CN-114765396-B - Motor with a motor housing

Abstract

The motor includes a shaft (10), a rotor (100), a stator (200), and a frame (300). The shaft is rotatably supported on the frame by means of axially positioned sleeve bearings (20, 30B) at each axial end of the shaft. The axial gap in one of the two axial positioning sleeve bearings, which limits the axial movement of the shaft, is larger than the axial gap in the other of the two axial positioning sleeve bearings. During normal operating conditions, axial movement of the shaft is limited only by the bearing with less axial play, and during abnormal events, axial movement of the shaft is limited by two bearings, with the bearing with greater axial play reducing the axial load of the first bearing.

Inventors

• Yang Nei Kampri
• Samuel Aniwa

Assignees

• ABB瑞士股份有限公司

Dates

Publication Date

20260512

Application Date

20220107

Priority Date

20210111

Claims (2)

1. 1. An electric machine, comprising: A shaft (10), A rotor (100), said rotor (100) being supported on said shaft (10), A stator (200), said stator (200) surrounding said rotor (100), -A frame (300), said frame (300) surrounding said stator (200), A first bearing (20) at a driving end (D) of the motor and a second bearing (30B) at a non-driving end (N) of the motor for rotatably supporting the shaft (10) on the frame (300), the first bearing (20) and the second bearing (30B) being axially positioned sleeve bearings, It is characterized in that the method comprises the steps of, An axial play in the second bearing (30B) that limits axial movement of the shaft (10) is larger than an axial play in the first bearing (20), such that during normal operating conditions, axial movement of the shaft (10) is limited only by the first bearing (20) with less axial play, and during an abnormal event, axial movement of the shaft (10) is limited by both the first bearing (20) and the second bearing (30B) with greater axial play reduces an axial load of the first bearing (20) with less axial play; Wherein each of the first bearing (20) and the second bearing (30B) comprises a sleeve bearing portion (21, 31B), the sleeve bearing portion (21, 31B) supporting the shaft (10) only in a radial direction, and an axial bearing portion (23, 24, 33B, 34B), the axial bearing portion (23, 24, 33B, 34B) comprising a first bearing support (23, 33B) and a second bearing support (24, 34B), wherein the first bearing support (23, 33B) seats against an inner radial surface of a collar extending radially outwardly from an outer surface of the shaft (10), and the second bearing support (24, 34B) seats against an outer radial surface of the collar such that the axial bearing portion (23, 24, 33B, 34B) supports the shaft (10) only in an axial direction.
2. 2. The electric machine of claim 1, wherein the second bearing (30B) with the larger axial play is sized to withstand approximately 50% of the axial impact load after the initial threshold force has been reached.

Description

Motor with a motor housing Technical Field The present invention relates to an electric motor. Background The motor may be provided with a rotor, a stator surrounding the rotor, and a frame surrounding the stator. The shaft of the motor may be rotatably supported on the frame with bearings at the drive end and at the non-drive end of the motor. The bearings may be sleeve bearings, whereby one of the sleeve bearings of the motor may be an axially positioned sleeve bearing and the other sleeve bearing of the motor may be a conventional sleeve bearing without any axial positioning capability. An axially locating sleeve bearing may be provided at the drive end of the motor. There is also provided a practical axial bearing comprising a disc attached to the shaft, and a support element acting on the opposite surface of the disc radially outside the outer surface of the shaft. The support element may be supported in a bearing frame. However, the actual axial bearing is an expensive component and is therefore only used in critical applications. The earthquake may cause ground acceleration which stresses the motor. The biggest problem in earthquakes is to keep the rotor in its position when an earthquake occurs. Disclosure of Invention The object of the present invention is to achieve an improved electric machine. The electric machine according to the invention is defined in claim 1. The motor includes: The axis of the shaft is provided with a plurality of grooves, A rotor supported on the shaft, A stator surrounding the rotor, A frame surrounding the stator, A bearing at the driving end of the motor and a bearing at the non-driving end, both bearings being sleeve bearings for rotatably supporting the shaft on the frame. The motor is characterized in that Both bearings are axial positioning sleeve bearings, the axial play in one of the two axial positioning sleeve bearings limiting the axial movement of the shaft being larger than the axial play of the other of the two axial positioning sleeve bearings, such that during normal operating conditions the axial movement of the shaft is limited only by the bearing with the smaller axial play and during an abnormal event, such as a seismic event, the axial movement of the shaft is limited by the two bearings, in which case the bearing with the larger axial play reduces the axial load of the first bearing. The present invention provides an effective way to address the problem of maintaining the rotor in a predetermined axial position during a seismic event. During normal operating conditions, the bearing with the greater axial play does not participate in limiting the axial movement of the rotor. Bearings with large axial play limit the axial movement of the rotor only during abnormal seismic events, such as earthquakes. During an earthquake, a bearing with a large axial play may bear 50% of the total axial impact load after the initial threshold force has been reached. This may be achieved by arranging axially positioned sleeve bearings at each end of the motor. The axial play of one of the axial positioning sleeve bearings may be larger than the axial play of the other axial positioning sleeve bearing. The larger axial play may be dimensioned such that the intended thermal expansion does not enable axial positioning of the axial positioning sleeve bearing with the larger play, i.e. they are handled by axial positioning of the axial positioning sleeve bearing with the smaller axial play. The impact load during an earthquake may be estimated to be about 800kN. During an earthquake, the axial deformation of an axially positioned sleeve bearing with less axial play may be a few millimeters. The axially positioned sleeve bearing is an axial load bearing. The electric machine may be an electric motor or a generator. The motor may be a large motor. The shaft height of the motor may be in the range 1120mm to 2000 mm. The motor may be a high voltage motor. The motor may be a rib cooled motor. The output power of the motor may be in the range of 1MW to 25 MW. The voltage of the motor may be as high as 11.5kV. Drawings The invention will be described in more detail hereinafter by means of preferred embodiments with reference to the accompanying drawings, in which: Figure 1A shows an axial cross section of an electric machine according to the prior art, Figure 1B shows an axial cross section of an electric machine according to an embodiment of the invention, Figure 2 shows an axially positioned sleeve bearing according to an embodiment of the invention, Figure 3A shows a conventional sleeve bearing according to the prior art without axial positioning, Figure 3B shows an axially positioned sleeve bearing on the non-drive side according to an embodiment of the invention, Figure 4 shows a sleeve bearing of an electric machine according to an embodiment of the invention mounted on a base, Fig. 5 shows a flange-mounted sleeve bearing of an electric machine according to an embodiment of t