Grease Blocking Member for Gear Reducer Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional grease leakage prevention methods for gear reducers fail to effectively prevent grease leakage at high-speed, high-output power applications, especially when using soft grease with high consistency, due to centrifugal splattering and pumping actions, and often require complex processes or increase friction load and costs.
Innovation Solution
A grease leakage preventing structure that covers the output shaft of a dynamoelectric machine with a grease blocking member featuring a cylindrical portion with linear, V-shaped, or U-shaped protrusions or cut portions, which are press-fitted onto the electric motor output shaft to block grease flow and prevent infiltration into the electric motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil seals are arranged on the base end of the gear tooth portion to prevent grease leakage, then grease infiltration into the electric motor is prevented, but friction load increases and loss ratio becomes great in low-output electric motors
Solution Approach 1:
The invention extracts the grease blocking function from the oil seal and implements it through a different mechanism - the helical groove structure on the output shaft. This groove structure passively redirects grease flow using the shaft's rotation, eliminating the need for contact-based sealing that causes friction loss.
Solution Approach 2:
The invention introduces an intermediary structure (helical groove) between the grease and the oil seal. The groove acts as a mediator that intercepts and redirects grease flow before it can reach the oil seal, reducing the oil seal's workload and associated friction losses.
2Reliability
If oil seals are arranged to detour around the gear tooth portion to prevent grease leakage, then grease infiltration is prevented, but the oil seal dimension must be increased to be long enough for detouring around the gear teeth
Solution Approach 1:
The invention removes the requirement for long detouring oil seals by extracting the grease blocking function and implementing it through the helical groove structure, which naturally guides grease flow without requiring extended sealing components.
Solution Approach 2:
Instead of making the oil seal go around the gear teeth (traditional approach), the invention inverts the approach by having the helical groove guide the grease in the opposite direction - back toward the gear reducer - thereby eliminating the need for detouring seals.
3Reliability
If flexible tube is provided to cover the gear tooth portion to prevent grease leakage, then grease infiltration is prevented for NLGI Consistency No. 2 grease, but grease leakage cannot be prevented when using softer grease with higher consistency for high-speed operation
Solution Approach 1:
The invention changes the mechanism from passive physical blocking (flexible tube) to active flow redirection using the helical groove. This groove structure utilizes the rotational motion parameter to dynamically control grease flow, making it effective across different grease consistencies and operating speeds.
Solution Approach 2:
The invention transitions from a static flexible tube to a dynamic helical groove structure that actively engages with rotating grease. The groove leverages the rotational motion to create a pumping action that redirects grease back into the reducer, adapting to various grease viscosities and speeds.
4Reliability
If helical groove is provided on the electric motor output shaft to prevent grease leakage, then grease infiltration is prevented, but complex processes are required and processing costs become high
Solution Approach 1:
The invention merges the grease leakage prevention function directly into the output shaft itself through the helical groove structure. This integration eliminates the need for separate prevention components and their associated complex assembly processes, simplifying manufacturing while maintaining effectiveness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively prevents grease leakage from the gear reducer to the dynamoelectric machine by using a grease blocking member that blocks and redirects grease flow back into the gear reducer, even at high speeds, without increasing friction load or processing costs, and is suitable for thin-type electric motors.
Implementation Method 1
the grease may be splattered in the centrifugal direction of the gear due to the centrifugal force from the high-speed rotation of the gear
Data Source
Figure 1~2
Figure 3(a)~4
Figure 5(a)~6(b)
AI summary
A grease leakage preventing structure is provided for a gear reducer of a dynamoelectric machine with a gear reducer, which is capable of preventing, if soft grease with high consistency is employed in a gear reducer driven at a high speed for high output power, leakage of grease from the reducer toward the dynamoelectric machine, by covering an output shaft of the dynamoelectric machine with a grease blocking member. In a grease leakage preventing structure for a gear reducer of a dynamoelectric machine with the gear reducer, in which gear teeth are provided in a leading edge portion of the output shaft of the dynamoelectric machine, the leading edge portion of the dynamoelectric machine output shaft is introduced into a case of the gear reducer via an input port of the gear reducer, and the dynamoelectric machine output shaft with the gear teeth is engaged with a gear arranged inside the case of the gear reducer, the grease leakage preventing structure is provided with a grease blocking member (3A, 3B, 3C, 3D) provided on a terminal end of an engagement portion (16b) of the dynamoelectric machine output shaft (14A) and is configured to inhibit inflow of grease into the dynamoelectric machine, and in this structure, the grease blocking member (3A, 3B, 3C, 3D) is provided with a wall surface portion (3Aa, 3Ba, 3Ca, 3Da) formed in a direction perpendicular to the gear teeth (16) provided in the leading edge portion of the dynamoelectric machine output shaft (14A).