DE102022122261A1 - Gear pump shaft assembly - Google Patents

Abstract

A gear pump shaft assembly for a 3D printer includes a gear pump shaft, a first thrust bearing, a second thrust bearing, and a pressure member. The gear pump shaft includes a longitudinal axis, a first support section, a second support section and a tooth section. The first thrust bearing is located on the first support section and the second thrust bearing is located on the second support section. The tooth section is located between the first support section and the second support section. The gear pump shaft is rotatable about the longitudinal axis and the pressure element is intended and suitable for exerting pressure on the second thrust bearing.

Description

The present application relates to the field of additive manufacturing. In particular, the present application relates to a gear pump shaft assembly for a 3D printer.

In the field of additive manufacturing, an additive manufacturing device is also called a 3D printer and the corresponding manufacturing process of workpieces is referred to as 3D printing. In 3D printing, parts or workpieces are created/generated/manufactured by depositing successive layers of building material together. Each layer comprises at least one bead or thread of the building material. This building material can be any thermoplastic material, e.g. plastic. Furthermore, the material deposition process can be the FDM or FFF or FLM process. Furthermore, it can be any other melt deposition process. The construction material fed to the 3D printer can be in filament form or granules, but is not limited to this.

A 3D printer usually includes a print head, which can move in at least three directions following a print path or a contour or a tool path. There are also 3D printers that have a print head that can move in two directions (usually the X and Y directions or axes) and a print bed (the surface or structure on which the workpieces are printed), which can move in the third direction (usually the Z direction or axis). In addition, there are printers in which the print head and/or the print bed move in at least one of X, Y and Z. There are also print heads that are mounted on well-known industrial robots (e.g. 6-axis), so that the print head can realize complex print paths.

In some cases, the printhead extrudes the build material using a known liquefier, which heats the build material and brings it into a printable state, and a gear pump downstream of the liquefier, which is supplied with build material from the liquefier. As is known, gear pumps include at least two meshing gears in order to convey or extrude or even discharge the building material. Typically one of the gears is idle (not driven) and the other is driven. The idle gear is moved by the meshing and driven gear. The driven gear is usually connected to a drive shaft.

There are some disadvantages with conventional printheads that include a gear pump. The storage for the gears and the drive shaft is complicated and complex, which results in larger component dimensions. Furthermore, these gear pumps also show increased wear and therefore maintenance costs.

It is the task of the present application to eliminate the disadvantages mentioned above. This task is solved by the subject matter of the appended independent claims. Each of these, alone or together with the dependent claims, may constitute an embodiment of the present application.

According to one aspect of the present application, a gear pump shaft assembly for a 3D printer includes a gear pump shaft, a first thrust bearing, a second thrust bearing, and a pressure member. The gear pump shaft includes a longitudinal axis, a first support section, a second support section and a tooth section. The first thrust bearing is arranged on the first support section and the second thrust bearing is arranged on the second support section. The tooth section is located between the first support section and the second support section. The gear pump shaft is rotatable about the longitudinal axis and the pressure element is intended and suitable for exerting pressure on the second axial bearing.

This can have the advantage that the arrangement can be made smaller and wear can be reduced. The pressure element defines pressure or preload in the second axial bearing (bearing play) and consequently the play or freedom of movement of the gear pump shaft assembly, which has the first axial bearing.

According to one aspect of the present application, a gear pump shaft assembly further includes a first support, the first support being in contact with the first thrust bearing. This can have the advantage that the first axial bearing includes a stop. The first support can be, for example, a (housing) cover or housing of a gear pump, at least partially defining a cavity of a gear pump or another suitable structure of a 3D print head. The first support is static with respect to the gear pump shaft.

According to one aspect of the present application, a gear pump shaft assembly further includes a second support, the second support in contact with the second thrust bearing or the pressure element. The second support can be, for example, a (housing) cover or housing section of a gear pump, at least partially a cavity Gear pump or other suitable structure defining a 3D print head. The second support is static in relation to the gear pump shaft.

According to one aspect of the present application, a gear pump shaft assembly further includes a ball. The ball is interposed between the first support and the first support section. This can have the advantage that the first axial bearing can be made smaller and consequently the size of the gear pump shaft arrangement can be reduced. The pressure that is exerted on the gear pump shaft can therefore be concentrated on one point, namely the ball. This has the advantage that imbalance is reduced and concentric running is improved.

According to one aspect of the present application, the pressure element comprises at least one spring. This can have the advantage that the printing element can be implemented inexpensively and in a small size. Furthermore, the applied pressure can be changed as desired by choosing different spring rates or spring constants and/or number of springs that can have different spring rates.

According to one aspect of the present application, the pressure element is adjustable so that the pressure exerted on the second thrust bearing is adjustable. This can have the advantage that the pressure exerted can be adjusted as desired without having to dismantle the gear pump shaft assembly. This can have the further advantage that the pressure exerted or applied can be adjusted during operation. This means that the play or freedom of movement of the gear pump shaft arrangement can be adjusted or adjusted depending on, for example, the building material and/or the discharge of a print head which includes the gear pump shaft arrangement. The pressure exerted or applied can also be adjusted depending on the position of the print head on the print path. The adjustment can be made via an adjustment device that is intended and suitable for changing the pressure applied by the pressure element.

According to one aspect of the present application, a gear pump shaft arrangement further comprises a pressure section in which the gear pump shaft is at least partially located. The second support section is arranged outside the printing section. The pressure section can be the pressurized area of a gear pump. This can have the advantage that, for example, the wear of the second support section is reduced if it is arranged outside a pressure section. This can also have the advantage that the general design of the gear pump shaft arrangement can be simpler and therefore more cost-effective.

According to one aspect of the present application, a gear pump shaft assembly further includes a pressure sensor operatively coupled to the pressure portion. Furthermore, the pressure applied to the second thrust bearing is adjusted or changed at least partially based on data from the pressure sensor. This can have the advantage that the applied pressure can be adjusted or changed depending on a specific operating point of the 3D printer, which includes the gear pump shaft arrangement.

According to one aspect of the present application, the gear pump shaft assembly is at least in two parts, with a first shaft part comprising the first support section and a first drive section. A second shaft part includes a second drive section and the second support section. The first drive section and the second drive section are intended and suitable to fit together. This can have the advantage that the gear pump shaft can be designed cost-effectively, since the quality requirements for the first shaft part can be different from those for the second shaft part. The drive sections are designed and suitable to ensure torque transmission between the two parts.

According to one aspect of the present application, the first shaft part of a gear pump shaft assembly is at least partially arranged in the pressure section. This can have the advantage that only the first part has to meet the quality requirements in order to be used in the area of the printing section. This can result in reduced production costs for the gear pump shaft assembly.

According to one aspect of the present application, the gear pump shaft assembly further comprises at least one radial bearing which supports the gear pump shaft. This can have the advantage that the gear pump shaft is mounted more stably.

According to one aspect of the present application, a radial bearing of a gear pump shaft assembly supports the first shaft part and/or the second shaft part. This can have the advantage that the gear pump shaft is mounted more stably.

According to one aspect of the present application, a gear pump shaft includes a Longitudinal axis, a first support section, a second support section and a tooth section which is located between the first support section and the second support section. The first support section includes a first stop and the second support section includes a second stop. This can have the advantage that the gear pump shaft can be manufactured inexpensively while achieving a high quality of the gear pump shaft.

According to one aspect of the present application, the gear pump shaft is at least in two parts and a first shaft part comprises the first support section and a first drive section, wherein a second shaft part comprises the second drive section and the second support section. The first drive section and the second drive section are intended and suitable to fit together. This can have the advantage that the gear pump shaft can be designed cost-effectively because the quality requirements for the first shaft part can be different from those for the second shaft part. The drive sections are designed and adapted to ensure the transmission of torque between the two parts.

Each of the above aspects is considered a separate invention. The aspects can be freely combined with each other. Furthermore, any feature that is disclosed independently of another feature can be freely combined with other features.

• 1 zeigt schematisch eine Schnittansicht einer Ausführungsform der Anmeldung.

Further advantages and features of the present disclosure will be apparent from the accompanying drawing. The drawing is for informational purposes only and is not restrictive in nature. The drawing shows an embodiment of the present application schematically. Accordingly, it cannot be viewed as limiting, for example, the dimensions of the present disclosure.

• 1 shows schematically a sectional view of an embodiment of the application.

Directional terms or position or location information in the description such as top, bottom, side, etc. refer to the drawing and must be transferred to the corresponding new position if the position changes. The individual components are not shown to scale.

With reference to 1 a schematic sectional view (without hatching for clarity) of a gear pump shaft assembly 10 is shown, which has a longitudinal axis L. The gear pump shaft arrangement 10 comprises a two-part gear pump shaft 20 with a first shaft part 27 and a second shaft part 28. The first shaft part 27 includes a first support section 21 with a first stop 32. Here, the first stop 32 is a conical indentation into which a ball 31 fits . This provides not only axial guidance but also radial guidance. Furthermore, the first shaft part 27 comprises a tooth section 23, which can mesh with, for example, an idle (gear) wheel when the gear pump shaft assembly 10 is used in a 3D print head (not shown). The gear pump shaft 20 is intended and suitable for rotating about the longitudinal axis L as the axis of rotation.

The ball 31 is arranged between the first stop 32 in the first support section 21 and a first support 60. The ball 31, the first support section 21 and the first support 60 result in a first axial bearing 30. Alternatively, the first axial bearing 30 can be any suitable axial or .Be a thrust bearing, e.g. a needle bearing in optional combination with a radial bearing.

The first shaft part 27 and the second shaft part 28 are connected by means of a first drive section 70 and a second drive section 71. The first shaft part 27 includes the first drive section 70 and the second shaft part 28 includes the second drive section 71. Both drive sections 70, 71 are intended and suitable to fit together and to transmit a torque by means of positive locking. Nevertheless, both drive sections 70, 71 can also be connected using all known types of connection or combinations thereof (e.g. positive connection, frictional connection, etc.).

The second shaft part 28 includes a second support section 22 with a second stop 33. A second thrust bearing 40 (thrust bearing) is arranged in the second support section 22 and stands against the second stop 33 (and a housing or structure, not shown, which). is static with respect to the gear pump shaft). A pressure member 50 is in contact with the second thrust bearing 40 and is intended and capable of applying pressure to the second thrust bearing 40 (when supported by a suitable structure, not shown).

The pressure element 50 can be used to adjust the axial play or the axial clearance in the gear pump shaft arrangement 10. This includes the bearing clearance or the bearing clearance of the first axial bearing 30. The pressure element 50 can include at least one spring 51 (eg a disc or plate spring). Furthermore, the pressure element 50 can be adjustable so that it acts on the second axial bearing 40 applied pressure is adjustable. The second thrust bearing 40 rests against a second support (not shown for clarity 1 , however the second support would be in 1 at least partially shown above the second thrust bearing 40). The pressure element 50 is shown touching the gear pump shaft 20 and the second thrust bearing 40 is shown touching the pressure element 50 and the second support. However, the arrangement of the pressure element 50 and the second thrust bearing 40 can be reversed: the second thrust bearing 40 touches the gear pump shaft 20 and the pressure element 50 in turn touches the second support.

The first shaft part 27 is partially included in a printing section P of a 3D print head (not shown), which in turn includes the gear pump shaft assembly 10. The interior of the pressure section P is sealed from the environment in a known manner. The second thrust bearing 40 and the pressure element 50 are located outside the pressure section P and are therefore exposed to less loads and thus reduced wear. A pressure sensor 61 is located in the pressure section P. The pressure sensor 61 is intended and suitable for detecting a pressure in the pressure section P. Typically, this is the pressure of a liquefied or printable building material within a gear pump, which includes the gear pump shaft assembly 10. The pressure element 50 can be adjusted in its pressure-exerting effect and this adjustment can also be made at least partially based on data provided by the pressure sensor 61.

REFERENCE SYMBOL LIST

10

Gear pump shaft assembly

20

Gear pump shaft

21

first support section

22

second support section

23

Tooth section

27

first wave part

28

second wave part

30

first thrust bearing

31

Bullet

32

first attack

33

second attack

40

second thrust bearing

50

Printing element

51

Feather

60

first support

61

Pressure sensor

70

first drive section

71

second drive section

L

Longitudinal axis

P

Print section

Claims (14)

Gear pump shaft arrangement (10) for a 3D printer, comprising a gear pump shaft (20), a first axial bearing (30), a second axial bearing (40) and a pressure element (50), the gear pump shaft having a longitudinal axis (L), a first support section ( 21), a second support section (22) and a tooth section (23), and wherein the first axial bearing (30) is arranged on the first support section (21), and wherein the second axial bearing (40) on the second support section (21) is arranged, and wherein the tooth portion (23) is located between the first support portion (21) and the second support portion (22), and wherein the gear pump shaft (20) is rotatable with respect to the longitudinal axis (L), and wherein the pressure element (50) is thereto intended and suitable to exert pressure on the second axial bearing (40). Gear pump shaft arrangement (10). Claim 1 , further comprising a first support (60), the first support being in contact with the first thrust bearing (30). Gear pump shaft arrangement (10) according to one of the Claims 1 or 2 , further comprising a second support, the second support being in contact with the second thrust bearing (40) or the pressure element (50). A gear pump shaft assembly (10) according to any one of the preceding claims, further comprising a ball (31), the ball being interposed between the first support (60) and the first support portion (21). Gear pump shaft assembly (10) according to one of the preceding claims, wherein the pressure element (50) comprises at least one spring (51). Gear pump shaft assembly (10) according to one of the preceding claims, wherein the pressure element (50) is adjustable so that the pressure exerted on the second thrust bearing (40) is adjustable. Gear pump shaft assembly (10) according to one of the preceding claims, further comprising a pressure section (P) in which the gear pump shaft (20) is at least partially is located, and wherein the second support section (22) is arranged outside the printing section. Gear pump shaft arrangement (10). Claim 7 , further comprising a pressure sensor (61) which is operatively coupled to the pressure section (P), and wherein the pressure exerted on the second thrust bearing (40) is adjustable, at least partially based on data provided by the pressure sensor. Gear pump shaft arrangement (10) according to one of the preceding claims, wherein the gear pump shaft (20) is at least in two parts and wherein a first shaft part (27) comprises the first support section (21) and a first drive section (70), and wherein a second shaft part (28) a second drive section (71) and the second support section (22), and wherein the first drive section (70) and the second drive section (71) are intended and adapted to fit together. Gear pump shaft arrangement (10). Claim 9 , wherein the first shaft part (27) is at least partially located in the printing section (P). A gear pump shaft assembly (10) according to any one of the preceding claims, further comprising at least one radial bearing which is in contact with the gear pump shaft (20). Gear pump shaft arrangement (10). Claim 11 , wherein a radial bearing is in contact with the first shaft part (27) and / or the second shaft part (28). Gear pump shaft (20) comprising a longitudinal axis (L), a first support section (21), a second support section (22) and a tooth section (23) between the first support section (21) and the second support section (22), the first support section ( 21) comprises a first stop (32) and the second support section (22) comprises a second stop (33). Gear pump shaft (20). Claim 13 , wherein the gear pump shaft (20) is at least in two parts and wherein a first shaft part (27) comprises the first support section (21) and a first drive section (70) and wherein a second shaft part (28) comprises a second drive section (71) and the second support section (22), and wherein the first drive section (70) and the second drive section (71) are intended and suitable to fit together.

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