channel 28 and several radial channels 29 to the bearing elements 30, 31 and 31a, then from here past labyrinth seals 18 into the intermediate space 20 or into an outer collecting space 20a and through the outlet channel 37 to the outside.

In addition to the aforementioned plate 6, the impeller 40 of a cooling air fan 41 (with a two-part fan housing 42, 43) is coupled to the shaft 2. In order to guide the cooling air under pressure into the motor interior 14, longitudinal channels 44 and radial bores 45 are provided in the housing parts 24 and 13. The air heats up, among other things, when it flows through grooves 46 provided on the outside of the stator 11. From here, the air reaches the outside via an annular channel 47 and an outlet channel 48. In addition, a cooling jacket 50 that can be filled with water (via lines 49) can be provided around the motor housing 13.

Claims (3)

1. Turbomachine unit with a blade wheel ( 1 ) which is directly coupled to the rotor ( 12 ) of an electrical machine ( 10 ), according to patent application DE 101 63 950.3, characterized in that the blade wheel ( 1 ) and its housing ( 3 , 4 ) are designed for the optional use of the unit as a gas compressor or as a gas turbine. 2. Turbomachine unit according to claim 1, characterized in that a cooling air blower ( 41 ) is coupled to the rotor ( 12 ), which supplies cooling air via channels ( 44 , 45 ) to the interior ( 14 ) of the electrical machine ( 10 ). 3. Turbomachine unit according to claim 1 or 2, characterized in that the housing ( 13 ) of the electrical machine ( 10 ) has a cooling jacket ( 50 ) that can be filled with coolant.