Rotor shaft end bearing arrangement and drive assembly

Abstract

A rotor shaft end bearing arrangement (30; 30'; 30"; 30"') is provided for supporting an end (34; 34'; 34"; 34"') of a rotor shaft (18; 18'; 18"; 18"') of an electric machine (12) having a longitudinal axis (L). The rotor shaft end bearing arrangement (30; 30'; 30"; 30"') comprises a shaft receiving portion (26; 26'; 26"; 26"') for axially supporting the rotor shaft (18; 18'; 18"; 18"') of the electric machine (12). The shaft receiving portion (26; 26'; 26"; 26"') is shaped such that it forms a first main contact area (32a; 32a'; 32a"; 32a"') and a second main contact area (32b; 32b'; 32b"; 32b"'), the first and second main contact areas (32a, 32b; 32a', 32b'; 32a", 32b"; 32a"', 32b"') being designed to contact the end (34; 34'; 34"; 34"') of the rotor shaft (18; 18'; 18"; 18"') of the electric (12) machine at least at first and second contact points (P1, P2; P1', P2'; P1", P2"; P1"', P2"') of the end (34; 34'; 34"; 34"') of the rotor shaft

Description

[Technical Field]

[0001] The present invention relates to a rotor shaft end bearing arrangement suitable for an actuator, and a drive device having such a rotor shaft end bearing arrangement. [Background Technology]

[0002] In an electric motor, the rotor will be provided with a rotor shaft, which is held in place along the rotor's axis of rotation. In some actuators, the rotor shaft rests against the plane of the actuator housing and typically has a rounded tip, allowing unimpeded radial movement of the rotor shaft. Although the motor itself will be fixedly confined within the actuator housing, the shaft tip will have some track on that plane. In itself, this is not a problem.

[0003] However, over time, the trajectory of the shaft tip tends to become chaotic. In the event of chaotic rotation, the rotor shaft will randomly collide with the contact surface, producing a rattling sound inside the actuator. This is a problem for electronic applications that aim for inherently silent operation. [Summary of the Invention]

[0004] The present invention aims to solve the problems of chaotic motion and rattling noise of axially supported rotor shafts.

[0005] According to a first aspect of the invention, a rotor shaft end bearing arrangement is provided for supporting the end of a rotor shaft of an electric motor having a longitudinal axis. The rotor shaft end bearing arrangement includes: a shaft receiving portion for axially supporting the rotor shaft of the electric motor; and the shaft receiving portion is shaped to form a first main contact area and a second main contact area, the first and second main contact areas being designed to contact the end of the rotor shaft of the electric motor at least at the first and second contact points at the end of the rotor shaft in the operating state of the electric motor.

[0006] If the rotor shaft in the actuator contacts a plane, a rattling sound will occur because the end of the rotor shaft drifts erratically. In this invention, the first and second main contact areas provide support for the end of the rotor shaft in a direction transverse to the longitudinal axis, which suppresses end drift. Rotation of the rotor shaft is unrestricted, and the rattling sound is significantly reduced.

[0007] The first and second main contact areas can converge on each other.

[0008] A pair of converging surfaces provides a simple way to contact the end of the rotor shaft, regardless of the shape of its ends.

[0009] Preferably, the shaft receiving portion is V-shaped or substantially V-shaped in a plane perpendicular to the longitudinal axis.

[0010] The V-shaped channel not only provides the necessary lateral support at the end but also allows for easy insertion of the rotor shaft. Minimal force is required to facilitate the push-in engagement of the rotor shaft, thus eliminating the need for biasing force to push the rotor shaft into the shaft receiver.

[0011] Optionally, the first and second main contact areas are formed as planes of a V-shaped shaft receiving portion. In one arrangement, the shaft receiving portion is U-shaped or substantially U-shaped in a plane perpendicular to the longitudinal axis. At least the first and second contact points may be symmetrically located on either side of the plane perpendicular to the longitudinal axis. At least one of the first and second main contact areas is shaped to be at least partially recessed or convex in a plane perpendicular to the longitudinal axis.

[0012] For example, the shapes of the first and second main contact areas can provide different benefits to simplify the molding of the actuator housing; for instance, certain shapes can better resist the ejection of the rotor shaft during use.

[0013] In one embodiment, the shaft receiving portion includes at least one lateral baffle. The lower lateral baffle is located below the first and second main contact areas.

[0014] Stops or similar lateral baffles can aid in the insertion and alignment of the rotor shaft, preventing it from being over-inserted into the shaft receiving section. The baffles provide a natural indication that the rotor shaft has been correctly inserted into the shaft receiving section. Depending on the requirements, the lateral baffles restrict the movement of the rotor shaft end in the direction perpendicular to the rotor shaft axis and in the direction perpendicular to the first and second main contact areas of the rotor shaft during the operation of the drive assembly.

[0015] Preferably, the shaft receiving portion includes a rotor shaft entry portion adjacent to the first and second main contact areas.

[0016] The dimensions of the rotor shaft entry section can be designed to assist in the insertion of the rotor shaft during actuator assembly, thereby reducing the force requirements and thus reducing the possibility of damage to the rotor shaft or shaft receiving section.

[0017] The rotor shaft channel portion can be an inclined channel surface. The inclined channel surface can smoothly connect to the first main contact area and the second main contact area, if necessary, for example, to facilitate the insertion of the rotor shaft end into the shaft receiving portion.

[0018] The inclined portion of the actuator housing greatly simplifies the push-in fit of the rotor shaft during drive assembly. This embodiment is advantageous because it prevents the shaft receiving portion from accidentally recessing at the end of the rotor shaft.

[0019] Optionally, the shaft receiving portion may include another contact area, which may be located between the first main contact area and the second main contact area.

[0020] The additional contact area can be used to provide additional support to the rotor shaft along the longitudinal axis, thereby further mitigating the effects of unwanted chaotic drift of the rotor shaft when the drive assembly is in operation, as it restricts the movement of the rotor shaft end in the direction of the rotor shaft axis.

[0021] According to a second aspect of the invention, a drive assembly is provided, the drive assembly comprising: a motor including a rotor having a rotor shaft defining a longitudinal axis; and a rotor shaft end bearing arrangement according to a first aspect of the invention, the rotor shaft being axially supported by a shaft receiving portion of the rotor shaft end bearing arrangement.

[0022] The end of the rotor shaft is shaped according to the first main contact area and the second main contact area to generate at least the first and second contact points.

[0023] Alternatively, the end of the rotor shaft can be shaped to create two or more contact points. This can reduce the manufacturing burden on the actuator housing.

[0024] The driving component of the present invention can preferably be configured as part of the actuator.

[0025] The actuator with the aforementioned rotor shaft end bearing arrangement will exhibit reduced rattling noise and will be quieter than the same actuator with a planar rotor shaft end bearing arrangement.

[0026] Preferably, the shaft receiving portion can be integrally formed with the actuator housing of the actuator.

[0027] The integral formation of the shaft receiving section, which is part of the actuator housing, creates a defined space in which the motor can be housed, thereby reducing the number of parts required during assembly.

[0028] Alternatively, the shaft receiver can be formed as a separate component receptively engaging with the actuator housing of the actuator. In such embodiments, the shaft receiver is an element separate from the retaining structure (e.g., the housing of the drive assembly, such as the actuator housing). Depending on the requirements, the shaft receiver can be form-fitted into, clamped to, or fixed to the retaining structure, for example, by adhesive.

[0029] If the shaft receiver is provided as a separate component mounted in the actuator housing, the shaft receiver can be formed with a finer shape or a support shape.

[0030] Optionally, it may further include a motor housing, to which the motor receptively engages, and is sized such that when the motor is engaged with the motor housing, the end of the rotor shaft in use abuts against the shaft receiving portion. [Attached Image Description]

[0031] The invention will now be described in more detail by way of example only and with reference to the accompanying drawings, wherein:

[0032] Figure 1 A schematic plan view of the actuator is shown, with the top cover of the actuator housing and the gear train removed for clarity. The actuator includes a rotor shaft end bearing arrangement according to a first aspect of the invention.

[0033] Figure 2 It is shown separately. Figure 1 A perspective view of the bearing arrangement at the end of the rotor shaft.

[0034] Figure 3 It shows the motor and other components. Figure 1 A perspective view of the bearing arrangement at the end of the rotor shaft.

[0035] Figure 4 It shows Figure 3 The diagram shows a horizontal cross-sectional view of the rotor shaft end bearing arrangement.

[0036] Figure 5 A horizontal cross-section of an alternative embodiment of the rotor shaft end bearing arrangement according to a first aspect of the invention is shown.

[0037] Figure 6 A horizontal cross-sectional view is shown of another alternative embodiment of the rotor shaft end bearing arrangement according to a first aspect of the invention.

[0038] Figure 7 A horizontal cross-section is shown of yet another alternative embodiment of the rotor shaft end bearing arrangement according to a first aspect of the invention.

Detailed Implementation Methods

[0039] Please refer to Figure 1 The actuator is shown, generally indicated by 10. The actuator 10 includes a motor 12, which is supported within an actuator housing 14.

[0040] The motor 12 includes a rotor and a stator, which are mounted in a motor housing 16, and has a rotor shaft 18 through which rotational output is transmitted to the actuator 10 via a drive and / or gear system. Figure 1 Gears are not shown, although the actuator housing 14 may include one or more gear shaft locators 20, which are preferably integrally formed with the actuator housing 14.

[0041] The motor 12 is accommodated within the actuator housing 14 to mesh with a gear train located therein. The rotor shaft 18 is configured to connect to the gear train, for example via a pinion. The actuator housing 14 defines a motor receiving portion 22. The dimensions of the motor receiving portion 22 are preferably matched to the dimensions of the motor housing 16. Thus, the motor housing 16 is press-fitted into the motor receiving portion 22, and the rotor shaft 18 extends from the motor receiving portion 22 toward the actuator housing 14. Here, a motor positioning element 24 is provided, which restricts the possible positions of the motor 12; however, it should be understood that alternative forms of positioning elements can be provided within the actuator housing 14. The motor positioning element 24 can be formed as a protrusion within the actuator housing 14, which restricts the possible positions of the motor 12 within the actuator 10.

[0042] The rotor shaft 18 extends from the motor 12 mounted in the motor receiving portion 22 to a shaft receiving portion 26, which may be integrally formed and / or continuously formed with the sidewall 28 of the actuator housing 14. The rotor shaft 18 may extend through the gap between adjacent motor positioning members 24. It is understood, of course, that the shaft receiving portion 26 may be configured as a completely separable component receptively engageable with the actuator housing 14; however, this may introduce unnecessarily additional tolerance requirements for assembly, and an integrally formed embodiment is preferred. For example, the shaft receiving portion may be configured as a separable element engaging with a retaining structure (e.g., a slot) of the actuator housing 14. Such a shaft receiving portion may be secured in place in many different possible ways, including but not limited to form-fit or push-fit engagement, snap-fit ​​positioning, or by using adhesives.

[0043] Figure 2 The rotor shaft end bearing arrangement 30, including the shaft receiver 26, is illustrated. The rotor shaft end bearing arrangement 30 may include only the shaft receiver 26, or it may include part or all of the actuator housing 14. There are first main contact regions 32a and second main contact regions 32b, located on opposite sides of the longitudinal axis L of the rotor shaft 18. It is understood that the longitudinal axis L is defined by the position of the rotor shaft 18 mounted within the actuator housing 14 and is intended to extend parallel to the plane (e.g., its bottom surface) of the main surface 31 of the actuator housing 14. Each of the first main contact regions 32a and the second main contact regions 32b is configured to contact and support the end 34 of the rotor shaft 18 at at least a first contact point and a second contact point different from the first contact point.

[0044] In one embodiment, this is achieved by providing converging first and second main contact regions 32a, 32b to form a V-shaped or substantially V-shaped shaft receiving portion 26. The first and second main contact regions 32a and 32b are respectively formed as planar contact surfaces angled relative to each other. Another contact region 36 may be located between the first and second main contact regions 32a, 32b, which may also support the end 34 of the rotor shaft 18. The other contact region 36 may also restrict the movement of the end 34 along the longitudinal axis L, thereby further mitigating the effects of undesirable chaotic drift.

[0045] A planar contact area can be used, but it is understood that the contact surface can instead be configured as a convex or concave surface.

[0046] The shaft receiving portion 26 itself can be configured to protrude from the interior of the side wall 28 of the actuator housing 14 and is provided with a rotor shaft entry portion 38 to allow the rotor shaft 18 to be pushed into place. This is formed as an inclined surface toward the first and second main contact areas 32a, 32b. Therefore, the rotor shaft entry portion 38 can smoothly engage, for example, along the arcuate surface toward the first and second main contact areas 32a and 32b. This simplifies the insertion of the end 34 into the shaft receiving portion 26 and prevents the end 34 from accidentally causing the shaft receiving portion 26 to dent during installation.

[0047] To prevent damage to the rotor shaft 18 during insertion, a side baffle 40 can be provided, preferably at the lower end of the shaft receiving portion 26 and opposite to the rotor shaft entry portion 38. A similar side baffle can be provided on the side of the shaft receiving portion 26, where, in the illustrated embodiment, the first main contact area 32a and the second main contact area 32b intersect the inward surface 42 of the shaft receiving portion 26 relative to the actuator housing 14. The side baffle 40 restricts the movement of the end 34 of the rotor shaft 18, aligning it vertically, perpendicular to the longitudinal axis L and in the direction in which the rotor shaft 18 is inserted into the shaft receiving portion 26, during operation of the motor 12. A similar horizontal side baffle can also be considered.

[0048] The engagement between the rotor shaft 18 and the shaft receiving part 26 is Figure 3 The diagram shows in detail the drive assembly 44 that forms the actuator 10. Such a drive assembly 44 can be disposed in other drive devices and is therefore not limited to use in actuators. To insert the motor 12 into the actuator housing 14, the motor housing 16 is inserted into the motor receiving portion 22, wherein the end 34 of the rotor shaft 18 is pushed into the shaft receiving portion 26 via the rotor shaft inlet 38. The end 34 will naturally be pushed along the inclined surface of the rotor shaft inlet 38.

[0049] The end 34 of the rotor shaft 18 therefore contacts the first main contact area 32a and the second main contact area 32b. In the case where the end 34 has a flat profile, the contact point will be on the circumference of the end 34, although for a circular end 34, as... Figure 3 As shown, the contact point will actually be on the end face of end 34. The rounded end 34 may also contact another contact area 36 on the longitudinal axis L.

[0050] The contact between the end 34 of the rotor shaft 18 and the shaft receiving part 26 can be Figure 4 The details are shown below. In this rotor shaft end bearing arrangement 30, the end 34 is arc-shaped, and therefore circular, and contacts the first main contact area 32a and the second main contact area 32b at two separate points P1 and P2 on the circular end face. Then, the more rounded end will also contact the other contact area 36.

[0051] As the rotor rotates, the rotor shaft 18 also rotates. Because the first main contact area 32a and the second contact area 32b impede lateral drift of the axial end of the rotor shaft 18, the tendency for the end 34 to drift during use is reduced. This significantly reduces the rattling noise that actuators with flat contact surfaces might encounter.

[0052] exist Figure 5 Another rotor shaft end bearing arrangement 30′ is shown, wherein a flat end 34′ of the rotor shaft 18′ is provided, which contacts a pure V-shaped shaft receiving portion 26′. Similarly, two contact points P1′ and P2′ are formed with the first main contact area 32a′ and the second main contact area 32b′, but these contact points are located on the circumference of the rotor shaft 18′.

[0053] Figure 6 An alternative rotor shaft end bearing arrangement 30” is shown, wherein the flat end 34” of the rotor shaft 18” is configured to contact a U-shaped or similarly bow-shaped shaft receiving portion 26”. Similarly, two contact points P1” and P2” are formed with the first main contact area 32a” and the second main contact area 32b”, as shown, and they are formed on a continuous arcuate surface. Contact points are again formed on the circumference of the rotor shaft 18”. This is in Figure 6 While shown as two contact points, both the shaft receiving portion 26” and the rotor shaft 18” actually have some clearance and manufacturing tolerances. Thus, a larger contact area may exist between the end portion 34” and the shaft receiving portion 26”. For example, a strip-shaped contact surface extending along the direction of the rotor shaft 18” may be present. This is particularly applicable when the end portion 34” is circular, and therefore is somewhat complementary to the U-shaped shaft receiving portion 26”.

[0054] exist Figure 7Another alternative rotor shaft end bearing arrangement 30″′ is shown, in which a shaft receiving portion 26″′ with a V-shaped or substantially V-shaped cross section is provided. However, the end 34″′ of the rotor shaft 18″′ is further shaped to ensure that there are no contact points between it and the shaft receiving portion 26″′. This is achieved by providing a recessed indentation in the end 34″′ of the rotor shaft 18″′, thus providing contact points P1″′ and P2″′ only on the circumference.

[0055] It should be understood that although the present invention is made for the purpose of HVAC actuators, for which noise is a problem, the described rotor bearing assembly can be applied to any actuator or drive assembly that requires support for its rotor shaft.

[0056] Therefore, it is possible to provide a rotor support assembly that axially supports the end of the rotor shaft in a non-planar manner, thereby limiting the track of the rotor shaft end during operation and greatly reducing the rattling noise from the actuator that integrates the rotor bearing assembly.

[0057] When used with reference to this invention, the terms “comprising / including” and “having / including” are used to specify the presence of the stated features, integers, steps, or components, but do not exclude the presence of one or more additional features, integers, steps, components, or groups.

[0058] It should be understood that certain features of the invention described in the context of individual embodiments for clarity may also be provided in combination in a single embodiment. Conversely, for brevity, various features of the invention described in the context of individual embodiments may also be provided individually or in any suitable sub-combination.

[0059] The above embodiments have been provided by way of example only, and various other modifications will be apparent to those skilled in the art without departing from the scope of the invention as defined herein.

Claims

1. A rotor shaft end bearing arrangement (30; 30'; 30''; 30''') for supporting the end (34; 34'; 34''; 34''') of a rotor shaft (18; 18''; 18''') of a motor (12) having a longitudinal axis (L), the rotor shaft end bearing arrangement (30; 30'; 30''; 30''') comprising: A shaft receiving portion (26; 26'; 26''; 26''') is used to axially support the rotor shaft (18; 18'; 18''; 18''') of the motor (12); and The shaft receiving portion (26; 26'; 26''; 26''') is characterized in that its shape forms a first main contact area (32a; 32a'; 32a''; 32a''') and a second main contact area (32b; 32b'; 32b''; 32b'''), the first main contact area and the second main contact area are respectively located on both sides of the longitudinal axis of the rotor shaft, and the first main contact area and the second main contact area are designed to contact the end (34; 34'; 34''; 34''') of the rotor shaft (18; 18''; 18''') of the motor (12) in the working state of the motor (12) at at least at the first contact point (P1; P1'; 18'') of the end (34; 34'; 34''; 34''') of the rotor shaft (18; 18'; 18''; 18'''). P1''; P1''') and the second contact point (P2; P2'; P2''; P2''; P2'''). The shaft receiving portion includes a rotor shaft entry portion (38) adjacent to the first main contact area and the second main contact area. The rotor shaft entry portion (38) is an inclined channel surface, and the end of the rotor shaft is pushed into the shaft receiving portion via the rotor shaft entry portion.

2. The rotor shaft end bearing arrangement (30; 30'; 30''; 30''') according to claim 1, characterized in that, The first main contact area and the second main contact area converge.

3. The rotor shaft end bearing arrangement (30; 30'; 30''') as described in claim 2, characterized in that, The shaft receiving part is V-shaped in a plane perpendicular to the longitudinal axis (L).

4. The rotor shaft end bearing arrangement (30; 30'; 30''') according to claim 3, characterized in that, The first main contact area and the second main contact area are formed as a plane of a V-shaped shaft receiving portion.

5. The rotor shaft end bearing arrangement (30; 30'; 30''; 30''') according to claim 1, characterized in that, At least one of the first main contact area and the second main contact area is shaped to be at least partially recessed or protruding in a plane perpendicular to the longitudinal axis (L).

6. The rotor shaft end bearing arrangement (30'') according to claim 1, characterized in that, The shaft receiving part (26'') is U-shaped in a plane perpendicular to the longitudinal axis (L).

7. The rotor shaft end bearing arrangement (30; 30'; 30''; 30''') according to claim 1, characterized in that, The first contact point and the second contact point are symmetrically located on both sides of a plane perpendicular to the longitudinal axis (L).

8. The rotor shaft end bearing arrangement (30; 30'; 30''; 30''') according to claim 1, characterized in that, The rotor shaft entry portion is adjacent to the first main contact area and the second main contact area in a direction perpendicular to the longitudinal axis (L).

9. The rotor shaft end bearing arrangement (30; 30'; 30''; 30''') according to claim 8, characterized in that, The shaft receiving part (26; 26'; 26''; 26''') includes at least one side baffle (40), and the side baffle (40) and the rotor shaft entry part (38) are located on the upper and lower sides of the first main contact area and the second main contact area, respectively.

10. The rotor shaft end bearing arrangement (30) according to any one of claims 1 to 9, characterized in that, The shaft receiving part (26) includes another contact area (36).

11. The rotor shaft end bearing arrangement (30) according to claim 10, characterized in that, The other contact area (36) is located between the first main contact area and the second main contact area, and is used to restrict the movement of the end of the rotor shaft along the longitudinal axis (L).

12. A driving component (44), comprising: An electric motor (12) includes a rotor having a rotor shaft (18; 18'; 18''; 18''') defining a longitudinal axis (L); and According to any one of claims 1 to 11, the rotor shaft end bearing arrangement (30; 30'; 30''; 30''') is axially supported by the shaft receiving portion (26; 26'; 26''; 26''') of the rotor shaft end bearing arrangement (30; 30'; 30''; 30''').

13. The driving component (44) according to claim 12, characterized in that, The end of the rotor shaft is shaped according to the first main contact area (32a''') and the second main contact area (32b''') to generate at least the first contact point and the second contact point.

14. The drive assembly (44) according to claim 12, which is in the form of an actuator (10).

15. The driving component (44) according to claim 14, characterized in that, The shaft receiving portion (26; 26'; 26''; 26''') is integrally formed with the side wall of the actuator housing (14) of the actuator (10).

16. The driving component (44) according to claim 14, characterized in that, The shaft receiving portion is formed as a separate component that can receptively engage with the side wall of the actuator housing of the actuator.

17. The drive assembly (44) according to any one of claims 14 to 16, characterized in that, It further includes a motor housing (22), to which the motor (12) is received and engaged, and is sized such that when the motor (12) is engaged with the motor housing (22), the end of the rotor shaft in use (34; 34'; 34''; 34''') abuts against the shaft receiving portion (26; 26'; 26''; 26''').

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